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PREGNANCY & CHILDBIRTH

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FERTILITY

Ovarian tumors in a cohort of infertile women.
 Rossing MA, Daling JR, Weiss NS, Moore DE, Self SG.
N Engl J Med 1994 Sep 22;331(12):771-6.

The results of this study, conducted on a sample population of 3837 women who received fertility drugs, show that use of these drugs is associated with a 2.4-fold increased risk of invasive or borderline ovarian cancer, compared to nonuse. Use of clomiphene for less than a year was not linked to an increased risk of cancer.

Human menopausal gonadotropin and the risk of epithelial ovarian cancer.
 Shushan A, Paltiel O, Iscovich J, Elchalal U, Peretz T, Schenker JG.
Fertil Steril 1996 Jan;65(1):13-8.

The results of this study show that women who reported having used any type of fertility drugs have a 30% increased risk of ovarian cancer, compared to nonusers. Use of hMG alone was associated with an over 3-fold increased risk of ovarian cancer.

Prevalence of Gynecologic Cancer in Women Exposed to Diethylstilbestrol in Utero.
 Verloop J, Rookus MA, van Leeuwen FE.
N Engl J Med, 342 (24), 2000 Jun 15.

The results of this study show that the increased risk of cancer of the vagina and uterus found in daughters of women who had been taking diethylstilbestrol (DES) during pregnancy persists through adulthood. In particular, the study found that these women have a 3-fold increased risk of cervical cancer, compared to the general population. This excess risk, according to the authors, is particularly striking because DES daughters undergo more intense screening and are more aggressively treated if any suspected lesion is detected during screening, and therefore they are expected to have a lower, rather than higher, incidence of cancer, compared to the general population.

CESAREAN SECTION

Rates of Cesarean delivery--United States, 1993.
 MMWR Morb Mortal Wkly Rep 1995 Apr 21;44(15):303-7.

This article indicates that in the U.S., almost 1 out of 4 deliveries are performed by Cesarean section. These rates are among the highest recorded in the developed countries. From 1970 to 1993, overall rates of primary Cesarean sections increased by 4-folds, from 5.5% to 22.8%. Since deliveries by Cesarean section carry a significantly higher risk of complications for both the mother and the newborn, the national health goal for the year 2000 has been to lower its rate to 15% or below, a value that has not been observed since 1978.

The rise in caesarean section rate: the same indications but a lower threshold.
 Leitch CR, Walker JJ.
Br J Obstet Gynaecol 1998 Jun;105(6):621-6.

The results of this study show that the rate of Cesarean sections in Scotland increased by over three-folds in the period from 1962 to 1992, with no apparent cause to justify this increase other than a lowered threshold of acceptance of the procedure in obstetric practice.

Rates and implications of caesarean sections in Latin America: ecological study.
 Belizan JM, Althabe F, Barros FC, Alexander S.
BMJ 1999 Nov 27;319(7222):1397-400.

This study evaluated the prevalence of Cesarean sections in 20 Latin American countries. Only 8 countries had Cesarean section rates below 15%; the remaining had rates varying from 17% to 40%. Since the accepted rate of justifiable Cesarean sections is 15%, these data show that every year, in the region, over 850,000 women deliver unnecessarily by Cesarean section. The excessive use of this procedure puts women and their babies needlessly at risk of increased illness and mortality.

Cesarean section: medical benefits and costs.
 Shearer EL.
Soc Sci Med 1993 Nov;37(10):1223-31.

This article emphasizes that half of the Cesarean sections performed in the U.S. are unnecessary. This surplus needlessly endangers women and their babies and adds over $1 billion to the annual health care costs. Cesarean section deliveries are associated with a 2- to 4-fold increased rate of maternal mortality and with a 5- to 10-fold increased rate of maternal morbidity, compared to vaginal deliveries. Newborns delivered via Cesarean section are at increased risk of respiratory disease and of being delivered before proper time. The author highlights how decisions concerning the need for Cesarean delivery seem to be influenced more by social, economic, and physicians' personal reasons, than by medical factors. This is well illustrated by the fact that those women who are at highest risk of pregnancy complications and who would benefit the most from a Cesarean section are the least likely to receive it. On the other hand, indications such as previous Cesarean, slow or difficult labor or delivery, presentation of the rear of the baby at the uterine cervix and fetal distress, are the main reason for performing a C-section, even though these conditions have been least clearly associated with benefits for the fetus and the mother.

Estimating the proportion of unnecessary Cesarean sections in Ohio using birth certificate data.
 Koroukian SM, Trisel B, Rimm AA.
J Clin Epidemiol 1998 Dec;51(12):1327-34.
The results of this study show that approximately 40% of Cesarean sections performed in Ohio have no medical indication that justifies their use and are therefore, unnecessary.

Lack of progress in labor as a reason for Cesarean.
 Gifford DS, Morton SC, Fiske M, Keesey J, Keeler E, Kahn KL.
Obstet Gynecol 2000 Apr;95(4):589-95.

The results of this study show that 1 in 4 Cesarean section performed for lack of progression during labor are done in disagreement with professional guidelines, and are therefore inappropriate. Every year, 1 million women deliver by Cesarean section in the U.S. In approximately 300,000 of cases, the reason for the Cesarean section is lack of progress in labor, meaning that the head of the baby is progressing slowly through the birth canal. According to the American College of Obstetricians and Gynecologists' guidelines, "lack of progress" can be diagnosed only after the cervix is dilated by 3 centimeters in primiparous (first time mothers) and by 4 centimeters in women who had delivered in the past. This study, conducted on 733 women who had an unplanned Cesarean section, showed that in 68% of them the reported reason for the C-section was lack of progress in labor. When the researchers reviewed their medical records they found that, counter to published guidelines, 24% of them had undergone C-section before their cervix was dilated enough to justify a diagnosis of slow progress. These findings suggest that every year in the U.S., approximately 75,000 Cesarean sections may be performed too early during labor, for unnecessary reasons.

Elective caesarean section on request. Unnecessary caesarean sections should be avoided.
 van Roosmalen J.
BMJ 1999 Jan 9;318(7176):121.

This letter discusses some of the risks associated with the widespread use of elective Cesarean section, including higher maternal morbidity and mortality rates, higher infant morbidity rates, and increased health care costs. In the Netherlands, 9% of deliveries are performed by Cesarean section. If the rate of Cesarean sections in the United States were similar to that of the Netherlands, every year approximately half million more births would be performed by the vaginal route rather than by Cesarean section.

Inconsistencies in clinical decisions in obstetrics.
 Barrett JF, Jarvis GJ, Macdonald HN, Buchan PC, Tyrrell SN, Lilford RJ.
Lancet 1990 Sep 1;336(8714):549-51.

The results of this study show that 30% of Cesarean sections performed in an English teaching hospital were unnecessary. There was significant disagreement between physicians as to whether perform or not a Cesarean section. Even more importantly, when physicians were presented at different times with the same information, their opinion as to whether perform or not a Cesarean section was inconsistent in 25% of cases. These data indicate that clinical decisions in obstetrics are often influenced by physicians' personal reasons rather than by medical factors.

Maternal mortality after Cesarean section in The Netherlands.
 Schuitemaker N, et al.
Acta Obstet Gynecol Scand 1997 Apr;76(4):332-4.

The results of this study show that maternal mortality rates in women delivering by Cesarean section are seven times higher than those of women delivering by vaginal route.

The relative risks of caesarean section (intrapartum and elective) and vaginal delivery
A detailed analysis to exclude the effects of medical disorders and other acute pre-existing physiological disturbances.
Lilford RJ, et al.
Br J Obstet Gynaecol 1990 Oct;97(10):883-92.

The results of this study show that Cesarean section delivery is associated with a 7-fold increased risk of maternal death, compared to vaginal delivery. After the exclusion of women who experienced medical complications before delivery, the risk of maternal death associated with Cesarean section was estimated to be 5 times higher than that associated with vaginal delivery.

Early neonatal mortality and Cesarean delivery in Mexico City.
 Bobadilla JL, Walker GJ.
Am J Obstet Gynecol 1991 Jan;164(1 Pt 1):22-8.

The results of this study, conducted on 3390 babies born in Mexico City (where 27% of deliveries are performed by Cesarean section), show that neonates of normal weight delivered by Cesarean section are 2.5 times more likely to die, compared to those delivered vaginally. This increase in mortality could not be justified by maternal or infant factors.

Elective caesarean section on request. Safest option is still to aim for vaginal delivery.
 BMJ 1999 Jan 9;318(7176):121.
Idama TO, et al.

This article highlights that there is lack of compelling scientific evidence in support of the belief, shared by most of the medical community, that Cesarean section delivery results in a lower incidence of pelvic floor damage, compared to vaginal delivery. The available studies have been criticized for using small number of patients, for containing patients' selection biases, for lacking long-term observation and for not taking in consideration the impact of risk factors in the study population that may predispose to pelvic floor damage. It is the authors' belief that vaginal delivery remains the safest option in women with uncomplicated pregnancy.

Maternal consequences of caesarean section
A retrospective study of intra-operative and postoperative maternal complications of caesarean section during a 10-year period.
van Ham MA, van Dongen PW, Mulder J.
Eur J Obstet Gynecol Reprod Biol 1997 Jul;74(1):1-6.

The results of this study show that Cesarean section delivery carries an overall 15% risk of intra-operative maternal complications and a 36% risk of postoperative maternal morbidity. In particular, the risk of intra-operative complications is 7.4% in women who undergo elective Cesarean section, and 23% in women who deliver by Cesarean section after failure of attempted vaginal delivery. The most common intra-operative complications are ruptured uterus and hemorrhage. The most frequent post-operative complications are fever, hemorrhage, haematoma and urinary tract infections.

The importance of neonatal asphyxia and caesarean section as risk factors for neonatal respiratory disorders in an unselected population.
 Hjalmarson O, Krantz ME, Jacobsson B, Sorensen SE.
Acta Paediatr Scand 1982 May;71(3):403-8.

The results of this study show that Cesarean section delivery increases the risk of neonatal respiratory disorders.

Association between method of delivery and maternal rehospitalization.
 Lydon-Rochelle M, Holt VL, Martin DP, Easterling TR.
JAMA 2000 May 10;283(18):2411-6.

The results of this study show that women who undergo Cesarean section or instrument-assisted delivery are at significantly increased risk of being hospitalized in the 60 days after giving birth, compared to women who undergo spontaneous vaginal delivery. The study was conducted on 256,795 women without chronic medical conditions who delivered between 1987 and 1996 in the Washington State area. Of these women, 21% had Cesarean section, 23% had assisted delivery, and the remaining gave birth spontaneously. Women who underwent Cesarean section had a 30-fold increased risk of being hospitalized for obstetrical wound infections in the 60 days after delivery, compared to those who delivered spontaneously. In addition, they had a 2- to 2.5- fold increased risk of being hospitalized for uterine infections, cardiopulmonary problems and thromboembolic conditions, and a 50% to 80% increased risk of being hospitalized for gallbladder disease, genitourinary tract conditions, and appendicitis. Women who received assisted vaginal delivery also were at increased risk of hospitalization, particularly for post-delivery bleeding (30% increased risk), genitourinary tract conditions (40% increased risk), pelvic injuries (2.5-fold increased risk), and obstetric wound complications (4.2-fold increased risk), compared to those who delivered spontaneously. These data indicate that Cesarean section and instrument-assisted delivery are associated with a significantly increased risk of morbidity in the 60 months after delivery. This risk is not found in women who have spontaneous vaginal delivery.

Post-discharge surveillance and infection rates in obstetric patients.
 Couto RC, Pedrosa TM, Nogueira JM, Gomes DL, Neto MF, Rezende NA.
Int J Gynaecol Obstet 1998 Jun;61(3):227-31.

The results of this study show that women who deliver by Cesarean section have an almost 50-fold increased risk of developing hospital-acquired surgical site infections, compared to women who deliver by the vaginal route. The study evaluated the incidence of this complication in 2431 women who delivered vaginally and 2032 women who delivered by Cesarean section, by monitoring patients during their hospital stay and up to 30 days after hospital discharge. While the incidence of surgical site infections detected during hospital stay was 1.6% in women who had undergone Cesarean delivery, this rate increased to 9.6% when cases detected by post-discharge surveillance were included. By comparison, the incidence of infections in women who delivered by the vaginal route was significantly lower, occurring in only 0.2% of cases. These findings indicate that unless data collected after hospital discharge are included in the estimates of the incidence of surgical site infections after Cesarean delivery, the true rate of this complication may be substantially underestimated.

Incidence of hospital-acquired infections associated with caesarean section.
 Henderson E, Love EJ.
J Hosp Infect 1995 Apr;29(4):245-55.

The results of this study, conducted on a cohort of 1335 women who underwent Caesarean section in a Canadian teaching hospital, show that the rate of hospital-acquired infections in women delivered by primary and secondary caesarean section is 42.1% and 46.1%, respectively. Women delivered by primary section had significantly higher incidence of deep wound infections, endometritis and bacteraemia, compared to those delivered by secondary section. Hospital-acquired infections significantly prolonged length of hospital stay and costs of care.

Postoperative morbidity following Caesarean delivery.
 Hillan EM.
J Adv Nurs 1995 Dec;22(6):1035-42.

The results of this study show that over 90% of women who deliver by Cesarean section develop post-operative morbidity such as wound infection, intrauterine infection, urinary tract infection, urinary catheterization, chest infection, fever, and hemorrhage.

Long-term effects of Cesarean sections: ectopic pregnancies and placental problems.
 Hemminki E, Merilainen J.
Am J Obstet Gynecol 1996 May;174(5):1569-74.

This study investigated some of the possible long-term effects associated with Cesarean section delivery, and focused on the rate of occurrence of ectopic pregnancy and placental complication in a cohort of almost 17,000 women who underwent Cesarean section and a similar number of women who delivered by the vaginal route. Women with a history of Cesarean section were found to have a 30% increased risk of subsequent ectopic pregnancy (gestation occurring elsewhere than in the uterus, for example in a fallopian tube or in the peritoneal cavity) and a 4-fold increased risk of placental complications (placenta previa and abruptio placentae), compared to those with a history of vaginal delivery.

Incisional endometriosis: an underappreciated diagnosis in general surgery.
 Nirula R, Greaney GC.
J Am Coll Surg 2000 Apr;190(4):404-7.

This study describes a rare but possible complication of Cesarean section, the development of endometriosis at the surgical scar tissue site. Endometriosis is a condition characterized by the presence of fragments of uterine lining in other locations of the body, generally within the pelvic cavity. During Cesarean section delivery, some cells of the uterine mucous membrane may be accidentally transplanted along the incision line, and may continue growing until they reach a visible mass. The study evaluated 10 women who underwent surgical excision of a painful mass averaging 3 cm in size, localized at the lateral edge of their Cesarean section incision. Women experienced symptoms anywhere from 2 months to 3 years, and in 2 patients symptoms changed with the menstrual cycle. Only two women received a correct diagnosis of incisional endometriosis, the others being diagnosed with other conditions such as lipoma, cyst, incisional hernia, abscess or granuloma. The authors conclude that this complication occurs more frequently than is generally recognized, and highlight that increased awareness of this disease process is necessary to provide appropriate treatment and to avoid unnecessary pre-operative diagnostic evaluation.

Is a paediatrician needed at all Caesarean sections?
 Parsons SJ, Sonneveld S, Nolan T.
J Paediatr Child Health 1998 Jun;34(3):241-4.

The results of this study indicate that the presence of a pediatrician is not required during routine Cesarean section deliveries in women who receive epidural anesthesia. On the contrary, deliveries in women under general anesthesia require the presence of a skilled neonatal resuscitator.

Obstetric outcome after one previous caesarean section.
 Perveen F, Shah Q.
J Paediatr Child Health 1998 Jun;34(3):241-4.

The results of this study show that 65% of women who attempted a trial of labor after a previous Cesarean section achieved successful vaginal delivery. These data demonstrate that selected women with a history of Cesarean section can safely attempt subsequent delivery by the vaginal route.

Association of epidural analgesia with Cesarean delivery in nulliparas.
 Lieberman E; Lang JM; Cohen A; D'Agostino R Jr; Datta S; Frigoletto FD Jr.
Obstet Gynecol, 88(6):993-1000 1996 Dec.

The results of this study show that women who receive epidural anesthesia during labor have a 3.7-fold increased risk of delivering by Cesarean section, compared to those who do not receive this type of anesthesia.

Is routine induction of labour at term ever justified?
 Cardozo L.
BMJ 1993 Mar 27;306(6881):840-1.

This article emphasizes that induced labor is associated with a higher risk of instrumental deliveries and of low Apgar scores, compared to natural labor. The main reason for inducing labor is that the baby is over term. However, results of ultrasound studies have shown that 9 out of 10 babies calculated to be over term were not-the calculation was incorrect, indicating that the majority of instrumental deliveries due to over term pregnancy are unnecessary.

EPISIOTOMY

Much ado about a little cut: is episiotomy worthwhile?
 Eason E, Feldman P.
Obstet Gynecol 2000 Apr;95(4):616-8.

This review emphasizes that the common obstetrical practice of cutting the tissue between the vagina and the anus (episiotomy) in women at stage 2 of delivery, has no scientific foundation and may, in fact, result in more trauma and suffering for the mother. Doctors perform episiotomy with the belief that this practice reduces the occurrence of pelvic prolapse and urinary incontinency in the mother, and the risk of brain damage in the baby. However, none of these assumptions have been confirmed by scientific studies. On the contrary, research has shown that leaving enough time for the muscles of the pelvic floor to stretch naturally results in lower rates of maternal incontinence. Among the reasons cited in the article for this practice to be still in use are: shorter time of delivery (which is advantageous for the physician), lack of experience with natural slow stretching of the pelvic floor muscles, and an interventionist attitude of the physician. The authors conclude that, based on available evidence, episiotomy should no longer be routinely performed during delivery.

Midline episiotomy and anal incontinence: retrospective cohort study.
 Signorello, LB, et al.
BMJ 2000;320:86-90 ( 8 January ).

The results of this study show that episiotomy, the surgical incision of the perineum and vagina performed during delivery to reduce the risk of injury to the pelvic floor, is associated with a 3- to 5.5-fold increased risk of anal incontinence, compared to vaginal delivery. The study, conducted on 626 women followed-up for 6 months after delivery, found that the rate of fecal incontinence was 5.5-fold higher in those who underwent episiotomy, compared to those who did not have such procedure. In addition, 6 months after delivery, women who underwent episiotomy had a 3-fold increased rate of fecal incontinence and a 2-fold increased rate of gas incontinence, compared to women who had spontaneous laceration. These findings demonstrate that episiotomy is associated with a significant increase, rather than reduction, in risk of anal incontinence.

HOME VERSUS HOSPITAL DELIVERY

Outcome of planned home and planned hospital births in low risk pregnancies
Prospective study in midwifery practices in The Netherlands.
Wiegers TA, Keirse MJ, van der Zee J, Berghs GA.
BMJ 1996 Nov 23;313(7068):1309-13.

The results of this study show that the pregnancy outcome of women who delivered their first baby at home is as good as that of women who gave birth to their first baby in the hospital. On the other hand, women who gave birth to at least one child and planned to deliver at home had significantly better pregnancy outcomes than those who planned to deliver in the hospital, indicating that home delivery is as safe, or safer, than hospital delivery.

Choosing between home and hospital delivery. Risk of home birth in Britain cannot be compared with data from other countries. Letter.
Chamberlain G.
BMJ 2000;320:798 ( 18 March ).

This letter was written in reply to an article published on the Times of May 20, describing hospital delivery as being 3 times safer than home delivery. The letter emphasizes that the author of Times article compared data from different countries to reach his conclusions, although data were actually not comparable. Evaluation of the National Birthday Trust survey of home births in the U.K., a certainly more appropriate approach to the question of safety of home versus hospital delivery, shows that within a group formed by 3,896 women who delivered at home, there was only one neonatal death (occurring from 0 to 27 days after birth) and no stillbirths, compared to 2 neonatal deaths and 2 stillbirths in a control group of similar, low-risk women who delivered in the hospital. The author concludes that there is no evidence indicating that home delivery carries more risk than hospital delivery in properly screened women. The letter emphasizes that women should receive accurate, up-to-date information, so that they may properly choose between home and hospital delivery.

Randomised, controlled trial of efficacy of midwife-managed care.
 Turnbull D, et al.
Lancet 1996 Jul 27;348(9022):213-8.

This randomized study, conducted on 1299 low-risk pregnant women, evaluated pregnancy outcome in women attended by midwives only, or by a combination of midwives, hospital doctors and general physicians. Labor was initiated significantly more often in women followed by physicians and midwives than in those followed by midwives only (33.3% vs. 23.9% of cases). Women attended only by midwives were more likely to have an intact perineum and less likely to undergo episiotomy (surgical enlargement of the vulval orifice during delivery). Perineal tears and rate of complications were similar in the two groups. Significantly more women expressed satisfaction with the midwife-managed care than with the physician-midwife managed care.

Midwifery care, social and medical risk factors, and birth outcomes in the USA.
 MacDorman MF, Singh GK.
J Epidemiol Community Health 1998 May;52(5):310-7.

The results of this study, conducted on all women who in 1991 delivered by the vaginal route a single baby at 35-43 weeks gestation, show that the risk of infant and neonatal death is 19% and 33% lower, respectively, in midwife-attended births compared to physician attended births. The likelihood of delivering a low birth-weight infant is 31% lower in midwives versus physician' assisted deliveries. These results suggest that delivery care provided by midwives may be superior to that provided by physicians.

Supportive nurse-midwife care is associated with a reduced incidence of Cesarean section.
Butler J, Abrams B, Parker J, Roberts JM, Laros RK Jr.
Am J Obstet Gynecol 1993 May;168(5):1407-13.

The results of this study show that women attended by midwives are 30% less likely to undergo Cesarean section compared to those attended by physicians. Furthermore, a diagnosis of fetal distress is made 50% less often in babies delivered by midwives, compared to those delivered by physicians.

A randomized controlled trial comparing midwife-managed care & obstetrician-managed care for women assessed to be at low risk in the initial intrapartum period.
 Law YY, Lam KY.
J Obstet Gynaecol Res 1999 Apr;25(2):107-12.

The results of this study show that pregnancy outcomes in women whose pregnancy has been followed by midwives are similar to those of women followed by obstetricians, indicating that routine visits of low-risk pregnant women by obstetricians are unnecessary. Women who experienced complications during labor were promptly recognized by midwives and transferred to obstetrician care.

Home versus hospital deliveries: follow up study of matched pairs for procedures and outcome.
Zurich Study Team.
Ackermann-Liebrich U, et al.
BMJ 1996 Nov 23;313(7068):1313-8.

The results of this study show that pregnancy outcomes in women who choose to deliver at home and are attended by midwives are similar to those of women who choose to deliver in hospital and are attended by obstetricians. Women who delivered at home received significantly less medication and fewer medical interventions, compared to those who delivered in the hospital. In case of complications or suspected complications, women were transferred to the hospital and were followed up by obstetricians.

ANTENATAL CARE

Amount of antenatal care and infant outcome.
 Gissler M, Hemminki E.
Eur J Obstet Gynecol Reprod Biol 1994 Jul;56(1):9-14.

The results of this study, conducted on over 57,000 women, show that those who received the most amount of prenatal care by their physicians had the worst pregnancy outcomes and the highest rate of Cesarean sections and induced labor.

Randomised controlled trial of a reduced-visits programme of antenatal care in Harare, Zimbabwe.
 Munjanja SP, Lindmark G, Nystrom L.
Lancet 1996 Aug 10;348(9024):364-9.

This randomized study, conducted on approximately 16,000 women in Zimbabwe, evaluated the effects of a new prenatal program for pregnant women consisting of fewer physician visits (an average of 4 instead of 6 visits), and fewer medical procedures per visit, on maternal and infant outcomes. Women who received less prenatal visits and less medical procedures had significantly lower risk of delivering preterm babies and of experiencing severe hypertension and eclampsia. Other outcomes were similar in the two groups.

Effect of frequency of prenatal care visits on perinatal outcome among low-risk women.
A randomized controlled trial.
McDuffie RS Jr, Beck A, Bischoff K, Cross J, Orleans M.
JAMA 1996 Mar 20;275(11):847-51.
The results of this study show that the introduction of a new program of prenatal care consisting of an average of 2.7 fewer than usual prenatal visits was associated with maternal and infant outcomes that were similar to those of women receiving standard number of prenatal visits.

Effect of prenatal ultrasound screening on perinatal outcome
RADIUS Study Group.
Ewigman BG, Crane JP, Frigoletto FD, LeFevre ML, Bain RP, McNellis D.
N Engl J Med 1993 Sep 16;329(12):821-7.

The results of this study show that routine ultrasound screening during pregnancy is not associated with improved newborn health. The study was conducted on 15,151 low-risk pregnant women randomized into two groups. Women in the first group received two ultrasound tests during their pregnancy, those in the second group received an ultrasound scan only if their doctor saw a specific medical need for the exam. No differences in perinatal outcome were detected between the two groups, indicating that routine ultrasound screening in low-risk women may increase health care costs without improving the health of women and their newborns.

A randomized trial of prenatal ultrasonographic screening: impact on the detection, management, and outcome of anomalous fetuses.
The RADIUS Study Group.
Crane JP, et al.
Am J Obstet Gynecol 1994 Aug;171(2):392-9.

The results of this study show that routine ultrasonographic screening in low-risk pregnant women is not associated with higher rates of abortion for congenital anomalies or with improved health outcomes of infants born with treatable malformations.

Six year survey of screening for Down's syndrome by maternal age and mid-trimester ultrasound scans.
 DT Howe, et al.
BMJ 2000;320:606-610 ( 4 March ).

The results of this study show that blood serum screening, introduced as the most effective screening method for Down's syndrome since 1993, is no more effective than traditional screening by ultrasound and maternal age at detecting cases of Down's syndrome, and is significantly more costly. The retrospective study was conducted on all women who gave birth at one institution in the period 1993 to 1998. Overall, there were 31,259 deliveries, including 53 cases of Down's syndrome. The traditional method of screening using maternal age in combination with ultrasound scans detected 68% cases of Down's syndrome, corresponding to the same effectiveness of screening through blood markers. Traditional screening has been replaced by blood screening based on the unverified assumption that traditional screening could only detect one-third of Down's cases. This study, however, demonstrates that the benefits of blood screening may be much less than supposed, and undermines the costs-benefit arguments for it.

FETAL HEART MONITORING

Do electronic fetal heart rate monitors improve delivery outcomes?
 Kaiser G.
J Fla Med Assoc 1991 May;78(5):303-7.

This article emphasizes that, despite early results from uncontrolled trials documenting the beneficial effects of fetal monitoring, randomized trials have consistently failed to demonstrate its efficacy in improving fetal outcome. Electronic monitoring of fetal-heart rates does not result in a decreased incidence of neurological complications or perinatal mortality and is, therefore, unnecessary.

Fetal heart rate monitoring: is it salvageable?
 Parer JT, King T.
Am J Obstet Gynecol 2000 Apr;182(4):982-7.

This article present evidence from randomized controlled trials indicating that fetal heart rate monitoring does not improve fetal outcome, and its use is therefore unjustified.

Effects of electronic fetal-heart-rate monitoring, as compared with periodic auscultation, on the neurologic development of premature infants.
 Shy KK, et al.
N Engl J Med 1990 Mar 1;322(9):588-93.

The results of this study indicate that premature babies who undergo electronic fetal heart rate monitoring have a worse neurological outcome, compared to those monitored with periodic auscultation. In the study, 189 premature babies were randomly assigned to either electronic fetal monitoring, or periodic auscultation. Neurological assessment performed at age of 4, 8, and 18 months revealed that babies monitored electronically had lower mental- and psychomotor-development scores, compared to those monitored by periodic auscultation. In addition, babies who underwent electronic monitoring had a 2.5-fold increased incidence of cerebral palsy, compared to those followed by auscultation. Median time to delivery after the recognition of an abnormal heart rate pattern was 104 minutes in babies monitored electronically and 60 minutes in those monitored by auscultation. These data indicate that fetal heart monitoring is ineffective in improving neurological outcome in prematurely born babies, and its use may be associated with harm.

Association of electronic fetal monitoring during labor with Cesarean section rate and with neonatal morbidity and mortality.
 McCusker J, Harris DR, Hosmer DW Jr.
Am J Public Health 1988 Sep;78(9):1170-4.

The results of this study show that electronic fetal monitoring does not improve delivery outcome, while being associated with an increased rate of Cesarean deliveries and low Apgar score.

BREAST FEEDING VERSUS FORMULA FEEDING

Office prenatal formula advertising and its effect on breast-feeding patterns.
 Howard C, Howard F, Lawrence R, Andresen E, DeBlieck E, Weitzman M.
Obstet Gynecol 2000 Feb;95(2):296-303.

The results of this study show that women who receive informational material publicizing infant formulas at their first prenatal visit are almost six times as likely to interrupt breast feeding before leaving the hospital, compared to woman who receive research material promoting the benefits of breast feeding. Women exposed to company-produced advertisement material are also almost twice as likely to cease breast-feeding before two weeks compared to those who receive research material. Babies who are breast-fed have improved health outcomes such as lower rates of infections, allergies and chronic diseases, compared to formula-fed babies. The authors emphasize that information material produced by formula manufacturers should not appear in doctor's offices, prenatal clinics and hospitals, especially considering that the World Health Organization's code regulating marketing of milk formulas "prohibits the distribution of free samples, the promotion of formula in health care facilities, and the use of pictures idealizing artificial feeding."

Effect of discharge samples on duration of breast-feeding.
 Dungy CI, Christensen-Szalanski J, Losch M, Russell D.
Pediatrics 1992 Aug;90(2 Pt 1):233-7.

The results of this study show that women who, upon delivery, received a hospital discharge package containing a manual breast pump, continued to breast-feed their baby significantly longer (4.2 weeks) than women who received a hospital discharge package containing an infant formula (2.8 weeks). Furthermore, women who felt that relief from nighttime feeding was important, were significantly more likely to breast-feed for more than 8 weeks if they received in the package the manual breast pump instead of the infant formula.

Violations of the international code of marketing of breast milk substitutes: prevalence in four countries.
 Taylor A.
BMJ 1998;316:1117-1122 ( 11 April ).

This study documented the extent of violation of the World Health Organization's code regulating the marketing of milk substitutes worldwide. Marketing efforts of milk substitutes' manufacturers have altered the perception of breast-feeding in women, and distribution of free samples of milk formulas and of advertisement material has resulted in a significant number of women opting for using commercial preparations rather than breast-feeding. This practice, however, is associated with significant harm, in that babies who have been bottle-fed have significantly higher rates of childhood diseases, impaired cognitive development, and higher risk of cardiovascular diseases in adulthood. The most devastating consequences of bottle-feeding occur in the developing countries, where neonates and infants are particularly at risk of contracting infectious diseases from contaminated water added to the formula. As reported in an editorial published in the same issue of the BMJ (BMJ 1998;316:1103-1104), the World Health Organization estimated that 1.5 million deaths could be prevented every year if women would breast-feed rather than bottle-feed their babies. To ensure protection of breast feeding the WHO developed a regulative code that prohibits the distribution of free samples of milk formulas to women or health facilities (except for professional research). In addition the code forbids the provision of incentives to health care workers, which has been associated with an increased likelihood of promotion of a particular product and with the lack of support of breast-feeding. The article highlights how several agencies have reported widespread violations of the code, but the companies have consistently rejected any allegation as unreliable and distorted by activists. This study monitored compliance to the WHO code by conducting a systematic, random survey of women and health care professionals in one city in each of Bangladesh, Poland, South Africa, and Thailand. Women were asked if they had been given free samples of milk substitutes, bottles and teats, while they were pregnant or in the six months after delivery. In addition, three health care workers in each facility were interviewed to assess whether the facility had received free samples of milk substitutes or gifts from companies involved in their production or distribution. The results of the survey showed that overall, 10% of all women (range 0-26%) and 25% of all health care facilities (range 8-50%) interviewed had been given free samples of milk, bottle, or teats for research purpose. Thirty percent of health facilities had received violating information and 11% of health care professionals had received gifts. These findings, which are likely underestimating the real dimension of the problem in the majority of the countries, point to the extent of violation of the WHO code by breast milk substitutes' manufacturers. The consequences of these violations in terms of increased mortality and loss of health are staggering.

Nestlé violates international marketing code, says audit. News.
 Yamey G.
BMJ 2000;321:8 ( 1 July ).

This article reports on the findings of an external audit demonstrating multiple violations of the World Health Organization's code of marketing of breast milk substitutes in Pakistan perpetrated by Nestlé. The discovery came after a former Nestlé employee exposed internal documents demonstrating that the company offered gifts to doctors as a recompense for promoting its products. In addition, the company was charged with offering free infant formulas to mothers and health care professionals, practices that are forbidden under the code's requirements.

Neurological differences between 9-year-old children fed breast-milk or formula-milk as babies.
 Lanting CI, Fidler V, Huisman M, Touwen BC, Boersma ER.
Lancet 1994 Nov 12;344(8933):1319-22.

The results of this study show that bottle-fed infants have a 50% increased risk of neurological dysfunction, compared to breast-fed infants. The authors propose that the presence of longer-chain polyunsaturated fatty acids -found in breast milk but not in most formula-milks, may be a factor involved in the excess risk, since these fatty acids play a vital role in brain development.

Breast-feeding and cognitive development: a meta-analysis.
 Anderson JW, Johnstone BM, Remley DT.
Am J Clin Nutr 1999 Oct;70(4):525-35.

The results of this meta-analysis, conducted on 20 previously published studies, show that breast-fed infants have significantly higher levels of cognitive development, compared to formula-fed infants. The differences were observed at 6-23 months and remained thereafter. The longer the duration of breast-feeding, the stronger the benefits observed on cognitive development. Premature children were found to benefit the most from breast-feeding.

Breast-feeding and cognitive development.
 Rogan WJ, Gladen BC.
Early Hum Dev 1993 Jan;31(3):181-93.

This study evaluated cognitive development in children aged 2 through 5 fed by different modes when infants. Breast-fed children were found to score significantly higher in developmental tests at all time points, compared to bottle-fed children.

Breastfeeding and later cognitive and academic outcomes.
 Horwood LJ, Fergusson DM.
Pediatrics 1998 Jan;101(1):E9.

The results of this study show that the improved performances in cognitive tests observed in breast- versus bottle-fed children early in life are maintained throughout childhood and young adulthood. Children who had been breast-fed as infants had significantly higher intelligence quotients and scholastic performances at all points tested, from first grade through high school. The longer the children were breast-fed, the better their cognitive development and academic performances into early adulthood.

Breast-feeding reduces incidence of hospital admissions for infection in infants.
 Fallot ME, Boyd JL 3d, Oski FA.
Pediatrics 1980 Jun;65(6):1121-4.

The results of this study show that infants aged 0 to 3 months who are breast-fed have significantly lower rates of infections and hospitalization compared to children who are bottle-fed.

Infant-feeding practices and their relationship with diarrheal and other diseases in Huascar (Lima), Peru.
 Brown KH, Black RE, Lopez de Romana G, Creed de Kanashiro H.
Pediatrics 1989 Jan;83(1):31-40.

The results of this study, conducted on 153 Peruvian newborns, show that during the first 6 months of their life infants who received other liquids in addition to breast milk had a twofold increased incidence of diarrheal disease, compared to those who received exclusively breast-milk. The incidence of diarrheal disease in infants in whom breast-feeding was discontinued during their first 6 months of life was four times higher than that of exclusively breast-fed infants. Rates of upper and lower respiratory infections and of skin infections were also lower in exclusively versus partially breast-fed infants.

Protective effect of breast feeding against infection.
 Howie PW, Forsyth JS, Ogston SA, Clark A, Florey CD.
BMJ 1990 Jan 6;300(6716):11-6.

The results of this study show that infants who have been breast-fed for at least 13 weeks have significantly lower rates of gastrointestinal illnesses and hospitalizations during the first year of their life, compared to those who have been bottle-fed from birth. Breast-feeding for less than 13 weeks is not associated with reduction of gastrointestinal disease.

A longitudinal analysis of infant morbidity and the extent of breastfeeding in the United States.
 Scariati PD, Grummer-Strawn LM, Fein SB.
Pediatrics 1997 Jun;99(6):E5.

The results of this study show that children who have been exclusively bottle-fed have an 80% increased risk of developing diarrhea and a 70% increased risk of developing middle ear infections, compared to those who have been exclusively breast-fed.

Artificial feeding and hospitalization in the first 18 months of life.
 Chen Y, Yu SZ, Li WX.
Pediatrics 1988 Jan;81(1):58-62.

The results of this study, conducted on 1,058 Chinese infants, show that those who were exclusively bottle-fed were twice as likely to be hospitalized for respiratory infections during their first 18 months of life, compared to those who were partially or exclusively breast fed.

Impact of breast feeding on admission for pneumonia during postneonatal period in Brazil: nested case-control study.
 Cesar JA, Victora CG, Barros FC, Santos IS, Flores JA.
BMJ 1999 May 15;318(7194):1316-20.

The results of this study, conducted on 152 infants aged 1 month to 1 year admitted to a Brazilian hospital for pneumonia and 2391matched controls, show that those who have been exclusively bottle-fed had an overall 17-fold increased risk of being hospitalized for this complication, compared to those who have been exclusively breast-fed. The risk was particularly high for children younger than 3 months, for whom bottle-feeding was associated with a 61-fold increased risk of pneumonia, and decreased down to 10 for older children. Strikingly, the study also found that the addition of solid foods to the diet of infants younger than 3 months of age was associated with a 175-folds increased risk of hospitalization for pneumonia, down to a 13-folds increase in children of all ages.

Relation of infant diet to childhood health: seven year follow up of cohort of children in Dundee infant feeding study.
 Wilson AC, Forsyth JS, Greene SA, Irvine L, Hau C, Howie PW.
BMJ 1998 Jan 3;316(7124):21-5.

The results of this study show that children who have been partially or exclusively bottle-fed during the first 15 weeks of life have an almost 2-fold higher risk of developing respiratory illness later in childhood, compared to those who have been exclusively breast-fed. Exclusive bottle-feeding was also associated with significantly higher levels of blood pressure later in childhood, compared to breast-feeding. In addition, the introduction of solid foods to the diet of infants younger than 15 weeks was found to be associated with an over 2-fold higher risk of wheeze during childhood, and with significantly increased percentage body weight and fat.

Association between breast feeding and asthma in 6 year old children: findings of a prospective birth cohort study.
 Oddy WH, Holt PG, Sly PD, Read AW, Landau LI, Stanley FJ, Kendall GE, Burton PR.
BMJ 1999 Sep 25;319(7213):815-9.

The results of this study show that the introduction of milk formulas to the diet of infants younger than 4 months is associated with a significantly higher risk of developing asthma and allergic disorders later in life. In particular, children who had been fed non-breast milk before four months of age were found to have a 25% higher risk of developing asthma and a 30% higher risk of having a positive skin prick test, compared to those who had been exclusively breast-fed.

Infant feeding and adult glucose tolerance, lipid profile, blood pressure, and obesity.
 Ravelli AC, van der Meulen JH, Osmond C, Barker DJ, Bleker OP.
Arch Dis Child 2000 Mar;82(3):248-52.

The results of this study show that individuals who have been bottle-fed when they were babies have more risk factors for cardiovascular disease and diabetes later in adulthood, compared to those who have been breast-fed. The study was conducted on 625 adults born in Amsterdam between 1943 and 1947. Those who had been bottle- fed had higher plasma glucose concentration after a glucose load test and higher cholesterol levels, compared to those who had been breast-fed. These data support previous research indicating an increased risk of cardiovascular diseases associated with bottle-feeding.

Environmental factors in childhood IDDM. A population-based, case-control study.
 Verge CF, Howard NJ, Irwig L, Simpson JM, Mackerras D, Silink M.
Diabetes Care 1994 Dec;17(12):1381-9.

The results of this study show that children who have received cow's milk-containing formulas when they were younger than 3 months have a 52% increased risk of developing insulin-dependent diabetes mellitus (IDDM or Type 1 diabetes), compared to those who have been exclusively breast-fed. Duration of exclusive breast-feeding for 3 months or longer was found to be associated with a 44% reduced risk of Type 1 diabetes.

Feeding in infancy and the risk of type 1 diabetes mellitus in Finnish children.
The 'Childhood Diabetes in Finland' Study Group.
Virtanen SM, Rasanen L, Aro A, Ylonen K, Lounamaa R, Tuomilehto J, Akerblom HK.
Diabet Med 1992 Nov;9(9):815-9.

The results of this study show that introduction of supplementary infant formulas into the diet of infants younger than 3 months is associated with a 52% higher risk of developing Type 1 diabetes later in life. Exclusive breast-feeding during the first 2 months of life, on the other hand, is protective, and is associated with a 40% lower risk of developing diabetes.

Infant feeding, early weight gain, and risk of type 1 diabetes. Childhood Diabetes in Finland (DiMe) Study Group.
Hypponen E, Kenward MG, Virtanen SM, Piitulainen A, Virta-Autio P, et al.
Diabetes Care 1999 Dec;22(12):1961-5.

The results of this study show that introduction of supplementary milk feeding to the diet of infants younger than 3 months is associated with a 53% higher risk of developing type 1 diabetes, compared to introduction of milk formulas after the age of 3 months.

Breastfeeding and incidence of non-insulin-dependent diabetes mellitus in Pima Indians.
 Pettitt DJ, Forman MR, Hanson RL, Knowler WC, Bennett PH.
Lancet 1997 Jul 19;350(9072):166-8.

The results of this study show that the risk of non-insulin-dependent diabetes mellitus (NIDDM or Type 2 diabetes) in a population of Pima Indians with a high prevalence of the disease is significantly higher in individuals who have been bottle-fed when infants, compared to those who have been breast-fed. In particular, after adjusting for several variables, exclusive breast-feeding was associated with a 60% lower risk of NIDDM, compared to exclusive bottle-feeding. This is one of the first studies demonstrating an association between bottle-feeding and Type 2 diabetes. The authors conclude that the increase in incidence of diabetes observed in some populations may partly be attributable to changes in infant feeding patterns.

Breast-feeding and risk of childhood acute leukemia.
 Shu XO, Linet MS, Steinbuch M, Wen WQ, Buckley JD, Neglia JP, Potter JD, et al.
J Natl Cancer Inst 1999 Oct 20;91(20):1765-72.

The results of this study show that breast-feeding is associated with a 21% lower risk of developing acute leukemia during childhood. The longer the duration of breast-feeding, the stronger the protective effect observed.

MISCELLANEOUS

Neonatal exposure to protoporphyrin-activating lighting as a contributing cause of childhood acute lymphocytic leukemia.
Ben-Sasson SA, Davis DL.
Cancer Causes Control 1992 Jul;3(4):383-7.

This article hypothesizes that infant exposure to fluorescent lamps may be a contributing factor to the development of acute lymphocytic leukemia (ALL) in children. The intensity of lights in U.S. nurseries has increased by 5-10 folds in the past twenty years. Fluorescent lamps and other strong illumination sources cause the formation of superoxides and free radicals involved in DNA mutation. The use of plastic filters could reduce this exposure considerably.

Prenatal and neonatal risk factors for childhood myeloid leukemia.
 Cnattingius S, Zack M, Ekbom A, Gunnarskog J, Linet M, Adami HO.
Cancer Epidemiol Biomarkers Prev 1995 Jul-Aug;4(5):441-5.

The results of this study show that the likelihood of developing myeloid leukemia was 2.5 times higher in children delivered by Cesarean section than in children delivered by the vaginal route. Children who were treated with phototherapy had a 7.5-fold increased risk of myeloid leukemia, and those who were treated in an incubator had a 3.5-fold increased risk.

Maternal and perinatal risk factors for childhood leukemia.
 Zack M, Adami HO, Ericson A.
Cancer Res 1991 Jul 15;51(14):3696-701.
The results of this study show that children born from women who received nitrous oxide anesthesia during delivery had a 30% increased risk of leukemia. The risk of leukemia was increased by 4.5-fold in children who had a diagnosis associated with difficult labor but unspecified complications.

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