Clinical Health Updates

Warm packs beneficial in labor

Clinical Question:
Do warm packs prevent perineal trauma when applied to the perineum during labor?

Bottom Line:
The application of perineal warm packs in late second stage does not reduce the likelihood of nulliparous women requiring perineal suturing but significantly reduces third- and fourth-degree lacerations, pain during the birth and on days 1 and 2, and urinary incontinence. This simple, inexpensive practice should be incorporated into second stage labor care.

Reference:
Dahlen HG, Homer CS, Cooke M, Upton AM, Nunn R, Brodrick B. Perineal outcomes and maternal comfort related to the application of perineal warm packs in the second stage of labor: A randomized controlled trial. Birth 2007;34(4):282-290.

Study Design:
Randomized controlled trial (nonblinded)

Synopsis:
In this randomized controlled trial of 717 women the use of warm packs from late second-stage labor until crowning was compared with usual care that did not include warm packs. Although masking of women and their birth attendants was not possible, the outcome assessors were masked. Eligible women were nulliparous with singleton term pregnancy in cephalic presentation who anticipated a normal delivery and had not performed perineal massage. Warm packs consisted of perineal pads soaked in boiled tap water at a temperature of approximately 45 degrees centigrade. The trial was conducted in an ethnically diverse population in Australia, where 75% of women are immigrants from other countries. With a study size adequate to detect a 10% difference, there was no difference between groups for the principal outcome of need for perineal suture. However, the number of third- and fourth-degree lacerations was reduced in the wam pack group, (31/357 vs 15/360; number needed to treat [NNT] = 22; 95% CI, 12-109). Women receiving warm packs were less likely to report severe pain during birth than women who were not given warm packs (59% vs 82%, respectively). There were also modest, statistically significant reductions in mean perineal pain scores on days 1 and 2 postpartum using a 10-point visual analog scale, with less than 1-point mean differences. At 3 months postpartum women who had received warm packs were less likely to report urinary incontinence (36/276 vs 46/277; NNT = 28).

Obesity associated with increased risk of stillbirth

Clinical Question:
Is maternal obesity associated with an increased risk of stillbirth?

Bottom Line:
Maternal obesity is associated with double the risk of stillbirth. This study did not provide information regarding absolute risk. Neither did it evaluate to what extent this association may be explained by other known risk factors for adverse perinatal outcomes that are frequently seen in obese women, such as hypertension and diabetes.

Reference:
Chu SY, Kim SY, Lau J, et al. Maternal obesity and risk of stillbirth: a metaanalysis. Am J Obstet Gynecol 2007;197(3):223-228.

Study Design:
Meta-analysis (other)

Synopsis:
The authors conducted this metaanalysis to summarize the available epidemiologic evidence on the relationship between maternal overweight and obesity and the risk of stillbirth. They identified studies from 3 sources:
(1) a PubMed search of relevant articles that were published between January 1980 and September 2005
(2) reference lists of publications that were selected from the PubMed search
(3) reference lists of review articles on obesity and maternal outcomes that were published between 2000 and 2005.
The investigators used a Bayesian random effects model to perform the metaanalysis and metaregression. Nine studies were included in the metaanalysis. The unadjusted odds ratios of a stillbirth were 1.47 (95% CI, 1.08-1.94) and 2.07 (95% CI, 1.59-2.74) among overweight and obese pregnant women, respectively, compared with normal-weight pregnant women. The metaregression analysis found no evidence that these estimates were affected by selected study characteristics. Maternal obesity is associated with an increased risk of stillbirth, although the mechanisms to explain this association are not clear.

No long-term benefit from multiple courses of antenatal corticosteroids

Clinical Question:
Do multiple courses of antenatal corticosteroids improve the long-term outcomes of children more than a single course?

Bottom Line:
Children treated with multiple courses of antenatal betamethasone showed no evidence of improved outcomes at 2 years to 3 years of age compared with those who received a single course. The study was too small to determine whether a 2% absolute increase in incidence of cerebral palsy with multiple courses was a true difference.

Reference:
Wapner RJ, Sorokin Y, Mele L, et al, for the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Long-term outcomes after repeat doses of antenatal corticosteroids. N Eng J Med 2007;357(12):1190-1198.

Study Design:
Randomized controlled trial (double-blinded)

Synopsis:
Previous trials have shown that repeat courses of antenatal corticosteroids improve some neonatal outcomes in preterm infants but reduce birth weight and increase the risk of intrauterine growth restriction. They reported long-term follow-up results of children enrolled in a randomized trial comparing single and repeat courses of antenatal corticosteroids. Women at 23 through 31 weeks of gestation who remained pregnant 7 days after an initial course of corticosteroids were randomly assigned to weekly courses of betamethasone, consisting of 12 mg given intramuscularly and repeated once at 24 hours, or an identical-appearing placebo. We studied the children who were born after these treatments when they were between 2 and 3 years of corrected age. Prespecified outcomes included scores on the Bayley Scales of Infant Development, anthropometric measurements, and the presence of cerebral palsy. A total of 556 infants were available for follow-up; 486 children (87.4%) underwent physical examination and 465 (83.6%) underwent Bayley testing at a mean (+/-SD) corrected age of 29.3+/-4.6 months. There were no significant differences in Bayley results or anthropometric measurements. Six children (2.9% of pregnancies) in the repeat-corticosteroid group had cerebral palsy as compared with one child (0.5% of pregnancies) in the placebo group (relative risk, 5.7; 95% confidence interval, 0.7 to 46.7; P=0.12).

No long-term harm from medical abortion

Clinical Question:
What are the long-term health consequences of medical abortion?

Bottom Line:
Subsequent pregnancy outcomes are similar after medical abortion using prostaglandins to the outcomes after surgical abortion.

Reference:
Virk J, Zhang J, Olsen J. Medical abortion and the risk of subsequent adverse pregnancy outcomes. N Engl J Med 2007;357:648-653.

Study Design:
Cohort (prospective)

Synopsis:
The long-term safety of surgical abortion in the first trimester is well established. Despite the increasing use of medical abortion (abortion by means of medication), limited information is available regarding the effects of this procedure on subsequent pregnancies. The authors identified all women living in Denmark who had undergone an abortion for nonmedical reasons between 1999 and 2004 and obtained information regarding subsequent pregnancies from national registries. Risks of ectopic pregnancy, spontaneous abortion, preterm birth (at <37 weeks of gestation), and low birth weight (<2500 g) in the first subsequent pregnancy in women who had had a first-trimester medical abortion were compared with risks in women who had had a first-trimester surgical abortion. Among 11,814 pregnancies in women who had had a previous first-trimester medical abortion (2710 women) or surgical abortion (9104 women), there were 274 ectopic pregnancies (respective incidence rates, 2.4% and 2.3%), 1426 spontaneous abortions (12.2% and 12.7%), 552 preterm births (5.4% and 6.7%), and 478 births with low birth weight (4.0% and 5.1%). After adjustment for maternal age, interval between pregnancies, gestational age at abortion, parity, cohabitation status, and urban or nonurban residence, medical abortion was not associated with a significantly increased risk of ectopic pregnancy (relative risk, 1.04; 95% confidence interval [CI], 0.76 to 1.41), spontaneous abortion (relative risk, 0.87; 95% CI, 0.72 to 1.05), preterm birth (relative risk, 0.88; 95% CI, 0.66 to 1.18), or low birth weight (relative risk, 0.82; 95% CI, 0.61 to 1.11). Gestational age at medical abortion was not significantly associated with any of these adverse outcomes.

No long-term harm from medical abortion

Clinical Question:
What are the long-term health consequences of medical abortion?

Bottom Line:
Subsequent pregnancy outcomes are similar after medical abortion using prostaglandins to the outcomes after surgical abortion. No evidence that a previous medical abortion, as compared with a previous surgical abortion, increases the risk of spontaneous abortion, ectopic pregnancy, preterm birth, or low birth weight.

Reference:
Virk J, Zhang J, Olsen J. Medical abortion and the risk of subsequent adverse pregnancy outcomes. N Engl J Med 2007;357:648-653.

Study Design:
Cohort (prospective)

Synopsis:
The long-term safety of surgical abortion in the first trimester is well established. Despite the increasing use of medical abortion (abortion by means of medication), limited information is available regarding the effects of this procedure on subsequent pregnancies. They identified all women living in Denmark who had undergone an abortion for nonmedical reasons between 1999 and 2004 and obtained information regarding subsequent pregnancies from national registries. Risks of ectopic pregnancy, spontaneous abortion, preterm birth (at <37 weeks of gestation), and low birth weight (<2500 g) in the first subsequent pregnancy in women who had had a first-trimester medical abortion were compared with risks in women who had had a first-trimester surgical abortion. Among 11,814 pregnancies in women who had had a previous first-trimester medical abortion (2710 women) or surgical abortion (9104 women), there were 274 ectopic pregnancies (respective incidence rates, 2.4% and 2.3%), 1426 spontaneous abortions (12.2% and 12.7%), 552 preterm births (5.4% and 6.7%), and 478 births with low birth weight (4.0% and 5.1%). After adjustment for maternal age, interval between pregnancies, gestational age at abortion, parity, cohabitation status, and urban or nonurban residence, medical abortion was not associated with a significantly increased risk of ectopic pregnancy (relative risk, 1.04; 95% confidence interval [CI], 0.76 to 1.41), spontaneous abortion (relative risk, 0.87; 95% CI, 0.72 to 1.05), preterm birth (relative risk, 0.88; 95% CI, 0.66 to 1.18), or low birth weight (relative risk, 0.82; 95% CI, 0.61 to 1.11). Gestational age at medical abortion was not significantly associated with any of these adverse outcomes.

Iron for nonanemic pregnant women not beneficial

Clinical Question:
Is iron supplementation of nonanemic pregnant women beneficial to them or their newborns?

Bottom Line:
Iron supplementation in pregnant women with a hemoglobin level of at least 13.2 is not beneficial and may be harmful.

Reference:
Ziaei S, Norrozi M. Faghihzadeh S, Jafarbegloo E. A randomised placebo-controlled trial to determine the effect of iron supplementation on pregnancy outcome in pregnant women with greater than or equal to haemoglobin 13.2 g/dl. BJOG 2007;114:684-688.

Study Design:
Randomized controlled trial (double-blinded)

Synopsis:
The authors studied the effect of iron supplementation on pregnancy outcome in pregnant women with haemoglobin (Hb) > or = 13.2 g/dl. They did a randomised, double-blind, placebo-controlled trial in a routine health services. Seven hundred and twenty-seven pregnant women with Hb > or = 13.2 g/dl in the early stage of the second trimester participated on this trial. Each woman took one tablet of 50 mg of ferrous sulphate daily in the case group (n = 370) or placebo in the control group (n = 357) throughout pregnancy. While there were no significant differences in demographic and obstetric characteristics between the two groups before any intervention, small-for-gestational-age birth rate and the number of women with hypertension disorder increased significantly in the case group in comparison with the control group (57 [15.7%] versus 36 [10.3%], P = 0.035, 10 [2.7%] versus 3 [8%], P = 0.05, respectively).

External cephalic version safe

Clinical Question:
Is external cephalic version for breech presentation at term pregnancy safe?

Bottom Line:
In this series of 805 consecutive version attempts, they reported an extremely low complication rate and 0.5% risk of emergency caesarean section after the procedure.

Reference:
Collins S, Ellaway P, Harrington D, Pandit M, Impey LW. The complications of external cephalic version: results from 805 consecutive attempts. BJOG 2007;114;636-638.

Study Design:
Case series

Synopsis:
Currently most women with fetus in breech presentation at term pregnancy undergo elective cesarean delivery. These UK authors present the results of all external cephalic versions (n=805) performed at their institution between June 2000 and March 2006 to demonstrate complication rates. Included were singleton pregnancies at or beyond 36 weeks’ for nulliparous women and 37 weeks’ in multiparous women. Women were not eligible if they had an absolute indication for cesarean delivery, growth restricted fetus with abnormal umbilical artery Doppler index, ruptured membranes, Rh isoimmunization, severe preeclampsia, or recent vaginal bleeding. A detailed ultrasound was performed before version attempt and to aid during the procedure. Up to 2 version attempts were made using a forward roll technique. Fetal heart rate was monitored after the version attempt until a normal reactive tracing was obtained. There was one unexplained stillbirth at 40 weeks and 5 days of gestation, after an uncomplicated successful version at 37 weeks. There were no cases with evidence of fetal trauma. There were 4 emergency cesarean deliveries (0.5%) at the time of attempted version, one neonate with trisomy 21 and the other 3 with normal Apgar scores and cord pH levels. Version was successful in 357 of 805 cases (44%). Of women with successful versions 90% delivered vaginally.

Methotrexate for ectopic pregnancy successful with beta-hCG < 5000

Clinical Question:
What is the appropriate cutoff for human chorionic gonadotropin to predict successful treatment of ectopic pregnancy with single-dose methotrexate?

Bottom Line:
The success rate of single-dose methotrexate therapy for ectopic pregnancy has been observed to be approximately 95% when the human chorionic gonadotropin (hCG) level is less than 5000 mIU/mL. The success rate is less than 90% when the hCG level is higher.

Reference:
Menon S, Colins J, Barnhart KT. Establishing a human chorionic gonadotropin cutoff to guide methotrexate treatment of ectopic pregnancy: a systematic review. Fertil Steril 2007;87:481-484.

Study Design:
Diagnostic test evaluation

Synopsis:
Successful medical management of an ectopic pregnancy is inversely associated with initial hCG level. The authors assessed whether there is a level of hCG above which failure rate substantially increases. A systematic review and summary analysis was performed, including studies reporting methotrexate treatment outcomes as stratified by various hCG ranges. They did it in a academic medical center. Review was done of published information regarding patients treated with methotrexate. Five observational studies, including 503 women, were found that reported successes in using single-dose methotrexate stratified by initial hCG concentration. Failure rates increase with increasing hCG levels. A substantial and statistically significant increase in failure rates is seen when comparing patients who have initial hCG levels of >5,000 mIU/mL with those who have initial levels of <5,000 mIU/mL (odds ratio: 5.45; 95% confidence interval: 3.04, 9.78). The failure rate for women who had an initial concentration between 5,000 and 9,999 mIU/mL was significantly higher than that for those who had initial levels between 2,000 and 4,999 mIU/mL (odds ratio: 3.76; 95% confidence interval: 1.16, 12.33).

Delayed cord clamping in full-term infants reduces risk of anemia

Clinical Question:
Should we routinely delay umbilical cord clamping in full-term infants for at least 2 minutes?

Bottom Line:
There is no evidence that routinely delaying clamping of the umbilical cord for at least 2 minutes after the birth of full-term infants increases the risk of any significant clinical outcome. Infants with late clamping are at a reduced risk of low ferritin levels and stored iron levels up to 6 months of age. Since there may be some potential long-term risks associated with anemia in the first 6 months of life, strong consideration should be given to routinely delaying the clamping of umbilical cords postdelivery. Additional large randomized trials that include maternal outcomes are needed.

Reference:
Hutton EK, Hassan ES. Late vs early clamping of the umbilical cord in full-term neonates. Systematic review and meta-analysis of controlled trials. JAMA 2007;297:1241-1252.

Study Design:
Meta-analysis (other)

Synopsis:
With few exceptions, the umbilical cord of every newborn is clamped and cut at birth, yet the optimal timing for this intervention remains controversial. The authors compared the potential benefits and harms of late vs early cord clamping in term infants.
Search of 6 electronic databases (on November 15, 2006, starting from the beginning of each):
1. the Cochrane Pregnancy and Childbirth Group trials register
2. the Cochrane Neonatal Group trials register
3. the Cochrane library
4. MEDLINE
5. EMBASE
6. CINHAL
hand search of secondary references in relevant studies; and contact of investigators about relevant published research. Controlled trials comparing late vs early cord clamping following birth in infants born at 37 or more weeks’ gestation. Two reviewers independently assessed eligibility and quality of trials and extracted data for outcomes of interest: infant hematologic status; iron status; and risk of adverse events such as jaundice, polycythemia, and respiratory distress. The meta-analysis included 15 controlled trials (1912 newborns). Late cord clamping was delayed for at least 2 minutes (n = 1001 newborns), while early clamping in most trials (n = 911 newborns) was performed immediately after birth. Benefits over ages 2 to 6 months associated with late cord clamping include improved hematologic status measured as hematocrit (weighted mean difference [WMD], 3.70%; 95% confidence interval [CI], 2.00%-5.40%); iron status as measured by ferritin concentration (WMD, 17.89; 95% CI, 16.58-19.21) and stored iron (WMD, 19.90; 95% CI, 7.67-32.13); and a clinically important reduction in the risk of anemia (relative risk (RR), 0.53; 95% CI, 0.40-0.70). Neonates with late clamping were at increased risk of experiencing asymptomatic polycythemia (7 studies [403 neonates]: RR, 3.82; 95% CI, 1.11-13.21; 2 high-quality studies only [281 infants]: RR, 3.91; 95% CI, 1.00-15.36).

Induction of labor after one prior cesarean is relatively safe

Clinical Question:
Does induction of labor increase the risk of uterine rupture in women with one prior cesarean section?

Bottom Line:
For women with one prior cesarean delivery and no prior vaginal delivery, induction of labor results in an absolute increase in the risk of uterine rupture of 0.7% compared with spontaneous delivery. No significant difference was seen between induced labor or spontaneous labor in women with one prior cesarean delivery and at least one prior vaginal delivery. Perinatal morbidity was not associated with labor induction. Since these are observational data, a randomized controlled trial is still needed to definitively settle the question.

Reference:
Grobman WA, Gilbert S, Landon MB, et al. Outcomes of induction of labor after one prior cesarean. Obstet Gynecol 2007;109:262-269.

Study Design:
Cohort (prospective)

Synopsis:
The authors compared pregnancy outcomes in women with one prior low-transverse cesarean delivery after induction of labor with pregnancy outcomes after spontaneous labor. This study is an analysis of women with one prior low-transverse cesarean and a singleton gestation who underwent a trial of labor and who were enrolled in a 4-year prospective observational study. Pregnancy outcomes were evaluated according to whether a woman underwent spontaneous labor or labor induction. Among the 11,778 women studied, vaginal delivery was less likely after induction of labor both in women without and with a prior vaginal delivery (51% versus 65%, P<.001; and 83% versus 88%, P<.001). An increased risk of uterine rupture after labor induction was found only in women with no prior vaginal delivery (1.5% versus 0.8%, P=.02; and 0.6% versus 0.4%, P=.42). Blood transfusion, venous thromboembolism, and hysterectomy were also more common with induction among women without a prior vaginal delivery. No measure of perinatal morbidity was associated with labor induction. An unfavorable cervix at labor induction was not associated with any adverse outcomes except an increased risk of cesarean delivery.