Adverse pregnancy outcomes among women with prior spontaneous or induced abortions

OBJECTIVE

The aim of the article is to determine whether prior spontaneous abortion (SAB) or induced abortion (IAB), or the interpregnancy interval are associated with subsequent adverse pregnancy outcomes in nulliparous women.

METHODS

We performed a secondary analysis of data collected from nulliparous women enrolled in a completed trial of vitamins C and E or placebo for preeclampsia prevention. Adjusted odds ratios (ORs) for maternal and fetal outcomes were determined for nulliparous women with prior SABs and IABs as compared with primigravid participants.

RESULTS

Compared with primigravidas, women with one prior SAB were at increased risk for perinatal death (adj. OR, 1.5; 95% CI, 1.1-2.3) in subsequent pregnancies. Two or more SABs were associated with an increased risk for spontaneous preterm birth (PTB) (adj. OR, 2.6, 95% CI, 1.7-4.0), preterm premature rupture of membranes (PROM) (adj. OR, 2.9; 95% CI, 1.6-5.3), and perinatal death (adj. OR, 2.8; 95% CI, 1.5-5.3). Women with one previous IAB had higher rates of spontaneous PTB (adj. OR, 1.4; 95% CI, 1.0-1.9) and preterm PROM (OR, 2.0; 95% CI, 1.4-3.0). An interpregnancy interval less than 6 months after SAB was not associated with adverse outcomes.

CONCLUSION

Nulliparous women with a history of SAB or IAB, especially multiple SABs, are at increased risk for adverse pregnancy outcomes.

Vaginal chlorhexidine during labour for preventing maternal and neonatal infections (excluding Group B Streptococcal and HIV)

BACKGROUND

The incidence of chorioamnionitis occurs in between eight and 12 women for every 1000 live births and 96% of cases of chorioamnionitis are due to ascending infection. Following spontaneous vaginal delivery, 1% to 4% of women develop postpartum endometritis. The incidence of neonatal sepsis is 0.5% to 1% of all infants born. Maternal vaginal bacteria are the main agents for these infections. It is reasonable to speculate that prevention of maternal and neonatal infections might be possible by washing the vagina and cervix with an antibacterial agent for all women during labour. Chlorhexidine belongs to the class of compounds known as the bis-biguanides. Chlorhexidine has antibacterial action against a wide range of aerobic and anaerobic bacteria, including those implicated in peripartal infections.

OBJECTIVES

To evaluate the effectiveness and side effects of chlorhexidine vaginal douching during labour in reducing maternal and neonatal infections (excluding group B streptococcal and HIV).

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 June 2014), reference lists of retrieved reports and journal letters and editorials.

SELECTION CRITERIA

Randomized or quasi-randomized trials comparing chlorhexidine vaginal douching during labour with placebo or other vaginal disinfectant to prevent (reduce) maternal and neonatal infections (excluding group B streptococcal and HIV).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and quality, extracted and interpreted the data. A third review author analyzed and interpreted the data. The fourth author also interpreted the data.

MAIN RESULTS

We included three studies (3012 participants). There was no evidence of an effect of vaginal chlorhexidine during labour in preventing maternal and neonatal infections. Although the data suggest a trend in reducing postpartum endometritis, the difference was not statistically significant (three trials, 3012 women, risk ratio 0.83; 95% confidence interval 0.61 to 1.13).Assessment of the quality of the evidence using GRADE indicated that the levels of evidence for all primary outcomes and one important secondary outcome were low to moderate.

AUTHORS' CONCLUSIONS

There is no evidence to support the use of vaginal chlorhexidine during labour in preventing maternal and neonatal infections. There is a need for a well-designed randomized controlled trial using appropriate concentration and volume of vaginal chlorhexidine irrigation solution and with adequate sample size.

Inadequate weight gain in overweight and obese pregnant women: what is the effect on fetal growth?

OBJECTIVE

We sought to evaluate inadequate gestational weight gain and fetal growth among overweight and obese women.

STUDY DESIGN

We conducted an analysis of prospective singleton term pregnancies in which 1053 overweight and obese women gained >5 kg (14.4 ± 6.2 kg) or 188 who either lost or gained ≤5 kg (1.1 ± 4.4 kg). Birthweight, fat mass, and lean mass were assessed using anthropometry. Small for gestational age (SGA) was defined as ≤10th percentile of a standard US population. Univariable and multivariable analysis evaluated the association between weight change and neonatal morphometry.

RESULTS

There was no significant difference in age, race, smoking, parity, or gestational age between groups. Weight loss or gain ≤5 kg was associated with SGA, 18/188 (9.6%) vs 51/1053 (4.9%); (adjusted odds ratio, 2.6; 95% confidence interval, 1.4-4.7; P = .003). Neonates of women who lost or gained ≤5 kg had lower birthweight (3258 ± 443 vs 3467 ± 492 g, P < .0001), fat mass (403 ± 175 vs 471 ± 193 g, P < .0001), and lean mass (2855 ± 321 vs 2995 ± 347 g, P < .0001), and smaller length, percent fat mass, and head circumference. Adjusting for diabetic status, prepregnancy body mass index, smoking, parity, study site, gestational age, and sex, neonates of women who gained ≤5 kg had significantly lower birthweight, lean body mass, fat mass, percent fat mass, head circumference, and length. There were no significant differences in neonatal outcomes between those who lost weight and those who gained ≤5 kg.

CONCLUSION

In overweight and obese women weight loss or gain ≤5 kg is associated with increased risk of SGA and decreased neonatal fat mass, lean mass, and head circumference.

Can differences in obstetric outcomes be explained by differences in the care provided? The MFMU Network APEX study

OBJECTIVE

The purpose of this study was to determine whether hospital differences in the frequency of adverse obstetric outcomes are related to differences in care.

STUDY DESIGN

The Assessment of Perinatal EXcellence cohort comprises 115,502 women and their neonates who were born in 25 hospitals in the United States between March 2008 and February 2011. Hierarchical logistic regression was used to quantify the amount of variation in postpartum hemorrhage, peripartum infection, severe perineal laceration, and a composite adverse neonatal outcome among hospitals that is explained by differences in patient characteristics, hospital characteristics, and obstetric care provided.

RESULTS

The study included 115,502 women. For most outcomes, 20-40% of hospital differences in outcomes were related to differences in patient populations. After adjusting for patient-, provider-, and hospital-level factors, multiple care processes were associated with the predefined adverse outcomes; however, these care processes did not explain significant variation in the frequency of adverse outcomes among hospitals. Ultimately, 50-100% of the interhospital variation in outcomes was unexplained.

CONCLUSION

Hospital differences in the frequency of adverse obstetric outcomes could not be explained by differences in frequency of types of care provided.

Frequency of and factors associated with severe maternal morbidity

OBJECTIVE

To estimate the frequency of severe maternal morbidity, assess its underlying etiologies, and develop a scoring system to predict its occurrence.Supplemental Digital Content is Available in the Text.

METHODS

This was a secondary analysis of a Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network cohort of 115,502 women and their neonates born in 25 hospitals across the United States over a 3-year period. Women were classified as having severe maternal morbidity according to a scoring system that takes into account the occurrence of red blood cell transfusion (more than three units), intubation, unanticipated surgical intervention, organ failure, and intensive care unit admission. The frequency of severe maternal morbidity was calculated and the underlying etiologies determined. Multivariable analysis identified patient factors present on admission that were independently associated with severe maternal morbidity; these were used to develop a prediction model for severe maternal morbidity.

RESULTS

Among 115,502 women who delivered during the study period, 332 (2.9/1,000 births, 95% confidence interval 2.6-3.2) experienced severe maternal morbidity. Postpartum hemorrhage was responsible for approximately half of severe maternal morbidity. Multiple patient factors were found to be independently associated with severe maternal morbidity and were used to develop a predictive model with an area under the receiver operating characteristic curve of 0.80.

CONCLUSION

Severe maternal morbidity occurs in approximately 2.9 per 1,000 births, is most commonly the result of postpartum hemorrhage, and occurs more commonly in association with several identifiable patient characteristics.

LEVEL OF EVIDENCE

: II.

Post-abortion and induced abortion services in two public hospitals in Colombia

OBJECTIVE

Until 2006, legal induced abortion was completely banned in Colombia. Few facilities are equipped or willing to offer abortion services; often adolescents experience even greater barriers of access in this context. We examined post abortion care (PAC) and legal induced abortion in two large public hospitals. We tested the association of hospital site, procedure type (manual vacuum aspiration vs. sharp curettage), and age (adolescents vs. women 20 years and over) with service type (PAC or legal induced abortion).

STUDY DESIGN

Retrospective cohort study using 2010 billing data routinely collected for reimbursement (N=1353 procedures). We utilized descriptive statistics, multivariable logistic regression and predicted probabilities.

RESULTS

Adolescents made up 22% of the overall sample (300/1353). Manual vacuum aspiration was used in one-third of cases (vs. sharp curettage). Adolescents had lower odds of documented PAC (vs. induced abortion) compared with women over age 20 (OR=0.42; 95% CI=0.21-0.86). The absolute difference of service type by age, however, is very small, controlling for hospital site and procedure type (.97 probability of PAC for adolescents compared with .99 for women 20 and over). Regardless of age, PAC via sharp curettage is the current standard in these two public hospitals.

CONCLUSION

Both adolescents and women over 20 are in need of access to legal abortion services utilizing modern technologies in the public sector in Colombia. Documentation of abortion care is an essential first step to determining barriers to access and opportunities for quality improvement and better health outcomes for women.

IMPLICATIONS

Following partial decriminalization of abortion in Colombia, in public hospitals nearly all abortion services are post-abortion care, not induced abortion. Sharp curettage is the dominant treatment for both adolescents and women over 20. Women seek care in the public sector for abortion, and must have access to safe, quality services.

Risk-adjusted models for adverse obstetric outcomes and variation in risk-adjusted outcomes across hospitals

OBJECTIVE

Regulatory bodies and insurers evaluate hospital quality using obstetrical outcomes, however meaningful comparisons should take preexisting patient characteristics into account. Furthermore, if risk-adjusted outcomes are consistent within a hospital, fewer measures and resources would be needed to assess obstetrical quality. Our objective was to establish risk-adjusted models for 5 obstetric outcomes and assess hospital performance across these outcomes.

STUDY DESIGN

We studied a cohort of 115,502 women and their neonates born in 25 hospitals in the United States from March 2008 through February 2011. Hospitals were ranked according to their unadjusted and risk-adjusted frequency of venous thromboembolism, postpartum hemorrhage, peripartum infection, severe perineal laceration, and a composite neonatal adverse outcome. Correlations between hospital risk-adjusted outcome frequencies were assessed.

RESULTS

Venous thromboembolism occurred too infrequently (0.03%; 95% confidence interval [CI], 0.02-0.04%) for meaningful assessment. Other outcomes occurred frequently enough for assessment (postpartum hemorrhage, 2.29%; 95% CI, 2.20-2.38, peripartum infection, 5.06%; 95% CI, 4.93-5.19, severe perineal laceration at spontaneous vaginal delivery, 2.16%; 95% CI, 2.06-2.27, neonatal composite, 2.73%; 95% CI, 2.63-2.84). Although there was high concordance between unadjusted and adjusted hospital rankings, several individual hospitals had an adjusted rank that was substantially different (as much as 12 rank tiers) than their unadjusted rank. None of the correlations between hospital-adjusted outcome frequencies was significant. For example, the hospital with the lowest adjusted frequency of peripartum infection had the highest adjusted frequency of severe perineal laceration.

CONCLUSION

Evaluations based on a single risk-adjusted outcome cannot be generalized to overall hospital obstetric performance.

Prophylactic oxytocin for the third stage of labour to prevent postpartum haemorrhage

BACKGROUND

Active management of the third stage of labour has been shown to reduce the risk of postpartum haemorrhage (PPH) greater than 1000 mL. One aspect of the active management protocol is the administration of prophylactic uterotonics, however, the type of uterotonic, dose, and route of administration vary across the globe and may have an impact on maternal outcomes.

OBJECTIVES

To determine the effectiveness of prophylactic oxytocin at any dose to prevent PPH and other adverse maternal outcomes related to the third stage of labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2013).

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials including pregnant women anticipating a vaginal delivery where prophylactic oxytocin was given during management of the third stage of labour. The primary outcomes were blood loss > 500 mL and the use of therapeutic uterotonics.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, assessed trial quality and extracted data. Data were checked for accuracy.

MAIN RESULTS

This updated review included 20 trials (involving 10,806 women). Prophylactic oxytocin versus placebo Prophylactic oxytocin compared with placebo reduced the risk of PPH greater than 500 mL, (risk ratio (RR) 0.53; 95% confidence interval (CI) 0.38 to 0.74; six trials, 4203 women; T² = 0.11, I² = 78%) and the need for therapeutic uterotonics (RR 0.56; 95% CI 0.36 to 0.87, four trials, 3174 women; T² = 0.10, I² = 58%). The benefit of prophylactic oxytocin to prevent PPH greater than 500 mL was seen in all subgroups. Decreased use of therapeutic uterotonics was only seen in the following subgroups: randomised trials with low risk of bias (RR 0.58; 95% CI 0.36 to 0.92; three trials, 3122 women; T² = 0.11, I² = 69%); trials that performed active management of the third stage (RR 0.39; 95% CI 0.26 to 0.58; one trial, 1901 women; heterogeneity not applicable); trials that delivered oxytocin as an IV bolus (RR 0.57; 95% CI 0.39 to 0.82; one trial, 1000 women; heterogeneity not applicable); and in trials that gave oxytocin at a dose of 10 IU (RR 0.48; 95% CI 0.33 to 0.68; two trials, 2901 women; T² = 0.02, I² = 27%). Prophylactic oxytocin versus ergot alkaloids. Prophylactic oxytocin was superior to ergot alkaloids in preventing PPH greater than 500 mL (RR 0.76; 95% CI 0.61 to 0.94; five trials, 2226 women; T² = 0.00, I² = 0%). The benefit of oxytocin over ergot alkaloids to prevent PPH greater than 500 mL only persisted in the subgroups of quasi-randomised trials (RR 0.71, 95% CI 0.53 to 0.96; three trials, 1402 women; T² = 0.00, I² = 0%) and in trials that performed active management of the third stage of labour (RR 0.58; 95% CI 0.38 to 0.89; two trials, 943 women; T² = 0.00, I² = 0%). Use of prophylactic oxytocin was associated with fewer side effects compared with use of ergot alkaloids; including decreased nausea between delivery of the baby and discharge from the labour ward (RR 0.18; 95% CI 0.06 to 0.53; three trials, 1091 women; T² = 0.41, I² = 41%) and vomiting between delivery of the baby and discharge from the labour ward (RR 0.07; 95% CI 0.02 to 0.25; three trials, 1091 women; T² = 0.45, I² = 30%). Prophylactic oxytocin + ergometrine versus ergot alkaloids: There was no benefit seen in the combination of oxytocin and ergometrine versus ergometrine alone in preventing PPH greater than 500 mL (RR 0.90; 95% CI 0.34 to 2.41; five trials, 2891 women; T² = 0.89, I² = 80%). The use of oxytocin and ergometrine was associated with increased mean blood loss (MD 61.0 mL; 95% CI 6.00 to 116.00 mL; fixed-effect analysis; one trial, 34 women; heterogeneity not applicable).In all three comparisons, there was no difference in mean length of the third stage or need for manual removal of the placenta between treatment arms.

AUTHORS' CONCLUSIONS

Prophylactic oxytocin at any dose decreases both PPH greater than 500 mL and the need for therapeutic uterotonics compared to placebo alone. Taking into account the subgroup analyses from both primary outcomes, to achieve maximal benefit providers may opt to implement a practice of giving prophylactic oxytocin as part of the active management of the third stage of labour at a dose of 10 IU given as an IV bolus. If IV delivery is not possible, IM delivery may be used as this route of delivery did show a benefit to prevent PPH greater than 500 mL and there was a trend to decrease the need for therapeutic uterotonics, albeit not statistically significant.Prophylactic oxytocin was superior to ergot alkaloids in preventing PPH greater than 500 mL; however, in subgroup analysis this benefit did not persist when only randomised trials with low risk of methodologic bias were analysed. Based on this, there is limited high-quality evidence supporting a benefit of prophylactic oxytocin over ergot alkaloids. However, the use of prophylactic oxytocin was associated with fewer side effects, specifically nausea and vomiting, making oxytocin the more desirable option for routine use to prevent PPH.There is no evidence of benefit when adding oxytocin to ergometrine compared to ergot alkaloids alone, and there may even be increased harm as one study showed evidence that using the combination was associated with increased mean blood loss compared to ergot alkaloids alone.Importantly, there is no evidence to suggest that prophylactic oxytocin increases the risk of retained placenta when compared to placebo or ergot alkaloids.More placebo-controlled, randomised, and double-blinded trials are needed to improve the quality of data used to evaluate the effective dose, timing, and route of administration of prophylactic oxytocin to prevent PPH. In addition, more trials are needed especially, but not only, in low- and middle-income countries to evaluate these interventions in the birth centres that shoulder the majority of the burden of PPH in order to improve maternal morbidity and mortality worldwide.

Adherence to criteria for transvaginal ultrasound imaging and measurement of cervical length

OBJECTIVE

Adherence to published criteria for transvaginal imaging and measurement of cervical length is uncertain. We sought to assess adherence by evaluating images submitted to certify research sonographers for participation in a clinical trial.

STUDY DESIGN

We reviewed qualifying test results of sonographers seeking certification to image and measure cervical length in a clinical trial. Participating sonographers were required to access training materials and submit 15 images, 3 each from 5 pregnant women not enrolled in the trial. One of 2 sonologists reviewed all qualifying images. We recorded the proportion of images that did not meet standard criteria (excess compression, landmarks not seen, improper image size, or full maternal bladder) and the proportion in which the cervical length was measured incorrectly. Failure for a given patient was defined as >1 unacceptable image, or >2 acceptable images with incorrect caliper placement or erroneous choice of the "shortest best" cervical length. Certification required satisfactory images and cervical length measurement from ≥4 patients.

RESULTS

A total of 327 sonographers submitted 4905 images. A total of 271 sonographers (83%) were certified on the first, 41 (13%) on the second, and 2 (0.6%) on the third submission. Thirteen never achieved certification. Of 314 who passed, 196 submitted 15 acceptable images that were appropriately measured for all 5 women. There were 1277 deficient images: 493 were acceptable but incorrectly measured images from sonographers who passed certification because mismeasurement occurred no more than twice. Of 784 deficient images submitted by sonographers who failed the certification, 471 were rejected because of improper measurement (caliper placement and/or failure to identify the shortest best image), and 313 because of failure to obtain a satisfactory image (excessive compression, required landmarks not visible, incorrect image size, brief examination, and/or full maternal bladder).

CONCLUSION

Although 83% of sonographers were certified on their first submission, >1 in 4 ultrasound images submitted did not meet published quality criteria. Increased attention to standardized education and credentials is warranted for persons who perform ultrasound examinations of the cervix in pregnancy.

Can changes in angiogenic biomarkers between the first and second trimesters of pregnancy predict development of pre-eclampsia in a low-risk nulliparous patient population?

OBJECTIVE

To determine if change in maternal angiogenic biomarkers between the first and second trimesters predicts pre-eclampsia in low-risk nulliparous women.

DESIGN

A nested case-control study of change in maternal plasma soluble Flt-1 (sFlt-1), soluble endoglin (sEng) and placenta growth factor (PlGF). We studied 158 pregnancies complicated by pre-eclampsia and 468 normotensive nonproteinuric controls.

SETTING

A multicentre study in 16 academic medical centres in the USA.

POPULATION

Low-risk nulliparous women.

METHODS

Luminex assays for PlGF, sFlt-1 and sEng performed on maternal EDTA plasma collected at 9-12, 15-18 and 23-26 weeks of gestation. Rate of change of analyte between first and either early or late second trimester was calculated with and without adjustment for baseline clinical characteristics.

MAIN OUTCOME MEASURES

Change in PlGF, sFlt-1 and sEng.

RESULTS

Rates of change of PlGF, sEng and sFlt-1 between first and either early or late second trimesters were significantly different in women who developed pre-eclampsia, severe pre-eclampsia or early-onset pre-eclampsia compared with women who remained normotensive. Inclusion of clinical characteristics (race, body mass index and blood pressure at entry) increased sensitivity for detecting severe and particularly early-onset pre-eclampsia but not pre-eclampsia overall. Receiver operating characteristics curves for change from first to early second trimester in sEng, PlGF and sFlt-1 with clinical characteristics had areas under the curve of 0.88, 0.84 and 0.86, respectively, and for early-onset pre-eclampsia with sensitivities of 88% (95% CI 64-99), 77% (95% CI 50-93) and 77% (95% CI 50-93) for 80% specificity, respectively. Similar results were seen in the change from first to late second trimester.

CONCLUSION

Change in angiogenic biomarkers between first and early second trimester combined with clinical characteristics has strong utility for predicting early-onset pre-eclampsia.

Customized versus population approach for evaluation of fetal overgrowth

OBJECTIVE

To compare the ability of customized versus normalized population fetal growth norms in identifying neonates at risk for adverse perinatal outcomes (APOs) associated with fetal overgrowth and gestational diabetes (GDM).

STUDY DESIGN

Secondary analysis of a multicenter treatment trial of mild GDM. The primary outcome was a composite of neonatal outcomes associated with fetal overgrowth and GDM. Birth weight percentiles were calculated using ethnicity- and gender-specific population and customized norms (Gardosi).

RESULTS

Two hundred three (9.8%) and 288 (13.8%) neonates were large for gestational age by population (LGApop) and customized (LGAcust) norms, respectively. Both LGApop and LGAcust were associated with the primary outcome and neonatal hyperinsulinemia, but neither was associated with hypoglycemia or hyperbilirubinemia. The ability of customized and population birth weight percentiles for predicting APOs were poor (area under the receiver operating characteristic curve < 0.6 for six of eight APOs).

CONCLUSION

Neither customized nor normalized population norms better identify neonates at risk of APOs related to fetal overgrowth and GDM.

Relationship between 1-hour glucose challenge test results and perinatal outcomes

OBJECTIVE

To estimate the relationship between 1-hour 50 g glucose challenge test values and perinatal outcomes.

METHODS

This was a secondary analysis of data from a multicenter treatment trial of mild gestational diabetes mellitus. Women with glucose challenge test values of 135-199 mg/dL completed a 3-hour oral glucose tolerance test. Mild gestational diabetes mellitus was defined as fasting glucose less than 95 mg/dL and two or more abnormal oral glucose tolerance test values: 1-hour 180 mg/dL or more; 2-hour 155 mg/dL or more; and 3-hour 140 mg/dL or more. Our study included untreated women with glucose challenge test values of 135-139 mg/dL and 140-199 mg/dL and a comparison group with values less than 120 mg/dL. Primary outcomes included a perinatal composite (stillbirth, neonatal death, hypoglycemia, hyperbilirubinemia, neonatal hyperinsulinemia, and birth trauma), large for gestational age (LGA, birth weight above the 90 percentile based on sex-specific and race-specific norms), and macrosomia (greater than 4,000 g).

RESULTS

There were 436 women with glucose challenge test values less than 120 mg/dL and 1,403 with values of 135 mg/dL or more (135-139, n=135; 140-199, n=1,268). The composite perinatal outcome occurred in 25.6% of those with glucose challenge test values less than 120 mg/dL compared with 21.1% for values of 135-139 mg/dL and 35.3% for values of 140-199 mg/dL. Rates of LGA by group were 6.6%, 6.8%, and 12.4%, respectively. Rates of macrosomia by group were 7.8%, 6.1%, and 12.1%, respectively. Compared with glucose challenge test values less than 120 mg/dL, the adjusted odds ratios (ORs) (95% confidence intervals [CIs]) for values of 140-199 mg/dL were 1.48 (1.14-1.93) for the composite outcome, 1.97 (1.29-3.11) for LGA, and 1.61 (1.07-2.49) for macrosomia. For glucose challenge test values of 135-139 mg/dL, adjusted ORs and 95% CIs were 0.75 (0.45-1.21), 1.04 (0.44-2.24), and 0.75 (0.30-1.66), respectively. The subcategories with glucose challenge test values of 140-144 mg/dL and 145-149 mg/dL also were associated with an increase in selected outcomes when compared with those with values less than 120 mg/dL.

CONCLUSIONS

Glucose challenge test values of 135-139 mg/dL were not associated with adverse outcomes compared with values less than 120 mg/dL; however, glucose challenge test values of 140 mg/dL or more were associated with an increase in odds of the composite perinatal outcome, LGA, and macrosomia.

Activity restriction among women with a short cervix

OBJECTIVE

To estimate determinants of and outcomes associated with activity restriction among women with a short cervix.

METHODS

This was a secondary analysis of a randomized trial of 17-α hydroxyprogesterone caproate for prevention of preterm birth among nulliparous women with singleton gestations and cervices less than 30 mm by midtrimester ultrasonography. Women were asked weekly whether they had been placed on pelvic, work, or nonwork rest. "Any activity restriction" was defined as being placed on any type of rest. Factors associated with any activity restriction were determined and the association between preterm birth and activity restriction was estimated with multivariable logistic regression.

RESULTS

Of the 657 women in the trial, 646 (98%) responded to questions regarding activity restriction. Two hundred fifty-two (39.0%) were placed on any activity restriction at a median of 23.9 weeks (interquartile range 22.6-27.9 weeks). Women on activity restriction were older, more likely to have private insurance, less likely to be Hispanic, had a shorter cervical length, and were more likely to have funneling and intra-amniotic debris. Preterm birth at less than 37 weeks of gestation was more common among women placed on activity restriction (37% compared with 17%, P<.001). After controlling for potential confounding factors, preterm birth remained more common among those placed on activity restriction (adjusted odds ratio 2.37, 95% confidence interval 1.60-3.53). Results were similar for preterm birth at less than 34 weeks of gestation.

CONCLUSION

Activity restriction did not reduce the rate of preterm birth in asymptomatic nulliparous women with a short cervix.

Placental villous hypermaturation is associated with idiopathic preterm birth

OBJECTIVE

Pregnancy complications such as intra-amniotic infection, preeclampsia, and fetal intrauterine growth restriction (IUGR) account for most cases of preterm birth (PTB), but many spontaneous PTB cases do not have a clear etiology. We hypothesize that placental insufficiency may be a potential cause of idiopathic PTB.

METHODS

Secondary analysis of 82 placental samples from women with PTB obtained from a multicenter trial of repeat versus single antenatal corticosteroids. Samples were centrally reviewed by a single placental pathologist masked to clinical outcomes. The histopathologic criterion for infection was the presence of acute chorioamnionitis defined as neutrophils marginating into the chorionic plate. Placental villous hypermaturation (PVH) was defined as a predominance of terminal villi (similar to term placenta) with extensive syncytial knotting. Idiopathic PTB comprised a group without another known etiology such as preeclampsia, IUGR or infection.

RESULTS

Acute chorioamnionitis was observed in 33/82 (40%) cases. Other known causes of PTB were reported in 18/82 (22%). The remaining 31/82 (38%) were idiopathic. The frequency of PVH in idiopathic PTB (26/31 = 84%) was similar to cases with IUGR or preeclampsia (16/18 = 89%), but significantly more common than PVH in the group with acute chorioamnionitis (10/33 = 30%) (p < 0.001).

CONCLUSIONS

PVH, which is a histologic marker of relative placental insufficiency, is a common finding in idiopathic PTB.

Pregnancy outcomes with weight gain above or below the 2009 Institute of Medicine guidelines

OBJECTIVE

To evaluate pregnancy outcomes according to 2009 Institute of Medicine (IOM) gestational weight gain guidelines.

METHODS

This study is a secondary analysis of a preeclampsia prevention trial among nulliparas carrying singletons. Odds ratios and 95% confidence intervals (adjusted for maternal age, race, smoking, and treatment group) were calculated based on total weight gain below or above the IOM guidelines stratified by prepregnancy body mass index (BMI). The referent group was weight gain within the guidelines.

RESULTS

Of 8,293 pregnancies, 9.5% had weight gain below, 17.5% within, and 73% above IOM guidelines. With excess weight gain, all BMI categories had an increased risk of hypertensive disorders; normal weight and overweight women also had increased risk of cesarean delivery and neonatal birth weight at or above the 90 centile but a decreased risk of weight below the 10 centile. There were no consistent associations with insufficient weight gain and adverse outcomes.

CONCLUSION

Excess weight gain was prevalent and associated with an increased risk of hypertensive disorders, cesarean delivery, and large-for-gestational-age neonates.

Haptoglobin phenotype, preeclampsia risk and the efficacy of vitamin C and E supplementation to prevent preeclampsia in a racially diverse population

Haptoglobin's (Hp) antioxidant and pro-angiogenic properties differ between the 1-1, 2-1, and 2-2 phenotypes. Hp phenotype affects cardiovascular disease risk and treatment response to antioxidant vitamins in some non-pregnant populations. We previously demonstrated that preeclampsia risk was doubled in white Hp 2-1 women, compared to Hp 1-1 women. Our objectives were to determine whether we could reproduce this finding in a larger cohort, and to determine whether Hp phenotype influences lack of efficacy of antioxidant vitamins in preventing preeclampsia and serious complications of pregnancy-associated hypertension (PAH). This is a secondary analysis of a randomized controlled trial in which 10,154 low-risk women received daily vitamin C and E, or placebo, from 9-16 weeks gestation until delivery. Hp phenotype was determined in the study prediction cohort (n = 2,393) and a case-control cohort (703 cases, 1,406 controls). The primary outcome was severe PAH, or mild or severe PAH with elevated liver enzymes, elevated serum creatinine, thrombocytopenia, eclampsia, fetal growth restriction, medically indicated preterm birth or perinatal death. Preeclampsia was a secondary outcome. Odds ratios were estimated by logistic regression. Sampling weights were used to reduce bias from an overrepresentation of women with preeclampsia or the primary outcome. There was no relationship between Hp phenotype and the primary outcome or preeclampsia in Hispanic, white/other or black women. Vitamin supplementation did not reduce the risk of the primary outcome or preeclampsia in women of any phenotype. Supplementation increased preeclampsia risk (odds ratio 3.30; 95% confidence interval 1.61-6.82, p<0.01) in Hispanic Hp 2-2 women. Hp phenotype does not influence preeclampsia risk, or identify a subset of women who may benefit from vitamin C and E supplementation to prevent preeclampsia.

17 alpha-hydroxyprogesterone caproate to prevent prematurity in nulliparas with cervical length less than 30 mm

OBJECTIVE

We sought to evaluate whether 17 alpha-hydroxyprogesterone caproate (17-OHP) reduces preterm birth (PTB) in nulliparous women with a midtrimester cervical length (CL) <30 mm.

STUDY DESIGN

In this multicenter randomized controlled trial, nulliparous women with a singleton gestation between 16 and 22 3/7 weeks with an endovaginal CL <30 mm (<10th percentile in this population) were randomized to weekly intramuscular 17-OHP (250 mg) or placebo through 36 weeks. The primary outcome was PTB <37 weeks.

RESULTS

The frequency of PTB did not differ between the 17-OHP (n = 327) and placebo (n = 330) groups (25.1% vs 24.2%; relative risk, 1.03; 95% confidence interval, 0.79-1.35). There also was no difference in the composite adverse neonatal outcome (7.0% vs 9.1%; relative risk, 0.77; 95% confidence interval, 0.46-1.30).

CONCLUSION

Weekly 17-OHP does not reduce the frequency of PTB in nulliparous women with a midtrimester CL <30 mm.

The utility of uterine artery Doppler velocimetry in prediction of preeclampsia in a low-risk population

OBJECTIVE

The underlying pathophysiology of preeclampsia is thought to be abnormal trophoblast invasion of the spiral arteries leading to maldevelopment of uteroplacental perfusion. We estimated whether uterine artery Doppler measurements made in the early second trimester would predict the subsequent development of preeclampsia.

METHODS

Uterine artery Doppler measurements before 21 weeks of gestation (median 16.6 weeks) were correlated with subsequent development of preeclampsia in a cohort of 2,188 low-risk nulliparous women in a randomized control trial of antioxidant supplementation for prevention of preeclampsia. Preeclampsia developed in 165 (7.5%) women.

RESULTS

Development of preeclampsia overall was associated with increased resistance index, pulsatility index, a pulsatility index or resistance index multiple of the median at or above the 75th percentile but not the presence of a notch or a bilateral notch before 21 weeks of gestation. The sensitivity was 43% (95% confidence interval [CI] 35-51) and specificity 67% (95% CI 65-69) for prediction of preeclampsia overall. The presence of a notch or bilateral notch, resistance index, and pulsatility index multiple of the median was significantly associated with early onset (before 34 weeks of gestation) compared with late onset or no preeclampsia (odds ratio [OR] 6.9, 95% CI 2.3-20.9; sensitivity 78%, 95% CI 52-94; specificity 66%, 95% CI 64-68). The presence of a notch or resistance index multiple of the median at or above the 75th percentile increased the odds of developing severe compared with mild or no preeclampsia (OR 2.2, 95% CI 1.4-3.7; sensitivity 53%, 95% CI 40-65; specificity 66%, 95% CI 64-68).

CONCLUSION

Our data show poor sensitivity of second-trimester Doppler ultrasound measurements for prediction of preeclampsia overall in a well-characterized, low-risk, nulliparous population. The technique has utility in identifying poor trophoblast invasion of spiral arteries of a magnitude that severely compromises uteroplacental blood flow and gives early-onset disease.

LEVEL OF EVIDENCE

II.

Prophylactic oral betamimetics for reducing preterm birth in women with a twin pregnancy

BACKGROUND

Twin pregnancies are associated with a high risk of neonatal mortality and morbidity due to an increased rate of preterm birth. Betamimetics can decrease contraction frequency or delay preterm birth in singleton pregnancies by 24 to 48 hours. The efficacy of oral betamimetics in women with a twin pregnancy is unproven.

OBJECTIVES

To assess the effectiveness of prophylactic oral betamimetics for the prevention of preterm labour and birth for women with twin pregnancies.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (31 January 2012), the Central Register of Controlled Trials (The Cochrane Library 2012, Issue 2), MEDLINE (January 1966 to 1 February 2012) and EMBASE (January 1985 to 1 February 2012).

SELECTION CRITERIA

Randomised controlled trials in twin pregnancies comparing oral betamimetics with placebo or any intervention with the specific aim of preventing preterm birth. Quasi-randomised controlled trials, cluster-randomised trials and cross-over trials were not included.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and trial quality. Two review authors extracted data. Data were checked for accuracy.

MAIN RESULTS

Six trials (374 twin pregnancies) were included, but only five trials (344 twin pregnancies) contributed data. All trials compared oral betamimetics with placebo.Betamimetics reduced the incidence of preterm labour (one trial, 50 twin pregnancies, risk ratio (RR) 0.40; 95% confidence interval (CI) 0.19 to 0.86). However, betamimetics did not reduce preterm birth less than 37 weeks' gestation (four trials, 276 twin pregnancies, RR 0.85; 95% CI 0.65 to 1.10) or less than 34 weeks' gestation (one trial, 144 twin pregnancies, RR 0.47; 95% CI 0.15 to 1.50). Mean neonatal birthweight in the betamimetic group was significantly higher than in the placebo group (three trials, 478 neonates, mean difference 111.22 g; 95% CI 22.2 to 200.2). Nevertheless, there was no evidence of an effect of betamimetics in reduction of low birthweight (two trials, 366 neonates, average RR 1.19; 95% CI 0.77 to 1.85, random-effects) or small-for-gestational age neonates (two trials, 178 neonates, RR 0.92; 95% CI 0.52 to 1.65). Two trials (388 neonates) showed that betamimetics significantly reduced the incidence of respiratory distress syndrome but the difference was not significant when the analysis was adjusted for correlation of babies from twins. Three trials (452 neonates) showed no evidence of an effect of betamimetics in reducing neonatal mortality (RR 0.80; 95% CI 0.35 to 1.82).

AUTHORS' CONCLUSIONS

There is insufficient evidence to support or refute the use of prophylactic oral betamimetics for preventing preterm birth in women with a twin pregnancy.

Pneumococcal vaccination during pregnancy for preventing infant infection

BACKGROUND

Each year at least one million children worldwide die of pneumococcal infections. The development of bacterial resistance to antimicrobials adds to the difficulty of treatment of diseases and emphasizes the need for a preventive approach. Newborn vaccination schedules could substantially reduce the impact of pneumococcal disease in immunized children, but does not have an effect on the morbidity and mortality of infants less than three months of age. Pneumococcal vaccination during pregnancy may be a way of preventing pneumococcal disease during the first months of life before the pneumococcal vaccine administered to the infant starts to produce protection.

OBJECTIVES

To assess the effect of pneumococcal vaccination during pregnancy for preventing infant infection.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 December 2011) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomized controlled trials in pregnant women comparing pneumococcal vaccine with placebo or doing nothing or with another vaccine to prevent infant infections.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, methodological quality and extracted data using a data collection form. Data were checked for accuracy. We contacted study authors for additional information.

MAIN RESULTS

Seven trials were included, but only five trials (579 participants) contributed data. There was no evidence that pneumococcal vaccination during pregnancy reduces the risk of neonatal infection (risk ratio (RR) 0.66; 95% confidence interval (CI) 0.30 to 1.46; two trials, 241 pregnancies). Although the data suggest an effect in reducing pneumococcal colonization in infants by 16 months of age (RR 0.33; 95% CI 0.11 to 0.98; one trial, 56 pregnancies), there was no evidence of this effect in infants at two to three months of age (RR 1.13; 95% CI 0.46 to 2.78; two trials, 146 pregnancies) or by six to seven months of age (RR 0.66; 95% CI 0.20 to 2.17; two trials, 144 pregnancies). No significant difference for tenderness at the injection site between women who received pneumococcal vaccine and those who received control vaccine (RR 3.20; 95% CI 0.32 to 31.54; two trials, 130 women).

AUTHORS' CONCLUSIONS

There is insufficient evidence to assess whether pneumococcal vaccination during pregnancy could reduce infant infections.

Maternal BMI, glucose tolerance, and adverse pregnancy outcomes

OBJECTIVE

The purpose of this study was to estimate the association of pregravid body mass index (BMI), independent of 3-hour oral glucose tolerance test (OGTT) results, with pregnancy outcome.

STUDY DESIGN

In this secondary analysis of a cohort of women with untreated mild gestational glucose intolerance, which was defined as a 50-g glucose loading test between 135 and 199 mg/dL and fasting glucose level of <95 mg/dL, we modeled the association between pregravid BMI, OGTT results, and both pregnancy complications and neonatal adiposity.

RESULTS

Among 1250 participants, both pregravid BMI and glucose at hour 3 of the OGTT were associated with increased risk of gestational hypertension. Maternal pregravid BMI also was associated positively with large-for-gestational-age infants; both maternal BMI and fasting glucose were associated with birthweight z-score and neonatal fat mass.

CONCLUSION

Among women with untreated mild gestational glucose intolerance, pregravid BMI is associated with increased gestational hypertension, birthweight, and neonatal fat mass, independent of OGTT values.

First-trimester prediction of preeclampsia in nulliparous women at low risk

OBJECTIVE

To identify clinical characteristics and biochemical markers in first-trimester samples that would possibly predict the subsequent development of preeclampsia.

METHODS

We conducted a multicenter observational study in 2,434 nulliparous women at low risk to identify biomarkers that possibly predict preeclampsia. Clinical history, complete blood count, and biochemical markers were assessed in the first trimester. The trophoblast and angiogenesis markers ADAM-12, pregnancy-associated plasma protein-A, placental protein 13, placental growth factor, soluble fms-like tyrosine kinase-1, and endoglin were measured in a case-control subset of 174 women with preeclampsia and 509 women in the control group.

RESULTS

Univariable analysis revealed maternal age, race, marital status, years of education, source of medical payment, prenatal caregiver, body mass index (BMI, calculated as weight (kg)/[height (m)]), and systolic blood pressure at enrollment were significantly associated with preeclampsia. Mean platelet volume was greater at enrollment in women who later had development of preeclampsia (median 9.4 compared with 9.0 femtoliter (fl); P=.02). First-trimester concentrations (multiples of the median) of ADAM-12 (1.14 compared with 1.04; P=.003), pregnancy-associated plasma protein-A (0.94 compared with 0.98; P=.04), and placental growth factor (0.83 compared with 1.04; P<.001) were significantly different in women who had development of preeclampsia compared with women in the control group. The optimal multivariable model included African American race, systolic blood pressure, BMI, education level, ADAM-12, pregnancy-associated plasma protein-A, and placental growth factor, and yielded an area under the curve of 0.73 (95% confidence interval 0.69-0.77) and a sensitivity of 46.1% (95% confidence interval 38.3-54.0) for 80% specificity.

CONCLUSION

A multivariable analysis of clinical data and biochemical markers in the first trimester did not identify a model that had clinical utility for predicting preeclampsia in a nulliparous population at low risk.

LEVEL OF EVIDENCE

II.