Midtrimester microbial DNA variations in maternal serum of women who experience spontaneous preterm birth.

Objectives: To evaluate if midtrimester maternal serum contains microbial DNA and whether it differs between women with spontaneous preterm birth (SPTB) and those delivering at term.Study design: In this retrospective case-control study, we identified 20 healthy nulliparas with SPTB at 24-33 weeks of a nonanomalous singleton in 2014. Each case was matched by race/ethnicity to a control delivering at 39-40 weeks. Serum samples, collected at 15-20 weeks and stored at -80 C, were thawed and DNA extracted. PCR with primers targeting the 16S rDNA V4 region were used to prepare an amplicon library, sequenced using Illumina MiSeq, and analyzed using quantitative insight into microbial ecology (QIIME). Taxonomy was assigned using Ribosomal Database program (RDP) Classifier (threshold 0.8) against a modified Greengenes database. Differences in number of observed species, microbial alpha-diversity and beta-diversity, and taxa level analyses were undertaken.Results: All 40 samples were included. Women with SPTB had more unique observed species (p = .046) and higher mean alpha-diversity by Shannon index (but not Chao1 or Simpson) (p = .024). Microbial composition was different between groups by Bray-Curtis clustering (p = .03) but not by weighted (p = .13) or unweighted Unifrac (p = .11). Numerous taxa in the Firmicutes, Proteobacteria, and Actinobacteria phyla differed between groups (p < .05).Conclusions: SPTB is associated with distinct microbial DNA changes detected in midtrimester maternal serum.

Elective Induction of Labor in the 39th Week of Gestation Compared With Expectant Management of Low-Risk Multiparous Women.

OBJECTIVE: To compare perinatal and maternal outcomes in low-risk multiparous women who underwent elective induction of labor in the 39th week of gestation with those who were expectantly managed. METHODS: We performed a single center retrospective cohort study of low-risk multiparous women delivering nonanomalous singletons between 39 and 42 completed weeks of gestation from 2014 to 2018. The primary outcome was a perinatal composite of death, neonatal respiratory support, a 5-minute Apgar score of 3 or less, and shoulder dystocia. Groups were compared using χ, Fisher exact, two sample t-test, and Wilcoxon rank sum tests, as appropriate. Multivariable logistic regression models were used to adjust for potential confounders. RESULTS: Of the 3,703 low-risk multiparous women meeting inclusion criteria, 453 (12%) delivered between 39 0/7 and 39 4/7 after an elective induction of labor. Women who underwent elective induction of labor were more likely to be privately insured, non-Hispanic, and weigh more at their first prenatal visit (all P<.01) compared with expectant management. An elective induction of labor was associated with decreased frequency of the perinatal composite morbidity (4.0% vs 7.1%; adjusted odds ratio [aOR] 0.57, 95% CI 0.34-0.96) compared with expectant management. Fewer cesarean deliveries occurred among women in the elective induction of labor group (5.1% vs 6.6%; aOR 0.60, 95% CI 0.37-0.97). Other maternal outcomes (hypertensive disorders, chorioamnionitis, and operative vaginal deliveries) as well as neonatal intensive care unit admissions were not different between groups. CONCLUSION: Elective induction of labor in low-risk multiparous women in the 39th week of gestation was associated with decreased perinatal morbidity and a lower frequency of cesarean delivery compared with expectant management.

HIV Status and Other Risk Factors for Prevalent and Incident Sexually Transmitted Infection during Pregnancy (2000-2014).

Background: Sexually transmitted infections (STIs) are associated with adverse birth outcomes. Current prenatal STI screening guidelines define "risk" without explicit consideration of HIV status. Our objective was to test the hypothesis that HIV status is associated with bacterial STI in pregnant women. Methods: We designed a retrospective cohort study to identify pregnant women with HIV who delivered at our facility during 2000-2014. HIV+ women were compared to HIV- women with matching by year of delivery. Logistic regression was used to model adjusted odds of prevalent and incident STI. Prevalent STI was defined as chlamydia (CT), gonorrhea (GC), syphilis, or trichomoniasis detected on an initial prenatal screening test and incident STI as a newly positive result following a negative prenatal test. Results: The cohort included 432 women, 210 HIV+ and 222 HIV-. Most pregnant women were screened for STI (92% of HIV+ women and 74% of HIV- women). STI rates were high and particularly elevated in HIV+ women: 29% vs 18% (p=0.02), for prevalent STI and 11% vs 2% (p<0.001) for incident STI. Risk factors for prevalent STI were as follows: HIV status (aOR 3.0, CI: 1.4-6.4), Black race (aOR 2.7, 95% CI: 1.1-6.6), and more recent delivery (2007-2014 compared to 2000-2006) (aOR 2.3, CI: 1.1-4.7). HIV status was an independent risk factor for incident STI (aOR 7.2, CI: 2.1-25.0). Conclusion: Pregnant women who delivered in our center had high STI rates. Since HIV infection was independently associated with prevalent and incident STI, prenatal screening guidelines may need to incorporate HIV status as a high-risk group for repeat testing.

Estimating Gestational Age With Sonography: Regression-Derived Formula Versus the Fetal Biometric Average.

OBJECTIVES: To compare the accuracy of a new regression-derived formula developed from the National Fetal Growth Studies data to the common alternative method that uses the average of the gestational ages (GAs) calculated for each fetal biometric measurement (biparietal diameter, head circumference, abdominal circumference, and femur length). METHODS: This retrospective cross-sectional study identified nonanomalous singleton pregnancies that had a crown-rump length plus at least 1 additional sonographic examination with complete fetal biometric measurements. With the use of the crown-rump length to establish the referent estimated date of delivery, each method's (National Institute of Child Health and Human Development regression versus Hadlock average [Radiology 1984; 152:497-501]), error at every examination was computed. Error, defined as the difference between the crown-rump length-derived GA and each method's predicted GA (weeks), was compared in 3 GA intervals: 1 (14 weeks-20 weeks 6 days), 2 (21 weeks-28 weeks 6 days), and 3 (≥29 weeks). In addition, the proportion of each method's examinations that had errors outside prespecified (±) day ranges was computed by using odds ratios. RESULTS: A total of 16,904 sonograms were identified. The overall and prespecified GA range subset mean errors were significantly smaller for the regression compared to the average (P < .01), and the regression had significantly lower odds of observing examinations outside the specified range of error in GA intervals 2 (odds ratio, 1.15; 95% confidence interval, 1.01-1.31) and 3 (odds ratio, 1.24; 95% confidence interval, 1.17-1.32) than the average method. CONCLUSIONS: In a contemporary unselected population of women dated by a crown-rump length-derived GA, the National Institute of Child Health and Human Development regression formula produced fewer estimates outside a prespecified margin of error than the commonly used Hadlock average; the differences were most pronounced for GA estimates at 29 weeks and later.

Trisomy 18: A single-center evaluation of management trends and experience with aggressive obstetric or neonatal intervention.

We conducted a retrospective cohort study including all prenatal and postnatal diagnoses of trisomy 18 (T18) from 2004 to 2014 at a single tertiary referral center in the southern United States to evaluate the natural history and perinatal outcomes associated with T18 over the past decade. We analyzed pregnancy outcome, mode of delivery, and for live-births, the number and types of neonatal interventions, and characterized interventions as aggressive or non-aggressive. Survival analyses were conducted based on mode of delivery and aggressive compared to non-aggressive interventions. A total of 167 cases of T18 were identified, 150 with available records. There were 141 (94.0%) with full T18; the remainder had mosaicism (1.3%), a translocation (0.7%), or an isochromosome 18 (4.0%). Most diagnoses were prenatal (73.3%, n = 110). Of the 150 patients, there were 54 live births: 21 (38.9%) delivered vaginally, 32 (59.3%) delivered by cesarean, and mode of delivery could not be ascertained for one. Median duration of survival was 12 days (interquartile range 3-90 days). Over time, there were no changes toward increased intervention (obstetric or neonatal). For the 49 neonates who received some intervention, there was no significant difference in survival time between neonates receiving aggressive (n = 36, median survival 24 days, interquartile range 6-247) and non-aggressive (n = 13, median survival 30 days, interquartile range 8-148) intervention (P = 0.90). There was similarly no difference in neonatal survival based on mode of delivery (P = 0.79). Survival of infants with T18 is not improved with aggressive obstetric or neonatal care.

Ultrasonographic Fetal Weight Estimation: Should Macrosomia-Specific Formulas Be Utilized?

OBJECTIVE: This study aims to derive an estimated fetal weight (EFW) formula in macrosomic fetuses, compare its accuracy to the 1986 Hadlock IV formula, and assess whether including maternal diabetes (MDM) improves estimation. STUDY DESIGN: Retrospective review of nonanomalous live-born singletons with birth weight (BWT) ≥ 4 kg and biometry within 14 days of birth. Formula accuracy included: (1) mean error (ME = EFW - BWT), (2) absolute mean error (AME = absolute value of [1]), and (3) mean percent error (MPE, [1]/BWT × 100%). Using loge BWT as the dependent variable, multivariable linear regression produced a macrosomic-specific formula in a "training" dataset which was verified by "validation" data. Formulas specific for MDM were also developed. RESULTS: Out of the 403 pregnancies, birth gestational age was 39.5 ± 1.4 weeks, and median BWT was 4,240 g. The macrosomic formula from the training data (n = 201) had associated ME = 54 ± 284 g, AME = 234 ± 167 g, and MPE = 1.6 ± 6.2%; evaluation in the validation dataset (n = 202) showed similar errors. The Hadlock formula had associated ME = -369 ± 422 g, AME = 451 ± 332 g, MPE = -8.3 ± 9.3% (all p < 0.0001). Diabetes-specific formula errors were similar to the macrosomic formula errors (all p = NS). CONCLUSIONS: With BWT ≥ 4 kg, the macrosomic formula was significantly more accurate than Hadlock IV, which systematically underestimates fetal/BWT. Diabetes-specific formulas did not improve accuracy. A specific formula should be considered when macrosomia is suspected.

Fetal anomalies in obese women: the contribution of diabetes.

OBJECTIVE: To examine temporal changes in maternal weight and the association with major structural anomalies and other factors, such as diabetes, in our primary obstetric population. METHODS: We conducted a serial, cross-sectional study using a perinatal database to identify all women with singletons who delivered in our system from 1991 to 2004. Three 5-year time epochs were defined to compare patient cohorts. Maternal weight, body mass index (BMI), diabetes status, incidence of major anomalies, and demographic data were compared. Multiple logistic regression was performed to estimate factors contributing to anomaly rates. RESULTS: A total of 41,902 pregnancies were included. In each time epoch, there was an increase in the mean maternal weight, the mean BMI, the proportion of women weighing in excess of 200 lb, the proportion with a BMI higher than 29, the prevalence of pregestational diabetes, and the prevalence of major anomalies (all P<.001). There was no significant independent association between maternal obesity and the presence of a major anomaly. In a multivariable logistic model, the major factor contributing to the increasing rate of congenital anomalies was the prevalence of pregestational diabetes (odds ratio 3.8, 95% confidence interval 2.1-6.6). The population-attributable risk of anomalies related to obesity increased from essentially 0% in 1991-1994 to 6.1% in 2000-2004, whereas that related to diabetes increased from 3.3% to 9.2% during the same time periods. CONCLUSION: Although the prevalence of maternal obesity and anomaly have increased, maternal weight alone was not associated with an increase in congenital anomalies. Instead, diabetes was significantly associated with the increase in the rate of anomalies seen in our population. Identification of maternal weight as a risk factor in epidemiologic studies may be a surrogate for pregestational diabetes. LEVEL OF EVIDENCE: II.

Medication effects on midtrimester maternal serum screening.

OBJECTIVE: To determine whether medication classes are associated with alterations in concentrations of Quad screen analytes or the screen-positive rate. STUDY DESIGN: We conducted a retrospective cohort study of women with singleton gestations who received prenatal care and had a Quad screen performed in the University of Alabama at Birmingham system. Information on prescription medications was abstracted. Mean multiples of the medians for each analyte (alpha-fetoprotein, estriol, human chorionic gonadotropin, and inhibin A) and overall screening results were compared between those taking the class of medication and controls not taking any medications. RESULTS: There were 6206 women evaluated; 1337 took at least 1 prescription medicine and 4869 were controls. Mean analyte multiples of the medians were significantly different in women taking some medications compared with controls. Women taking certain medications had an increased screen-positive rate. CONCLUSION: Medications taken around the time of maternal serum screening are associated with alterations in individual analyte multiples of the medians, as well as the screen-positive rates.

Perinatal and maternal outcomes in women with sickle or hemoglobin C trait.

OBJECTIVE: Recent studies have reported increased fetal loss and preeclampsia in women with sickle cell trait (hemoglobin [Hb] AS). There is a paucity of studies of outcomes in carriers of hemoglobin C. We examined the prevalence of hemoglobin C and S carrier status (Hb AC and Hb AS, respectively) and their effect on pregnancy outcomes. METHODS: This was a retrospective cohort study using data prospectively collected from 1991 to 2006. Perinatal and maternal outcomes for African-American women with Hb AS and Hb AC were compared with those with normal hemoglobin (Hb AA). Multivariable regression was performed by applying generalized estimating equations to account for correlation between births from the same woman. RESULTS: Among 22,096 eligible African-American women (36,897 pregnancies) with routine antenatal hemoglobin electrophoresis, 88.5% had a normal (Hb AA) pattern. Hemoglobin AS was identified in 8.2% and Hb AC in 2.4% of women. Hemoglobin SS and Hb SC each accounted for less than 0.2% and Hb CC for 0.01%. Prevalence and relative risks for adverse outcomes in 3,019 AS pregnancies (3,062 births) and 875 AC (886 births), compared with 32,724 AA pregnancies (33,213 births), were not increased. Adjusted relative risks (95% confidence intervals) for perinatal mortality and preeclampsia were 0.7 (0.5-1.0) and 1.0 (0.8-1.2), respectively, for AS and 0.7 (0.3-1.4) and 1.0 (0.6-1.3), respectively, for AC. Risks of stillbirths and pregnancy-associated hypertension were also not increased. CONCLUSION: Contrary to other recent reports, perinatal mortality and preeclampsia are not increased in carriers of sickle cell trait or hemoglobin C. LEVEL OF EVIDENCE: II.

Risk factors for anal sphincter tear in multiparas.

OBJECTIVE: To assess maternal, newborn, and obstetric risk factors associated with anal sphincter tear in multiparous women. METHODS: This case-control study identified 18,779 multiparous vaginal deliveries from 1992 to 2004 from an obstetric automated record database at the University of Alabama at Birmingham. Two hundred eighty-four patients were selected, 145 cases and 139 controls. Variables from the index pregnancy and prior pregnancies were analyzed, and multivariable logistic regression models were constructed to determine significant predictor variables for anal sphincter tear in multiparous women. RESULTS: One hundred forty-five multiparous women with no history of cesarean delivery sustained a sphincter tear. Multivariable logistic regression showed a significant association with episiotomy (odds ratio [OR] 16.3, 95% confidence interval [CI] 7.7-34.4), shoulder dystocia (OR 7.9, CI 1.6-38), forceps delivery (OR 4.7, CI 2.0-11.2), and being married (OR 2.2, CI 1.1-4.6). A second exploratory model that included variables from previous pregnancies, showed that in addition to episiotomy (OR 34.6, CI 8.8-136), shoulder dystocia (OR 11.1, CI 1.3-95.2), forceps delivery (OR 6.1, CI 1.6-23.5), previous sphincter tear (OR 7.7, CI 1.2-48.7), and second stage of labor greater than 1 hour (OR 6.7, CI 1.1-42.5) were associated with tear. CONCLUSION: The strongest clinical risk factors for anal sphincter tear in multiparous women are episiotomy, shoulder dystocia, previous sphincter tear, prolonged second stage of labor, and forceps delivery. LEVEL OF EVIDENCE: II-2.

Subcutaneous tissue reapproximation, alone or in combination with drain, in obese women undergoing cesarean delivery.

OBJECTIVE: To compare the efficacy of subcutaneous suture reapproximation alone with suture plus subcutaneous drain for the prevention of wound complications in obese women undergoing cesarean delivery. METHODS: We conducted a multicenter randomized trial of women undergoing cesarean delivery. Consenting women with 4 cm or more of subcutaneous thickness were randomized to either subcutaneous suture closure alone (n = 149) or suture plus drain (n = 131). The drain was attached to bulb suction and removed at 72 hours or earlier if output was less than 30 mL/24 h. The primary study outcome was a composite wound morbidity rate (defined by any of the following: subcutaneous tissue dehiscence, seroma, hematoma, abscess, or fascial dehiscence). RESULTS: From April 2001 to July 2004, a total of 280 women were enrolled. Ninety-five percent of women (268/280) had a follow-up wound assessment. Both groups were similar with respect to age, race, parity, weight, cesarean indication, diabetes, steroid/antibiotic use, chorioamnionitis, and subcutaneous thickness. The composite wound morbidity rate was 17.4% (25/144) in the suture group and 22.7% (28/124) in the suture plus drain group (relative risk 1.3, 95% confidence interval 0.8-2.1). Individual wound complication rates, including subcutaneous dehiscence (15.3% versus 21.8%), seroma (9.0% versus 10.6%), hematoma (2.2% versus 2.4%), abscess (0.7% versus 3.3%), fascial dehiscence (1.4% versus 1.7%), and hospital readmission for wound complications (3.5% versus 6.6%), were similar (P > .05) between women treated with suture alone and those treated with suture plus drain, respectively. CONCLUSION: The additional use of a subcutaneous drain along with a standard subcutaneous suture reapproximation technique is not effective for the prevention of wound complications in obese women undergoing cesarean delivery.

Risk factors associated with anal sphincter tear: a comparison of primiparous patients, vaginal births after cesarean deliveries, and patients with previous vaginal delivery.

OBJECTIVE: This study was conducted to identify obstetric risk factors for anal sphincter tear in primiparous patients, patients with a previous cesarean delivery (VBAC), and patients with a previous vaginal delivery (PVD). STUDY DESIGN: An obstetrics automated record system was accessed to retrospectively review records of all singleton vaginal deliveries at greater than 36 weeks' gestation (excluding breech and stillbirth) from 1995 through 2000 (n = 10,928). A number of potential risk factors for anal sphincter tear (third- and fourth-degree episiotomy extensions and lacerations) were tested with use of multivariate logistic regression analysis. RESULTS: The risk of anal sphincter tear was significantly increased with primiparity (relative risk [RR] 4.08) and VBAC (RR 5.46) compared with PVD, birth weight greater than 4000 g (RR 2.41), forceps delivery (RR 6.00), vacuum delivery (RR 2.18), shoulder dystocia (RR 3.28), and episiotomy (RR 2.59). CONCLUSION: Efforts to prevent anal sphincter tear might include reconsideration of modifiable risk factors such as episiotomy, operative vaginal delivery, and VBAC.