The incidence of obesity is increasing rapidly, and it affects a greater proportion of women than men. Unfortunately, obesity has a negative impact on women's reproductive health, including increased adverse perinatal outcomes. Weight loss surgery, also known as bariatric surgery, is performed in many hospitals, and can allow for significant weight loss and improvement in medical comorbidities such as diabetes and hypertension. A woman who becomes pregnant after bariatric surgery usually has an uncomplicated pregnancy but requires special attention to some complications that can occur after these procedures. This article reviews the perinatal outcomes and provides recommendations for care regarding the unique issues that arise during a pregnancy after bariatric surgery.

Pretenn birth is among the most complex and important challenges in obstetrics. Despite decades of research and clinical advancement, approximately 1 in 10 newborns in the United States is born prematurely. These newborns account for approximately three-quarters of perinatal mortality and more than one half of long-term neonatal morbidity, at significant social and economic cost (1-3). Because preteen birth is the common endpoint for multiple pathophysiologic processes, detailed classification schemes for preterm birth phenotype and etiology have been proposed (4, 5). In general, approximately one half of preterm births follow spontaneous preterm labor, about a quarter follow preterm prelabor rupture of membranes (PPROM), and the remaining quarter of preterm births are intentional, medically indicated by maternal or fetal complications. There are pronounced racial disparities in the preterm birth rate in the United States.The purpose of this document is to describe the risk factors, screening methods, and treatments for preventing spontaneous preterm birth, and to review the evidence supporting their roles in clinical practice. his Practice Bulletin has been updated to include information on increasing rates of preteen birth in the United States, disparities in preterm birth rates, and approaches to screening and prevention strategies for patients at risk for spontaneous preterm birth.

Zahn, Christopher M. MD; Jackson, Marc MD, MBA; Simhan, Hyagriv N. MD, MS; Pettker, Christian M. MD Author Information

Caudal regression syndrome (CRS), also known as caudal regression sequence, caudal dysplasia, caudal apalasia, femoral hypoplasia, phocomelic diabetic embryopathy, or sacral agenesis, is a spectrum of anomalies involving the caudal trunk. The frequency is about 1:10,000 live births, and maternal hyperglycemia markedly increases the risk. Abnormal differentiation of the developing spine, spinal cord, and caudal mesoderm is the pathogenesis. Classically, it appears as the sudden interruption of the spine with abnormal positioning or hypoplasia of the lower extremities on ultrasound assessment. Associated anomalies are common and include gastrointestinal, genitourinary, and others. The prognosis depends on the level of spinal termination and associated anomalies. No intrauterine treatment is available. Patients who chose to continue the pregnancy should have consultation with pediatric subspecialists.

Objective: We sought to determine if women who had an atrial switch procedure for d-transposition of the great arteries (d-TGA) are being counseled regarding pregnancy, and if the counseling is modified based on baseline cardiac function in accordance with American Heart Association/American College of Cardiology guidelines. Methods: Medical records of reproductive age women with an atrial switch repair for d-TGA receiving care at one tertiary center over 10 years were reviewed. Cardiology counseling recommendations regarding pregnancy made prior to the first conception, or in the case of nulligravid women, at the last routine encounter, were reviewed. Women who were instructed to avoid pregnancy were compared to those who were cleared for pregnancy. Univariate comparisons were made for baseline cardiac status and demographics. Odds ratios were generated using univariable logistic regression. Results: Pre-pregnancy counseling recommendations were made in 24/28 (85.7%) of encounters while no advice was given in the remainder. Of the women who received counseling, 12 (50%) were instructed to avoid pregnancy and 12 (50%) were cleared for pregnancy. Women who were counseled to avoid pregnancy did not differ from those cleared for pregnancy by: presence of pacemaker, cardiac medication use, NYHA classification, degree of tricuspid regurgitation, or prevalence of ventricular dysfunction. Patients instructed to avoid pregnancy were more likely to have been counseled by a pediatric cardiologist (OR 22.0, 95%CI 2.1, 236.1). Pregnancy occurred in 25% of those instructed to avoid pregnancy and 42% of those cleared for pregnancy (p=.7) prior to the next cardiology appointment. Conclusions: Cardiologists’ pre-pregnancy counseling efforts for women with a history of an atrial switch procedure for d-TGA appear to be subjective and not based on an individual patient’s cardiac status or current guidelines. When compared to adult congenital cardiology specialists, pediatric cardiologists are more likely to advise against pregnancy.

BACKGROUND: Hypomethylated cell-free DNA from senescent placental trophoblasts may be involved in the activation of the inflammatory cascade to initiate labor. OBJECTIVE: To determine the changes in cell-free DNA concentrations, the methylation ratio, and inflammatory markers between women in labor at term vs women without labor. STUDY DESIGN: In this prospective cohort study, eligible participants carried a nonanomalous singleton fetus. Women with major medical comorbidity, preterm labor, progesterone use, aneuploidy, infectious disease, vaginal bleeding, abdominal trauma, or invasive procedures during the pregnancy were excluded. Maternal blood samples were collected at 28 weeks, 36 weeks, and at admission for delivery. Total cell-free DNA concentration, methylation ratio, and interleukin-6 were analyzed. The primary outcome was the difference in methylation ratio in women with labor vs without labor. Secondary outcomes included the longitudinal changes in these biomarkers corresponding to labor status. RESULTS: A total of 55 women were included; 20 presented in labor on admission and 35 presented without labor. Women in labor had significantly greater methylation ratio (P = .001) and interleukin-6 (P < .001) on admission for delivery than women without labor. After we controlled for body mass index and maternal age, methylation ratio (adjusted relative risk, 1.38; 95% confidence interval, 1.13 to 1.68) and interleukin-6 (adjusted relative risk, 1.12, 95% confidence interval, 1.07 to 1.17) remained greater in women presenting in labor. Total cell-free DNA was not significantly different in women with labor compared with women without. Longitudinally, total cell-free DNA (P < .001 in labor, P = .002 without labor) and interleukin-6 (P < .001 in labor, P = .01 without labor) increased significantly across gestation in both groups. The methylation ratio increased significantly in women with labor from 36 weeks to delivery (P = .02). CONCLUSION: Spontaneous labor at term is associated with a greater cell-free DNA methylation ratio and interleukin-6 compared with non-labored controls. As gestation advances, total cell-free DNA concentrations and interleukin-6 levels increase. A greater methylation ratio reflects a greater maternal contribution (vs placental) in women with labor, likely resulting from greater levels of neutrophils, lymphocytes, and uterine activation proteins at the time of labor. Although not significant, women in labor had a greater total cell-free DNA concentration and thus could theoretically have more hypomethylated DNA available for interaction with the inflammatory cascade. Larger studies are needed to investigate this theory.

This month we focus on current research in cervical insufficiency. Dr. Jackson discusses four recent publications, which are concluded with a "bottom line" that is the take-home message. The complete reference for each can be found in on this page, along with direct links to the abstracts.

This month we focus on current research in cervical insufficiency. Dr. Jackson discusses four recent publications, which are concluded with a “bottom line” that is the take-home message. The complete reference for each can be found in Box 1 on this page, along with direct links to the abstracts.

Prenatal genetic diagnostic testing is intended to determine, with as much certainty as possible, whether a specific genetic disorder or condition is present in the fetus. In contrast, prenatal genetic screening is designed to assess whether a patient is at increased risk of having a fetus affected by a genetic disorder. Originally, prenatal genetic testing focused primarily on Down syndrome (trisomy 21), but now it is able to detect a broad range of genetic disorders. Although it is necessary to perform amniocentesis or chorionic villus sampling (CVS) to definitively diagnose most genetic disorders, in some circumstances, fetal imaging with ultrasonography, echocardiography, or magnetic resonance imaging may be diagnostic of a particular structural fetal abnormality that is suggestive of an underlying genetic condition.The objective of prenatal genetic testing is to detect health problems that could affect the woman, fetus, or newborn and provide the patient and her obstetrician-gynecologist or other obstetric care provider with enough information to allow a fully informed decision about pregnancy management. Prenatal genetic testing cannot identify all abnormalities or problems in a fetus, and any testing should be focused on the individual patient's risks, reproductive goals, and preferences. It is important that patients understand the benefits and limitations of all prenatal screening and diagnostic testing, including the conditions for which tests are available and the conditions that will not be detected by testing. It also is important that patients realize that there is a broad range of clinical presentations, or phenotypes, for many genetic disorders and that results of genetic testing cannot predict all outcomes. Prenatal genetic testing has many benefits, including reassuring patients when results are normal, identifying disorders for which prenatal treatment may provide benefit, optimizing neonatal outcomes by ensuring the appropriate location for delivery and the necessary personnel to care for affected infants, and allowing the opportunity for pregnancy termination.The purpose of this Practice Bulletin is to review the current status of prenatal genetic diagnostic testing and the evidence supporting its use. For information regarding screening for fetal aneuploidy, refer to Practice Bulletin No. 163, Screening for Fetal Aneuploidy.

It has been proposed that hypomethylated cfDNA activates the TLR9 receptor of the inflammatory cascade to initiate labor. We sought to determine the changes in cfDNA volumes, hypomethylated fractions, and inflammatory markers across gestation and their relationship to labor. Prospective cohort study of singleton pregnancies enrolled before 28 weeks. Women with major medical comorbidity, preterm labor, progesterone use, aneuploidy, infectious disease, vaginal bleeding, abdominal trauma, or invasive procedures were excluded. Maternal blood samples were obtained at 28 weeks, 36 weeks, and admission to Labor and Delivery at term. Total volume and percent hypomethylation of cfDNA, alpha-interferon (alpha-IFN), and interleukin-6 (IL-6) (proxies for TLR9) were evaluated longitudinally through gestation, and at term between women presenting in spontaneous labor or not in labor. Statistical analysis was by a linear mixed effects model with time as the fixed factor and patient as the random effect. 58 women were enrolled. 2 delivered late preterm (36 weeks); 2 are undelivered. Demographics are presented in Table 1. Mean cfDNA volumes increased from 0.121 ng/uL at 28 weeks to 0.432 ng/uL on admission (0.312, CI 0.218-0.406, p <0.0001). Hypomethylated cfDNA did not change significantly over time (p=0.82). Mean IL-6 increased significantly from 2.31 pg/mL at 28 weeks to 4.24 pg/mL on admission (p <0.0001). There was no significant change in alpha-IFN over time (p=0.08). 26 women presented in labor; 27 women were admitted for induction or scheduled cesarean. Women with spontaneous labor had significantly higher IL-6 than those without labor, but there were no significant differences in cfDNA, hypomethylated cfDNA, or alpha-IFN (Table 2). Spontaneous labor at term is associated with higher levels of IL-6 compared to non-laboring controls. As gestation advances, cfDNA volumes and IL-6 levels increase, while percent hypomethylated cfDNA remains stable. cfDNA, IL-6, and other inflammatory markers require further study to define their role in initiation of labor.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Selective reduction (SR) via intravascular potassium chloride (KCl) injection is contraindicated in monochorionic twins due to the presence of placental vascular communications, which may serve as a conduit for inter-twin passage of KCl or allow exsanguination of the living twin into the demised twin. After successful selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS), the twins' circulatory systems are rendered independent. Theoretically, intravascular KCl injection into one twin after successful SLPCV should not result in passage of the feticidal agent nor cause hemodynamic alterations in the co-twin. We describe 3 cases of 1,069 patients (0.3%) that underwent SLPCV for TTTS between 2003 and 2013 and subsequent SR. SLPCV was successfully completed at 18⁰, 226, and 23⁰ weeks' gestational age for Quintero stages III, IV, and III TTTS, respectively. SR via intravascular KCl injection was later performed at maternal request due to the risk of neurological compromise in one twin at 226, 254, and 236 weeks' gestational age. All co-twins survived after SR, and no neurological sequelae were suspected after birth. Further study is necessary before SR can be routinely considered after laser surgery for TTTS.

To compare published intrapartum FHR monitoring algorithms for the prediction and early identification of fetal acidemia (arterial cord pH <7.1 at birth) and their effect on cesarean delivery (CD). Cases and controls were randomly selected from term, singleton deliveries between 2010 and 2014 with ≥2 hours of FHR monitoring and arterial cord blood gas results. Cases had pH <7.10 without a documented unpreventable cause of acidemia such as cord prolapse. We created rules for intervention from each of 3 published FHR interpretation systems (the 3 Tier (3T), 5 Tier (5T) and Clark systems)[references 1-3] that clearly defined when intervention was indicated, based on recommendations by the authors of each algorithm (figure 1). FHR tracings were reviewed in their entirety in 30-minute intervals by 10 NCC-certified MFM physicians or fellows who were blinded to the outcome. Sensitivity, specificity, false positive and false negative rates were calculated for each algorithm as well as the number of additional CDs that would be expected. 265 tracings were reviewed. There were 41 cases (15.5%) with a pH <7.1 and 224 (84.5%) with a pH ≥7.1. Figure 2 shows the sensitivity, specificity, false positive and false negative rate for each algorithm. The algorithm recommended early intervention (≥30 minutes prior to actual delivery) in 4/10 cases identified by the 5T system and in 5/9 cases identified by the Clark algorithm. Application of the 5T algorithm would have resulted in 17 additional CDs (increase of 6.4%) while the Clark algorithm would have resulted in 24 additional CDs (increase of 9%). The 3T system does not effectively identify fetal acidemia. The 5T and Clark algorithms perform poorly in identifying fetal acidemia at birth, with detection rates of only 24% and 22%, respectively. Use of either system would result in 4 to 5 additional CD for every case of early detection. Improved methods of predicting fetal acidemia are needed.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

OBJECTIVE:To characterize tocolytic use and examine perinatal outcomes among women presenting very preterm with spontaneous labor and cervical dilation 4 cm or greater. METHODS:This was a retrospective cohort study. Data from January 2000 to June 2011 in a single health care system were reviewed. Women with singleton, nonanomalous fetuses and preterm labor with intact membranes between 23 and 32 weeks of gestation who had cervical dilation 4 cm or greater and less than 8 cm at admission were included. Women receiving one or more tocolytics (magnesium sulfate, indomethacin, or nifedipine) were compared with those who did not receive tocolysis. The primary outcome was composite major neonatal morbidity. RESULTS:Two hundred ninety-seven women were included; 233 (78.5%) received at least one tocolytic. Women receiving tocolysis were slightly less dilated (median 5 compared with 6 cm, P<.001) at presentation and were more likely to receive at least a partial course of corticosteroids (88.4% compared with 56.3%, P<.001). Initial composite severe neonatal morbidity rates were similar (41.6% compared with 43.8%, P=.761) regardless of tocolytic administration. Those receiving tocolysis were significantly more likely to be pregnant at least 48 hours after admission (23.6% compared with 7.8%, P=.005), but a similar proportion delivered within 7 days of admission (94.8% compared with 95.3%, P>.99), and delivery gestational ages were similar (28.9 compared with 29.2 weeks, P=.408). The incidence of chorioamnionitis and postpartum endometritis was similar between groups. CONCLUSION:The majority of women presenting very preterm with advanced cervical dilation received tocolysis. Although tocolysis administration increased the likelihood of achieving at least 48 hours of latency, initial neonatal outcomes were similar. LEVEL OF EVIDENCE:II.

An increasing proportion of U.S. births occur to women over 35 years of age (AMA). Some experts recommend antepartum fetal testing for AMA though data are limited. We sought to compare composite morbidity among women who underwent antenatal surveillance for the sole indication of AMA compared to those who did not. A retrospective cohort study of women over 35 delivering in the Intermountain Healthcare system from 2007-2013. The tested cohort consisted of women with a singleton pregnancy undergoing NST/AFI (mBPP) for the sole indication of AMA. A comparison group of untested women was matched for age, race, parity, BMI, and year of delivery (table 1). The primary outcomes were stillbirth and a composite neonatal morbidity (umbilical artery pH < 7.0, 5 min APGAR < 7, NICU admission, or neonatal death). Secondary outcomes included gestational age at delivery, induction, cesarean, and the need for additional fetal testing. Groups were compared using Pearson Chi-Square, Fisher's Exact Test, and Mann-Whitney U test. There were 218 women in the tested cohort and 222 in the matched, untested cohort. Tested women underwent a median of 5 mBPPs (range 1-19) beginning at a median gestational age of 35 weeks (range 27-40). There were no cases of stillbirth. There was no difference in composite neonatal morbidity between the tested and untested cohorts (9.5% vs. 6.0%; p= 0.170). Tested women had a higher rate of labor induction (44% vs. 27.9%; p= 0.01) with no difference in cesarean or gestational age at delivery. Testing prompted further evaluation without delivery in 71 (33%) cases and delivery in 34 (16%) cases (table 2). Among the 34 test-indicated deliveries, there were 3 cases of NICU admission to rule out sepsis without other neonatal morbidity. Antepartum testing for AMA leads to higher rates of intervention but no apparent increase in cesarean. Although underpowered for rare outcomes, testing in this cohort did not decrease rates of stillbirth or neonatal complications. Further study is warranted to establish the cost/benefit of routine fetal testing for AMA.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

This month, we focus on current research on multiple gestations. Dr. Jackson discusses four recent publications, and each is concluded with a "bottom line" that is the take-home message. The complete reference for each can be found in on this page, along with direct links to the abstracts.