In-Orbit Performance of the GRACE Follow-on Laser Ranging Interferometer.

The Laser Ranging Interferometer (LRI) instrument on the Gravity Recovery and Climate Experiment (GRACE) Follow-On mission has provided the first laser interferometric range measurements between remote spacecraft, separated by approximately 220 km. Autonomous controls that lock the laser frequency to a cavity reference and establish the 5 degrees of freedom two-way laser link between remote spacecraft succeeded on the first attempt. Active beam pointing based on differential wave front sensing compensates spacecraft attitude fluctuations.

Impact of Azithromycin-Based Extended-Spectrum Antibiotic Prophylaxis on Noninfectious Cesarean Wound Complications.

Objective: Adding azithromycin to standard antibiotic prophylaxis for unscheduled cesarean delivery has been shown to reduce postcesarean infections. Because wound infection with ureaplasmas may not be overtly purulent, we assessed the hypothesis that azithromycin-based extended-spectrum antibiotic prophylaxis also reduces wound complications that are identified as noninfectious.

Study Design: This is a secondary analysis of the C/SOAP (Cesarean Section Optimal Antibiotic Prophylaxis) randomized controlled trial, which enrolled women with singleton pregnancies ≥24 weeks who were undergoing nonelective cesarean.

Family Physicians' Perceived Prevalence, Safety, and Screening for Cigarettes, Marijuana, and Electronic-Nicotine Delivery Systems (ENDS) Use during Pregnancy.

Objective: Assess perceptions of prevalence, safety, and screening practices for cigarettes and secondhand smoke exposure (SHSe), marijuana (and synthetic marijuana), electronic nicotine delivery systems (ENDS; eg, e-cigarettes), nicotine-replacement therapy (NRT), and smoking-cessation medications during pregnancy, among primary care physicians (PCPs) providing obstetric care.

Methods: A web-based, cross-sectional survey was e-mailed to 3750 US physicians (belonging to organizations within the Council of Academic Family Medicine Educational Research Alliance). Several research groups' questions were included in the survey.

The effect of omega-3 supplementation on pregnancy outcomes by smoking status.

Background: Smoking during pregnancy is associated with adverse maternal and neonatal outcomes such as preterm delivery, intrauterine growth restriction, stillbirth, and low birth weight. Because smoking causes oxidative stress, some have suggested using antioxidants to counteract the effects of oxidative stress. Smokers have lower serum levels of omega-3 fatty acids, an important antioxidant, and thus, investigating whether omega-3 supplementation in smokers reduces adverse maternal and neonatal outcomes represents an important area of research.

Adjunctive Azithromycin Prophylaxis for Cesarean Delivery.

Background: The addition of azithromycin to standard regimens for antibiotic prophylaxis before cesarean delivery may further reduce the rate of postoperative infection. We evaluated the benefits and safety of azithromycin-based extended-spectrum prophylaxis in women undergoing nonelective cesarean section.

Methods: In this trial conducted at 14 centers in the United States, we studied 2013 women who had a singleton pregnancy with a gestation of 24 weeks or more and who were undergoing cesarean delivery during labor or after membrane rupture.

A qualitative assessment of the perceived risks of electronic cigarette and hookah use in pregnancy.

Background: Studies reveal that electronic cigarette (e-cigarette) and hookah use are increasing among adolescents and young adults. However, the long-term health effects are unknown, especially with regards to pregnancy. Because of the increased use in women of reproductive age, and the unknown long-term health risks, our primary objectives were to determine the perceived risks of e-cigarette and hookah use in pregnancy, and learn common colloquial terms associated with e-cigarettes.

Vaginal Microbiota in Pregnancy: Evaluation Based on Vaginal Flora, Birth Outcome, and Race.

Objective: This study aims to evaluate vaginal microbiota differences by bacterial vaginosis (BV), birth timing, and race, and to estimate parameters to power future vaginal microbiome studies.

Methods: Previously, vaginal swabs were collected at 21 to 25 weeks (stored at -80°C), and vaginal smears evaluated for BV (Nugent criteria). In a blinded fashion, 40 samples were selected, creating 8 equal-sized groups stratified by race (black/white), BV (present/absent), and birth timing (preterm/term).

In utero nicotine exposure epigenetically alters fetal chromatin structure and differentially regulates transcription of the glucocorticoid receptor in a rat model.

Background: Fetal exposure to nicotine is not limited to maternal tobacco smoke, as electronic cigarettes have an increased prevalence of use among reproductive aged women. Animal models have shown that nicotine exposure in utero is associated with increased risk of asthma and cognitive deficits, as well as increased expression of the hippocampal glucocorticoid receptor. We hypothesized that in utero nicotine exposure is associated with epigenetic changes in the offspring lung and brain which may contribute to a memory of this exposure

Methods: Sprague-Dawley rat dams received either saline or 2 mg/kg of nicotine by intraperitoneal injection once daily from embryonic day 6 (e6) to e22.

Quantitative Polymerase Chain Reaction to Assess Response to Treatment of Bacterial Vaginosis and Risk of Preterm Birth.

Objective: The aim of this study was to determine whether quantitative polymerase chain reaction (qPCR) bacterial load measurement is a valid method to assess response to treatment of bacterial vaginosis and risk of preterm birth in pregnant women.

Study Design: Secondary analysis by utilizing stored vaginal samples obtained during a previous randomized controlled trial studying the effect of antibiotics on preterm birth (PTB). All women had risk factors for PTB: (1) positive fetal fibronectin (n=146), (2) bacterial vaginosis (BV) and a prior PTB (n=43), or (3) BV and a prepregnancy weight<50 kg (n=54).

Prenatal vitamin C and E supplementation in smokers is associated with reduced placental abruption and preterm birth: a secondary analysis.

Objective: Smoking and pre-eclampsia (PE) are associated with increases in preterm birth, placental abruption and low birthweight. We evaluated the relationship between prenatal vitamin C and E (C/E) supplementation and perinatal outcomes by maternal self-reported smoking status focusing on outcomes known to be impacted by maternal smoking.

Design/setting/population: A secondary analysis of a multi-centre trial of vitamin C/E supplementation starting at 9-16 weeks in low-risk nulliparous women with singleton gestations.

Low-dose aspirin, smoking status, and the risk of spontaneous preterm birth.

Objective: We evaluated the relationship between aspirin supplementation and perinatal outcomes for potential effect modification by smoking status.

Study Design: A secondary analysis of two multicenter trials for which prophylactic aspirin supplementation was given to either low- or high-risk women for prevention of preeclampsia (PE). We examined the effect of aspirin by smoking status using the Breslow-Day test.

Review of multicenter studies by multiple institutional review boards: characteristics and outcomes for perinatal studies implemented by a multicenter network.

Objective: The objective of the study was to describe characteristics and outcomes of a review of multisite perinatal studies by individual institutional review boards (IRBs) and identify barriers and opportunities for streamlined IRB review.

Study Design: We compared the review of 5 collaborative protocols by individual IRBs at National Perinatal Research Consortium centers from 2007 through 2012. Three randomized trials, 1 observational study, and 1 follow-up study of a trial were selected.

Is low-dose aspirin therapy to prevent preeclampsia more efficacious in non-obese women or when initiated early in pregnancy?

Objective: Late timing of intervention and maternal obesity are potential explanations for the modest effect of aspirin for preeclampsia prevention. We explored whether low-dose aspirin (LDA) is more effective in women at increased risk when initiated before 16 weeks' gestation or given to non-obese women.

Methods: Secondary analysis of a trial to evaluate LDA (60 mg/d) for preeclampsia prevention in high-risk women.

Epidural use and clinical chorioamnionitis among women who delivered vaginally.

Objective: Chorioamnionitis, an important cause of maternal and neonatal morbidity, is influenced by epidural use and the occurrence of epidural fever. We evaluated the association between chorioamnionitis, histologic placental findings, and intrapartum factors focusing on epidural use.

Materials And Methods: We conducted a secondary analysis of a randomized controlled trial of different doses of oxytocin to prevent postpartum hemorrhage among women who delivered vaginally.

Higher-dose oxytocin to prevent obstetric hemorrhage at vaginal delivery-does duration of infusion matter?

Objective: Postpartum higher-dose oxytocin (80 U) compared with lower dose (10 U) given in 500 mL over 1 hour does not decrease postpartum hemorrhage (PPH) requiring treatment, but reduces the risk of hematocrit decline ≥ 6% among women delivering vaginally. Our objective was to evaluate whether the duration of administration of oxytocin influences outcomes.

Study Design: We compared a cohort receiving a postpartum oxytocin infusion of 80 U/500 mL over 1 hour to a concurrent cohort of women receiving 80 U/500 mL over 8 hours.

Is midtrimester vitamin D status associated with spontaneous preterm birth and preeclampsia?

Objective: The objective of this study is to evaluate whether midtrimester maternal vitamin D is associated with preeclampsia < 37 weeks or spontaneous preterm birth (SPTB) < 35 weeks.

Study Design: Nested case-control comprising two case subsets: (1) 100 women with preeclampsia < 37 weeks and (2) 100 women with SPB < 35 weeks. Controls consisted of 200 women delivered between 39 and 40 weeks.

Dose and duration of oxytocin to prevent postpartum hemorrhage: a review.

Objective: Oxytocin, the most commonly used uterotonic agent in the United States to prevent postpartum hemorrhage, has no established standard dose. The aim of this review is to present data on oxytocin dosing for the prevention of postpartum hemorrhage.

Study Design: We conducted a PubMed search for clinical trials that utilized oxytocin for hemorrhage prophylaxis following either vaginal or cesarean delivery.

PP170. Prenatal vitamin C and E supplementation is associated with a reduction in placental abruption and preterm birth in smokers.

Introduction: Maternal tobacco use increases the incidence of numerous adverse pregnancy outcomes including miscarriage, small for gestational age infants, spontaneous preterm birth and placental abruption.

Objectives: We evaluated the relationship between prenatal vitamin C/E supplementation and perinatal outcomes by maternal smoking status.

Methods: Secondary analysis of a multicenter trial of vitamin C/E starting at 9-16 weeks in low-risk nulliparous women with singletons.

Antimicrobials for preterm birth prevention: an overview.

Objective: Preterm birth (PTB) remains a major cause of neonatal morbidity and mortality. The association between PTB and infection is clear. The purpose of this report is to present a focused review of information on the use of antibiotics to prevent PTB.

Tocolytic therapy for acute preterm labor.

The pathophysiology leading to preterm labor is not well understood and often multifactorial; initiating factors include intrauterine infection, inflammation, ischemia, overdistension, and hemorrhage. Given these different potential causes, directing therapy for preterm labor has been difficult and suboptimal. To date, no single drug has been identified as successful in treating all of the underlying mechanisms leading to preterm labor.

Maternal tobacco use modestly alters correlated epigenome-wide placental DNA methylation and gene expression.

Several studies linking alterations in differential placental methylation with pregnancy disorders have implicated (de)regulation of the placental epigenome with fetal programming and later-in-life disease. We have previously demonstrated that maternal tobacco use is associated with alterations in promoter methylation of placental CYP1A1 and that these changes are correlated with CYP1A1 gene expression and fetal growth restriction. In this study we sought to expand our analysis of promoter methylation by correlating it to gene expression on a genome-wide scale.

Maternal tobacco use is associated with increased markers of oxidative stress in the placenta.

Objective: We sought to extend our prior observations and histopathologically characterize key metabolic enzymes (CYP1A1) with markers of oxidative damage in the placental sections from smokers.

Study Design: Placental specimens were collected from term singleton deliveries from smokers (n = 10) and nonsmokers (n = 10) and subjected to a detailed histopathological examination. To quantify the extent of oxidative damage, masked score-graded (0-6) histopathology against 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxydeoxyguanisine (8-OHdG) was performed.

Genetic and epigenetic influences associated with intrauterine growth restriction due to in utero tobacco exposure.

While many fetuses are exposed to tobacco in utero, not all experience adverse outcomes as a result of this exposure. Mechanisms leading to the attenuation of fetal birth weight and adverse pregnancy outcomes are complex. Therefore many studies have begun to focus, not only on the contribution of maternal and fetal genes to phenotypic outcome, but also on epigenetic changes associated with exposure to maternal tobacco smoke.

In utero tobacco exposure epigenetically modifies placental CYP1A1 expression.

The metabolic pathways used by higher-eukaryotic organisms to deal with potentially carcinogenic xenobiotic compounds from tobacco smoke have been well characterized. Carcinogenic compounds such as polycyclic aromatic hydrocarbons are metabolized sequentially in 2 phases: in phase I, CYP1A1 catalyzes conversion into harmful hydrophilic DNA adducts, whereas in phase II, GSTT1 enables excretion via conjugation into polar electrophiles. In an effort to understand susceptibility to in utero tobacco exposure, we previously characterized known metabolic functional polymorphisms and demonstrated that although deletion of fetal GSTT1 significantly modified birth weight in smokers, no polymorphism fully accounted for fetal growth restriction.