In fetuses without hydrops that are at risk because of maternal red-cell alloimmunization, moderate and severe anemia can be detected noninvasively by Doppler ultrasonography on the basis of an increase in the peak velocity of systolic blood flow in the middle cerebral artery.

Background Infants born at 34 to 36 weeks’ gestation (late preterm) have greater risks of adverse respiratory and other outcomes, than those born at 37 weeks gestation or later. It is not known whether betamethasone administered to women at risk for late preterm delivery decreases risks of neonatal morbidities. Methods We conducted a multicenter randomized trial of women with a singleton gestation at high risk for late preterm delivery. Participants were randomized to two injections of 12 mg betamethasone or matching placebo 24 hours apart. The primary outcome was a neonatal composite of treatment in the first 72 hours (continuous positive airway pressure or high flow nasal cannula for at least two hours, supplemental oxygen with a fraction of inspired oxygen of at least 30 percent for at least four hours, extra corporeal membrane oxygenation or mechanical ventilation) or stillbirth or neonatal death before 72 hours. Results 2,831 patients were randomized. The primary outcome occurred in 11.6% of the betamethasone group versus 14.4%, in the placebo group (Relative Risk 0.80, 95% confidence interval 0.66-0.97, P=0.02). Severe respiratory morbidity, transient tachypnea of the newborn, surfactant use, and bronchopulmonary dysplasia were also significantly less common in the betamethasone group. There were no significant differences between groups in the incidence of chorioamnionitis or neonatal sepsis. Neonatal hypoglycemia was more common in the betamethasone group. (24.0% versus 14.9%, RR 1.61, 95% CI 1.38-1.88, P<0.001) Conclusions Administration of betamethasone to women at risk for late preterm delivery significantly reduced the rate of neonatal respiratory morbidity.

The growing public health awareness of prematurity and its complications has prompted careful evaluation of the timing of deliveries by clinicians and hospitals. Preterm birth is associated with significant morbidity and mortality, and affects over half a million births in the United States each year. In some situations, however, a late-preterm birth or early-term birth is the optimal outcome for the mother, baby, or both, due to conditions that can result in worse outcomes if pregnancy is allowed to continue. These conditions may be categorized as placental, maternal, fetal, or all of these such as placenta previa, preeclampsia, and multiple gestations respectively. Some risks associated with early delivery are common to all conditions, including prematurity-related morbidities such as respiratory distress syndrome and intraventricular hemorrhage, as well as maternal delivery-related morbidities such as failed induction and cesarean delivery. However, when continuation of the pregnancy is associated with more risks such as hemorrhage, uterine rupture and stillbirth, preterm delivery maybe indicated. In February 2011, the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Society for Maternal Fetal Medicine held a workshop on the “Timing of Indicated Late Preterm and Early Term Births”. The goal of the workshop was to synthesize the available information regarding conditions that may result in medically-indicated late preterm and early term births in order to determine the potential risks and benefits of delivery versus continued pregnancy, determine the optimal gestational age for delivery of affected pregnancies when possible, and inform future research regarding these issues. Based on available data and expert opinion, optimal timing for delivery for specific conditions was determined by consensus, along with associated risks and benefits.