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Fetomaternal alloimmune thrombocytopenia (FMAIT) is a relatively uncommon disease, but is the leading cause of severe thrombocytopenia in the newborn. It can cause severe complications and long-term disabilities. The main objective of screening is to reduce both the morbidity and mortality associated with FMAIT, primarily by preventing intracranial hemorrhage. However, controversy surrounds both pre- and antenatal management. This article discusses pathogenesis, screening, diagnosis, and both pre- and neonatal management of FMAIT.

Prenatal detection of chromosome abnormalities has been offered for more than 40 years, first by amniocentesis in the early 1970s and additionally by chorionic villus sampling (CVS) in the early 1980s. Given the well-recognized association between increasing maternal age and trisomy,1-3 the primary utilization of prenatal testing has been by older mothers. This has drastically reduced the incidence of aneuploid children born to older mothers.4 Although younger women have relatively low risks of conceiving a child with aneuploidy, the majority of pregnant women are in their late teens, 20s, and early 30s. As such, most viable aneuploid babies are born to these younger mothers.5 Invasive prenatal diagnosis (CVS and amniocentesis) is not a feasible option for all low-risk mothers, as these procedures carry a small but finite risk and would ultimately cause more miscarriages than they would detect aneuploidy. For this reason, a number of noninvasive tests have been developed-including first-trimester risk assessment at 11 to 14 weeks, maternal serum analyte (quad) screening at 15 to 20 weeks, and sonographic fetal structural survey at 18 to 22 weeks-all of which are designed to give a woman an adjusted (more accurate) estimate of having an aneuploid fetus using as baseline her a priori age-related risk. Ultrasound and maternal serum analysis are considered screening procedures and both require follow up by CVS or amniocentesis in screen-positive cases for a definitive diagnosis of a chromosome abnormality in the fetus. The ability to isolate fetal cells and fetal DNA from maternal blood during pregnancy has opened up exciting opportunities for improved noninvasive prenatal testing (NIPT). Direct analysis of fetal cells from maternal circulation has been challenging given the scarcity of fetal cells in maternal blood (1:10,000-1:1,000,000) and the focus has shifted to the analysis of cell-free fetal DNA, which is found at a concentration almost 25 times higher than that available from nucleated blood cells extracted from a similar volume of whole maternal blood. There have now been numerous reports on the use of cell-free DNA (cfDNA) for NIPT for chromosomal aneuploidies-especially trisomy (an extra copy of a chromosome) or monosomy (a missing chromosome)-and a number of commercial products are already being marketed for this indication. This article reviews the various techniques being used to analyze cell-free DNA in the maternal circulation for the prenatal detection of chromosome abnormalities and the evidence in support of each. A number of areas of ongoing controversy are addressed, including the timing of maternal blood sampling, the need for genetic counseling, and the use of confirmatory invasive testing. Future applications for this technology are also reviewed.

Puerperal infection remains a major cause of maternal morbidity and mortality. The primary risk factor is cesarean delivery, which increases the risk 5- to 20-fold. This article reviews in detail the risk of puerperal infection following cesarean delivery, both endometritis and surgical site infection, in both high- and low-risk populations. Strategies to prevent such infections are also discussed using a systematic evidence-based approach.

Preeclampsia (gestational proteinuric hypertension) complicates 5% to 8% of all pregnancies, and is a major cause of maternal and perinatal morbidity and mortality. It is a multisystem disorder specific to human pregnancy and the puerperium. Although the etiology is unknown, increasing evidence from both animal and human studies suggests that an imbalance in circulating pro-(vascular endothelial growth factor [VEGF], placental growth factor) and anti-angiogenic factors (soluble fms-like tyrosine kinase 1, soluble endoglin) may be important. Bevacizumab (Avastin®; Genentech, South San Francisco, CA), a humanized recombinant monoclonal IgG antibody that binds VEGF, has been shown to inhibit endothelial cell proliferation, suppress angiogenesis, and shrink a variety of solid tumors. We present two cases of bevacizumab toxicity that mimic preeclampsia with a reversible syndrome characterized by acute-onset severe hypertension, proteinuria, central nervous system irritability (headache, photophobia, blurred vision, seizures), abnormal laboratory tests (elevated liver function tests, thrombocytopenia), and evidence of reversible posterior leukoencephalopathy on neuroimaging. In both cases, the clinical and laboratory manifestations returned to normal with discontinuation of bevacizumab therapy and supportive care. Bevacizumab toxicity can mimic preeclampsia in nonpregnant women. These data suggest that interference with VEGF signaling is sufficient to induce a preeclampsia-like syndrome in nonpregnant patients. VEGF signaling therefore appears to play a central role-perhaps the central role-in the pathogenesis of preeclampsia, and provides a potential biomarker for the prediction, prevention, and treatment of this dangerous disorder.

Preterm birth is currently the most important problem in maternal-child health in the United States and possibly throughout the world. It complicates one in eight US deliveries, and accounts for over 85% of all perinatal morbidity and mortality. Although survival of preterm infants has increased steadily over the past four decades-due in large part to the use of antenatal corticosteroids, improvements in neonatal resuscitation, and the introduction of neonatal intensive care units-efforts to prevent preterm birth have been largely unsuccessful. On February 3, 2011, the US Food and Drug Administration (FDA) approved the use of progesterone supplementation (hydroxyprogesterone caproate) during pregnancy to reduce the risk of recurrent preterm birth in women with a history of at least one prior spontaneous preterm delivery. This is the first time that the FDA has approved a medication for the prevention of preterm birth, and represents the first approval of a drug specifically for use in pregnancy in almost 15 years. This article reviews the evidence behind the use of progesterone for the prevention of preterm birth, and provides guidelines for the use of progesterone supplementation in clinical practice. A number of areas of ongoing controversy are addressed, including the optimal formulation and route of administration, the safety of progesterone supplementation in pregnancy, and its proposed mode of action.

Pulmonary hypoplasia is a rare congenital disorder; most cases occur in association with other congenital abnormalities, including congenital diaphragmatic hernia, oligohydramnios, and/or skeletal deformities. The authors report a case of unilateral pulmonary hypoplasia diagnosed prenatally and confirmed at autopsy.

Uterine fibroids are a very common finding in women of reproductive age. The majority of fibroids do not change their size during pregnancy, but one-third may grow in the first trimester. Although the data are conflicting and most women with fibroids have uneventful pregnancies, the weight of evidence in the literature suggests that uterine fibroids are associated with an increased rate of spontaneous miscarriage, preterm labor, placenta abruption, malpresentation, labor dystocia, cesarean delivery, and postpartum hemorrhage.

Cytomegalovirus (CMV) is the most common cause of congenital infection and complicates approximately 1% of all live births. Primary maternal CMV infection carries a 30% to 40% risk of vertical transmission to the fetus. In cases where maternal CMV infection is suspected, it is important to evaluate the risk to the fetus to provide appropriate counseling and guidance to parents. This article reviews the published literature and summarizes current diagnostic and management recommendations to help answer the question, should all women be screened for CMV infection in pregnancy?

Approximately 5% (1 in 20) of all deliveries in the United States are operative vaginal deliveries. The past 20 years have seen a progressive shift away from the use of forceps in favor of the vacuum extractor as the instrument of choice. This article reviews in detail the indications, contraindications, patient selection criteria, choice of instrument, and technique for vacuum-assisted vaginal delivery. The use of vacuum extraction at the time of cesarean delivery will also be discussed. With vacuum extraction becoming increasingly popular, it is important that obstetric care providers are aware of the maternal and neonatal risks associated with such deliveries and of the options available to effect a safe and expedient delivery.

Pregnant women and their fetuses are at high risk of infection with the novel H1N1 influenza A virus. Obstetric providers need to be prepared to provide the care necessary to address the increased morbidity, mortality, and pregnancy-related complications (including spontaneous miscarriage and preterm birth) faced by pregnant women during an influenza pandemic. This article reviews the epidemiology, pathogenesis, clinical manifestations, diagnosis, treatment, and prevention strategies for the current H1N1 influenza pandemic.

Preterm birth (PTB), defined as birth before 37 weeks of gestation, is the leading cause of perinatal morbidity and mortality. PTB is a major cause of long-term health problems in neonates, including respiratory distress syndrome, chronic lung disease (bronchopulmonary dysplasia), infection, intraventricular hemorrhage, and severe neurologic deficit. In the absence of reliable clinical predictors of PTB, obstetric care providers should focus their attention on the 2 best and most widely accepted methods of identifying women at high risk of PTB in both nullipara and multipara: fetal fibronectin and cervical length measurements.

Spontaneous rupture of membranes (ROM) is a normal component of labor and delivery. Premature ROM (PROM) refers to rupture of the fetal membranes prior to the onset of labor irrespective of gestational age. Once the membranes rupture, delivery is recommended when the risk of ascending infection outweighs the risk of prematurity. When PROM occurs at term, labor typically ensues spontaneously or is induced within 12 to 24 hours. The management of pregnancies complicated by preterm PROM (defined as PROM occurring prior to 37 weeks of gestation) is more challenging. Preterm PROM complicates 2% to 20% of all deliveries and is associated with 18% to 20% of perinatal deaths. Management options include admission to hospital, amniocentesis to exclude intra-amniotic infection, and administration of antenatal corticosteroids and broad-spectrum antibiotics, if indicated. This article reviews in detail the contemporary diagnosis and management of preterm PROM.

Respiratory distress syndrome (RDS) remains a major cause of perinatal morbidity and mortality in premature infants. To avoid iatrogenic RDS, The American College of Obstetricians and Gynecologists (ACOG) recommends that obstetricians confirm fetal pulmonary maturity prior to elective delivery less than 39 weeks' gestation. However, ACOG based such recommendations primarily on studies carried out prior to the routine use of antenatal corticosteroids to accelerate lung maturity and the liberal use of ultrasound to confirm gestational age. Recent studies suggest that testing for fetal lung maturity at more advanced gestational ages is neither reliable nor cost effective. This article reviews the current literature on the use of amniocentesis to confirm fetal lung maturity prior to elective delivery at 36 to 39 weeks' gestation.