Short-term neonatal outcomes in diamniotic twin pregnancies delivered after 32 weeks and indications of late preterm deliveries.

OBJECTIVE: We sought to compare neonatal outcomes in twin pregnancies following moderately preterm birth (MPTB), late preterm birth (LPTB), and term birth and determine the indications of LPTB. STUDY DESIGN: We performed a retrospective cohort study. MPTB was defined as delivery between 32(0/7) and 33(6/7) weeks and LPTB between 34(0/7) and 36(6/7) weeks. The composite neonatal adverse respiratory outcome was defined as respiratory distress syndrome and/or bronchopulmonary dysplasia. The composite neonatal adverse nonrespiratory outcome included early onset culture-proven sepsis, necrotizing enterocolitis, retinopathy of prematurity, intraventricular hemorrhage, or periventricular leukomalacia. LPTB cases were categorized as spontaneous (noniatrogenic), evidence-based iatrogenic, and non-evidence-based (NEB) iatrogenic. RESULTS: Of the 747 twin deliveries during the study period, 453 sets met the inclusion criteria with 22.7% (n = 145) MPTB, 32.1% (n = 206) LPTB, and 15.9% (n = 102) term births. Compared with term neonates, the composite neonatal adverse respiratory outcome was increased following MPTB (relative risk [RR] 24; 95% confidence interval [CI] 3.0 to 193.6) and LPTB (RR 13.7; 95% CI 1.8 to 101.8). Compared with term neonates, the composite neonatal adverse nonrespiratory outcome was increased following MPTB (RR 22.3; 95% CI 3.9 to 127.8) and LPTB (RR 5.5; 95% CI 1.1 to 27.6). Spontaneous delivery of LPTB was 63.6% (n = 131/206) and the rate of iatrogenic delivery was 36.4% (n = 75/206). The majority, 66.6% (n = 50/75), of these iatrogenic deliveries were deemed NEB, giving a total of 24.2% (50/206) NEB deliveries in LPTB group. CONCLUSION: Our data demonstrate a high rate of late preterm birth among twin pregnancies, with over half of nonspontaneous early deliveries due to NEB indications. Although our morbidity data will be helpful to providers in counseling patients, our finding of high NEB indications underscores the need for systematic evaluation of indications for delivery in LPTB twin deliveries. Furthermore, this may lead to more effective LPTB rate reduction efforts.

Demographic differences in Down syndrome livebirths in the US from 1989 to 2006.

OBJECTIVE: To explore demographic differences in Down syndrome livebirths in the United States. METHODS: Using National Center for Health Statistics (NCHS) birth certificate data from 1989 to 2006 we analyzed Down syndrome livebirths after correcting for under-reporting. We created six subsets based on maternal age (15-34 and 35-49 years old); US regions, that is, Northeast, Midwest, South and West; marital status, (married, unmarried); education, ( ≤ 12 years, ≥ 13 years); race, (white, black); and Hispanic ethnicity, (non-Hispanic, Hispanic). We estimated expected Down syndrome livebirths assuming no change in birth certificate reporting. The percentage of expected Down syndrome livebirths actually born was calculated by year. RESULTS: There were 72 613 424 livebirths from 1989 to 2006. There were 122 519 Down syndrome livebirths expected and 65 492 were actually born. The Midwest had the most expected Down syndrome livebirths actually born (67.6%); the West was lowest (44.4%). More expected Down syndrome livebirths were born to women who were 15 to 34 years old (61 vs 43.8%) and to those with ≤ 12 years education (60.4 vs 46.9%), white race (56.6 vs 37%), unmarried (56.0 vs 52.5%), and of Hispanic ethnicity (55.0 vs 53.3%). CONCLUSION: The percentage of expected Down syndrome livebirths actually born varies by demographics.

Modifying risk for aneuploidy with second-trimester ultrasound after a positive serum screen.

Prenatal diagnosis for aneuploidy (primarily Down syndrome) has evolved over the past 4 decades. It started as a screening process using maternal age of 35 years or older as a risk factor to offer patients the option for prenatal diagnosis. The actual diagnosis used an invasive procedure (amniocentesis) to obtain fetal cells for processing to determine fetal karyotype. This had a potential risk for miscarriage. The development of noninvasive prenatal screening to better identify pregnant patients at high risk for Down syndrome improved the ability to detect cases of aneuploidy and limit amniocentesis to only patients considered at high risk. This approach has a higher detection rate and a lower procedure-related rate of fetal loss than use of maternal age of 35 years or older alone. This article presents an overview of how prenatal diagnosis has evolved and then focuses on the current status of using ultrasound to evaluate patients considered to be screen-positive for Down syndrome based on first-trimester screening (10-14 weeks) or second-trimester (15-22 weeks) maternal serum analyte screening.

Toxoplasmosis, parvovirus, and cytomegalovirus in pregnancy.

Several infections in adults warrant special consideration in pregnant women given the potential fetal consequences. Among these are toxoplasmosis, parvovirus B19, and cytomegalovirus. These infections have an important effect on the developing fetus depending on the timing of infection. This article reviews the modes of transmission as well as maternal and neonatal effects of each of these infections. In addition, recommended testing, fetal surveillance, and treatment where indicated are outlined.