Maternal serum alpha-fetoprotein in twin pregnancies uncomplicated by neural tube defect

Second-trimester maternal serum alpha-fetoprotein, human chorionic gonadotropin, and unconjugated oestriol after early transvaginal multifetal pregnancy reduction

Maternal serum alpha-fetoprotein (MSAFP), human chorionic gonadotropin (hCG), and unconjugated oestriol (UE3) are used as second-trimester screening markers for the detection of various fetal abnormalities. Previous studies have suggested that second-trimester MSAFP is consistently elevated after late first-trimester transabdominal multifetal pregnancy reduction (MFPR). The present study was undertaken to evaluate the levels of all three markers after early transvaginal MFPR. Maternal serum was examined for MSAFP, hCG, and UE3 at 16-18 weeks' gestation in 28 patients who underwent transvaginal MFPR at approximately 10 weeks' gestation. The mean interval between the reduction procedure and the screening test was 7.2 +/- 0.9 weeks. The mean MSAFP value in 24 patients carrying viable twins was 2.49 +/- 0.99 multiples of the median (MOM). Two patients had elevated MSAFP values: one in association with omphalocoele and the other in relation to an adverse pregnancy outcome. All but two patients had normal hCG values (mean 1.98 +/- 1.26 MOM). Two cases with elevated hCG were associated with an adverse pregnancy outcome. Unconjugated oestriol values were within the normal range in all patients (mean 1.69 +/- 0.61 MOM). These results suggest that early transvaginal MFPR, at approximately 10 weeks' gestation, does not appear to influence second-trimester MSAFP, hCG, and UE3 levels. The values of these markers may therefore be interpreted by using the same criteria as those for the general obstetric population.

Antepartum management of the multiple gestation: the case for specialized care

Multiple gestations are increasingly more common and represent one of the highest risk conditions faced in pregnancy. The population-attributable fetal and newborn risks of twin and triplet gestations are compelling. This article is dedicated to a discussion of the antepartum management of multiple gestations and a conclusion that specialized care can improve both perinatal morbidity and mortality in these pregnancies. Prenatal care for multiple gestations should be provided by an experienced and dedicated staff that can anticipate and manage the various and complex problems presented by the multifetal gestation. Specialized care for multiple gestations should include components such as consistent evaluation of maternal symptoms and cervical status by a single care-provider, intensive preterm birth prevention education, individualized modification of maternal activity, increased attention to nutrition, ultrasonography, tracking of clinic nonattenders, and a supportive clinical environment. This sort of specialization and individualization of antepartum care for multiple gestations provides the best opportunity to maximize intrauterine fetal growth, identify congenital anomalies, prevent extremely preterm or very low birth weight deliveries, and identify fetal or maternal complications that may necessitate more intensive fetal surveillance or even delivery to reduce adverse perinatal outcome.

Maternal serum alpha-fetoprotein in twin pregnancy

Maternal serum alpha-fetoprotein concentration was measured at 14 to 20 weeks' gestation in 138 twin pregnancies. All patients had at least one ultrasonographic examination (86% before 20 weeks' gestation). Two pregnancies were discordant for open fetal defects (one anencephaly, one gastroschisis). The median serum alpha-fetoprotein value in the remaining 136 twin pregnancies paralleled a curve 2.5 times the median curve for singleton pregnancies over the gestational range studied. Higher serum alpha-fetoprotein values correlated significantly with increasing incidence of fetal and neonatal death, premature delivery (less than 35 weeks' gestation), and twin-to-twin birth discordance (greater than 20%), most pronounced at greater than 4 multiples of the singleton median level. A significant negative correlation between alpha-fetoprotein and birth weight was observed (p less than 0.001), but was related more to prematurity than to poor fetal growth. Theoretically, serum alpha-fetoprotein screening detected 56.5% of the twins in this study when a cutoff level of 2.5 multiples of the median was used, enhancing twin detection in the study population by 40%. These data indicate that maternal serum alpha-fetoprotein screening has a valuable role in the management of twin pregnancy, both in the detection of twins and in the prediction of perinatal outcome in twin pregnancy.

The value of early third-trimester maternal serum alpha-fetoprotein determination

The value of determination of maternal serum of alpha-fetoprotein (MSAFP) concentration in the second trimester is well established. In addition to open neural tube defects, pregnancies associated with elevated second-trimester MSAFP have been shown to be at increased risk for a variety of problems, including low birth weight, preterm delivery, and pregnancy-induced hypertension (PIH). We evaluated the potential usefulness of MSAFP in the early third trimester. MSAFP concentration was determined in over 200 women at the time of glucose screening. Results were analysed with regard to gestational age at sampling, maternal weight, race, diabetes, and presence of twins. MSAFP was twice as high in twin gestation, but not affected by race or the presence of diabetes. In contrast to levels in early gestation, third-trimester MSAFP does not appear to be predictive of preterm delivery, low birth weight, or PIH.