[Pregnancy complications with abnormal results of biochemical screening for Down syndrome in second trimester and normal fetal karyotype].

Pregnancy complications were studied in the following groups of pregnancies with structurally and chromosomally normal fetuses: 1) 216--with elevated free beta-hCG above 2 MoM and 134--above 2.5 MoM; 2) 37--with elevated alpha-fetoprotein [AFP] above 2 MoM; 3) 67 screen-positive patients below the age of 35. The following complications were compared in the studied and the control groups: preterm delivery and premature rupture of membranes [PROM], preeclampsia (in general and severe one), IUGR without preeclampsia, delivery of small for gestational age [SGA] and low birth weight [LBW] infants and perinatal fetal loss. Pregnancy outcome in cases with free beta-hCG above 2 MoM was not different from that in the control group. With 2.5 cut-off level the incidence of preeclampsia and of LBW infants was higher in the studied than in the control group. Elevated AFP above 2 MoM alone was associated with more frequent preeclampsia including severe one (in all the latter cases--IUGR present). In the screen-positive group the incidence of preeclampsia (in general and severe one with IUGR), SGA and LBW infants and perinatal mortality rate were significantly higher than in the control group. No difference was found between the studied and the control groups regarding subsequent development of IUGR without preeclampsia, preterm delivery and PROM. Abnormal second trimester serum screening test results (elevated free beta-hCG or AFP alone above 2.5 and 2 MoM respectively) in pregnancies with normal fetal karyotype indicate higher risk for subsequent development of preeclampsia. Screen-positive patients, being a heterogeneous group (including ones with elevated free bb-hCG alone and ones with elevated both free beta-hCG and AFP), are at increased risk for other pregnancy complications too.