Maternal serum analyte levels after first-trimester multifetal pregnancy reduction

OBJECTIVE: Our purpose was to assess the effect of multifetal pregnancy reduction on maternal serum levels of analytes used for screening low-risk women for fetal chromosome abnormalities and neural tube defects. STUDY DESIGN: Peripheral blood samples were obtained between 15.0 and 20.9 weeks' gestation from 10 consecutive women who had undergone first-trimester multifetal pregnancy reduction. The samples were assayed for levels of alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol. Analyte concentrations were interpreted within our maternal serum screening program. RESULTS: Levels of alpha-fetoprotein were significantly elevated in all samples. In each pregnancy levels of human chorionic gonadotropin and unconjugated estriol were consistent with the number of continuing gestations. CONCLUSIONS: First-trimester multifetal reduction does not alter second-trimester levels of human chorionic gonadotropin and unconjugated estriol. Further study is needed to determine whether these analytes could be used to screen pregnancies for fetal chromosome abnormalities after first-trimester multifetal reduction.