Winn et al. profiled gene expression at the human maternal-fetal interface during five gestational age intervals: 14-16, 18-19, 21, 23-24, and 37-40 weeks. Basal plate biopsy specimens were obtained from placentas after second-trimester elective terminations of singleton pregnancies or normal nonlabored singleton pregnancies. Pregnancies complicated by fetal anomalies, hypertension, diabetes, or other significant maternal health issues were excluded.
||21 weeks pregnant
||18-19 weeks pregnant