Third-trimester persistent maternal hypotension effects on late-onset small for gestational age and adverse perinatal outcomes

INTRODUCTION: The purpose of the current study was to examine whether third-trimester persistent maternal hypotension is related to small for gestational age (SGA) and adverse perinatal outcomes. METHODS: In this large retrospective cohort study, 6560 pregnant women were enrolled and divided into two groups according to maternal tension status: a normotensive group (n: 6290) and a persistent maternal hypotensive group (n: 270). Persistent maternal hypotension was defined as an SBP <100 mmHg and/or DBP <60 mmHg at three antenatal visits: visit 1 (26(0/7)–29(6/7) gestation weeks), visit 2 (30(0/7)–33(6/7) gestation weeks), and visit 3 (34(0/7)–36(6/7) gestation weeks). Following the Delphi consensus criteria, a fetal growth restriction diagnosis was employed. The presence of an SGA neonate was the primary outcome of the study. SGA was defined as fetal abdominal circumference below the 10th percentile or fetal birth weight below the 10th percentile in the absence of abnormal Doppler findings. The secondary outcomes were defined as the presence of other adverse perinatal outcomes. RESULTS: The baseline characteristics of the study population were similar. We found that SGA rates were 6.3% in the control group and 7.0% in the persistent maternal hypotension group, which were statistically similar. In the present study, the secondary outcomes which prematurity, low 5-min Apgar score, and NICU admission were similarly between groups. DISCUSSION: Our results indicate that third-trimester persistent hypotension is not associated with SGA neonates or adverse perinatal outcomes. Hence, it can be concluded that third-trimester persistent hypotension is a physiological phenomenon during pregnancy that should not cause anxiety in mothers.