Association of Amniotic Fluid Volume and Fetal Cardiac and Cerebrovascular Parameters in Fetal Growth Restriction

Objectives-To investigate the prevalence of oligohydramnios, brain sparing, and cardiac dysfunction among a cohort of fetal growth restriction (FGR). Methods-To assess the prevalence of oligohydramnios amongst a large sample of FGR fetuses, we screened a database of ultrasounds of FGR pregnancies from our maternal-fetal medicine clinics (clinical cohort) for diminished amniotic fluid volume. Using a threshold of a maximum vertical pocket (MVP) of <2 cm for "oligohydramnios," and 2 to 3 cm as a "reduced fluid" group, trends of Doppler values and cardiac parameters were assessed from pregnancies in an ongoing research study (comprehensive cohort). Results-In the clinical cohort, oligohydramnios was identified in only 2/229 (0.8%) and reduced fluid in 19/229 (8%). In the comprehensive cohort, oligohydramnios was seen in 3/126 (2.3%) and reduced fluid in 14/126 (11.1%). A high rate of cardiac and Doppler abnormalities were observed in the oligohydramnios group of the comprehensive cohort. The patients with oligohydramnios had a distinctly different cardiac phenotype with small (2/3 with cardiac area <5th%) (P = 0.01) and round (3/3 with global sphericity index <5th%) (P = 0.02) hearts. Conclusion-Oligohydramnios, when present with FGR, is accompanied by high rates of cerebral and cardiovascular abnormalities.