Maternal outcomes of a cohort of pregnancies affected by non‐immune hydrops fetalis

Objective To describe the maternal outcomes of a prospective cohort of non‐immune hydrops fetalis (NIHF) pregnancies with negative standard‐of‐care evaluations. Methods This study was a secondary analysis of a prospective cohort study of NIHF pregnancies with negative work‐ups (infection, alloimmune anemia, fetomaternal hemorrhage, and chromosomal disorders). Outcomes were obstetric complications, including pre‐eclampsia, mirror syndrome, preterm birth, polyhydramnios, postpartum hemorrhage, and maternal mental health. Results Forty pregnancies were included. Four patients developed pre‐eclampsia (4/40, 10.0%); three occurred postpartum. None was diagnosed with mirror syndrome. Of the 31 continued pregnancies, 16 (51.6%) resulted in early fetal death or stillbirth and 15 (48.4%) resulted in live births. Of the 15 live births, 8 (53.3%) were delivered by primary cesarean delivery; 5 (62.5%) were for hydrops fetalis. Eleven live births (73.3%) were delivered preterm; 9 (81.8%) were indicated, most commonly for fetal indications (7/9, 77.8%). Polyhydramnios occurred in 14/40 (35.0%) cases. Where EBL was recorded (n=37), there were 5 (13.5%) cases of postpartum hemorrhage and an additional 3 (8.1%) had uterine atony without hemorrhage. Eighteen patients (18/40, 45.0%) had new‐onset or exacerbated depression or anxiety symptoms. Conclusion Our study identified several important adverse outcomes of pregnancies complicated by NIHF with negative standard‐of‐care evaluations, including a high rate of postpartum pre‐eclampsia and worsened mental health. We identified a higher rate of cesarean delivery and preterm birth, both primarily for fetal indications. We also observed the known relationship between polyhydramnios, hemorrhage, and atony, but noted that this risk included pregnancies concluding in dilation and evacuation. Counseling after a diagnosis of NIHF should include these adverse outcomes. Synopsis NIHF pregnancies have higher rates of postpartum pre‐eclampsia, mental health symptoms, medically‐indicated preterm birth, cesarean delivery for fetal hydrops, and postpartum hemorrhage.