(912) Neonatal Respiratory Morbidity in Pregnancies with Great Obstetrical Syndromes at Risk for Preterm Delivery

Objective:
The Great Obstetrical Syndromes (GOS) are designated as specific pregnancy complications (pre-eclampsia, spontaneous preterm labor or PPROM, IUGR, placental abruption, and stillbirth) that stem from failure to achieve deep placentation. This adverse environment leads to increased placental glucocorticoids, which may promote fetal lung maturity. We assessed whether neonatal respiratory morbidity (NRM) in late preterm pregnancies with GOS was different to those without GOS, and whether betamethasone (BMZ) mitigated the effect.

Study Design:
Secondary analysis of a multicenter, randomized controlled trial that assessed BMZ in non-anomalous singleton gestations 34w0d – 36w5d at risk for preterm birth. Individuals with likelihood of utero-placental pathology, but not designated as GOS (chronic hypertension, gestational diabetes and gestational hypertension) were excluded. The remaining participants were divided into 2 groups: GOS (defined above) and non-GOS (all others at risk for late preterm delivery). The primary outcome, a composite neonatal respiratory outcome (defined in table 1), and other respiratory outcomes were compared between groups. Logistic regression models adjusted for confounders.

Results:
Of 2497 participants, 2009 (80.5%) were affected by GOS and 488 (19.5%) were unaffected. GOS pregnancies were more likely nulliparous, while non-GOS pregnancies were more likely > 35 years old and had a previous liveborn with NRM. The primary outcome was significantly less frequent in the GOS group (11.9% vs 17.0%, p < 0.01), as was major respiratory morbidity (MRM) (8.8% vs 13.6%, p < 0.01, table 1), despite GOS pregnancies having a slightly lower GA at delivery (table 2). These findings remained significant after adjusting for confounders (table 1), and BMZ decreased the risk of the primary outcome (OR 0.79, 90% CI 0.62, 1.00) and MRM (OR 0.67, 95% CI 0.51, 0.88).

Conclusion:

Neonates from GOS pregnancies were less likely to have NRM compared to those from non-GOS pregnancies. Nonetheless, BMZ administration further mitigated this risk.