Patterns of use and optimal timing of antenatal corticosteroids in twin compared with singleton pregnancies

Previous reports have shown that suboptimal antenatal corticosteroids administration occurs in most cases. However, as multifetal gestations were either excluded or constituted a small proportion of the participants in these studies, little is known about the patterns of use of antenatal corticosteroids in twin pregnancies.

We reviewed the records of women who received antenatal corticosteroids and delivered between 24^0/7 and 34^6/7 weeks of gestation during 2015-2017 at 2 university hospitals. Optimal antenatal corticosteroids timing was defined as delivery ≥24 hours ≤7 days from the previous antenatal corticosteroids course.

Of 424 pregnancies, 307 (72.4%) were singleton and 117 were (27.6%) twin. For twin compared with singleton pregnancies, gestational age at initial antenatal corticosteroids administration was lower (P = 0.02), the proportion of deliveries within the optimal window of the initial antenatal corticosteroids course was lower (19.7% vs 33.2%, P = 0.001), and the proportion of women eligible for a rescue antenatal corticosteroids course was higher (58.1% vs 32.9%, P < 0.0001). However, despite similar rates of rescue antenatal corticosteroids administration (P = 0.64), the overall rate of delivery within any optimal window (either initial or rescue course) was lower in twin than singleton pregnancies (26.5% vs 42.3%, P = 0.004), and the antenatal corticosteroids-to-delivery interval was longer (median 6.9 vs 4.2 days, P = 0.0009). In multivariate analysis, optimal antenatal corticosteroids administration was negatively associated with twin pregnancy (P = 0.04) and preterm labor (P = 0.05), and positively associated with the presence of gestational hypertensive disorders (P = 0.03).

Twin pregnancy is an independent risk factor for suboptimal antenatal corticosteroids administration. Directed efforts should be made to improve the utilization of antenatal corticosteroids in this vulnerable group of women.