The Effect of Plurality and Obesity on Betamethasone Concentrations in Women at Risk for Preterm Delivery

Abstract

Objective-Antenatal corticosteroids (ACS) decrease respiratory distress syndrome in singleton gestations. Twin data is less clear. Obesity and BMI also affect medication distribution volume. We evaluated whether maternal or neonatal cord betamethasone concentrations differed in twin gestations or in obese patients.Study Design-Participants receiving betamethasone in a randomized controlled trial of weekly ACS were identified. We analyzed maternal delivery and cord serum betamethasone concentrations comparing singletons with twins and obese (BMI≥30) with non-obese women.Results-55 maternal and 45 cord blood samples were available. Unadjusted median maternal serum concentrations appeared paradoxically higher in both twin gestations and the obese. However, after controlling for confounders, there were no differences in betamethasone concentrations in maternal serum or cord blood between singletons and twins (p=0.61 v. p=0.14) or non-obese and obese women (p=0.67 v. 0.12).Conclusion-Maternal and umbilical cord blood serum betamethasone concentrations are not different in twin gestations or obese women.

Pharmacokinetics and Pharmacodynamics of Intramuscular and Oral Betamethasone and Dexamethasone in Reproductive Age Women in India

“…In the present trial, the BetaP plus BetaA regimen caused even longer adrenal suppression. Our results showing sustained concentrations of Beta following BetaP plus BetaA are not unique but are underappreciated by the field …”

Fetal and neonatal outcomes after term and preterm delivery following betamethasone administration in twin pregnancies

“…The incidence of multiple pregnancies has been increasing in the past 4 decades [9,10], and twins are at increased risk of preterm birth, making administration of prenatal glucocorticoids more likely. However, the effect of glucocorticoids on prenatal lung maturation in multiple pregnancies remains unclear because trials in twins are limited and evidence is lacking [1,11–16].…”

Use of antenatal corticosteroids in special circumstances: a comprehensive review

“…Gyamfi et al. found that maternal and umbilical cord serum betamethasone concentrations at delivery were similar in singleton and twin gestations, suggesting that any decrease in effectiveness is not due to inadequate fetal drug levels. The most likely reason that twins have not demonstrated improvement following steroids is probably related to the small sample size of the randomized controlled trials, which gives them insufficient power to confirm a difference.…”

“…A large population‐based study examined RDS in singleton, twin, and triplet gestations exposed to corticosteroids with delivery at 24–32 weeks (Figure ). Corticosteroids reduced the risk of RDS in both twins and triplets but the benefit was less than with singletons.…”