School Performance After Maintenance Tocolysis With Nifedipine for Threatened Preterm Birth: 12-Year Follow-Up of the APOSTEL 2 Trial

Objective: To evaluate school performance at 12 years of age in children prenatally exposed to maintenance tocolysis with nifedipine versus placebo. Design: 12-year follow-up of the multicentre APOSTEL 2 trial, in which participants with threatened preterm birth between 26+0 and 32+2 weeks of gestation, who remained pregnant after initial 48-h tocolysis, were randomised to nifedipine maintenance tocolysis or placebo for up to 12 days. Setting: The APOSTEL 2 trial was conducted in 11 Dutch hospitals from 2008 to 2010. School outcomes were assessed at age 12. Participants: Children from singleton and multiple pregnancies born to APOSTEL 2 participants. Methods: School performance data were received through linkage with a national registry (Statistics Netherlands). Main Outcome Measures: A high track recommendation for secondary school, adjusted for maternal education level, socioeconomic status, and child's biological sex. Results: Of 492 eligible children, 357 were included (follow-up rate 73%). In the nifedipine group, significantly fewer children received a high track recommendation for secondary school, 67/189 (35.4%), compared to 74/168 (44.0%) in the placebo group (adjusted risk ratio (aRR) 0.76; 95% confidence interval (CI) 0.61–0.95). Outcomes were significantly poorer in children with the longest nifedipine exposure (9–14 days) compared to those not exposed (aRR 0.58; 95% CI 0.41–0.83). Conclusions: Children prenatally exposed to maintenance tocolysis with nifedipine had significantly poorer school performance at 12 years of age compared to those exposed to placebo. These findings further discourage nifedipine's use for maintenance tocolysis, and more research is warranted regarding its long-term effects on child development.