Impact of two dual active ingredient long-lasting insecticidal nets on pregnancy birth outcomes in Benin.

Background: The WHO recently recommended the widespread use of new classes of long-lasting insecticidal nets (LLINs) to control malaria, but there is little evidence of their efficacy in pregnant women. This study aimed to assess the impact of two dual active ingredient (AI) LLINs on poor birth outcomes under pragmatic conditions.

Methods: A community-based cross-sectional survey was conducted during March-May 2023 in 1644 women of reproductive age who delivered in the 3 y following net distribution. Multivariate logistic regression models with random effects were used to assess the dual AI LLINs effects on poor pregnancy birth outcomes.

Results: Poor birth outcomes prevalence during pregnancy was 21.9%. Dual AI LLINs did not provide protection against poor birth outcomes in comparison with standard LLINs. However, among women who reported using allocated study nets, the odds of poor pregnancy birth outcomes were reduced in the pyriproxyfen-pyrethroid LLIN (adjusted OR [aOR] 0.50, 95% CI 0.31 to 0.82) and chlorfenapyr-pyrethroid LLIN (aOR 0.67, 95% CI 0.43 to 1.04) groups.

Conclusion: Poor birth outcomes were similar for women living in the dual AI LLIN groups and those in the pyrethroid-only LLIN group, regardless of the type of net used. However, women using allocated dual AI LLINs were better protected than those using standard LLINs. National malaria control programmes should consider these new-generation LLINs for malaria control during pregnancy.