Strengths and limitations
Strengths of our study include longitudinal plasma samples from preconception through pregnancy to 6 months postdelivery, an interventional component, a relatively large sample size, and inclusion of multiple ethnic groups. The robust conduct of this double-blind randomized controlled trial, which included prospectively collected data and minimization of residual confounding through randomization, with external oversight by an independent data monitoring and trial steering committee, is a strength. Over 96% of women showed good adherence defined 