Delayed pregnancy detection and return to fertility with extended levonorgestrel-containing oral contraceptives: A real world setting cohort study.
Sigal KaplanMonica L BertoiaAmir LassFlorence T WangAlison EvansSandeep DhandaDebabrata RoyJohn D SeegerPublished in: Pharmacoepidemiology and drug safety (2022)
. Differences in the fertility analysis may be related to unmeasured residual confounding.