The effects of oocyte donor and recipient body mass index on live birth rates and pregnancy outcomes following assisted reproduction

Abstract

ObjectiveTo investigate the effects of oocyte donor and recipient body mass index (BMI) on outcomes of vitrified donor oocyte assisted reproductive technology (ART).DesignRetrospective cohort study.SettingPrivate fertility center.Patient(s)A total of 338 oocyte donors and 932 recipients who underwent 1,651 embryo transfer cycles in 2008–2015.Intervention(s)Multivariable log binomial regression models with cluster-weighted generalized estimating equations were used to estimate the adjusted risk ratios.Main Outcome Measure(s)Live birth, defined as the delivery of at least one live-born infant, including all embryo transfer cycles. Secondary outcomes included birth weight and gestational length only among singleton live births.ResultsThe mean ± SD body mass indexes (BMIs) of donors and recipients were 22.6 ± 2.5 kg/m2 and 24.6 ± 4.8 kg/m2, respectively. There were no significant associations between donor BMI and probability of live birth. Recipients with BMI ≥35 kg/m2 had a significantly higher probability of live birth compared with normal-weight recipients. Among singleton live births, recipients with BMI <18.5 kg/m2 had a lower risk whereas women with BMI ≥35 kg/m2 had a higher risk of delivery in an earlier gestational week compared with normal weight women. Recipients with a BMI ≥35 kg/m2 also had a higher risk of having a low birth weight infant compared with normal-weight women.ConclusionsIn the setting of vitrified donor oocyte ART, recipient BMI was positively associated with probability of live birth but negatively associated with gestational length and birth weight among singleton births.