Mendelian randomization study of maternal coffee consumption and its influence on birthweight, stillbirth, miscarriage, gestational age and pre-term birth
International Journal of Epidemiology
Title: Mendelian randomization study of maternal coffee consumption and its influence on birthweight, stillbirth, miscarriage, gestational age and pre-term birth
First author: Caroline Brito Nunes
Journal: International Journal of Epidemiology
Month, year: January 2023
Synopsis
This open-access original article uses Mendelian randomization to test whether maternal coffee consumption has a causal effect on miscarriage, stillbirth, gestational age, preterm birth, and birthweight. The authors performed two-sample MR using coffee-consumption GWAS instruments and outcome GWAS data, plus one-sample genetic risk score analyses in UK Biobank and ALSPAC. Across analyses, they found no evidence that higher genetically predicted coffee consumption increases risk of sporadic miscarriage, stillbirth, or preterm birth, and no clear effect on gestational age. They observed an inconsistent association suggesting higher coffee consumption might be linked to higher birthweight, but results varied by instrument set and were flagged as potentially influenced by pleiotropy. Observational associations in ALSPAC showing lower birthweight with higher coffee intake attenuated after adjusting for smoking and alcohol, supporting confounding as a key explanation. The authors conclude that any adverse causal effects, if present, are likely small.
