Vitamin K1 monitoring in pregnancies after bariatric surgery: a prospective cohort study

Abstract Background Neonatal intracranial bleedings and birth defects have been reported, possibly related to maternal vitamin K1 deficiency during pregnancy after bariatric surgery. The objective of this study was to investigate the effects of screening and supplementation on K1 serum levels in pregnant women with bariatric surgery, and to compare K1 levels and prothrombin time (PT %) in the first trimester with pregnant women without bariatric surgery. Methods A prospective cohort study including 49 pregnant women with bariatric surgery. Nutritional deficiencies were prospectively screened. In case of observed low K1 serum levels, supplementation was provided. K1 serum levels and PT (%) during the first trimester were compared with a nonsurgical control group of 27 women. Results During the first trimester, most women had low K1 serum levels (