RESUMEN
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 (<0.8 nmol/l). Mean vitamin K1 levels were significantly lower in the surgical group compared to the nonsurgical control group (.44 versus .64 nmol/l; P = .016). PT (%) remained in the normal range, The surgery group showed a higher mean PT compared to the controls (111.3 versus 98.9%; P<.001) Mean K1 serum levels in the study group were higher during the third than during the first trimester (P = .014). PT (%) was significantly higher during the second and third than during the first trimester (P = .004). Most of the coagulation factors, including II, V, VII, IX, and X, remained within normal ranges. CONCLUSION: Low circulating K1 appears to be common in pregnant women with and without bariatric surgery. Supplementation during pregnancy can restore vitamin K1 in women with bariatric surgery, potentially protecting the fetus and newborn against intracranial hemorrhage.