Influence of Roux-en-Y Gastric Bypass on the Nutritional Status of Vitamin A in Pregnant Women: a Comparative Study

Objective The objective of the present study is to evaluate the nutritional status of vitamin A through biochemical and functional indicators of pregnant women who underwent Roux-en-Y gastric bypass (RYGB) surgery compared to pregnant women who did not undergo this surgery. Methods The present study is a cross-sectional study of the analytical type with pregnant women paired by age and prepregnancy body mass index (BMI). Group 1 (G1) comprised 80 pregnant women without previous submission to RYGB and group 2 (G2) by 40 pregnant women who previously underwent this surgery. We used high-performance liquid chromatography with UV detector for quantification of retinol and beta-carotene, and the functional evaluation of vitamin A deficiency (VAD) was performed through standardized interview validated for pregnant women. Results G1 mean age was 29.3 +/- 5.3 and 30.8 +/- 4.4 in G2. BMI mean prepregnancy found in G1 was 25.7 +/- 3.2 and 26.8 +/- 3.1 in G2, featuring overweight. Serum retinol and beta-carotene means were significantly higher in G1 (1.8 +/- 0.9; 87.4 +/- 62.2) compared to G2 (0.99 +/- 0.39; 22.7 +/- 18.0), respectively (p < 0.001). Regarding the functional indicator for evaluation of VAD, approximately 75.0 % of pregnant women in G2 showed night blindness and 20.0 % in G1, and the percentage of pregnant women with this functional impairment was significantly higher in G2 compared to G1 with p < 0.001. Conclusion Results show that pregnancy after RYGB can represent a high-risk situation for VAD. We recommend interdisciplinary monitoring added to the prenatal routine consultations and the conduction of studies addressed to the investigation of a safe and effective dose of oral supplementation of vitamin A to pregnant women undergoing RYGB.