Pregnancy nutritional indices and birth weight after Roux-en-Y gastric bypass

Maternal metabolic profile and nutritional course of pregnancy after bariatric interventions is incompletely known. Their impact on birth weight has also not been hitherto addressed. Aiming to document such variables, a retrospective study was undertaken.

Women previously submitted to silastic ring Roux-en-Y gastric bypass, who conceived after 0-5 years (n = 14), were investigated. Intake of selected macro- and micronutrients, representative laboratory measurements, and correlation of these findings with birth weight and time to conception was documented.

Mean calorie intake was restricted to about 1,800 kcal/day. Protein (71 +/- 17 g/day) and supplementary iron (60 mg/day) were barely adequate, and calcium and vitamin B(12) did not meet current recommendations, only folic acid being optimal. Biochemical monitoring reflected these inconsistencies, with occasional low values for serum albumin (4.1 +/- 0.4 g/dL), hemoglobin (11.4 +/- 1.5 g/dL), iron (78 +/- 50 mug/dL) and vitamin B(12) (193 +/- 102 pg/mL) but not folate. Lipids, glucose, and uric acid were much better than before the anti-obesity intervention. Reduced plasma lipids, glucose, and uric acid were associated with larger birth weight, albeit within the normal range.

(1) Anemia as well as additional nutritional deficits during pregnancy were not totally eliminated, despite dietary guidance and micronutrient supplementation; (2) alleviation of metabolic comorbidities was demonstrated, and improved normalization predicted higher birth weight; (3) energy and folate intake was sufficient, but other nutrients probably did not reach ideal levels; (4) recent dietary guidelines for this population represent a step forward, but additional studies are needed.