Impact of Roux-en-Y gastric bypass and sleeve gastrectomy on fetal growth and relationship with maternal nutritional status.

•Sleeve gastrectomy alters fetal growth as Roux-en-Y gastric bypass.•Sleeve gastrectomy induces as many maternal deficiencies as gastric bypass.•Decrease in maternal protein intake is associated with fetal growth restriction.•Increase in iron load is associated with fetal growth restriction.