Pregnancy after Bariatric Surgery
Little is known about the impact of bariatric surgery weight loss on pregnancy rate but a meta-analysis of data from 589 infertile obese women indicates a 58% pregnancy rate after surgery . An obesity- fertility protocol study suggests that even a loss of 5%-10% body weight can restore ovulation  so contraceptive counseling needs to be considered for women of child bearing age. Pregnancy after bariatric surgery has complications in nutritional and gastrointestinal tract issues that need management by a multidisciplinary team that includes a nutritionist, obstetrician, anesthesiologist along with the bariatric surgeon .
Every pregnant woman needs an individual assessment of her nutritional status to identify preconception nutrition issues, medical history, previous reproductive performance, and economic status. Nutritional risk factors during the pregnancy of a bariatric surgery patient need to be outlined especially regarding adequate weight gain and anemia management.
During pregnancy, plasma proteins are diluted so serum albumin of 3.0 g/mL and a total protein value of 6.0 g/mL are considered normal. Blood glucose and glycohemoglobin levels should be monitored regularly to assess gestational diabetes . Anemia is the most common nutritional complication of pregnancy but minimum reports have been published on bariatric surgery cases with respect to this condition.
Gastric bypass surgery increases the risk of gastrointestinal complications during pregnancy with symptoms varying from abdominal pain to nausea and vomiting resulting from internal hernias created by the surgery . Pain is usually exacerbated by eating, which adds intraabdominal pressure as the uterus grows and places pressure on the intestines . As the uterus enlarges, the diaphragm
is elevated, which reduces lung capacity by 5% and residual volume by 20% . Kidneys increase slightly in length and weight during pregnancy, which increases glomerular filtration rate but may result in preeclampsia and higher excretion rates of glucose, amino acids, and water-soluble vitamins. Changes along the gastrointestinal tract require increased nutrient intake during pregnancy. Motility of the gut and increased levels of progesterone that reduce motilin may lead to gastric emptying time changes or symptoms of gastrointestinal distress , especially in bariatric surgery pregnancy cases.
Gastric banding is not a risk-free surgery for pregnancy according to Jacquemyn and Meesters . They report that a 20-week gestational age female reported to the emergency department with severe nausea and vomiting. Imaging studies were not done to avoid harming the fetus but the patient continued vomiting and fetal death was noted at 23 weeks. When symptoms did not resolve postdelivery, a computed tomography (CT) scan demonstrated gastric band slippage over the pylorus resulting in obstruction. Chevrot et al. discuss the complications from band slippage resulting in dysphagia with no fetal loss .
Pregnancy after bariatric surgery does reduce the risk of gestational diabetes and excessive fetal growth but an increased risk of small-for-gestational-age infant with an increased risk of mortality . Due to decreased food intake and variable degrees of malabsorption, newborns are at greater risk for neural defects due to folate malnutrition . Other adverse neonatal outcomes caused from maternal nutrient deficiencies are visual complications (vitamin A), intracranial hemorrhage (vitamin K1 or phylloquinone), neurological and developmental impairment (vitamin B12) . Vitamin A deficiency in pregnancy after Roux-en-Y Gastric Bypass (RYGB) can represent a high-risk situation and oral supplementation is recommended .
A multicenter study, including women with restrictive (lapband) or malabsorptive (gastric bypass) surgeries, reports that most nutrients were depleted and declined significantly during pregnancy. Throughout the first trimester, most women took a multivitamin and during the second- and third trimester, the majority took additional supplements to try to normalize low levels of nutrients .
Bariatric surgery malabsorption is associated with increased risk of fetal growth  but despite the low birth weight has resulted in adequate growth of these children born after the surgery .