Maternal and fetal/neonatal outcomes in pregnancy, delivery and postpartum following bariatric surgery and comparison with pregnant women with obesity: a study protocol for a prospective cohort
Authors: Navaee Maryam , Kashanian Maryam , Kabir Ali , Zamaninour Negar , Chamari Maryam , Pazouki Abdolreza 
Published: October 2023

Abstract
Background:
Obesity is a risk factor for several pregnancy complications, like Gestational Diabetes Mellitus (GDM), pregnancy-induced hypertension (PIH), Pre-Eclampsia (PE), and Large Gestational Age (LGA) pregnancy. While bariatric surgery is an effective treatment for obesity, it can also lead to complications and may be associated with small for gestational age (SGA) fetuses. This protocol of a cohort study aims to assess the maternal and fetal/neonatal outcomes during pregnancy, labor, and postpartum in two groups of Iranian pregnant women: those with a history of bariatric surgery and those with obesity but no history of bariatric surgery.
Methods:
In this study Pregnant women (< 14 weeks’ gestation) (n = 38 per group) are recruited either from obesity clinic of Hazrat-e Rasool Hospital (exposure group =with a history of bariatric surgery) or primary healthcare clinics in Tehran city (comparison group=pregnant women with obesity and and no history of bariatric surgery). Dietary intake and nutrient status are assessed at <14, 28, and 36 weeks. Maternal and fetal/neonatal outcomes are compared between the two groups, including gestational diabetes, preeclampsia, preterm labor, intrauterine growth restriction, severe nausea and vomiting, abortion, placenta previa and abruption, venous thrombosis, vaginal bleeding, cesarean delivery, meconium aspiration, and respiratory distress. Maternal serum levels of ferritin, albumin, zinc, calcium, magnesium, selenium, copper, vitamins A, B9, B12, and 25-hydroxy Vit D are checked during 24th to 28th weeks. Maternal and neonatal outcomes, including height, weight, head circumference, fetal abnormality, infection, small or large fetus, low birth weight, macrosomia, NICU admission, and total weight gain during pregnancy, are measured at birth. Maternal and offspring outcomes, including weight, height, head circumference, total weight gain during pregnancy, newborn diseases, postpartum bleeding, breastfeeding, and related problems, are assessed 6 weeks after delivery. Child's weight, height, and head circumference are followed at 2, 4, 6, 8, 10, and 12 months after birth. Maternal stress, anxiety, and depression are assessed with the DASS-21 questionnaire, and physical activity is evaluated using the PPAQ questionnaire in the first and third trimesters.
Discussion:
By measuring the levels of micronutrients in the blood of pregnant women along with the evaluation of pregnancy outcomes, it is possible to find out more precisely the impact of bariatric surgery on the health or possible complications of the mother and the fetus/newborn. This information can help specialists and patients make more informed decisions about the surgery. Additionally, by examining issues such as stress, anxiety, and depression in women undergoing surgery, this study can contribute to recognizing these problems, which can also affect pregnancy outcomes.