Mother and Offspring's Nutritional Status -Pregnancy After Maternal Bariatric Surgery

The Maternal Outcomes after Bariatric Surgery (MOBS) study is a prospective, multicenter observational cohort study investigating maternal nutritional status, glucose regulation, gestational weight gain, pregnancy complications, and neonatal outcomes following bariatric surgery.

The study aims to include 210 pregnant women, comprising 70 women with previous bariatric surgery (Roux-en-Y gastric bypass or sleeve gastrectomy) and 140 pregnant women without previous bariatric surgery who had a prepregnancy body mass index (BMI) ≥25 kg/m².

Participants are recruited before gestational week 19 and followed throughout pregnancy and up to 12 weeks postpartum. Data are collected at several study visits during pregnancy and after delivery.

Maternal assessments include dietary intake, nutritional supplement use, anthropometric measurements, body composition assessed by bioelectrical impedance analysis (BIA), blood pressure, and biochemical markers of nutritional status. Dietary intake is assessed using food frequency questionnaires and 24-hour dietary recalls. Blood and urine samples are collected to assess vitamin and mineral status and other relevant biochemical parameters.

Continuous glucose monitoring (CGM) is performed for approximately 15 days during mid-pregnancy to assess glucose patterns, glycemic variability, and episodes of hypoglycemia.

Information on maternal health, pregnancy complications, gestational diabetes, hypertensive disorders of pregnancy, and delivery outcomes is obtained from questionnaires and medical records.

Neonatal assessments include birth weight, length, and biochemical markers of nutritional status measured in samples collected at birth.

The study will compare maternal and neonatal outcomes between women with and without previous bariatric surgery. Associations between nutritional status, dietary intake, glucose regulation, gestational weight gain, and pregnancy outcomes will also be investigated. Among women with previous bariatric surgery, the potential association between time since surgery and pregnancy outcomes will be explored.

The findings are expected to contribute to improved nutritional monitoring and clinical follow-up of women during pregnancy after bariatric surgery.

• Post-Bariatric Maternal and Infant Health Study (Other): Comprehensive Nutritional and Pregnancy Monitoring in Women Following Bariatric Surgery This intervention involves systematic monitoring of nutritional status, gestational weight gain, and pregnancy outcomes in women who have undergone bariatric surgery (Roux-en-Y gastric bypass or sleeve gastrectomy). It includes blood and urine sampling, dietary assessments, body composition analysis, and continuous glucose monitoring throughout pregnancy and postpartum. The study also includes matched control groups of non-operated pregnant women and their newborns.
• Observation arm (Other): Comparing antropometri and Blood sampels between groups

Primary outcomes

• Maternal Iron status [At four time points: ≤19 weeks of gestation, 24-26 weeks of gestation, 30-34 weeks of gestation, and 6-12 weeks postpartum.]: Ferritin (µg/L)
• Maternal gestational weight gain following bariatric surgery, compared with non-operated controls. [2.th, 3.th trimester and 6 weeks postpartum]: Changes in maternal weight (kg) at the different timpoints

Secondary outcomes

• Newborn birth weight [at birth]: Birth weight (g)
• Birth length [at birth]: Length (cm)
• Vitamin B12 concentration in neonatal cord blood [at birth]: Vitamin B12 concentration (pmol/L) in cord blood from newborns of mothers with previous bariatric surgery compared with newborns of mothers without previous bariatric surgery.

Sex: Female, ages: 18 Years to 45 Years

Inclusion Criteria:

* pregnant
* sufficient understanding of the Norwegian or Scandinavian language
* written informed consent

Exclusion Criteria:

* multiple gestations,
* pre-pregnancy BMI < 18.5 kg/m2
* insulin treated diabetes mellitus
* termination of pregnancy before 14 weeks (spontaneously or induced)
* anorexia
* bullemia