The Impact of Preconception Gastric Bypass Surgery on Maternal Micronutrient Status before and during Pregnancy: A Retrospective Cohort Study in the Netherlands between 2009 and 2019

Preconception maternal gastric bypass surgery and the impact on fetal growth parameters

BACKGROUND

Bariatric surgery is increasingly performed in women of reproductive age. As bariatric surgery will result in postoperative rapid catabolic weight loss which potentially leads to fetal malnutrition and directly related impaired intra-uterine growth, it is advised to postpone pregnancy for at least 12-18 months after surgery.

OBJECTIVES

To investigate the consequences of preconception gastric bypass surgery (pGB) on fetal growth parameters and maternal pregnancy outcome.

SETTING

Maasstad Hospital, The Netherlands, general hospital and Erasmus Medical Center, The Netherlands, university hospital.

METHODS

We included 97 pGB pregnancies (Maasstad hospital) and 440 non-bariatric pregnancies (Rotterdam Periconception cohort, Erasmus Medical Center). Longitudinal second and third trimester fetal growth parameters (head circumference, biparietal diameter, femur length, abdominal circumference, estimated fetal weight) were analyzed using linear mixed models, adjusting for covariates and possible confounders. Fetal growth and birthweight in pGB pregnancies were compared to non-bariatric pregnancies and Dutch reference curves. Maternal pregnancy outcome in the pGB group was compared to non-bariatric pregnancies.

RESULTS

All fetal growth parameters of pGB pregnancies were significantly decreased at 20 weeks' gestation (P < .001) and throughout the remaining part of pregnancy (P < .05) compared with non-bariatric pregnancies (crude and adjusted models). In our cohort, gestational weight gain was not significantly associated with birthweight corrected for gestational age. Birthweight was significantly lower in pGB pregnancies (estimate -241 grams [95% CI, -342.7 to -140.0]) with a 2-fold increased risk of small-for-gestational-age (SGA) (adjusted odds ratio 2.053 [95% CI, 1.058 to 3.872]). Compared to the non-bariatric pregnancies, we found no significant differences in maternal pregnancy outcome.

CONCLUSIONS

PGB is associated with overall reduced fetal growth trajectories and a 2-fold increased risk of SGA, without significant adverse consequences for maternal pregnancy outcome. We recommend close monitoring of fetal growth after pGB.

Nutritional Implications of Bariatric Surgery on Pregnancy Management-A Narrative Review of the Literature

One in three women of reproductive age is obese. The mainstay treatment for obesity is bariatric surgery, and the following weight reduction results in a decrease in pregnancy adverse effects, including gestational diabetes mellitus, pregnancy-induced hypertension, and macrosomia. However, nutritional and vitamin deficiencies due to changes in the gastrointestinal tract after bariatric surgery are associated with an increase in the risk of fetal growth retardation and small for gestational-age neonates. The purpose of this review was to analyze the available recent literature on the subject of the management of pregnancy after bariatric surgery. We searched for available articles from 2007 to 2023 and chose articles of the greatest scientific and clinical value. Micronutrient, vitamin, and protein supplementation is recommended in the prenatal period and throughout the pregnancy. It is advised that pregnant women with a history of bariatric surgery should be provided with regular specialist dietary care. There is still a lack of recommendations about the optimum gestational weight gain after different types of bariatric surgery and for patients of different metabolic statuses. Women of reproductive age undergoing bariatric procedures should be provided with appropriate counseling about adequate contraception, the recommended time-to-conception interval, and the positive and negative influence of bariatric surgery on perinatal outcomes.

Micronutrients in Pregnancy after Bariatric Surgery: A Narrative Review

Bariatric surgery is increasingly used in women of childbearing age due to the rising prevalence of obesity and the effectiveness and availability of this treatment. Pregnancy in women with previous bariatric surgery deserves special attention. Weight loss induced by surgery reduces the risks that obesity poses to pregnancy. But on the other hand, decreased intake and malabsorption may increase the risk of malnutrition and micronutrient deficiency and negatively affect maternal and foetal health. The aim of this narrative review is to provide an updated analysis of the impact of different bariatric surgery techniques on mineral and micronutrient nutritional status during pregnancy and the possible effect on maternal-foetal health.

Pre-Operative Assessment of Micronutrients, Amino Acids, Phospholipids and Oxidative Stress in Bariatric Surgery Candidates

Obesity has been linked to lower concentrations of fat-soluble micronutrients and higher concentrations of oxidative stress markers as well as an altered metabolism of branched chain amino acids and phospholipids. In the context of morbid obesity, the aim of this study was to investigate whether and to which extent plasma status of micronutrients, amino acids, phospholipids and oxidative stress differs between morbidly obese (n = 23) and non-obese patients (n = 13). In addition to plasma, malondialdehyde, retinol, cholesterol and triglycerides were assessed in visceral and subcutaneous adipose tissue in both groups. Plasma γ-tocopherol was significantly lower (p < 0.011) in the obese group while other fat-soluble micronutrients showed no statistically significant differences between both groups. Branched-chain amino acids (all p < 0.008) and lysine (p < 0.006) were significantly higher in morbidly obese patients compared to the control group. Malondialdehyde concentrations in both visceral (p < 0.016) and subcutaneous (p < 0.002) adipose tissue were significantly higher in the morbidly obese group while plasma markers of oxidative stress showed no significant differences between both groups. Significantly lower plasma concentrations of phosphatidylcholine, phosphatidylethanolamine, lyso-phosphatidylethanolamine (all p < 0.05) and their corresponding ether-linked analogs were observed, which were all reduced in obese participants compared to the control group. Pre-operative assessment of micronutrients in patients undergoing bariatric surgery is recommended for early identification of patients who might be at higher risk to develop a severe micronutrient deficiency post-surgery. Assessment of plasma BCAAs and phospholipids in obese patients might help to differentiate between metabolic healthy patients and those with metabolic disorders.