As the prevalence of adult obesity increases in the world, physicians are more often caring for patients who have undergone or who are considering bariatric surgery. Counseling and treating women who become pregnant after bariatric surgery present unique challenges. Although outcomes are generally good, nutritional and surgical complications can arise.
Obesity is associated with reduced fertility, primarily because of oligo-ovulation and anovulation. In women who become pregnant, obesity confers increased risks of gestational diabetes mellitus, preeclampsia, cesarean delivery, and infectious morbidity. Operative morbidity is also increased, and obese women are less likely to have successful vaginal birth after a previous cesarean delivery.
Bariatric surgery is one option for weight loss in patients with a body mass index (BMI) of at least 40 kg per m2, or in those with a BMI of at least 35 kg per m2 who have comorbidities.
Management in preparation for and after bariatric surgery, the approach during pregnancy should continue to be multidisciplinary with an emphasis on consultations from the nutritionist and surgeon. Patient education regarding nutrition and clinical management to prevent and detect nutritional deficiencies is key. Furthermore, bariatric surgery is not a guarantee for weight loss, so many of these patients continue to require medical care for comorbidities.
There are several case reports of unexpected vitamin deficiencies and adverse pregnancy outcomes. For these reasons, ensuring appropriate maternal nutrition before and after delivery takes precedence in prenatal care. The etiology for deficiencies vary from decreased intake of certain foods due to intolerance, decreased gastric acid, and duodenal exclusion. Folic acid deficiency can occur as a result of decreased gastric production of hydrochloric acid which ordinarily allows for absorption of folic acid in the upper third of the intestine.
There is no standard approach to screening and treating deficiencies during a pregnancy after bariatric surgery
For the non-pregnant population, at least 60g of protein daily are required. The recommendations also state that a daily long-term vitamin and mineral supplement be considered, with malabsorptive procedures (RYGB, gastric sleeve, BPD) requiring more replacement. Furthermore, according to best practice guidelines, a daily multivitamin and calcium with vitamin D is recommended for all bariatric surgery patients. Calcium carbonate is available in chewable forms but should be taken with meals to enhance absorption. Calcium citrate preparations are preferred in bariatric surgery patients because they are better absorbed when gastric acid production is diminished. Iron deficiency is thought to increase over time with >50% of patients having low ferritin levels several years after bariatric surgery. It is also more common in women with menorrhagia. As such, empiric iron supplementation is recommended.
Periodic clinical and biochemical monitoring is recommended after malabsorptive types of bariatric surgery even if patients tolerate their diet well without vomiting or diarrhea. This is so that subclinical nutritional deficiencies can be detected prior to the development of overt deficiencies. Testing includes a complete blood count, glucose, electrolytes, and creatinine every 3 months for the first year after surgery and tests for nutritional deficiencies (albumin, iron, vitamin B12, folate, calcium, and vitamin D) every 6 months in the first year and then repeated yearly. Restrictive procedures such as the AGB may also require testing and supplementation if there is decreased intake or poor tolerance to certain foods or food groups. In pregnancy, one option is to perform these tests once a trimester if the levels are normal. Abnormal levels or persistent deficiencies despite supplementation would require additional testing and management in consultation with the bariatric surgery team.
One of the routine recommendations after bariatric surgery is to minimize or eliminate the intake of simple carbohydrate-dense foods and beverages after RYGB as these can precipitate dumping syndrome. It is thought that these symptoms occur as a result of gut peptides released when food bypasses the stomach and enters the small intestine directly. As such, an alternative method to the 50g glucola for gestational diabetes screening is recommended.
For pregnancies after AGB, one of the issues that arise is how to manage the band. Common practice is to deflate the band either prior to or early in the pregnancy to lessen complications such as band migration and nausea and vomiting in pregnancy. Some groups do not routinely release the band except when complications develop such as vomiting or lack of weight gain. In these cases, it is common for the practice to be individualized and performed in consultation with a bariatric surgeon.
The literature continues to describe case reports of surgical complications during pregnancies after bariatric surgery including adhesions, internal hernias, small intestine ischemia, and band slippage. Unfortunately there are no preventive measures to avoid these complications and they are known to occur in a small percentage of patients after bariatric surgery. Two maternal deaths, attributed to a delay in diagnosis and management of complications, have been reported. As such, early recognition and treatment is key. Abdominal pain in a bariatric surgery patient is considered an emergent condition, regardless of a pregnancy. Other common complaints during pregnancy such as nausea and vomiting should be carefully evaluated.
At the end of
Pregnancy outcomes after bariatric surgery tend to approach those of the general obstetrical population. Special considerations are necessary in the management of a pregnancy after bariatric surgery. Further research should consider a greater role for bariatric surgery in improved pregnancy outcomes along with the long-term impact on offspring.