Bariatric surgery can improve fertility, but there are nutritional complications to consider before becoming pregnant after weight loss surgery (WLS). We look at the potential complications and how you can navigate pregnancy safely after bariatric surgery.
Key takeaways
- It is generally recommended to avoid pregnancy for at least 12–24 months after bariatric surgery.
- Have nutritional labs done every trimester to screen for deficiencies.
- Several supplement recommendations change during pregnancy – always agree them with your bariatric team.
- Weight gain during pregnancy is expected and encouraged.
Fertility after WLS
While obesity is a well-known contributor to female infertility, studies have also shown that weight loss "can restore ovulatory cycles, allowing for spontaneous pregnancy" in obese patients with PCOS.1 Bariatric surgery has been proven to improve menstrual regulation and fertility2, but there are nutritional complications to consider before becoming pregnant after bariatric surgery.
Potential complications
Malnutrition and vitamin/mineral deficiencies are high-risk nutritional complications that can affect fetal growth. They are due to rapid weight loss and the inability to eat large portions of food (adequate nutrients) in the first year after bariatric surgery. It is generally recommended to avoid pregnancy for at least 12–24 months after bariatric surgery to avoid these risks.3 Optimal care for women who have bariatric surgery and plan to become pregnant includes "pre-conception counselling, optimisation of nutrition before, during and after pregnancy, and monitoring for complications".4
Recommendations for a safe pregnancy after WLS
In addition to following the ASMBS guidelines for nutritional supplementation after bariatric surgery, a few modifications are needed during pregnancy. It is recommended that pregnant women have nutritional labs done every trimester to screen for deficiencies. Always consult your bariatric team to make sure any modifications and recommendations are appropriate for you. The following are general guidelines:3,4
| Nutrient | General guideline in pregnancy |
|---|---|
| Energy and protein | Requirements are best determined by your bariatric team to ensure adequate gestational weight gain and optimal fetal development and growth. Generally, energy intake is increased by 200 kcal per day in the final three months of pregnancy. Protein: 1.2 g/kg of ideal body weight daily (minimum 60 g daily). |
| Folic acid | An additional 5,000 mcg daily from 2 months before conception and for the first 12 weeks of pregnancy. After the first 12 weeks, return to the standard ASMBS guideline of 400–800 mcg daily. |
| Calcium and vitamin D | Calcium: 1,500 mg daily, the upper end of the ASMBS guidelines for RNY and VSG. Vitamin D: in addition to the ASMBS guideline of 3,000 IU daily, extra vitamin D may be required if deficiencies exist. |
| Vitamin A | 5,000 IU daily; do not exceed 10,000 IU daily, as excess vitamin A can lead to fetal malformation. Choose vitamin A in the form of beta-carotene, as "a high intake of beta-carotene was not found to be associated with congenital defects".5 |
| Vitamin B12 | 1,000 mcg orally, daily. |
| Iron | At least 45–60 mg daily, up to 100 mg elemental iron daily, based on your individual needs. |
| Thiamine | Follow the ASMBS guideline of at least 12 mg daily, unless prolonged vomiting is experienced; in that case, take an additional 200–300 mg daily. |
| After BPD/DS | Get additional screening for the fat-soluble vitamins (A, D, E, K), as these are at higher risk of deficiency. |
Other considerations
- Weight gain: while weight gain can seem daunting after bariatric surgery, it is expected and encouraged during pregnancy. For women with a pre-pregnancy BMI of 25–29, the recommended total pregnancy weight gain is about 6–12 kg; with a pre-pregnancy BMI of 30 or higher, about 5–8 kg.3 While pregnant, your nutritional goals should promote healthy fetal growth, not weight loss.
- Gestational diabetes screening: dumping syndrome may be triggered by the oral glucose tolerance test used to test for gestational diabetes. While screening is recommended, "capillary blood glucose monitoring daily before and after meals for a week at 24 to 28 weeks' gestation [is] a safer alternative to the oral glucose tolerance test".6
Bottom line
While there are potential complications and risks to becoming pregnant after bariatric surgery, it can absolutely be done in a safe and healthy way. It is of the utmost importance to be open and honest with your bariatric and healthcare team before, during and after pregnancy, so they can guide you through a healthy pregnancy.
Sources
- Crosignani PG, Colombo M, Vegetti W, Somigliana E, Gessati A, Ragni G. Overweight and obese anovulatory patients with polycystic ovaries: parallel improvements in anthropometric indices, ovarian physiology and fertility rate induced by diet. Hum Reprod. 2003;18(9):1928-1932. doi:10.1093/humrep/deg367
- Moran LJ, Norman RJ. The effect of bariatric surgery on female reproductive function. J Clin Endocrinol Metab. 2012;97(12):4352–4354. doi:10.1210/jc.2012-3606
- Cummings S, Isom KA. Academy of Nutrition and Dietetics Pocket Guide to Bariatric Surgery. Academy of Nutrition and Dietetics, 2015.
- Slater C, et al. Nutrition in pregnancy following bariatric surgery. Nutrients. 2017;9(12):1338. doi:10.3390/nu9121338
- Bastos Maia S, et al. Vitamin A and pregnancy: a narrative review. Nutrients. 2019;11(3):681. doi:10.3390/nu11030681
- Adam S, Ammori B, Soran H, Syed AA. Pregnancy after bariatric surgery: screening for gestational diabetes. BMJ. 2017;356:j533.
This article is for general information only and does not replace personal medical advice. Always discuss your situation, blood test results and supplementation with your bariatric team or healthcare provider.