Pregnancy after weight loss surgery

Obesity is increasingly prevalent in Australia, particularly in women of childbearing age. Unfortunately, obesity has a negative impact on fertility, and future pregnancies were important to 30% of women planning to have bariatric surgery in one survey. Bariatric surgery generally leads to more than a 20% loss of total body weight, which is enough to eliminate PCOS, diabetes and hypertension. This type of surgery has also been shown to improve fertility and pregnancy-related outcomes for mother and baby. 

Bariatric surgery is surgery that affects the stomach and how food is digested. There are various types of bariatric surgery available in Australia, including lap band surgery (also called gastric banding or AGB – adjustable gastric band), gastric bypass (also called Roux-en-Y gastric bypass or RYGB) and gastric sleeve surgery (also known as sleeve gastrectomy). 

It is believed weight loss has a beneficial influence on the regulation of menstrual cycles, increasing ovulatory capacity and improving fertility in overweight or obese women who aren’t experiencing a cycle. However, there are a few things to be aware of if you’re planning a pregnancy after bariatric surgery due to the impact of the surgery on nutrient absorption.

Pregnancy planning after bariatric surgery

Bariatric surgery can lead to multiple nutritional deficiencies due to changes in gastric pH levels, dumping syndrome (a condition in which food moves too quickly from your stomach to your duodenum) and reduced absorption. The absorption changes after bariatric surgery can be seen for at least 5 years post-surgery, which can present challenges for preconception and pregnancy care when nutritional demands are higher. The key nutrients to be aware of include protein, carbohydrates, iron, vitamin B12, zinc, copper, selenium, vitamin D, vitamin E, vitamin K and folate. Liver function also needs to be monitored in the preconception period. Ideally, preconception care should begin 3-6 months prior to conception for those who have had bariatric surgery, to address these nutritional deficiencies before the demands of pregnancy.

A clinical practice guideline by the American Association of Clinical Endocrinology (AACE), The Obesity Society (TOS) and the ASMBS recommends that pregnancy be delayed by 12 to 18 months after bariatric surgery. This is due to the rapid and significant weight loss expected after bariatric surgery, and there is some evidence (although limited) that nutritional deficiencies in this period may lead to adverse pregnancy outcomes. However, this delay can be problematic for those who are either older or have experienced infertility, in which case, it may be preferable to conceive in a shorter period of time. The risks in this case are manageable

Recommendations when planning a pregnancy after bariatric surgery include:

What to expect in pregnancy after bariatric surgery

One of the biggest concerns in pregnancy and the postpartum period after bariatric surgery is meeting your nutritional requirements. You can expect a few more blood tests to keep an eye on your nutritional status during your pregnancy! You may also need to take some additional supplements, like a multivitamin or multi-mineral supplement, alongside your prenatal supplement to overcome the reduced absorption. This is also something to be aware of if you plan on breastfeeding.

You will need to be aware of pregancy symptoms such as abdominal pain, nausea and vomiting, which can also be signs of complications of bariatric surgery. The main sugical complications to be aware of in pregnancy are internal herniation following RYGB and gastric band slippage following AGB. The most frequent symptoms of internal herniation are upper abdominal pain, nausea and vomiting, which can easily be mistaken for early pregnancy symptoms. 

Some bariatric procedures, like RYGB and gastric sleeve surgery, cause an exaggerated increase in blood glucose levels after eating, followed by high insulin levels and low blood glucose levels. Due to this altered glycemic control, the standard test for gestational diabetes (the 2-hour 75g oral glucose tolerance test) isn’t appropriate for those who have had RYGB and gastric sleeve surgery. Alternative tests such as regular HbA1c or at-home glucose monitoring may be more appropriate. It’s important your healthcare providers are aware you’ve previously had bariatric surgery to manage this effectively.

There is no requirement for additional ultrasounds due to previous bariatric surgery unless your healthcare provider has concerns for your baby. In a pregnancy after bariatric surgery, your little one is at an increased risk of being small for gestational age or having a low birth weight. Low birth weight appears to have a long-term effect on the offspring, increasing their risk of developing insulin resistance and type 2 diabetes, metabolic syndrome and cardiovascular diseases in adulthood. This is believed to be due to the epigenetic changes that happen in the womb of malnourished mothers, highlighting the importance of meeting the nutritional requirements of pregnancy.

The relationship between obesity and mental health is bidirectional and deserves special attention during pregnancy. Many people who have experienced obesity have also experienced weight bias and stigmatisation from health care professionals. For some people, the necessary weight gain associated with pregnancy can be triggering. It is important to have appropriate support in place, like a psychologist, you can talk to. 

How to manage a pregnancy after bariatric surgery

Building a team around you of people who you trust and can rely on, and who are aware of your previous surgery, is important to ensure you’re supported through your pregnancy. This may include a clinical nutritionist, psychologist, midwife, OB/GYN and GP. 

Working with a clinical nutritionist before, during and after your pregnancy will assist in making sure you’re meeting all your nutritional requirements, consuming adequate energy and protein, gaining appropriate weight and monitoring any symptoms that might come up. 

If you’re interested in taking any supplements, please discuss this with your practitioner to ensure you’re taking the correct dose and form for you. This article is not intended to be medical advice and is purely for education purposes.