Fertility hub

Pregnancy and Weight Loss Surgery

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Studies show that more than 80% of weight loss surgery procedures are on females, and more than half of those are on women in reproductive age women (1). We think both proportions are even higher among private patients. It’s reasonable therefore to think that about 60% of private weight loss procedures are for women of reproductive age. Certainly, that is our own experience at Healthier Weight. For many of our patients, losing weight to start or grow their family is one of the main reasons for going ahead. The link between obesity and lower fertility is well established. We know from numerous studies that obesity reduces ovulation and responsiveness to fertility treatment. This is one of the reasons the NHS uses BMI in its selection process for fertility treatment. Put simply, it is less effective in patients with a  higher BMI. While not directly relevant to this article it should also be noted that obese men are less fertile.

As well as those women who want to lose weight to become pregnant there are those who, after weight loss surgery, are exposed to an increased risk of an unplanned pregnancy due to their increased fertility. This increase is almost immediate and needs to be planned for. Often women who were not having normal periods before surgery will resume them within 3-4 months (2).

It’s also important to note that your family planning intentions will be a factor in which procedure is best for you; eg. band, sleeve or bypass. The optimal procedure will depend on your personal situation and your surgeon will discuss this with you at consultation.

5 Point Guide to Contraception and Pregnancy After Weight Loss Surgery

1. Weight Loss Surgery Can Increase Fertility 

Multiple studies show that obese women who have weight loss surgery significantly increase their fertility and thus their chances of becoming pregnant. In one study 15 of 32 women who were unable to conceive before weight loss surgery became pregnant afterwards(3). If you are obese and struggling to start or grow your family, surgery could be a good option for you. Weight loss surgery can improve fertility and reproductive outcomes in obese women according to a Scientific Impact Paper (SIP) published by the Royal College of Obstetricians and Gynaecologists (RCOG)(4).

2. Plan for Pregnancy Before Surgery

Fertility usually increases very soon after weight loss surgery so pregnancy planning and contraception should be considered beforehand to reduce the risk of unplanned pregnancy. Oral contraceptives may be less effective for those who have undergone malabsorptive procedures such as gastric bypass. Alternatives would need to be discussed with your GP in this situation or discussed in the pre-pregnancy clinic in the hospital.

3. Delay Your Attempts to Conceive After Weight Loss Surgery

Delay your attempts to conceive for a period after your weight loss surgery. We suggest a delay of at least 12 months from the date of weight loss surgery before trying to conceive. Studies show that after this period there has been an opportunity for weight and nutrition to stabilise after the period of weight loss. This period may change depending on the rate of weight loss and type of procedure. Some studies show that a period of fewer than 24 months from the date of weight loss surgery to birth can result in higher rates of prematurity, neonatal intensive care treatment and small for gestational age status, than for those with periods above 24 months. There is conflicting data however that says the period doesn’t make a difference1. On balance we favour the view that a 24 month+ gap is better if possible. IMPORTANT – Women who conceive within 24 months need not be concerned. They should, however, refer to their GP or Obstetrician to ensure nutrition is optimised and monitored during pregnancy.

4. Higher Success Rate for IVF and Other Assisted Conceptions

Weight loss surgery is also associated with higher success rates of assisted conception, including IVF. In pregnancy, most research has shown improved maternal and infant outcomes in women who have had weight loss surgery compared with similarly obese women or previous pregnancies in the same women. This includes a reduced risk of miscarriage, gestational diabetes, hypertension, macrosomia (large baby) and congenital abnormalities.

5. Tell Your GP About Your Weight Loss Surgery

When you fall pregnant after weight loss surgery it is important to disclose that you have had surgery to your GP and/or Obstetrician. It is also important to disclose the type of procedure that was done as this will influence the prevention and management of potential complications and reproductive issues. 

I see a lot of fertility patients with raised BMI and there is a lot of evidence of increased success rate of IVF with optimal BMI."

Mrs Singh has her NHS practice based at Birmingham Women`s Hospital in Edgbaston, Birmingham where she is the Deputy Clinical Director of Gynecology. 

The studies we have drawn from in preparing this information include patients who have had all of the various forms of weight loss surgery, including band, sleeve, bypass, VBG and some of the more obscure. There are pros and cons of each of the procedures where pregnancy is concerned, and more generally. These will be discussed in detail with you at your surgeon consultation when you are exploring the form of weight loss surgery that best meets your needs. 

If you would like to understand more about weight loss surgery to increase your fertility, please contact our team to arrange a free of charge consultation with one of our surgeons. 

Useful Links:


  1. David Ouyang MD, Fertility and Pregnancy after Bariatric Surgery, December 2018. Up to Date Literature Review
  2. Eid GM et al Effective Treatment of Polycystic Ovarian Syndrome With Roux en Y Gastric Bypass. Surg Obes Rel Disease 2005, 1:77
  3. Marceua et al Outcomes of Pregnancies after biliopancreatic diversion Obes Surgery 2004; 14-318
  4. Royal College of Obstetricians and Gynaecologists. Scientific Impact Paper #17. The role of Bariatric Surgery in Improving Reproductive Health. October 2015. https://www.rcog.org.uk/globalassets/documents/guidelines/scientific-impact-papers/sip_17.pdf 
Picture of Rishi Singhal

Rishi Singhal

Rishi is an expert bariatric surgeon based in the West Midlands and also Medical Director at Healthier Weight

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