Tommy's PregnancyHub

Pregnant after weight-loss surgery

Most women who get pregnant after weight-loss surgery have an uncomplicated pregnancy and birth.

If you’ve had weight-loss surgery, it’s best to wait for at least 12 to 18 months after surgery and once your weight has stabilised to get pregnant. But many women have babies safely before 12 months.

Is pregnancy safe after weight-loss surgery?

Yes. Women with a higher BMI are more likely to have complications such as gestational diabeteshigh blood pressure and babies with larger birth weights. Weight loss after surgery can reduce these risks and help you have a safer pregnancy.

Talk to your care team

It’s important to talk to your care team as soon as you know you’re pregnant so you can get the best advice. This includes your midwife and your weight-loss surgery team. If you had your operation abroad, ask your GP if you need to be referred to a UK specialist weight loss surgery clinic. If you’ve already been discharged by your weight-loss surgery team you can ask your midwife about whether you should contact them again.

Your care should be based on the type of surgery you had and when you had your operation. If it was more than 18 months ago, you may just need to follow the usual pregnancy advice on healthy eating and exercise. If your surgery was less than 12 months ago, you will need more specific advice.

Early Contact

It’s important to talk to your care team as soon as you know you’re pregnant so you can get the best advice. This includes your midwife and your weight-loss surgery team.

Will my post-surgery diet be enough for me and my baby?

How you eat is probably different from before you had surgery. You may be used to taking vitamin and mineral supplements every day now. Talk to your weight loss surgery team about your diet and the supplements you’re taking. This will help you make sure you’re doing the right thing.

Your midwifery team also need to know what they’ve advised you to do, so don’t forget to tell them. You may also need some regular blood tests to keep an eye on the levels of nutrients in your body.

You may worry that if you eat less after surgery, you won’t be getting enough food to support your baby’s development. This is unlikely, because your baby takes what they need for growth from you. You do not need to eat any extra food in the first two trimesters of pregnancy. In the third trimester you may need to eat around 200 calories extra.

Talk to your weight loss team about anything that worries you and make sure you follow the advice they give you on healthy eating. They will be able to explain what amounts and types of foods are suitable at this time to give you enough nutrients for you and your baby.

Supplements needed in pregnancy for different types of surgery

You will need pregnancy-specific vitamin and mineral supplements after any type of weight loss surgery. Make sure you talk to your weight loss surgery team about your diet and the supplements you’re taking.

Gastric bypass

  • Pregnancy-specific vitamin and mineral supplements. You may also need vitamin D, calcium and possibly iron supplements
  • Your levels of Vitamin B12, iron (ferritin), calcium, folate and fat-soluble vitamins should be checked at the start of pregnancy.
  • You may need regular blood tests to check nutrient levels in each trimester. 

Gastric sleeve

  • You will need pregnancy-specific vitamin and mineral supplements.
  • Your levels of Vitamin B12, iron, calcium and folate and fat-soluble vitamins should be checked at the start of pregnancy.
  • You may need regular blood tests to check nutrient levels each trimester. 

Duodenal switch

  • You will need pregnancy-specific vitamin and mineral supplements. You may also need vitamin D, calcium and possibly iron supplements.
  • Your levels of Vitamin B12, iron, calcium, folate and fat-soluble vitamins should be checked at the start of pregnancy.
  • You may need regular blood tests to check nutrient levels each trimester. 
  • Your levels of vitamin A may need to be adjusted and monitored as too much vitamin A could hard your baby. Your levels of vitamin E and K may also need to be assessed.

Bilopancreatic Diversion (BPD)

  • You will need pregnancy-specific vitamin and mineral supplements. You may also need vitamin D, calcium and possibly iron supplements.
  • Your levels of Vitamin B12, iron, calcium, folate and fat-soluble vitamins should be checked at the start of pregnancy.
  • You may need regular blood tests to check nutrient levels each trimester. 
  • Your levels of vitamin A may need to be adjusted and monitored as too much vitamin A could hard your baby. Your levels of vitamin E and K may also need to be assessed.

Gastric band

  • You will need pregnancy-specific vitamin and mineral supplements.
  • Your levels of Vitamin B12, iron, calcium, folate and fat-soluble vitamins should be checked at the start of pregnancy.
  • Some surgery teams may suggest fluid is removed from your band while you’re pregnant.   

Folic acid 

All pregnant women are advised to take 400mcg of folic acid every day until they are 12 weeks pregnant. If you’ve had weight loss surgery you may need to take up to 5mg of folic acid. This isn’t available without a prescription, so talk to your weight-loss surgery and midwifery team to see if you need it.

Am I going to put all the weight back on?

This is unlikely, although during pregnancy it is likely that you may gain some weight. Your baby is growing and surrounded by amniotic fluid and placenta. Your body is producing more blood, your breasts are getting bigger, and so are your muscles and bone mass.

"I gained weight during pregnancy, but I soon lost it again after my daughter was born."

Sarah. Read more...

Weight gain is different for everyone during pregnancy, and it is something many women worry about, whether they had weight-loss surgery or not.

It’s natural to worry about your weight. Chat with your midwife and weight-loss surgery team about how you feel so they can support and advise you. Remember they are there to help.

Changes to your weight will depend on several factors, including:

How long it has been since your surgery

You may continue to lose weight if it hasn’t been long since your operation. If this is the case, ask your surgery or midwifery team for advice. If it has been 18 months or more since your surgery and your weight is now stable, you may need to look after your weight as you normally would during pregnancy.

The type of surgery you had

Some weight loss surgery teams may remove fluid from a gastric band if you’re pregnant, and you may gain weight as a result. This can be managed as normal through healthy eating and exercise.

"I worked so hard to lose weight that, although I was thrilled to be pregnant, I was also scared that my body would be out of control again. But I talked to the bariatric nurse and my GP and it’s been fine."

Tara, mum of one, 4 months post-birth

Pregnancy can cause weird and wonderful changes to your body. Many are perfectly normal but, following surgery, some symptoms should be checked out quickly with your surgery team to make sure all is well.

I feel sick

Although nausea and/or sickness in early pregnancy are common, vomiting in pregnancy following weight loss surgery should be checked out. If you are having regurgitation and vomiting due to food intolerance but you should discuss this with your weight loss surgery team.

I’m in pain

Any severe pain, particularly in the stomach, needs to be looked at.

I am losing weight very quickly

If you had your operation in the last 12 to 18 months, you may still be losing weight because of it. But if the weight loss is faster than expected, go back to your weight loss and midwifery teams for support, as you should not be actively losing weight during pregnancy.

If you have a BMI over 30, it is normal practice for you to be monitored more carefully by your midwifery team because there is a higher risk of pregnancy related complications, such as increased blood pressure, gestational diabetes and blood clots. You should get extra care and support to make sure that you have the healthiest pregnancy possible.

Glucose tolerance test (OGTT) after weight-loss surgery

Women with a BMI of over 30 are usually given a glucose tolerance test (OGTT or mini-GTT) to check for gestational diabetes. This involves having a sugary drink followed by blood tests to see how your body copes with the sugar.

If you had bypass surgery, you are not advised to have an OGTT as there is a risk of having a reaction called ‘dumping syndrome’. You must let your midwife and consultant know about your weight loss surgery and contact your surgery team for guidance on your situation and to arrange other types of testing or monitoring.

Find out more about being overweight in pregnancy.

Mechanick JI et al (2013) Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery. Obesity (Silver Spring), 2013. 21 Suppl 1: p. S1-27

Royal College of Obstetricians and Gynaecologists Why your weight matters during pregnancy and after birth (Page last reviewed: Nov 2011) www.rcog.org.uk/globalassets/documents/patients/patient-information-leaflets/pregnancy/pi-why-your-weight-matters-during-pregnancy-and-after-birth.pdf

Maggard MA et al (2008) Pregnancy and fertility following bariatric surgery: a systematic review. Jama, 2008. 300(19): p. 2286-96.

Kjaer MM et al (2013) The risk of adverse pregnancy outcome after bariatric surgery: a nationwide register-based matched cohort study. American Journal of Obstetrics and Gynecology, 2013. 208(6): p. 464.e1-5

NICE Guidelines (2010) Weight management before, during and after pregnancy National Institute for Health and Care Excellence https://www.nice.org.uk/guidance/ph27

Khan R et al (2013) Pregnancy outcome following bariatric surgery. The Obstetrician & Gynaecologist 2013;15:37–43.

British Obesity and Metabolic Surgery Society (2014) BOMSS Guidelines on peri-operative and postoperative biochemical monitoring and micronutrient replacement for patients undergoing bariatric surgery. 

American College of Obstetricians and Gyncologists (2009) ACOG practice bulletin no. 105: bariatric surgery and pregnancy. Obstet Gynecol, 2009. 113(6): p. 1405-13

Review dates
Reviewed: 15 November 2018
Next review: 15 November 2021

This content is currently being reviewed by our team. Updated information will be coming soon.