Pregnancy after bariatric surgery

Bariatric surgery is an effective treatment option to reduce the risks of weight-related comorbidities and can provide additional benefits in terms of fertility and pregnancy outcomes in women of childbearing age.

However, it is recommended that you avoid pregnancy for at least 18 months after bariatric surgery as you will experience rapid weight loss during this period.

You are therefore at greater risk of nutritional deficiencies, which may cause complications for both you and your baby during pregnancy.

For this reason, you are recommended to use contraception during the first 18 months after surgery.

Oral contraception may not provide sufficient protection after bariatric surgery, particularly following malabsorptive procedures such as gastric bypass, as absorption may be reduced.

It is therefore recommended that you use an alternative method of contraception. Please discuss this with your GP or gynaecologist.

What happens if I become pregnant more than 18 months after surgery?

Speak to your GP about referral to an obstetrician at your local hospital. Your GP will need to inform the obstetrician of the importance of serial ultrasound examinations every 4–6 weeks to evaluate fetal growth from the 24th week of pregnancy, particularly if you have poor weight gain. There is a possible increased risk of intrauterine growth restriction (IUGR) and babies being small for gestational age (SGA) following bariatric surgery.
Contact the Bariatric Service immediately and tell them about your pregnancy so follow-up appointments can be arranged with the bariatric dietitians.
You will be invited to regular follow-up appointments with the bariatric dietitians at least once every trimester. This will help ensure you are eating the correct balance of nutrients and allow any nutritional deficiencies to be identified and treated at an early stage.
You will need regular nutritional blood tests at least once every trimester, either at the hospital or through your GP practice.

Nutrition during pregnancy

Managing nausea

Nausea and vomiting are common during pregnancy. Early management with dietary advice and/or clinically approved anti-emetics is recommended to help prevent or treat complications.

Dietary and behavioural changes that may help improve your nutritional intake when you feel nauseous include:

eating small, frequent meals
avoiding foods with strong odours
choosing cold food options
taking anti-emetics if prescribed by your GP
taking a short walk before meals
making a list of foods that particularly cause nausea and avoiding these for a period of time

Severe or prolonged nausea and vomiting may result in reduced nutritional intake, increased nutrient losses or poor nutrient absorption. This can increase the risk of thiamine deficiency. You may therefore need to take additional thiamine supplements.

If you are experiencing severe nausea and vomiting, please discuss this with your dietitian and/or doctor.

Healthy eating

It is important to eat a good variety of foods during pregnancy. Food groups include protein-rich foods, fruit and vegetables, dairy and dairy alternatives and starchy carbohydrates such as bread, rice, pasta and potatoes.
Continue to prioritise protein-containing foods such as chicken, red meat, fish, beans, lentils, tofu, soya, eggs, dairy and dairy alternatives.
Aim to fill half of your plate with protein-rich foods, with the remaining two quarters consisting of vegetables or salad and carbohydrates. Remember your daily protein requirement: 70–100g per day.
Choose healthy protein-rich snacks between meals, such as a handful of nuts, hummus with carrot sticks, low-fat cheese and crackers, a protein bar, high-protein yoghurt, a glass of skimmed or semi-skimmed milk, cooked chicken or ham slices, low-fat custard or rice pudding.
Avoid snacks high in fat and sugar to help prevent dumping syndrome symptoms and excessive weight gain.
Aim to drink at least 1.5–2 litres of fluid throughout the day. Avoid sugary and fizzy drinks and avoid alcohol.
If you feel nauseous and cannot manage a meal, try having a protein shake or high-protein yoghurt, as you may tolerate this better.
Continue to follow the Golden Rules: eat slowly, chew thoroughly, separate eating and drinking and stop eating when you feel full.
Continue to use your side plate and small cutlery.

Foods to avoid during pregnancy

Remember to follow pregnancy food safety guidance to reduce the risk of complications such as gastroenteritis and toxicity.

Food group	What you can eat	What to avoid
Cheese, milk and dairy	hard cheeses, such as cheddar and Parmesan pasteurised soft cheeses, such as mozzarella, feta, cream cheese and cottage cheese soft or blue cheeses cooked until steaming hot	mould-ripened soft cheeses, such as Brie and Camembert, unless cooked soft blue cheeses, such as Gorgonzola and Roquefort, unless cooked unpasteurised milk and dairy products
Meat and poultry	well-cooked meat and poultry with no pink meat or blood	raw or undercooked meat cold cured meats, such as salami and chorizo, unless thoroughly cooked liver and liver products, which are high in vitamin A
Eggs	British Lion eggs, either runny or cooked fully cooked eggs of all types foods containing raw eggs if made with British Lion eggs	raw or undercooked eggs that are not produced under the British Lion or Laid in Britain scheme
Fish and seafood	cooked fish and shellfish up to 2 portions of oily fish per week, such as salmon or mackerel up to 2 tuna steaks or 4 cans of tuna per week	raw shellfish cold-smoked or cured fish, such as smoked salmon, unless cooked excess tuna and oily fish due to mercury and pollutants
Caffeine	up to 200mg per day	more than 200mg per day
Alcohol	avoid completely	any alcohol
Fruit, vegetables and salads	all fruit and vegetables if thoroughly washed	unwashed produce because of the risk of infection from soil
Other foods	peanuts, unless you are allergic or have been advised otherwise liquorice in small amounts herbal tea, 1–2 cups per day	liquorice root excess herbal tea, as some herbs may be unsafe in large amounts enoki mushrooms unless fully cooked
Supplements	standard pregnancy vitamins as advised	high-dose vitamin A supplements or multivitamins containing vitamin A

Fish and shellfish

You should not eat more than 2 portions of oily fish a week, such as salmon, trout, mackerel, sardines or herring, because they contain pollutants such as dioxins and polychlorinated biphenyls. Eating too much may be harmful to your unborn baby.
You should not eat more than 2 cooked tuna steaks, approximately 140g cooked or 170g raw each, or 4 medium-sized cans of tuna, approximately 140g when drained, per week. Tuna contains more mercury than other fish and consuming too much mercury may be harmful to your unborn baby.
You should avoid raw shellfish because it can contain harmful bacteria, viruses or toxins that can make you unwell and cause food poisoning.

Caffeine

Limit your caffeine intake to no more than 200mg per day.

Approximate amounts of caffeine include:

100mg in a mug of instant coffee
140mg in a mug of filter coffee
75mg in a mug of tea. Green tea can contain the same amount of caffeine as regular tea
40mg in a can of cola
80mg in a 250ml can of energy drink
less than 25mg in a 50g bar of plain dark chocolate
less than 10mg in a 50g bar of plain milk chocolate

Alcohol

If you are pregnant or planning to become pregnant, the safest approach is not to drink alcohol at all. Drinking alcohol during pregnancy can cause long-term harm to your baby. Some studies also suggest an increased risk of alcohol dependency following bariatric surgery.

Vitamin and mineral supplementation during pregnancy

Supplement	Adjustable gastric band or intra-gastric balloon	Sleeve gastrectomy or Roux-en-Y gastric bypass	One anastomosis gastric bypass	Single anastomosis duodenal ileal bypass with sleeve or biliopancreatic diversion with duodenal switch
Multivitamin and minerals	Pregnacare, 1 tablet per day. Stop Forceval.	Pregnacare, 2 tablets per day.	Forceval, 1 tablet per day. Do not use soluble Forceval.	Please refer immediately to a bariatric dietitian. Forceval, 1 tablet per day. Do not use soluble Forceval.
Folic acid	5mg per day. Continue for the first 12 weeks.
Vitamin D	2,000–4,000 IU per day.
Iron	–	Ferrous sulphate, ferrous fumarate or ferrous glutamate, 1 tablet per day.
Vitamin B12	–	1mg injection every 3 months.
Calcium	–	Adcal D3, 2 tablets per day.

Considerations for patients with a gastric band

If you have a gastric band and become pregnant, you will need to contact the specialist bariatric nurse to discuss whether your band will need to be adjusted during pregnancy.

If the band is not adjusted appropriately, you may experience increased nausea, vomiting, food intolerance and abdominal pain.

Please note that excessive vomiting may increase the risk of band slippage.

Expected weight gain during pregnancy

Starting BMI category (kg/m²)	Recommended weight gain
Below 18.5	12.5–18kg (2 stone to 2 stone 12lb)
18.5–24.9	11.5–15kg (1 stone 11lb to 2 stone 5lb)
25–29.9	7–11.5kg (1 stone 1lb to 1 stone 11lb)
30 or above	5–9kg (11lb to 1 stone 6lb)

Gestational weight gain guidelines do not exist specifically for women who have had bariatric surgery. Individualised monitoring and nutritional counselling are therefore required to optimise pregnancy outcomes.

Breastfeeding

Your antenatal team will discuss feeding techniques, including breastfeeding, during your pregnancy.

Points to consider include:

Vitamin and mineral supplementation during breastfeeding should remain the same as during pregnancy. Please see the table above.
Your nutritional status should be assessed by your GP at 3 months after giving birth.
Breast milk is unique and meets a baby's nutritional requirements. The World Health Organization (WHO) recommends exclusive breastfeeding until your baby is 6 months old. From 6 months, babies require additional nutrition from solid foods while continuing to breastfeed. There are no known contraindications to breastfeeding after bariatric surgery.
Breastfeeding normally uses around 500 calories a day once established. You do not usually need to eat additional calories for this unless you have lost a lot of weight or are underweight. Continue to have regular protein-rich meals and snacks and foods rich in calcium, such as dairy foods and dairy alternatives, throughout the day to help ensure that you and your baby receive adequate nutrition.

Contact the Bariatric Dietitians

If you have any questions, please contact the Bariatric Dietitians.

T: 020 3315 8161
E: chelwest.bariatric.dietitians@nhs.net

Contributors

Liz Alden George Vasilopoulos