Obesity, pregnancy and planning a baby

Talk about it before pregnancy

A consultation is an opportunity to review your health, your treatments and your nutritional needs. Diabetes, high blood pressure or any deficiencies can then be addressed in advance.

The aim is to plan your pregnancy as safely as possible, with decisions suited to your situation.

Medication and planning a pregnancy

Medicines such as semaglutide and tirzepatide are not used to treat obesity during pregnancy. Stopping them must be planned with the prescriber, because how long before conception they need to be stopped depends on the medicine.

Contraception and the timing of your plans are discussed during this preparation. If you find out you are pregnant during treatment, contact the prescriber promptly to agree on what to do.

After obesity surgery

At the Centre, we recommend not starting a pregnancy during the first 12 months after bariatric surgery. Before considering a pregnancy, it is also important that your weight has stabilised and that any nutritional deficiencies have been corrected. Depending on your progress, a longer wait may be advised.

During the period of rapid weight loss, nutritional intake and reserves need particular attention. Some deficiencies can affect the baby’s growth and development; in particular, a lack of folate (vitamin B9) increases the risk of certain birth defects.

Suitable contraception, a pre-conception assessment and personalised supplements help you prepare for pregnancy in the best possible way.

If you become pregnant before this time, contact your team promptly to arrange suitable follow-up.

Coordinated follow-up

During pregnancy, particular attention is paid to diet, vitamins and minerals, and the baby’s growth. Supplements and tests are adjusted with the teams caring for you.

Always tell the obstetric team that you have had bariatric surgery. After a gastric bypass, severe or persistent abdominal pain needs prompt assessment.

After the birth

Follow-up continues to support your recovery, your diet and, if you wish, breastfeeding. Restarting a medicine is discussed taking into account breastfeeding and your situation.

Medical review of the French version: Dr Pierre Fournier

Scientific sources and references

Sources accessed on 15 October 2026.

1. Shawe J, Ceulemans D, Akhter Z, et al. Pregnancy after bariatric surgery: consensus recommendations for periconception, antenatal and postnatal care. Obes Rev. 2019;20(11):1507-22. doi:10.1111/obr.12927. View source
2. Wilson RD, O’Connor DL. Guideline No. 427: Folic acid and multivitamin supplementation for prevention of folic acid-sensitive congenital anomalies. J Obstet Gynaecol Can. 2022;44(6):707-19.e1. doi:10.1016/j.jogc.2022.04.004. Guideline of the Society of Obstetricians and Gynaecologists of Canada (SOGC). View source
3. Swiss professional information for Wegovy (semaglutide), authorisation no. 68798, swissmedicinfo.ch, accessed on 15 October 2026 (section Pregnancy and breastfeeding). View source
4. Swiss professional information for Mounjaro (tirzepatide), authorisation no. 68726, swissmedicinfo.ch, accessed on 15 October 2026 (section Pregnancy and breastfeeding). View source