Supervisor in VK warns of unplanned pregnancy by weight loss drugs. How is that possible?

Is it a warning or a boost? People who use weight loss agents such as Ozempic or Mounjaro must also use good contraceptives if they do not want to get pregnant, so advised The British supervisor for medicines MHRA on Thursday. Because weight loss drugs can promote fertility, use can lead to (unplanned) pregnancy.

The regulator received forty reports from people who became pregnant while they used weight loss agents. It is unclear whether it concerns planned or unplanned pregnancies, and how many of these forty people used contraceptives.

Babybump

A year ago written The Guardian Already about a possible link between the use of slimming agents and pregnancy, on the basis of experiences of people who wrote about it on Reddit and in a Facebook group called it I GOT PREGNANT ON OZEMPIC. Experts said at the time that an increase in pregnancies had not yet been demonstrated, but it was ‘plausible’. Slimming drugs can actually be a small one babybump cause? Data that pointing to such a context in practice were missing.

Now there are cautious signals that it prevents ‘side effect’ of the resources. The majority of the reports that the MHRA received was about the Mounjaro drug with the active substance tirzepatide. There were also eight reports about the Ozempic and Wegovy drugs, both with the working substance Semaglutide, and nine reports about Saxenda based on the Liraglutide substance.

Also in the Netherlands some reports were received from pregnancies during the use of slimming agents, which were therefore associated with each other. That reported Lareb side effects center on Friday to RTL News. It concerns four reports about drugs with the active substance Semaglutide, such as Ozempic. For three of the four reports, contraception would have been used, with the fourth that is unclear. There are also two reports of pregnancy when using diabetes drugs. Based on these figures, it is too early for Lareb to send a warning.

Improved fertility

How could these means increase the chance of pregnancy? There are various ‘routes’ for this, the British MHRA has explained. The health service focuses in particular on the Mounjaro drug, which may have a direct effect on the functioning of the contraceptive pill. That side effect was already stated on the package leaflet. MHRA advises Mounjaro users urgently to use a non-oral contraceptive, such as a condom or spiral, to prevent unwanted pregnancy.

A second explanation is the fact that obesity leads to reduced fertility. By using drugs against obesity, fertility would logically increase again. In this way, drugs that do not have a direct effect on contraception can still indirectly increase the chance of pregnancy.

It was already clear that weight loss drugs can have a beneficial effect on fertility, says Liesbeth van Rossum, internist-endocrinologist and professor of obesity at Erasmus MC. « These resources are prescribed for women who are overweight and have a desire to have children and want to be eligible for an IVF process, for example. We sometimes see women who still get pregnant in the natural way, simply because they have fallen off and their cycle starts again. »

She does warn – just like the British regulator – that it is unknown what the consequences are of weight loss drugs for the unborn child. That is why people have to stop using weight loss drugs two months before the start of an IVF procedure. After that period, the agent disappeared from the body again.

Joop Laven, reproductive endocrinologist at Erasmus MC, hopes that this ‘break period’ turns out to be unnecessary. « The annoying thing is that weight loss drugs not only disappear fatty tissue, but also bone and muscle mass. » In the interim period without medication use, fatty tissue comes back, but not the rest – undesirable during pregnancy. Perhaps positive results will follow soon from a major study by Erasmus MC, says Laven. « The data that is there are reassuring. Many cases have been described that show that children do not get any abnormalities. »

With the cooperation of Emma Vos.

<dmt-util-bar article="4896176" data-paywall-belowarticle="" headline="Toezichthouder in VK waarschuwt voor ongeplande zwangerschap Through slimming drugs. How is that possible? « URL = » https://www.nrc.nl/nieuws/2025/06/07/ZEEZEEZHOHODER-in-vk-waarschuwt-voor-ongeplande-wangerschap-door-door-hoe-kan-dat-a4896176 « >>>


To share

Mail the editors