Recent headlines mentioning an “Ozempic baby boom” and stories about unexpected pregnancies by women who have started utilising weight reduction pharmaceuticals like semaglutide or liraglutide have raised queries as to the reason and any potential implications. The medicines haven’t undergone testing for use in expectant women or those wishing to conceive. Moreover, some research pointing to a link between semaglutide, a key component in Ozempic, and animal birth defects has been discovered.
Simplifying the first part, the term “Ozempic babies” coined on social media is a misrepresentation of the truth. The real fact is that these are not semaglutide babies, rather they are babies resulting from weight loss. Contrary to what headlines suggest, the drug hasn’t magically rejuvenated the reproductive system, but triggered weight loss which has reinstated ovulation.
The strong correlation between body weight and fertility has been long established for both sexes. It implies that being overweight or underweight may impair fertility chances. The body recognises when the conditions aren’t right for pregnancy. We each have a specific body weight range that enables optimal fertility, and any weight beyond this range can cause problems. From an evolutionary standpoint, this logic holds water. In the event that a woman is underweight for whatever reason, it means that she probably lacks sufficient nutrients for her foetus. Similarly, excessive fat accumulation -or excessive bodily adipose tissue, poses increased risk of complications for both the mother and baby during pregnancy. The body’s mechanism of “shutting down” the reproductive system helps to protect our species from detrimental outcomes.
The interplay between body weight regulation and reproductive function is indeed complicated yet intriguing.
The human brain governs both our body mass and guides the mechanisms of reproduction. It gauges the energy levels in our body through a hormone known as leptin, which is created by fat. Our fat functions as an advanced organ that communicates with the brain, using leptin as a conduit. The brain is capable of detecting low and high levels of this hormone, typically associated with being underweight or overweight respectively, and subsequently shuts down the reproductive system. Men may produce inadequate or poor-quality sperm, and women could cease to ovulate, preventing conception. In women, being overweight can exacerbate a condition known as polycystic ovarian syndrome, which could further decrease ovulation and the probability of conception.
There is some proof from animal-based studies suggesting that medicinal intake at the time of conception could potentially lead to abnormalities in the foetus.
Shedding excess weight significantly increases the likelihood of fertility, noticeably in females compared to males. Although it isn’t precisely determined how much weight loss is required for women to regain their ability to ovulate, a rough estimation would be a reduction of 5-10 per cent of their body weight. Such a level of weight loss can be surprisingly quick, sometimes resulting in unexpected pregnancies.
Historically, we have observed instances where women conceived in merely a few weeks following bariatric surgery. Our recent research (Samarasinghe et al, Lancet 2024) – the first randomised clinical trial in this area – highlighted that women suffering from obesity and polycystic ovarian syndrome began ovulating between four to eight weeks post bariatric surgery. This effect was progressively more apparent as weight loss continued over a 12-month period.
Consequently, it isn’t unexpected to observe this occurrence in women who use weight loss medications to counter obesity, such as liraglutide and semaglutide.
Given the widespread use of such weight loss drugs for obesity treatment, concerns have been raised about the health of the resulting offspring. An unequivocal answer to this remains elusive as we don’t have enough conclusive data yet.
Research conducted on animals has suggested that certain medications may have the potential to cause abnormalities in the foetus if used at the time of conception. This research has not yet been extended to humans, and due to the complexities involving studies on pregnant women, a definitive report may remain elusive. However, global and national bodies are currently establishing databases to collate information regarding maternal and neonatal effects during and post-pregnancy.
In the interim, the guidance for women utilising these medications is to ensure they are informed about their potential impact on fertility. Consequently, they should implement suitable contraceptive methods if they wish to avoid pregnancy.
Contrastingly, women taking these drugs to boost their likelihood of conception face a trickier situation. Weight reduction could augment not only their chance of becoming pregnant but also result in a healthier pregnancy. However, the cessation of the medication is still necessary. If the usage of medication is discontinued to mitigate the theoretical risk of foetal abnormalities, they may regain the weight, reverting to their initial position.
Presently, the advice is that women should continue with the medication, but cease usage a few weeks or months prior to attempting to conceive. Given that advice can vary based on the type of medication used, women are advised to seek medical advice.
This new text has been articulated by Dr Alexander Miras, a Professor of Endocrinology at Ulster University.