The UK's health authorities have identified glucagon-like peptide-1 (GLP-1) obesity treatments, including Wegovy and Maunja, which are gaining popularity worldwide, as medications that require caution for women of childbearing age, pregnant individuals, and breastfeeding mothers.
This is due to several cases where women of childbearing age taking GLP-1 obesity medications experienced decreased effectiveness of oral contraceptives, resulting in unplanned pregnancies. Additionally, administering these drugs during pregnancy or breastfeeding can pose risks to the health of the fetus and infant.
On the 6th (local time), the UK Medicines and Healthcare products Regulatory Agency (MHRA) recommended that women of childbearing age taking GLP-1 obesity medications use stronger contraception methods than existing oral contraceptives. They also officially advised pregnant women, those planning to become pregnant, and breastfeeding mothers to avoid taking these medications.
Wegovy from Denmark's Novo Nordisk and Maunja from the U.S. company Eli Lilly are medications that mimic GLP-1, a hormone released from the intestines after meals. They promote insulin hormone secretion that lowers blood sugar and inhibit glucagon, which raises blood sugar, thereby increasing feelings of fullness. They have received significant attention for their ability to reduce appetite and help with weight loss.
However, there are also side effects. Nausea and diarrhea, along with delayed gastric emptying, are typical examples. This occurs when the ability of food in the stomach to be released into the duodenum is diminished, leading to symptoms such as bloating and discomfort due to prolonged retention of food in the stomach.
The UK health authorities have reported that this delayed digestion may hinder the absorption of oral contraceptives, thereby decreasing their effectiveness. Oral contraceptives must be absorbed within a certain timeframe primarily in the intestines to provide reliable contraceptive effects. The GLP-1 medications may prolong the time that food and drugs stay in the stomach, delaying absorption, which means that the absorption rate could be reduced.
Moreover, it is analyzed that women patients whose ovulation was suppressed due to obesity have shown recovery in natural ovulation after weight loss through GLP-1 drug usage. Indeed, in recent reports from the UK, there have been instances of women who underwent GLP-1 treatment becoming pregnant despite taking oral contraceptives.
Health authorities recommend using non-oral contraceptive methods, such as contraceptive implants or intrauterine devices (IUDs), in addition to oral contraceptives.
Additionally, caution is advised for immediately attempting pregnancy right after discontinuing obesity medications. The UK health authorities recommend maintaining contraception for two months after stopping Wegovy and one month after stopping Maunja before attempting pregnancy. This guidance stems from reports that GLP-1 obesity medication components have caused fetal growth delays and anatomical malformations in animal experiments.
However, human clinical trials have not included women of childbearing potential or pregnant individuals, leaving data on their actual impact and safety on humans still insufficient.
Caroline Ovadia, a professor of obstetrics at the University of Edinburgh in the UK, noted to the Science Media Centre that "GLP-1 medication can have a positive impact on pregnancy through weight loss and improvement of metabolic diseases, but data on safety during pregnancy is very limited"; she emphasized that contraceptive planning before use is essential and advised to immediately stop the medication if pregnancy is confirmed during treatment and consult with an obstetrics specialist for early precise testing.
Channa Jayasena, a professor at Imperial College London (ICL), also explained, "While obesity decreases female fertility, weight reduction through GLP-1 medications improves fertility, increasing the likelihood of pregnancy compared to before weight loss" and added, "The recent guidelines from authorities emphasize that women taking GLP-1 medications may face unintended pregnancies."
There are no specific guidelines in Korea, but experts recommend that women who are pregnant or breastfeeding should avoid taking GLP-1 and other obesity medications.
Professor Kim Yang-hyun of the Department of Family Medicine at Korea University Anam Hospital emphasized, "Women of childbearing potential should be cautious about using not only GLP-1 but all obesity medications," suggesting that if they must be used, thorough contraceptive measures should be taken during that period, or they could consider daily medications that help achieve weight loss goals more quickly, as opposed to taking medications like Wegovy and Maunja weekly. He added, "To conceive safely, it is best to attempt pregnancy at least one month after using obesity medications, as recommended by UK authorities."