Babies born to mothers with PCOS and obesity are smaller in size

Women with polycystic ovary syndrome (PCOS) and obesity have a higher risk of giving birth to babies that are smaller in terms of birth weight, length and head circumference, according to a recent study conducted at the Norwegian University of Science and Technology (NTNU). .

One in eight women is affected by the hormone disorder PCOS. Their common features are high levels of male sex hormones, infrequent or irregular menstrual periods, and the formation of small cysts on the ovaries.

The study compared 390 children born to women with PCOS with approximately 70,000 children from the Norwegian Mother, Father and Child Cohort Study (MoBa) (see Information box).

Researchers found that babies born to mothers with PCOS were, on average, less heavy, shorter, and had smaller head circumferences at birth. This was especially true when mothers were obese, meaning their body mass index was over 30.

Co-occurrence of PCOS and obesity has the worst effect.

We found that in normal-weight women with PCOS, only their children had lower birth weights than in women without PCOS. It is the most prominent group among children born to mothers with obesity. These babies have lower weight, shorter height and smaller head circumference. “Obesity puts an additional burden on mothers with PCOS and their children.”

Professor Eszter Vanky, Department of Clinical and Molecular Medicine, NTNU

PCOS is a disease that follows women throughout their lives and can trigger various metabolic diseases and challenges such as diabetes, high blood pressure, obesity. Women with PCOS are generally more likely to develop overweight and obesity.

“What’s unusual is that women who are often overweight and gain a lot of weight during pregnancy are often at increased risk of giving birth to large babies. This also applies to women who develop gestational diabetes. On average, women with PCOS have a higher BMI during pregnancy.” They gain more weight and 25 percent develop gestational diabetes. But the result is the opposite: We still don’t know why, but we see that the placenta is affected in these women,” Vanky said.

Placenta in overdrive

Newly qualified doctors Maren Talmo and Ingvild Fløysand carried out the study as a master’s thesis and were supervised by Eszter Vanky and Melanie Rae Simpson. Although the placenta is smaller in size in these women, it appears to provide more nutrients per baby’s body weight compared to a normal placenta, explains Talmo. Vanky describes it as the placenta in overdrive.

“The placenta delivers nutrients to the baby through the umbilical cord. We see that the placenta is generally smaller in women with PCOS. At the same time, it has to provide everything the baby needs, so it has to work hard. But sometimes the placenta cannot keep up, which causes the placenta to “It can lead to failure and, in rare cases, fetal death.”

Researchers don’t know why this is the case.

“There are many hypotheses, but I don’t think anyone has a definitive answer yet. We previously thought the cause was linked to high levels of male sex hormones, but we couldn’t quite link the two. I do know that women with PCOS have a slightly different immune profile during pregnancy.”

Follow-up during pregnancy

Researchers believe this is important information for both affected women and healthcare professionals.

“A newborn baby is not a blank slate. Much of our long-term health is established in the womb. Genes play a role, as does what we are exposed to during the fetal stage and early in life,” Vanky said.

NTNU researchers now want to learn more about what happens to children’s health.

“What are the consequences of maternal PCOS? diagnosis for the child? Is there anything that can be done before or during pregnancy to prevent expectant mothers with PCOS from gaining too much weight? Can monitoring and good glucose regulation be ensured so that the child gets the best possible outcome? This all depends on knowing more about the mother’s condition,” Vanky said.

It is affected throughout life

NTNU researchers also followed some of the children as they turned 7 years old.

“We found that children born to mothers with PCOS often had more central obesity, meaning they had a larger waist circumference,” Vanky said.

Other studies have shown that children born to mothers with PCOS have a higher risk of developing overweight and obesity at a young age. Research has also shown that low birth weight is linked to the development of type 2 diabetes and cardiovascular disease later in life.

“We see differences in children as early as age 7 or 8, where children born to mothers with PCOS have a larger waist circumference and a higher body mass index. They carry little signs that their mothers have PCOS. Therefore, knowledge about this may be an advantage.” ” “This way we can provide guidance on lifestyle and diet,” Vanky said.