Fatty Liver During Pregnancy can Increase the Risk of Premature Birth

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects around 25% of the world’s population. Pregnant women with this condition have an increased risk of premature birth, and this increase cannot be explained by being overweight. This is according to a new study by the Karolinska Institute, published in the journal eClinicalMedicine. It is estimated that one in five people in Sweden suffer from MASLD, formerly known as non-alcoholic fatty liver disease, and worldwide the figure may be as high as one in ten. The disease is becoming increasingly common, even in women of childbearing age. It is usually a consequence of poor diet, lack of exercise, and obesity. These conditions lead to fat accumulation in the liver, which can cause inflammation and scarring. Over time, this can result in severe liver damage.

Three Times Higher Risk of Premature Birth

The study is based on Swedish registry data and includes a total of 240 births to women with fatty liver disease and 1,140 comparable births to women from the general population. Women with MASLD had more than a threefold increased risk of premature birth. The risk did not increase with the severity of the disease and remained elevated compared to overweight or obese women without known MASLD.

“This suggests that the association is not solely due to high BMI, but that the liver disease itself may have negative effects,” explains lead author Carole A. Marxer, postdoctoral researcher at the Department of Medical Epidemiology and Biostatistics at the Karolinska Institute. “It is important that pregnant women with MASLD are closely monitored during pregnancy to reduce the risk of complications. Consideration should also be given to including specific recommendations for pregnant women in clinical guidelines for MASLD.”

High BMI Associated With Cesarean Section

Women with fatty liver disease also had a 63 percent higher risk of cesarean section than the control group. However, this appears to be explained by the high BMI, as no increased risk was found compared to overweight or obese women without fatty liver disease. “It is also worth noting that we did not find an increased risk of children with congenital malformations or of children who died at birth in women with MASLD,” says lead author Jonas F. Ludvigsson, pediatrician at Örebro University Hospital and professor at the Department of Medical Epidemiology and Biostatistics at the Karolinska Institute.

Common risk factors include metabolic disorders such as type 2 diabetes and overweight or obesity. Despite extensive adjustments for a number of confounding factors and several other strengths of this study, such as complete BMI data for the mothers, the authors cannot rule out that the increased risk may have been influenced by other factors.