Fatty liver in pregnancy may increase risk of preterm birth, suggests study

Pregnant women with metabolic dysfunction-associated steatotic liver disease (MASLD) have an increased risk of giving birth prematurely and the risk increase cannot be explained by obesity, according to a new study from Karolinska Institutet published in the journal eClinicalMedicine.

It is estimated that one in five people in Sweden has MASLD, previously called non-alcoholic fatty liver disease, and globally it may be as many as three out of ten. Common risk factors are metabolic disorders such as type 2 diabetes and overweight or obesity. The disease has become increasingly common, including among women of reproductive age. Researchers have now investigated the association between maternal MASLD and pregnancy and neonatal birth outcomes.

Threefold increase in risk

The study is based on Swedish registry data and includes a total of 240 births among women with MASLD and 1140 matched births of women from the general population. Women with MASLD were more than three times more likely to give birth prematurely. The risk did not increase with MASLD severity and the increase in risk persisted even when compared to overweight or obese women without known MASLD.

“This suggests that the association is not only due to a high BMI and that the liver disease itself can have negative effects,” explains lead author Carole A. Marxer, postdoctoral researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. “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 adding specific recommendations for pregnant women to the clinical guidelines for MASLD.”

High BMI linked to caesarean section

Women with MASLD also had a 63 per cent higher risk of caesarean section than the control group. However, this seems to be explained by high BMI as no increase in risk was seen compared to overweight or obese women without fatty liver disease.

“It is also worth noting that we did not find any increased risk in women with MASLD of having children with congenital malformations or of having children who died at birth,” says senior author Jonas F. Ludvigsson, paediatrician at Örebro University Hospital and professor at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.

Despite extensive adjustment for a range of confounders and several other strengths of this study, such as complete BMI information among mothers, the authors cannot rule out that the increased risk may have been influenced by other factors.

Reference:

Marxer, Carole A. et al., Adverse pregnancy and birth outcomes in women with biopsy-proven MASLD: a nationwide cohort study, EClinicalMedicine, DOI: 10.1016/j.eclinm.2025.103238