Metabolic markers in routine blood tests may predict pregnancy risks years ahead

Subtle abnormalities in blood lipids, glucose metabolism and inflammation several years before conception have been linked to a higher risk of hypertensive disorders in pregnancy, according to a large Swedish cohort study, with implications for earlier risk assessment in antenatal care

Even small deviations in blood sugar, lipid profiles or inflammatory markers seen in blood tests years before pregnancy can been associated with an increased likelihood of high blood pressure during pregnancy, according to a study led by researchers at Karolinska Institutet, Stockholm, Sweden. The findings suggest that routinely collected metabolic data could support early identification of women who may be at elevated risk in pregnancy – well before they conceive.

Hypertensive disorders of pregnancy – including pre-eclampsia – remain a significant contributor to maternal and perinatal morbidity worldwide. Clinicians have relied largely on measurements obtained after pregnancy begins, with blood pressure monitoring at antenatal appointments serving as a cornerstone of surveillance. However, the analysis presented in this study has indicated that underlying metabolic changes may precede clinical signs by several years so raising the opportunity to stratify preconception risk.

“Our study shows that early blood tests – already used in other contexts for healthcare – can help identify women at risk long before they become pregnant,” said Dr. Karin Leander of the Institute of Environmental Medicine at the Karolinska Institutet, who led the research.

“In the long term, this could open up novel opportunities to prevent pregnancy complications,” she said.

The investigation drew on data from the AMORIS cohort, a large population-based database in Sweden. The analysis included more than 35,000 women in Stockholm who later experienced their first pregnancy. Between four and six years before conception, participants underwent health assessments that included biochemical measurements of blood glucose, serum lipids and markers of low-grade inflammation. Researchers subsequently linked these data to national health registers in order to track pregnancy outcomes.

Across the cohort, 5.5 per cent of women developed either gestational hypertension or pre-eclampsia. Among those with evidence of metabolic disturbance prior to pregnancy, the proportion affected ranged from 5.5 to 12.8 per cent, depending on the specific biomarker. By contrast, women whose measurements remained within established reference ranges showed incidence rates between 4.1 and 5.3 per cent.

The analysis identified several indicators that correlated with increased risk, even when values fell within ranges typically considered clinically acceptable. These included low-density lipoprotein cholesterol, triglycerides and apolipoprotein B, alongside the inflammatory protein haptoglobin. The triglyceride–glucose index, a composite measure that reflects impaired glucose metabolism, also emerged as a relevant predictor.

“Our results suggest that the increased risk may begin even at levels currently considered normal,” said Leander.

“This means that routine blood tests could be used as an additional tool to help healthcare professionals assess risk and discuss lifestyle [modifications] with women of childbearing age, both before and early in pregnancy,” she added.

The findings have aligned with a broader shift in obstetric research that has sought to integrate cardiometabolic health into reproductive risk models. Pregnancy has long been recognised as a physiological stress test that can reveal latent cardiovascular vulnerability. The present study has extended that concept further by indicating that vulnerabilities could be detected years in advance with standard laboratory measures.

Nevertheless, the authors stressed that the biological mechanisms underpinning hypertensive disorders of pregnancy remain complex and multifactorial. As an observational study, the analysis cannot establish causality, and residual confounding may influence the associations observed. Factors such as diet, physical activity, genetic predisposition and socioeconomic status may also contribute to both metabolic profiles and pregnancy outcomes.

The researchers have proposed further work to examine whether similar preconception markers can predict additional complications, including gestational diabetes and preterm birth. They have also indicated plans to explore long-term cardiovascular outcomes in women who exhibit early metabolic abnormalities, in order to determine whether pregnancy-related hypertension represents part of a broader life course trajectory of cardiometabolic disease.

If validated in additional populations, these findings may support a more proactive model of reproductive healthcare, in which risk assessment begins well before pregnancy. Such an approach could enable clinicians to advise targeted lifestyle interventions or monitoring strategies at an earlier stage, with the aim to reduce the incidence and severity of pregnancy complications.

For further reading please visit: 10.1001/jamanetworkopen.2026.10037