Seasonal Variations in Hypertensive Disorders During Pregnancy Identified

Seasonal variations have been observed in the risk of the hypertensive disorders of pregnancy--including gestational hypertension and preeclampsia, said new study.

In the Acta Obstetricia et Gynecologica Scandinavica study, the highest risk for hypertensive disorders was seen in pregnancies conceived during spring and summer.

‘Vitamin D may have caused the observed seasonal variation in the hypertensive disorders of pregnancy including gestational hypertension and preeclampsia.’

Of 50,665 women included in the study, 8.5% were diagnosed with a hypertensive disorder of pregnancy. There appeared to be increasing risk when conceiving during the spring and early summer, peaking midsummer, and subsequently decreasing steadily during the autumn to reach a low by winter. Seasonal variations in vitamin D levels may help to explain these findings.

"It has long been assumed that vitamin D affects the pathogenesis of hypertensive disorders of pregnancy--including preeclampsia--and our results support this hypothesis," said lead author Christine Rohr Thomsen, of Aarhus University Hospital, in Denmark.

Source: Eurekalert