Early-onset severe HDP carries highest recurrence risk, study finds

A retrospective cohort study published in O & G Open estimated the risk of recurrent severe hypertensive disorders of pregnancy (HDP) using a large United States administrative claims database and examined how recurrence risk varied by the severity and timing of HDP in a prior pregnancy. The study aimed to address a gap in existing recurrence estimates, which have previously ranged widely from 10% to 83% across smaller studies.

Researchers used the Premier Inpatient database to identify individuals with 2 or more observed pregnancies between October 2015 and December 2020. Clinical characteristics were identified using International Classification of Diseases, Tenth Revision codes. Severe HDP was defined as preeclampsia with severe features, superimposed preeclampsia, HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome, or eclampsia.

Risk and relative risk (RR) of developing severe HDP in a subsequent pregnancy were estimated using multivariable risk regression, stratified by the presence and severity of HDP in the first observed (index) pregnancy and by gestational age at delivery.

Key data

• 560,295 patients had 2 or more pregnancies during the study period
• 57,584 patients (10.3%) had HDP and 11,433 patients (2.0%) had severe HDP during the index pregnancy
• 1,703 individuals (14.9%) with severe HDP in the index pregnancy experienced recurrent HDP in a subsequent pregnancy
• Patients with severe HDP at any gestational age had an increased risk of severe HDP in a subsequent pregnancy compared with patients with no index HDP (14.9%, RR 16.0, 95% CI, 15.2-17.0)
• Patients with severe HDP before 28 weeks of gestation had the highest overall recurrence risk (22.9%, RR 23.1, 95% CI, 19.1-27.9)
• Severe HDP before 28 weeks conferred the highest risk of recurrent HDP before 28 weeks specifically in a subsequent pregnancy (4.7%, RR 184.9, 95% CI, 107.2-318.9)
• History of HELLP syndrome was associated with elevated risk of severe HDP in a subsequent pregnancy (11.5%, RR 9.7, 95% CI, 8.3-11.3), including recurrent HELLP syndrome specifically (4.6%, RR 61.0, 95% CI, 46.2-80.6)
• History of eclampsia was associated with elevated risk of severe HDP in a subsequent pregnancy (11.0%, RR 9.2, 95% CI, 7.2-11.8), including recurrent eclampsia specifically (1.1%, RR 40.1, 95% CI, 16.3-98.3)

Early-onset disease before 28 weeks carried the steepest recurrence risk

Patients whose severe HDP occurred before 28 weeks of gestation faced not only the highest overall risk of recurrent severe HDP among all subgroups studied, but a dramatically elevated risk, with an RR of 184.9.

HELLP syndrome and eclampsia recurred infrequently but carried substantial relative risk

Although recurrent HELLP syndrome and recurrent eclampsia were uncommon in absolute terms, occurring in 4.6% and 1.1% of at-risk patients respectively, the relative risk associated with a prior episode of either condition was substantial, with RRs of 61.0 and 40.1, respectively.

Reference:
Trawick E, Kucirka LM, Fuller M, et al. Risk of recurrent severe preeclampsia, hellp (Hemolysis, elevated liver enzymes, and low platelet count) syndrome, and eclampsia in a subsequent pregnancy. Obstetrics & Gynecology. Published online August 20, 2026. doi:10.1097/AOG.0000000000006398