Clinical Course, Associated Factors, and Blood Pressure Profile of Delayed-Onset Postpartum Preeclampsia.

OBJECTIVE: To identify clinical risk factors associated with development of delayed-onset postpartum preeclampsia, and to characterize management and subsequent risk of cardiovascular disease.
METHODS: This is a case-control study of women admitted to the hospital with delayed-onset postpartum preeclampsia (defined as a new diagnosis of preeclampsia presenting between 48 hours and 6 weeks postpartum) compared with women with full-term, uncomplicated pregnancies without a hypertensive diagnosis or diabetes. Included women delivered between January 2014 and June 2018 at a single tertiary care center. Women with an antenatal diagnosis of preeclampsia or chronic hypertension were excluded. Univariate analysis was used to identify risk factors associated with delayed-onset postpartum preeclampsia and to compare rates of hypertension and antihypertensive medication use, with follow-up beyond 3 months postpartum among a subset of women in the control group who were matched 2:1 with women in the case group. Multivariable logistic regression was performed and included covariates identified in a backward stepwise approach.
RESULTS: Compared with women in the control group (n=26,936), women with delayed-onset postpartum preeclampsia (n=121) were significantly more likely to be of non-Hispanic black race (31.4% vs 18.0%), obese (39.7% vs 20.1%), and deliver by cesarean (40.5% vs 25.8%), all P<.01. For women diagnosed with delayed-onset postpartum preeclampsia, the median postpartum day of presentation was 7.0 (interquartile range 5.0-9.0), with 93.4% presenting secondary to symptoms, which was most commonly a headache. A majority (73.6%) underwent imaging studies, and 49.6% received intravenous antihypertensive agents. A total of 86 (71.0%) women with delayed-onset postpartum preeclampsia and 169 (72.8%) women in the control group had longer term information available, with a median follow-up time of 1.5 years (interquartile range 0.8-2.8). Delayed-onset postpartum preeclampsia was associated with higher blood pressures at 3 months postpartum or later (median systolic 130 mm Hg vs 112 mm Hg and median diastolic 80 mm Hg vs 70 mm Hg, P<.001).
CONCLUSION: Delayed-onset postpartum preeclampsia is associated with variable management strategies. There is substantial overlap between the clinical risk factors for delayed-onset postpartum preeclampsia and antepartum preeclampsia. Our findings suggest that delayed-onset postpartum preeclampsia is also associated with an increased risk of progression to chronic hypertension.