On testing for strength of correlation, it was found that body mass index and time to blood pressure normalization had a strong positive correlation (r = 0.8). The remaining parameters (ie, gestational age at onset, gestational age at delivery, severity and complications of hypertension and number of antihypertensive medications) and time to recovery were weakly correlated ( r = 0.3 to 0.5 [+/–]).
Women with gestational hypertension and mild preeclampsia had faster normalization of blood pressure compared to those with severe preeclampsia and eclampsia ( Figure 2 ). Only 15% of women with gestational hypertension had persistent hypertension beyond 6 weeks, whereas in the groups with nonsevere preeclampsia, severe preeclampsia, and eclampsia, blood pressure
Eighteen women had additional medical problems: gestational diabetes ( n = 5), anemia ( n = 3), hypothyroidism ( n = 4), rheumatic heart disease ( n = 2), antiphospholipid antibody syndrome ( n = 1) chronic kidney disease ( n = 1), post atrial septal defect closure (n = 1), and tricuspid valve prolapse (TVP) with regurgitation and pulmonary arterial hypertension ( n = 1). With the exception of the woman with chronic kidney disease, all reverted to normal blood pressure by 6 weeks; the woman with TVP reverted after corrective cardiac surgery in puerperium.
Discussion
In the present study we assessed possible correlations of obstetric profile with time to postpartum recovery of blood pressure in women with pregnancy hypertension. Women with advanced age, higher body mass index, early gestational age at the onset of hypertension, early gestational age at delivery, severe hypertension, and those with complications of hypertension took longer time in the postnatal period for normalization of blood pressure.
The strength of this study was its prospective design and high rate of follow-up. Those who missed a visit were followed up over telephone. However, 19 women were not available even by phone. A limitation of this study is that the information regarding when the antihypertensive was stopped was obtained by patient recall, raising the possibility of recall bias. However, as the range of recovery times was wide, an error of few days may not be significant.
In the study we noted that women with preeclampsia took a longer time to recovery compared with women with gestational hypertension. Earlier and more severe disease was associated with delay to recovery or persistence of hypertension beyond 10 weeks postpartum.
Similar to our observation, other authors have observed a consistent association of time to reversion of hypertension and early-onset hypertension in pregnancy [3–5]. Ferrazzani explained the longer time to normalization of blood pressure in preeclampsia compared to gestational hypertension as the recovery time of the endothelial damage in preeclampsia [4].
Berks et al [6] found a correlation of maximum diastolic blood pressure, maximum proteinuria in pregnancy, and diagnosis-to-delivery interval with time taken for resolution of hypertension; however, they did not find that time to resolution was correlated with gestational age at onset of preeclampsia. They opined that their observations reflected endothelial recovery after preeclampsia. They also suggested further research in the area of temporizing management of preeclampsia to determine if a conservative approach increases remote cardiovascular risk [6]. We did not study the diagnosis-to-delivery interval, but those with early delivery in our group had late postpartum recovery, indicating that they had severe/complicated preeclampsia that demanded early termination.