Aims:
To establish normal ranges for central and peripheral blood pressure (BP), systemic vascular compliance, and cardiac function 6 months following birth, and compare values in women who had an uncomplicated pregnancy vs. pregnancy complicated by gestational hypertension (GH) or preeclampsia (PE).
Methods:
Prospective cohort of women recruited to the P4 (Postpartum Physiology, Psychology and Paediatric Follow Up) study at St George Hospital from July 2013-June 2015, after either a normal or hypertensive pregnancy (GH or PE) resulting in live birth. At 6 months postpartum, cardiovascular measures included three manual (sphygmomanometer) BP measurements, central BP and augmentation index to assess systemic vascular compliance measured by applanation tonometry, and 24-hr ambulatory BP monitoring (24-hABPM). Cardiac function was analysed using transthoracic echocardiography.
Results:
127 women were studied after normotensive pregnancy and 38 after hypertensive pregnancy. Manual, central, and 24-h ABPM were all significantly higher after hypertensive pregnancy (Table). Although only one woman after hypertensive pregnancy had average manual BP ≥140/90mmHg, 11% vs. 0% had high average 24-hABPM (≥130/80mmHg; p<0.001), 8% vs. 1% had high awake ABP (≥135/85mmHg; p=0.015), and 22% vs. 4% had high sleep ABP (≥120/70mmHg; p=0.001) post hypertensive and normotensive pregnancies respectively. 34% of hypertensive women had at least one ABP measure more than 2 SD above that for women who had normotensive pregnancies (p<0.001). Mean augmentation index for hypertensive and normotensive women was similar (17.3% vs. 18.0%). Echocardiographic measurements showed a lower mean E/A ratio between groups, but no significant difference in the proportion of women with abnormal measurements.
Conclusions:
At 6 months postpartum, women who had GH or PE during pregnancy had higher BP compared to women who had a normal pregnancy, particularly evident on 24-hABPM. Importantly, approximately one-third of women who had hypertension in pregnancy have BP outside a new putative normal range for young women at 6 months postpartum. Such knowledge should enable earlier identification of women at increased risk of future CVD morbidity.