TOPLINE:
For most obstetric patients in the first trimester, preeclampsia risk rises at a blood pressure threshold of 140/90 mmHg. For some subgroups, the risk evaluation should occur at lower thresholds. No blood pressure reassures against possible later preeclampsia.
METHODOLOGY:
- Analysis of data collected in a two-centre prospective cohort study of 137,458 singleton pregnancies that delivered at ≥ 24 weeks (2006-2020).
- Authors compared first-trimester blood pressure readings against preterm and term preeclampsia risks.
- They checked if alternative blood pressure thresholds were stronger predictors in certain subgroups.
- The primary outcome was preeclampsia.
TAKEAWAY:
- Compared with lower cutoffs, 140/90 mmHg was an appropriate threshold to identify most patients with higher preeclampsia risk.
- For patients with a body mass index of < 18.5, 130/80 mmHg was a more appropriate threshold.
- For parous patients without a preeclampsia history, 135/85 mmHg was more appropriate.
- No blood pressure was so low that preeclampsia might not later develop.
IN PRACTICE:
Though the findings do not support treating elevated blood pressure or stage 1 hypertension in the general obstetric population to prevent preeclampsia, the authors wrote, “our data suggest that it would be particularly important to [preeclampsia] risk-assess them accurately” using, eg, uterine artery pulsatility index and serum placental growth factor.
SOURCE:
Conducted by a team based primarily in London, the study appeared in the American Journal of Obstetrics and Gynecology.
LIMITATIONS:
A trial would be needed to determine if people in the subgroups with lower predictive cutoffs would benefit from antihypertensive treatment. Results may not be generalised to multiple pregnancies.
DISCLOSURES:
Authors reported no conflicts of interest.