The CHIPS Randomized Controlled Trial (Control of Hypertension in Pregnancy Study):Is Severe Hypertension Just an Elevated Blood Pressure?

To determine whether clinical outcomes differed by occurrence of severe hypertension in the international CHIPS trial (Control of Hypertension in Pregnancy Study), adjusting for the interventions of textquotedblleftless tighttextquotedblright (target diastolic blood pressure [dBP] 100 mm Hg) versus textquotedbllefttighttextquotedblright control (target dBP 85 mm Hg). In this post-hoc analysis of CHIPS data from 987 women with nonsevere nonproteinuric preexisting or gestational hypertension, mixed effects logistic regression was used to compare the following outcomes according to occurrence of severe hypertension, adjusting for allocated group and the influence of baseline factors: CHIPS primary (perinatal loss or high-level neonatal care for gt;48 hours) and secondary outcomes (serious maternal complications), birth weight lt;10th percentile, preeclampsia, delivery at lt;34 or lt;37 weeks, platelets lt;100texttimes109/L, elevated liver enzymes with symptoms, maternal length of stay >=10 days, and maternal readmission before 6 weeks postpartum. Three hundred and thirty-four (34.1 women in CHIPS developed severe hypertension that was associated with all outcomes examined except for maternal readmission (P=0.20): CHIPS primary outcome, birth weight lt;10th percentile, preeclampsia, preterm delivery, elevated liver enzymes (all Plt;0.001), platelets lt;100texttimes109/L (P=0.006), and prolonged hospital stay (P=0.03). The association between severe hypertension and serious maternal complications was seen only in less tight control (P=0.02). Adjustment for preeclampsia (464, 47.3 did not negate the relationship between severe hypertension and the CHIPS primary outcome (Plt;0.001), birth weight lt;10th percentile (P=0.005), delivery at lt;37 (Plt;0.001) or lt;34 weeks (Plt;0.001), or elevated liver enzymes with symptoms (P=0.02). Severe hypertension is a risk marker for adverse maternal and perinatal outcomes, independent of BP control or preeclampsia co-occurrence.Clinical Trial RegistrationtextemdashURL: http://pre-empt.cfri.ca/. Unique identifier: ISRCTN 71416914. URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01192412.Novelty and Significanc