CHAP primary composite outcome

Overview

Definition

Any one or more of: pre-eclampsia with severe features within 2 weeks after birth; a preterm birth before 35 weeks that was medically indicated (because of illness in the mother or fetus, and not because labor began on its own or the membranes ruptured); placental abruption; death of the fetus or newborn. Pre-eclampsia was defined by ACOG criteria.

Unit

patients

Components

• Pre-eclampsia with severe features (CHAP definition)
• Medically indicated preterm birth before 35 weeks (CHAP definition)
• Placental abruption leading to delivery (CHAP definition)
• Fetal or neonatal death (CHAP definition)

Measured in

Studies in this atlas that report this outcome, by the claim each finding supports. Each finding keeps its own population, denominator and time window on the study page.

• Primary endpoint CHAP (Chronic Hypertension and Pregnancy) trial · See the findings

  Applies to Mixed recipients

  • The same women as the maternal CHAP context, with the outcomes of their pregnancies. The primary composite combines a maternal event (pre-eclampsia with severe features up to 2 weeks after birth), pregnancy events (medically indicated preterm birth before 35 weeks and placental abruption) and a fetal or neonatal event (fetal or neonatal death). It is used only for the composite as the trial defined it and is never split by recipient.
  • Recruiting sites of the CHAP Trial Consortium in the United States; see the maternal CHAP context.
  • United States
  • Pregnancy and the newborn period
  • Gestational age Not reported
  • Postnatal age Not reported

  Follow-up Pre-eclampsia counted up to 2 weeks after birth. Fetal or neonatal death is listed at under 28 days in the manuscript table; the registry gives up to 90 days for neonatal death.
  In the CHAP trial in the United States, women with mild chronic hypertension who enrolled before 23 weeks of pregnancy and were treated to a blood-pressure goal below 140/90 mm Hg had fewer of the combined serious pregnancy problems than women whose treatment was held back unless their blood pressure became severe. The combined outcome (pre-eclampsia with severe features, a medically indicated preterm birth before 35 weeks, placental abruption, or the death of the fetus or newborn) occurred in 353 of 1170 women with outcome data in the treated group (30.2%) and 427 of 1155 in the control group (37.0%). A separate analysis that fills in missing outcomes gave an adjusted risk ratio of 0.82 (95% CI 0.74 to 0.92).

  Limitations. Open-label trial in one country, so women and clinicians knew the assigned strategy. The composite mixes a maternal event with pregnancy events and fetal or neonatal events; the sources do not split it by recipient and the atlas does not either. The percentages and counts come from the complete-case analysis (2325 of 2408 women had enough data); the adjusted risk ratio comes from a multiple-imputation analysis of all 2408. They are different analyses. The authors’ secondary composites of serious maternal complications and of severe neonatal complications did not show clear differences in the abstract; they are about the mother and the newborn separately, so they are not recorded here as claims of their own. Secondary results were not adjusted for multiplicity. For women with newly diagnosed hypertension and for a body-mass index of 40 or more, the risk ratios were close to 1.00 with wide intervals. About 12 women were screened for each woman randomized. The sample size was reduced from a planned 4700 women to a final 2404 that the data and safety monitoring board approved, and the abstract and the Methods word the upper blood-pressure limit differently (below 160/100 vs below 160 and below 105 mm Hg). The registry calls the primary outcome perinatal although it includes a maternal event.

Record details

Record id

maternal:outcome-chap-primary-composite

Content hash

91f734512ef1880290ee8f2340e806c6d09de65fe9af545373655de5080fa55c