[1-OR] The control of hypertension in pregnancy study (CHIPS) randomized controlled trial

ObjectivesNormalizing blood pressure in pregnancy may reduce maternal complications but increase adverse perinatal effects. CHIPS aimed to determine whether a higher (vs. lower) blood pressure target improves perinatal outcome, without compromising maternal safety in non-severe pregnancy hypertension.MethodsIn an open pragmatic international multicenter trial, women at 14+0−33+6 weeks gestation with non-proteinuric pre-existing or gestational hypertension, office diastolic BP (dBP) 90–105mmHg (or 85–105mmHg if on antihypertensives) and a live fetus were randomized to ‘less tight’ (target dBP 100mmHg) or ‘tight’ control (target dBP 85mmHg). The composite primary outcome was pregnancy loss or high level neonatal care for >48h in the first 28d of life, and the secondary, serious maternal complications before 6weeks postpartum. Outcomes were compared between groups using logistic regression adjusted for key prognostic factors.ResultsOf 1030 women randomized, 987 (94 sites) were included in the analysis. 74.6% had pre-existing hypertension. Women in ‘less tight’ (n=497) compared with ‘tight’ (n=490) control had similar rates of adverse perinatal (31.4% vs. 30.7%; aOR 1.02 [0.77, 1.35]) and maternal outcomes (3.7% vs. 2.0%; aOR 1.74 [0.79, 3.84]), despite higher mean dBP by 4.6mmHg (95% confidence interval 3.7, 5.4). Severe hypertension (⩾160/110mmHg) developed more frequently in ‘less tight’ (vs. ‘tight’) control (40.6% vs. 27.5%; aOR 1.80 [1.36, 2.38]).Conclusions‘Less tight’ (vs. ‘tight’) control did not improve perinatal outcome, but did result in more severe hypertension. Our results do not support ‘less tight’ control of non-severe pregnancy hypertension.DisclosuresL.A. Magee: Research Support Recipient; Commercial Interest(s): BMGF. P. von Dadelszen: Consultant; Commercial Interest: Alere International; Research Support Recipient; Commercial Interest: BMGF. E. Rey: None. S. Ross: None. E. Asztalos: None. K.E. Murphy: None. J. Menzies: None. J. Sanchez: None. J. Singer: None. A. Gafni: None. A. Gruslin: None. M. Helewa: None. E. Hutton: None. S.K. Lee: None. A.G. Logan: None. W. Ganzevoort: None. R. Welch: None. J.G. Thornton: None. J. Moutquin: None. T. Study Group: None.