The Control of Hypertension In Pregnancy Study pilot trial.
OBJECTIVE
To determine whether 'less tight' (versus 'tight') control of nonsevere hypertension results in a difference in diastolic blood pressure (dBP) between groups.


METHODS
Randomised controlled trial (ISRCTN#57277508).


METHODS
Seventeen obstetric centres in Canada, Australia, New Zealand, and UK.


METHODS
Inclusion: pregnant women, dBP 90-109 mmHg, pre-existing/gestational hypertension; live fetus(es); and 20-33(+6) weeks. Exclusion: systolic blood pressure > or = 170 mmHg and proteinuria, contraindication, or major fetal anomaly.


METHODS
Randomisation to less tight (target dBP, 100 mmHg) or tight (target dBP, 85 mmHg) blood pressure control.


METHODS
Primary: mean dBP at 28, 32 and 36 weeks. Secondary: clinician compliance and women's satisfaction. Other: serious perinatal and maternal complications.


RESULTS
A total of 132 women were randomised to less tight (n = 66; seven had no study visit) or tight control (n= 66; one was lost to follow up; seven had no study visit). Mean dBP was significantly lower with tight control: -3.5 mmHg, 95% credible interval (-6.4, -0.6). Clinician compliance was 79% in both groups. Women were satisfied with their care. With less tight (versus tight) control, the rates of other treatments and outcomes were the following: post-randomisation antenatal antihypertensive medication use: 46 (69.7%) versus 58 (89.2%), severe hypertension: 38 (57.6%) versus 26 (40.0%), proteinuria: 16 (24.2%) versus 20 (30.8%), serious maternal complications: 3 (4.6%) versus 2 (3.1%), preterm birth: 24 (36.4%) versus 26 (40.0%), birthweight: 2675 +/- 858 versus 2501 +/- 855 g, neonatal intensive care unit (NICU) admission: 15 (22.7%) versus 22 (34.4%), and serious perinatal complications: 9 (13.6%) versus 14 (21.5%).


CONCLUSIONS
The CHIPS pilot trial confirms the feasibility and importance of a large definitive trial to determine the effects of less tight control on serious perinatal and maternal complications.
Magee
L A
LA
Department of Medicine, University of British Columbia, Vancouver, Canada. LMagee@cw.bc.ca
von Dadelszen
P
P
Chan
S
S
Gafni
A
A
Gruslin
A
A
Helewa
M
M
Hewson
S
S
Kavuma
E
E
Lee
S K
SK
Logan
A G
AG
McKay
D
D
Moutquin
J-M
JM
Ohlsson
A
A
Rey
E
E
Ross
S
S
Singer
J
J
Willan
A R
AR
Hannah
M E
ME
D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000517:prevention & control*; D007741:Labetalol / Q000627:therapeutic use*; D017060:Patient Satisfaction; D010865:Pilot Projects; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000517:prevention & control*; D011256:Pregnancy Outcome; D016896:Treatment Outcome
D000959:Antihypertensive Agents; D007741:Labetalol