Risk of adverse pregnancy outcomes in women with mild chronic hypertension before 20 weeks of gestation.
OBJECTIVE
To evaluate whether blood pressure (BP) less than 140/90 mm Hg is associated with lower risk of adverse pregnancy outcomes in women with mild chronic hypertension.


METHODS
This was a secondary analysis of women with chronic hypertension diagnosed before 20 weeks of gestation (either BP 140/90 mm Hg or greater on two occasions at least four hours apart or previously diagnosed and on antihypertensive therapy) enrolled in the Maternal-Fetal Medicine Units Network's High-risk Aspirin preeclampsia prevention trial. Outcomes including a primary composite (perinatal death, severe preeclampsia, placental abruption, and indicated preterm birth less than 35 weeks of gestation) and small for gestational age (SGA) were compared by study preenrollment BP analyzed as a categorical (less than 140/90, 140-150/90-99, or 151-159/100-109 mm Hg) and as a continuous variable.


RESULTS
Among 759 women with singleton pregnancy and preenrollment BP less than 160/110 mm Hg, the incidence of the primary composite outcome (10.7%, 19.0%, 30%) and SGA (8.8%, 12.3%, 23.7%) increased with increasing BP category (P values≤.001). The adjusted odds ratio (95% confidence interval) for the primary composite was 2.0 (1.3-3.2) for 140-150/90-99 mm Hg and 3.2 (1.6-6.3) for 151-159/100-109 mm Hg compared with BP less than 140/90 mm Hg. The results for SGA were 1.6 (0.9-2.8) and 3.8 (1.8-7.9), respectively. Models including continuous systolic and diastolic BP revealed increasing adverse outcomes per 5-mm Hg rise in diastolic but not systolic BP: primary composite (19% per 5 mm Hg) and SGA (22% per 5 mm Hg).


CONCLUSIONS
The risks of adverse pregnancy outcomes in women with chronic hypertension are lower with preenrollment BP less than 140/90 mm Hg as compared with higher BP categories and increase with increasing BP.


METHODS
II.
Maternal-Fetal Medicine Division, Department of Obstetrics and Gynecology and the Center for Women's Reproductive Health, University of Alabama at Birmingham, Birmingham, Alabama.
Nana-Ama
NA
Ankumah
Jessica
J
Cantu
Victoria
V
Jauk
Joseph
J
Biggio
John
J
Hauth
William
W
Andrews
Alan Thevenet N
ATN
Tita
D000037:Abruptio Placentae / Q000453:epidemiology; D000328:Adult; D001794:Blood Pressure; D002908:Chronic Disease; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D015994:Incidence; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D054238:Perinatal Mortality; D011225:Pre-Eclampsia / Q000453:epidemiology; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000503:physiopathology*; D011256:Pregnancy Outcome / Q000453:epidemiology*; D047928:Premature Birth / Q000453:epidemiology; D018570:Risk Assessment; D055815:Young Adult