Background
Recently updated American College of Cardiology/ American Heart Association (ACC/AHA)
guidelines redefine blood pressure categories as stage 1 hypertension (systolic, 130–139
mm Hg or diastolic, 80–89 mm Hg), elevated (systolic, 120–129 mm Hg and diastolic,
<80 mm Hg), and normal (<120/<80 mm Hg), but their relevance to an obstetric population
is uncertain.
Objective
We sought to evaluate the risk of gestational hypertension or preeclampsia based on
early pregnancy blood pressure category and trajectory.
Study Design
We utilized data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be
cohort, a prospective observational study of nulliparous women with singleton pregnancies
conducted at 8 clinical sites between 2010 and 2014. Women included in this analysis
had no known history of prepregnancy hypertension (blood pressure, ≥140/90 mm Hg)
or diabetes. We compared the frequency of hypertensive disorders of pregnancy, including
preeclampsia and gestational hypertension, among women based on ACC/AHA blood pressure
category at a first-trimester study visit and blood pressure trajectory between study
visits in the first and second trimesters. Blood pressure trajectories were categorized
based on blood pressure difference between visits 1 and 2 as stable (<5 mm Hg difference),
upward (≥5 mm Hg), or downward (≤-5 mm Hg). Associations of blood pressure category
and trajectory with preeclampsia and gestational hypertension were assessed via univariate
analysis and multinomial logistic regression analysis with covariates identified a
priori.
Results
A total of 8899 women were included in the analysis. Study visit 1 occurred at a mean
gestational age of 11.6 ± 1.5 weeks and study visit 2 at a mean gestational age of
19.0 ± 1.6 weeks. First-trimester blood pressure category was significantly associated
with both preeclampsia and gestational hypertension, with increasing blood pressure
category associated with a higher risk of all hypertensive disorders of pregnancy.
Elevated blood pressure was associated with an adjusted relative risk of 1.54 (95%
confidence interval, 1.18–2.02) and stage 1 hypertension was associated with adjusted
relative risk of 2.16 (95% confidence interval, 1.31–3.57) of any hypertensive disorder
of pregnancy. Stage 1 hypertension was associated with the highest risk of preeclampsia
with severe features, with an adjusted relative risk of 2.48 (95% confidence interval,
1.38–8.74). Both systolic and diastolic blood pressure trajectories were also significantly
associated with the risk of hypertensive disorders of pregnancy independent of blood
pressure category (P < .001). Women with a blood pressure categorized as normal and with an upward systolic
trajectory had a 41% increased risk of any hypertensive disorder of pregnancy (adjusted
relative risk, 1.41; 95% confidence interval, 1.20–1.65) compared to women with a
downward systolic trajectory.
Conclusion
In nulliparous women, blood pressure category and trajectory in early pregnancy are
independently associated with risk of preeclampsia and gestational hypertension. Our
study demonstrates that blood pressure categories with lower thresholds than those
traditionally used to identify individuals as hypertensive may identify more women
at risk for preeclampsia and gestational hypertension.
Key words
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References
- 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.Hypertension. 2018; 71: e13-e15
- Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies.Lancet. 2002; 360: 1903-1913
- Risk of adverse pregnancy outcomes in women with mild chronic hypertension before 20 weeks of gestation.Obstet Gynecol. 2014; 123: 966-972
- Chronic hypertension and pregnancy outcomes: systematic review and meta-analysis.BMJ. 2014; 348: g2301
- Aspirin versus placebo in pregnancies at high risk for preterm preeclampsia.N Engl J Med. 2017; 377: 613-622
- Predictable blood pressure variability in healthy and complicated pregnancies.Hypertension. 2001; 38: 736-741
- Blood pressure variability during gestation in healthy and complicated pregnancies.Hypertension. 1997; 30: 611-618
- Aspirin effect on adverse pregnancy outcomes associated with stage 1 hypertension in a high-risk cohort.Hypertension. 2018; 72: 202-207
- Maternal outcomes associated with lower range stage 1 hypertension.Obstet Gynecol. 2018; 132: 843-849
- A description of the methods of the Nulliparous Pregnancy Outcomes Study: monitoring mothers-to-be (nuMoM2b).Am J Obstet Gynecol. 2015; 212: 539.e1-539.e4
- Recommendations for blood pressure measurement in humans and experimental animals.Circulation. 2005; 111: 697-716
- Association between sleep-disordered breathing and hypertensive disorders of pregnancy and gestational diabetes mellitus.Obstet Gynecol. 2017; 129: 31-41
- Gestational Hypertension and Preeclampsia.Obstet Gynecol. 2019; 133: e1-e25
- Estimated impact of the 2017 American College of Cardiology/American Heart Association blood pressure guidelines on reproductive-aged women.Hypertension. 2018; 72
- Impact of the new American hypertension guidelines on the prevalence of postpartum hypertension.Am J Perinatol. 2019; 36: 440-442
- Chronic Hypertension in Pregnancy.Obstet Gynecol. 2019; 133: e26-e50
- Prehypertension in early pregnancy: what is the significance?.Am J Perinatol. 2017; 34: 117-122
- Prehypertension during pregnancy and risk of small for gestational age: a systematic review and meta-analysis.J Matern Neonatal Med. 2018; : 1-8
- The prevalence and nature of the use of preconception services by women with chronic health conditions: an integrative review.BMC Womens Health. 2015; 15: 14
- Potential US population impact of the 2017 ACC/AHA high blood pressure guideline.Circulation. 2018; 137: 109-118
Article Info
Publication History
Published online: June 27, 2019
Accepted:
June 12,
2019
Received in revised form:
June 10,
2019
Received:
February 27,
2019
Footnotes
The authors report no conflict of interest.
This work was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development : U10 HD063036 , RTI International ; U10 HD063072 , Case Western Reserve University ; U10 HD063047 , Columbia University ; U10 HD063037 , Indiana University ; U10 HD063041 , University of Pittsburgh ; U10 HD063020 , Northwestern University ; U10 HD063046 , University of California, Irvine ; U10 HD063048 , University of Pennsylvania ; and U10 HD063053 , University of Utah, and NIH/ORWH Building Interdisciplinary Research Careers in Women's Health (BIRCWH) NIH K12HD043441 scholar funds to A.H.
Cite this article as: Hauspurg H, Parry S, Mercer BM, et al. Blood pressure trajectory and category and risk of hypertensive disorders of pregnancy in nulliparous women. Am J Obstet Gynecol 2019;221:277.e1-8.
Identification
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© 2019 Elsevier Inc. All rights reserved.
