Chronic Hypertension: First Trimester BP Control and Risk of Adverse Pregnancy Outcomes

Sarfaroj Khan 


March 01, 2021


  • Adverse perinatal outcomes, including foetal growth restriction (FGR), admission to neonatal (NNU) or neonatal intensive care unit (NICU), and composite neonatal morbidity, are worse in women with known chronic hypertension (CH) who are on antihypertensive medication in the first trimester of pregnancy.

Why this matters

  • Findings warrant intensive monitoring in women with CH who fail to adapt optimally in early pregnancy.

Study details

  • This prospective observational study assessed perinatal outcomes in 798 women with CH stratified into 4 groups according to their blood pressure (BP) control in the first trimester of pregnancy:

    • Group 1, n=100: no CH history presenting with BP>140/90 mmHg;

    • Group 2, n=234: BP<140/90 mmHg without antihypertensives;

    • Group 3, n=272: BP<140/90 mmHg with antihypertensives; and

    • Group 4, n=192: BP≥140/90 mmHg despite antihypertensives.

  • Funding: None.

Key results

  • Groups 3 and 4 vs groups 1 and 2 had a higher incidence of:

    • FGR: 17.6% and 18.2% vs 10.0% and 11.1%; P=.04;

    • admissions to the NNU for ≥2 days: 23.2% and 25.0% vs 17.0% and 13.2%; P=.008;

    • admissions to NICU for ≥2 days: 9.2% and 9.4% vs 3.0% and 3.4%; P=.01; and

    • composite neonatal morbidity: 22.4% and 21.4% vs 17.0% and 11.5%; P=.009, respectively.

  • The incidence of serious adverse postnatal outcome was higher in groups 3 and 4 vs groups 1 and 2 (3.3% and 4.2% vs 1.0% and 0.9%), but the difference did not reach statistical significance (P=.09).

  • Groups 3 and 4 vs groups 1 and 2 had a significantly higher rate of:

    • severe hypertension: 25% and 53.1% vs 16% and 11.1%; P<.0001;

    • superimposed pre-eclampsia: 38.6% and 42.2% vs 27% and 23.1%; P<.0001;

    • preterm birth: 17.6% and 23.4% vs 15% and 9%; P=.001; and

    • caesarean section delivery: 55.9% and 51.6% vs 38% and 36.3%; P<.0001.


  • Small sample size in group 1.


Dumitrascu-Biris D, Nzelu D, Dassios T, Nicolaides K, Kametas NA. Chronic hypertension in pregnancy stratified by first trimester blood pressure control and adverse perinatal outcomes: a prospective observational study. Acta Obstet Gynecol Scand. 2021 Feb 20 [Epub ahead of print]. doi: 10.1111/aogs.14132. PMID: 33609284. View abstract 

This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.


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