Maternal BP and the Risk of Hypertensive Disorders of Pregnancy at High Altitudes

Pavankumar Kamat


June 10, 2021


  • Systemic arterial blood pressure (BP) was higher at full term in pregnancies at high altitudes (>2500 m) compared with low altitudes (<2500 m), which was associated with an increased risk of gestational hypertension, but not pre-eclampsia.

  • In addition, the risk of stillbirth was greater at high altitudes.

Why this matters

  • Findings emphasise the importance of BP monitoring during pregnancy at high altitudes, as this population may be at a higher risk of complications resulting from high BP.

Study design

  • Researchers at the University of Cambridge performed a meta-analysis of 27 studies involving 1,721,984 pregnancies, identified through a search across electronic databases.

  • Funding: None.

Key results

  • Maternal systolic BP (SBP; 4.8±1.6 mmHg; P<.01) and diastolic BP (DBP; 4.0±0.8 mmHg; P<.001) at term were higher at high vs low altitudes.

  • The magnitude of difference was similar for both SBP and DBP.

  • Hypertensive disorders of pregnancy were significantly more common in pregnancies at high vs low altitudes (OR, 1.31; 95% CI, 1.03-1.65; P<.05; I2, 52.5%).

  • The risk of gestational hypertension was almost twice as likely in high altitude pregnancies than in low altitude pregnancies (OR, 1.92; 95% CI, 1.15-3.22; P<.05; I2, 66.8%).

  • The risk of pre-eclampsia was significantly lower in high vs low altitude pregnancies (OR, 0.57; 95% CI, 0.46-0.70; P<.001; I2, 95.2%).

  • The risk of stillbirth was higher in high altitude pregnancies vs low altitude pregnancies (OR, 1.63; 95% CI, 1.12-2.35; P<.01; I2, 85.0%).


  • Heterogeneity among studies.


Grant I, Giussani DA, Aiken CE. Blood pressure and hypertensive disorders of pregnancy at high altitude: A systematic review and meta-analysis. Am J Obstet Gynecol MFM. 2021 May 20 [Epub ahead of print]:100400. doi: 10.1016/j.ajogmf.2021.100400. PMID: 34023533.  View full text

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


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