Seasonal trends of blood pressure during pregnancy in Japan: The Babies and their Parents Longitudinal Observation in Suzuki Memorial Hospital in Intrauterine Period study

Hirohito Metoki, Takayoshi Ohkubo, Yumiko Watanabe, Misato Nishimura, Yurie Sato, Maiko Kawaguchi, Azusa Hara, Takuo Hirose, Taku Obara, Kei Asayama, Masahiro Kikuya, Katsuyo Yagihashi, Yoichi Matsubara, Kunihiro Okamura, Shigeru Mori, Masakuni Suzuki, Yutaka Imai

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Abstract

OBJECTIVE: Blood pressure (BP) increases both in winter and in the last trimester of pregnancy. Some interaction seems to exist between season and gestational age. The present study observed home BP values during pregnancy with adjustment for seasonal variation and gestational age. METHODS: We observed 10 353 home BP measurements from 101 normal pregnant women attending a maternity hospital in Japan. Home BP values were examined by mixed linear model adjusting for meteorological data and gestational age. RESULTS: The lowest home BP values were observed in the second trimester [mean (±standard deviation) systolic/diastolic BP, 101.8 ± 7.9/59.8 ± 5.8 mmHg at gestational week 20]. In the last trimester, home BP values gradually increased and the values after gestational week 26 were significantly higher than those at gestational week 20 (110.1 ± 9.7/66.8 ± 7.7 mmHg at gestational week 40). A 10°C increase in daily minimum outdoor temperature was associated with a mean reduction of 2.5/2.5 mmHg (Δ systolic BP/Δ diastolic BP: 95% confidence interval, 2.3/2.4 to 2.6/2.7 mmHg) in home BP with adjustment for gestational age. The largest and smallest estimated home BP changes during pregnancy were 12.8/12.5 and 3.1/3.0 mmHg in pregnant woman who delivered in January and July, respectively. CONCLUSION: Interactions among BP, season and gestational age should be considered when evaluating BP in pregnant women. Risks associated with high BP might be underestimated in pregnant woman in summer who will deliver in winter.

Original languageEnglish
Pages (from-to)2406-2413
Number of pages8
JournalJournal of hypertension
Volume26
Issue number12
DOIs
Publication statusPublished - 2008 Dec 1
Externally publishedYes

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Keywords

  • Blood pressure measurement/monitoring
  • Clinical science
  • Home blood pressure
  • Preeclampsia/pregnancy

ASJC Scopus subject areas

  • Internal Medicine
  • Physiology
  • Cardiology and Cardiovascular Medicine

Cite this

Metoki, H., Ohkubo, T., Watanabe, Y., Nishimura, M., Sato, Y., Kawaguchi, M., Hara, A., Hirose, T., Obara, T., Asayama, K., Kikuya, M., Yagihashi, K., Matsubara, Y., Okamura, K., Mori, S., Suzuki, M., & Imai, Y. (2008). Seasonal trends of blood pressure during pregnancy in Japan: The Babies and their Parents Longitudinal Observation in Suzuki Memorial Hospital in Intrauterine Period study. Journal of hypertension, 26(12), 2406-2413. https://doi.org/10.1097/HJH.0b013e32831364a7