Blood pressure measured in the clinic and at home during pregnancy among nulliparous and multiparous women: the BOSHI study.

BACKGROUND: Hypertension during pregnancy can cause serious problems during delivery, such as stroke, premature delivery, or low birthweight. Nulliparity is believed to be a risk factor for hypertension during pregnancy. However, the relationship between parity and blood pressure determined at home during pregnancy is still unknown. METHODS: We assessed the incidence of gestational hypertension or preeclampsia in 575 nulliparous and multiparous women. Also, we examined blood pressure measured in the clinic and at home among 530 normotensive pregnant women who received antenatal care at a maternity hospital in Japan. Clinic blood pressures (CBPs) were obtained by duplicate measurement at each antenatal care visit. The participants were also required to measure their own blood pressures every morning at home while they were pregnant. A linear mixed model was used for analysis of the blood pressure course throughout pregnancy. RESULTS: A total of 315 nulliparous and 215 multiparous women were entered into this study (mean age, 30.1 ± 4.6 years and 33.0 ± 4.1 years, respectively). CBP levels during pregnancy among nulliparous women were significantly higher than among multiparous women (P = 0.02/P <0.0001 for systolic/diastolic blood pressure), whereas there were no significant differences in home blood pressure (HBP) levels during pregnancy between the two groups (P = 0.4/P = 0.2 for systolic/diastolic blood pressure). CONCLUSIONS: HBP levels during pregnancy were shown not to differ between nulliparous and multiparous women, while CBP levels during pregnancy were higher among nulliparous than among multiparous women.

Daily serial hemodynamic data during pregnancy and seasonal variation: the BOSHI study.

Although there are some reports that low plasma volume or increased cardiac output is associated with developing preeclampsia, there are few reports of daily serial hemodynamic data during pregnancy. A total of 37,092 home blood pressure (BP) and heart rate (HR) measurements were obtained from 425 normal pregnant women. Heart rate and shock index (SI) gradually increased by gestational week 32 and then decreased, whereas double product (DP) increased linearly during pregnancy. Although systolic BP and DP were consistently and negatively correlated with daily minimum outside temperature, HR and SI were positively correlated with minimum outside temperature in summer.