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This study aimed to evaluate the associations of fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c) levels at <24 weeks of gestation with hypertensive disorders of pregnancy (HDP) and compare the strengths of the associations of HDP with FPG and HbA1c levels. Totally, 1,178 participants were included in this prospective cohort study. HDP, FPG, HbA1c, and potential confounding factors were included in multiple logistic regression models. The number of HDP cases was 136 (11.5%). When FPG and HbA1c were included in the model separately, quartile 4 (Q4) of FPG (87-125 mg/dL) and HbA1c (5.2-6.3% [33-45 mmol/mol]) levels had higher odds of HDP than quartile 1. The odds ratios (ORs) were 1.334 (95% confidence interval [CI]: 1.002-1.775) for Q4 of FPG and 1.405 (95% CI: 1.051-1.878) for Q4 of HbA1c. When the participants were divided into two categories based on the cut-off value with the maximum Youden Index of FPG or HbA1c, the ORs for high FPG (≥84 mg/dL) or high HbA1c (≥5.2% [33 mmol/mol]) were 1.223 (95% CI: 1.000-1.496) and 1.392 (95% CI: 1.122-1.728), respectively. When both FPG and HbA1c were included in the model simultaneously, the statistical significance of Q4 of FPG disappeared, whereas that of HbA1c remained. In two-category models, the same results were obtained. High FPG and HbA1c levels at <24 weeks of gestation were risk factors for HDP in pregnant Japanese women. In addition, high HbA1c levels were more strongly associated with HDP than high FPG levels.

Background: Global studies exploring the relationship between parity and chronic kidney disease (CKD) are scarce. Furthermore, no study has examined the relationship between parity and CKD in Japan. Therefore, this study aimed to examine the relationship between parity and the prevalence of CKD in a Japanese population, considering the clinical history of hypertensive disorders of pregnancy (HDP) and current body mass index (BMI) based on menopausal status., Methods: This cross-sectional study included 26,945 Japanese multiparous women (5,006 premenopausal and 21,939 postmenopausal women) and 3,247 nulliparous women (1,599 premenopausal and 1,648 postmenopausal women). Participants were divided into two groups based on their menopausal status (premenopausal and postmenopausal women). The relationship between parity and the prevalence of CKD was evaluated using a multiple logistic regression model adjusted for several covariates, including a clinical history of HDP and current BMI., Results: The relationship between parity and the prevalence of CKD was not statistically significant in either premenopausal or postmenopausal multiparous women. A clinical history of HDP was significantly associated with an increased risk of CKD in premenopausal and postmenopausal multiparous women. However, the relationship between a clinical history of HDP and CKD in premenopausal women was weakened after adjusting for current BMI. Furthermore, the current BMI was significantly associated with an increased risk of CKD in both premenopausal and postmenopausal women., Conclusions: Parity is not significantly associated with the prevalence of CKD in premenopausal and postmenopausal multiparous women. A clinical history of HDP is a risk factor for CKD in both premenopausal and postmenopausal women. Current BMI is also associated with an increased risk of CKD in premenopausal and postmenopausal women. Therefore, continuous surveillance and preventive measures against CKD should be provided to women with a clinical history of HDP. In addition, maintaining an appropriate body weight is beneficial in reducing the risk of CKD., (© 2024. The Author(s).)

This study investigated the association of parity with hypertension prevalence in Japanese women while considering a clinical history of hypertensive disorders of pregnancy (HDP) and menopausal status. This cross-sectional study included 30,530 Japanese women (6700 premenopausal; 23 830 postmenopausal). The association between parity and the prevalence of hypertension was evaluated using a multiple logistic regression model with possible confounders. In premenopausal women, no statistically significant association between parity and hypertension prevalence was found. When not adjusted for current body mass index (BMI), a linear graded association was observed between parity and the prevalence of hypertension in postmenopausal women. However, the association between parity and hypertension prevalence in postmenopausal women was attenuated after adjustment for current BMI. Both current BMI and a clinical history of HDP were significantly associated with a high risk of hypertension in both premenopausal and postmenopausal women. Our results also suggest that continuous surveillance and preventive measures for hypertension should be provided for women with HDP and high parity., (© 2023 The Authors. The Journal of Clinical Hypertension published by Wiley Periodicals LLC.)

Objectives: This study aimed to investigate the association between maternal birth weight (MBW) and hypertensive disorders of pregnancy (HDP) according to the gestational age when HDP develops., Study Design: A total of 77,345 subjects were included in this prospective birth cohort study. The association between MBW and HDP was investigated by a multinomial logistic regression model., Main Outcome Measures: Early-onset HDP (EO-HDP), preterm late-onset HDP (preterm LO-HDP), and term late-onset HDP (term LO-HDP)., Results: Lower MBW was associated with higher odds of preterm and term LO-HDP (p-values for trend < 0.0001 and = 0.0005, respectively). A linear association between MBW and EO-HDP was observed (p-values for trend = 0.0496). The shape of the association between MBW and preterm LO-HDP was a combination of the associations between MBW with EO-HDP or LO-HDP. The effect size of the association between MBW < 2,500 g and EO-HDP was lower than that of MBW < 2,500 g with preterm or term LO-HDP. The adjusted odds ratios for EO-HDP, preterm LO-HDP, and term LO-HDP in subjects with MBW < 2,500 g were 1.052 (95 % confidence interval [CI]: 0.665-1.664), 1.745 (95 % CI: 1.220-2.496), and 1.496 (95 % CI: 1.154-1.939), respectively., Conclusions: MBW was associated with HDP, regardless of gestational age when HDP developed. Furthermore, the association of MBW < 2,500 g with preterm or term LO-HDP was stronger than that with EO-HDP., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Hypertensive disorders of pregnancy (HDP) are associated with poor maternal and neonatal prognoses. Although several studies have indicated an effect of secondhand smoke (SHS) exposure on HDP, such evidence is lacking in Japan. Therefore, we analyzed data from the Japan Environment and Children's Study, a large-scale epidemiological investigation, to elucidate a possible link between SHS exposure and HDP risk. Data were obtained from the all-birth fixed datasets and included information on 104,062 fetuses and their parents. SHS exposure was assessed in terms of the frequency (rarely, 1-3, or 4-7 days/week) and the daily duration of exposure (<1, 1-2, or ≥2 h(s)/day). Modified Poisson regression model analyses were performed with adjustment for known risk factors for HDP. Additionally, the population attributable fractions (PAFs) of SHS exposure and maternal smoking to HDP prevalence were estimated. The relative risks of developing HDP among individuals with SHS exposures of 4-7 days/week and ≥2 h/day were 1.18 and 1.27 (95% confidence interval: 1.02-1.36 and 0.96-1.67), respectively, compared to the reference groups (rare exposure and <1 h/day). The PAFs for the risk of HDP due to SHS exposure and perinatal smoking were 3.8% and 1.8%, respectively. Japanese women with greater exposure to SHS have a higher risk of HDP after adjustment for possible confounding factors; thus, relevant measures are required to reduce SHS exposure to alleviate HDP risk. The association between second-hand smoking exposure and hypertensive disorders of pregnancy risk was analyzed using the JECS data. The relative risks in 4-7 days/week and ≥2 h/day of SHS exposures were 1.18 and 1.27, respectively. The PAFs due to SHS exposure and maternal smoking were 3.80% and 1.81%, respectively., (© 2023. The Author(s).)

Background: The present study analyzed the relation of disaster exposure prior to pregnancy with maternal characteristics and obstetric outcomes., Methods: The participants were 13,148 pregnant women recruited from 2013 to 2017. The women were classified into three groups by the severity of housing damage caused by the Great East Japan Earthquake of 2011: group A, house was not destroyed/did not live in the disaster area; group B, half/part of the house was destroyed; and group C, house was totally/mostly destroyed. Maternal characteristics, hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), and gestational weeks were obtained using questionnaires and medical records. Multiple logistic regression analyses were performed to investigate the relation between disaster exposure and maternal characteristics, HDP, and GDM. A structural equation model was applied to investigate the relation of disaster exposure with HDP and gestational weeks., Results: The homes of about 11% of the women were totally/mostly destroyed. For groups B and C compared with those in group A, the adjusted ORs for HDP were 1.04 and 1.26 (P for trend = 0.01), and for GDM were 0.89 and 1.14 (P for trend = 0.9), respectively. Pre-pregnancy body mass index (BMI) mediated 23.2% of the relation between disaster exposure and HDP. Disaster exposure was associated with gestational weeks., Conclusion: Disaster exposure at least 2.5 years before pregnancy was found to be associated with maternal characteristics and the prevalence of HDP. Pre-pregnancy BMI mediated the relation between disaster exposure and the prevalence of HDP, and gestational weeks were reduced through HDP.

Objectives: To evaluate the major congenital malformation (MCM) risk of first-trimester antihypertensive exposure, specifically of amlodipine and methyldopa., Study Design: A large administrative claims database was used., Main Outcome Measures: The prevalence of antihypertensive prescriptions during pregnancy was described in 91,390 women giving birth between 2010 and 2019. The MCM risk of first-trimester antihypertensives was evaluated in 1,185 women diagnosed with hypertensive disorders in the first trimester. The MCM risk of first-trimester amlodipine and methyldopa was evaluated in 178 women who were prescribed antihypertensives in the first trimester., Results: Antihypertensives were prescribed to 278 (0.30%) women during their first trimester. The prescription prevalence in the first trimester was highest for methyldopa (115, 0.13%), followed by amlodipine (55, 0.06%). Antihypertensives were prescribed to 2,955 (3.23%) women during pregnancy. Nifedipine (903, 0.99%) and nicardipine (758, 0.83%) were the most frequently prescribed oral and injectable antihypertensives during pregnancy, both with a significant increase in annual prevalence. Of the 1,185 women diagnosed with hypertensive disorders in the first trimester, antihypertensives were prescribed to 178 women. The adjusted odds ratio (aOR) of MCMs in the first-trimester prescription of any antihypertensive medication was 1.124 (95% confidence interval [CI], 0.618-2.045). Amlodipine and methyldopa were prescribed to 44 and 93 of the 178 women, respectively. The aORs of MCMs in the first-trimester prescription of amlodipine and methyldopa were 1.219 (95% CI, 0.400-3.721) and 0.921 (0.331-2.564), respectively., Conclusions: The MCM risk of first-trimester exposure to antihypertensives, including amlodipine and methyldopa, was not suggested., Competing Interests: Declaration of Competing Interest Tomofumi Ishikawa is an employee of Pfizer R&D in Japan and a research collaborator at Tohoku University and has contributed to the present study independently of Pfizer R&D, Japan. Manabu Akazawa received consultation fees from RAD-AR: Risk/Benefit Assessment of Drugs Analysis and Response. Nariyasu Mano received presentation fees from Daiichi Sankyo Co. Ltd. The other authors have no conflicts of interest to declare., (Copyright © 2023 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.)

This study aimed to explore the relationship between dietary electrolyte intake and the prevalence of hypertensive disorders of pregnancy (HDP) subtypes. Our analysis included 19 914 pregnant women from the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. A food frequency questionnaire was used to estimate dietary calcium, potassium, sodium, and magnesium intakes. HDP was determined based on the medical records during regular antenatal care. Logistic regression analysis assessed the relationship between dietary electrolytes intake quintiles, and HDP subtypes with adjustment for basic characteristics. Dietary electrolyte intakes were applied for the prediction model. Of the cohort, 547 participants delivered with pre-eclampsia (PE), 278 with superimposed PE (SP), and 896 with gestational hypertension (GH). PE was associated with low crude calcium intake (odds ratio of the first quintile [<251 mg/day] to the fifth quintile [>623 mg/day] and 95% confidence interval, 1.31 [1.00-1.70]) and P for trend was .02. SP was not associated with any nutritional intake; however, the combined outcome of PE and SP was related to low crude calcium and potassium and energy-adjusted calcium, potassium, and magnesium intakes (P for trend, .01, .048, .02, .04, and .02, respectively). The same tendency was observed for GH. A prediction model that included crude calcium and potassium intakes performed better than a model without them. In conclusion, low dietary calcium, potassium, and magnesium were associated with higher HDP subtypes prevalence. The prediction model implied that crude calcium and potassium intakes might play a critical role in PE and SP pathogenesis., (© 2022 The Authors. The Journal of Clinical Hypertension published by Wiley Periodicals LLC.)

Hypertensive disorders of pregnancy increase the risk of adverse maternal and fetal outcomes. In 2018, the Japanese classification of hypertensive disorders of pregnancy was standardized with those of other countries, and a hypertensive disorder of pregnancy was considered to be present if hypertension existed during pregnancy and up to 12 weeks after delivery. Strategies for the prevention of hypertensive disorders of pregnancy have become much clearer, but further research is needed on appropriate subjects and methods of administration, and these have not been clarified in Japan. Although guidelines for the use of antihypertensive drugs are also being studied and standardized with those of other countries, the use of calcium antagonists before 20 weeks of gestation is still contraindicated in Japan because of the safety concerns that were raised regarding possible fetal anomalies associated with their use at the time of their market launch. Chronic hypertension is now included in the definition of hypertensive disorders of pregnancy, and blood pressure measurement is a fundamental component of the diagnosis of hypertensive disorders of pregnancy. Out-of-office blood pressure measurements, including ambulatory and home blood pressure measurements, are important for pregnant and nonpregnant women. Although conditions such as white-coat hypertension and masked hypertension have been reported, determining their occurrence in pregnancy is complicated by the gestational week. This narrative review focused on recent reports on hypertensive disorders of pregnancy, including those related to blood pressure measurement and classification., (© 2022. The Author(s), under exclusive licence to The Japanese Society of Hypertension.)

Low birth weight is known to be associated with hypertension, cardiovascular disease and hypertensive disorders of pregnancy (HDP); however, this association might vary by race/ethnicity. This study aimed to clarify the association between women's own birth weight and their subsequent risk for HDP in a Japanese population, in combination with pre-pregnancy body mass index (BMI). We conducted a cohort study as part of the Tohoku Medical Megabank Birth and Three-Generation Cohort Study in Miyagi, Japan. Our study's population included 4810 women. A multivariate logistic regression analysis was performed to calculate the adjusted odds ratio (aOR) and the 95% confidence interval (CI) of the women's own birth weight for HDP, in the combination categories of birth weight and pre-pregnancy BMI. As a result, the group with a low birth weight of <2500 g had a significant association with HDP (the aOR, 1.50; 95% CI, 1.02-2.21). In the subtype analysis, the odds ratio for only preeclampsia was significantly increased in the low birth weight group (aOR, 3.37; 95% CI, 1.84-6.16). In the group with a low birth weight, the prevalence of HDP was higher in both the underweight and overweight groups. In conclusion, there was a significant association between low birth weight and subsequent HDP in Japanese women. Furthermore, a significant association with HDP was found for women born with a low birth weight who were underweight or overweight as adults. Maintaining a normal weight may be effective for preventing HDP even if a woman was born small., (Copyright © 2020. Published by Elsevier B.V.)

A hypertensive disorder of pregnancy (HDP) is defined as hypertension emerging after 20 weeks of gestation and resolving up to 12 weeks post-partum, and occurs in about 5% of all pregnancies. Complications associated with HDP have poor prognoses, and maternal deaths attributable to HDP are predicted to exceed 70 000 per year worldwide. Understanding the pathogenesis and risk factors of hypertensive disorders of pregnancy is important, and they are often investigated in observational studies. Given that therapeutic interventions cannot be controlled in observed studies, it is necessary to interpret which factors correspond to exposure and which factors correspond to confounding and intermediate factors in each study. From the Babies and their parents' longitudinal observation in the Suzuki Memorial Hospital on Intrauterine period study, blood pressure in early pregnancy was not only predictive of a child's birthweight, but the trajectory was also associated with the birthweight. From the larger-scale birth cohort studies currently conducted in Japan will provide the novel potential risk factors of hypertensive disorders of pregnancy and preventive strategies of them. In Japan, observational or intervention studies are just beginning to emerge. The continuation of both a distinctive cohort and a large cohort is needed, and the development of good quality intervention trials based on the results of observational studies is important., (© 2020 Japan Society of Obstetrics and Gynecology.)

This study investigated the association between maternal home blood pressure (HBP) trajectory during pregnancy and infant birth weight. A total of 755 pregnant women were included in this prospective cohort study. A group-based trajectory model identified six trajectory groups for home systolic blood pressure (SBP), diastolic BP (DBP), and mean arterial pressure (MAP). Next, the association of HBP trajectory groups with infant birth weight was evaluated using a general linear model considering potential confounding factors. For home SBP and MAP, the trajectory groups with a low-steep J-curve, moderate J-curve, little high J-curve, and high J-curve were significantly associated with lower infant birth weight than the low-J-curve group. Among the trajectory groups for home DBP, the moderate-steep J-curve, little high J-curve, and high J-curve were significantly associated with lower infant birth weight than the group with low-J-curve. The effect sizes of the trajectory groups varied in infant birth weight from -0.21 standard deviations (SDs) (95% confidence interval (CI): -0.42 to -0.01 SD) to -1.13 SD (95% CI: -1.54 to -0.72 SD). In the analyses of infant birth weight in grams, effect sizes that were significantly associated with infant birth weight varied from -84 g (95% CI: -167 to -1 g) to -567 g (95% CI: -732 to -402 g). Trajectory groups with a moderate-reverse J-curve for home SBP, DBP, and MAP were not significantly associated with infant birth weight. Maternal HBP trajectory during pregnancy was an indicator of infant birth weight. Further studies evaluating the associations between HBP during pregnancy and other perinatal outcomes are needed.

Smoking during pregnancy is a risk factor for various adverse birth outcomes but lowers the risk of preeclampsia. Cardiovascular adaptations might underlie these associations. We examined the association of maternal smoking with the risk of hypertensive disorders of pregnancy (HDP) in a low-risk population-based cohort of 76,303 pregnant women. This study was a part of the Japan Environment and Children's Study. Smoking status was assessed using questionnaires completed by participants. Information about HDP was assessed using questionnaires completed by doctors. Compared with that for women who did not smoke, women who continued smoking >10 cigarettes per day during pregnancy had a significantly higher risk of developing HDP (odds ratio: 1.58, 95% confidence interval: 1.11-2.25). In multivariate analyses with adjustment for possible confounding factors, the association still remained (odds ratio: 1.51, 95% confidence interval: 1.04-2.19). When we regarded the number of cigarettes as a continuous variable, there was a linear association between the number of cigarettes and risk of HDP, with an odds ratio of 1.02 per cigarette per day (95% confidence interval: 1.00-1.04). Smoking a greater number of cigarettes was associated with a higher risk of HDP after adjustment for possible confounding factors. Cigarette smoking cessation may avoid the complications of HDP. Our findings suggest that, in addition to the risk of small-for-gestational-age children, an increased risk of HDP should be considered in the management of pregnant women who smoke cigarettes.

Blood pressure (BP) is important to measure during pregnancy because it provides the basis for classifying hypertension, which has several etiologies. Similarly, monitoring home and ambulatory BP can provide useful information outside a medical setting for adults who are not pregnant. Office BP is higher during early pregnancy in primiparous women than in multiparous women, whereas out-of-office BP does not differ between them. White-coat hypertension might be benign compared with hypertension determined from ambulatory BP values that might be associated with a high risk for preeclampsia. Although reference values have been proposed on the basis of the distribution of BP among normotensive pregnant women, prognosis-based reference values are also required.

Parity has previously been reported to affect the difference in blood pressure (BP) measured in the office and at home, also known as the white-coat effect, during pregnancy. The objective of this study was to identify possible factors that cause the white-coat effect during pregnancy, focusing on parity. In total, 530 pregnant women (31.3±4.7 years old) who delivered at a maternal clinic were eligible for the study. The association between parity and the white-coat effect (clinic BP compared with home BP) was investigated for each trimester of pregnancy by multivariate analysis of covariance adjusted for age, body mass index, family history of hypertension and smoking habits. The magnitudes of the white-coat effect for systolic BP in the first, second and third trimesters were 4.1±9.8, 3.4±7.1 and 1.8±6.0 mm Hg, respectively and those for diastolic BP were 3.8±7.4, 1.6±5.8 and 2.4±4.9 mm Hg, respectively. Parity was significantly and negatively associated with the white-coat effect for systolic BP in the first trimester of pregnancy (nulliparous women: 5.07±0.61 mm Hg and multiparous women: 2.78±0.74 mm Hg, P=0.02) as well as for diastolic BP in the second and third trimesters of pregnancy. Age, body mass index, family history of hypertension and smoking were not significantly associated with the white-coat effect in any trimester of pregnancy. Parity may have an influence on the white-coat effect in pregnancy; however, the observed effect, on average 1-2 mm Hg, was small.

Objective: To assess the present status of clinical care for postpartum patients with hypertensive disorders of pregnancy (HDP) in Japan., Methods: We conducted a nationwide questionnaire survey of obstetricians, internists and hypertension specialists and analyzed 686 valid responses., Results: Though HDP is widely known as a risk factor for subsequent hypertension and cardiovascular disease, over one-third of obstetricians terminated their postpartum follow-up of HDP patients without referring them to other departments., Conclusion: It is important to establish an effective referral system, whereby patients with HDP can be smoothly transferred to primary care or a specialist physician after childbirth for long-term monitoring and management of blood pressure.

Background: Information regarding salt intake in pregnant women in Japan is limited. An electronic system for the assessment of salt intake using a 24-h dietary recall method has been developed in Japan. The objectives of the present study were to investigate salt intake in pregnant women and to compare the salt intake estimated by the electronic salt intake assessment system with that measured by 24-h urinary salt excretion (24-hUNaCl)., Methods: Data were collected on 24-hUNaCl and salt intake estimated by the salt intake assessment system for 35 pregnant Japanese women at approximately 20 weeks of gestation. The adjusted 24-hUNaCl (24-hUNaCl/[the number of urinations during the examination day--the number of missing urine collections] × the number of urinations during the examination day, g/day) was used as a standard., Results: The mean adjusted 24-hUNaCl was 7.7 ± 2.5 g/day, and mean systolic/diastolic blood pressure values were 106.1 ± 8.6/62.8 ± 6.5 mmHg. The adjusted 24-hUNaCl was significantly correlated with the salt intake estimated by the salt intake assessment system (r = 0.47, p = 0.004). Bland-Altman analysis showed no significant mean difference (adjusted 24-hUNaCl--salt intake estimated by the assessment system = -0.36 g/day, p = 0.4) and no significant proportional bias (p = 0.1)., Conclusion: These results suggest that pregnant women in Japan restrict their salt intake, at least when they are being examined for salt intake. They also suggest that repeated use of the described system may be useful in estimating salt intake in pregnant women.

The aim of this study was to determine the effects of pre-gestational body mass index on pregnancy outcomes of women with gestational diabetes in Japan. A multi-institutional retrospective study was performed. We examined pregnant women who met the former criteria for gestational diabetes in Japan, receiving dietary intervention with self-monitoring of blood glucose with or without insulin therapy. Women with gestational diabetes were divided into three groups according to pre-gestational body mass index: body mass index <25 (control group), 25 ≤ body mass index <30 (overweight group), body mass index ≥30 (obese group). Data from a total of 1,758 eligible women were collected from 40 institutions. Participants included 960 controls, 426 overweight women, and 372 obese women with gestational diabetes. Gestational weight gain was highest in the control and lowest in the obese group. The prevalences of chronic hypertension and pregnancy induced hypertension were higher in the overweight and obese groups than in the control group. Multiple logistic regression analysis revealed pre-gestational body mass index, gestational weight gain, chronic hypertension, and nulliparity to be associated with the onset of pregnancy induced hypertension, while the 75-g OGTT results were unrelated to pregnancy induced hypertension. The prevalence of large-for-gestational age was lower in infants born to obese women than in those born to overweight or control women. The present results suggest that medical interventions for obese women with gestational diabetes may contribute to reducing the prevalence of large-for-gestational age but would not achieve marked reductions in maternal complications.

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.