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Gestational-age-specific reference ranges for blood pressure in pregnancy: findings from a prospective cohort.

Macdonald-Wallis C, Silverwood RJ, Fraser A, Nelson SM, Tilling K, Lawlor DA, de Stavola BL - J. Hypertens. (2015)

Bottom Line: Stratified reference ranges were higher for women in higher prepregnancy BMI categories, and lower for smokers than for nonsmokers throughout pregnancy.Normal ranges for blood pressure vary with gestation age and by maternal subgroups.Whole population and stratified normograms could be used as a reference to identify abnormal trajectories.

View Article: PubMed Central - PubMed

Affiliation: aMRC Integrative Epidemiology Unit at the University of Bristol bSchool of Social and Community Medicine, University of Bristol, Bristol cCentre for Statistical Methodology dDepartment of Medical Statistics, London School of Hygiene and Tropical Medicine, London eSchool of Medicine, University of Glasgow, Glasgow, UK.

ABSTRACT

Objective: Pregnancy is a period of considerable change in blood pressure, with an early pregnancy decrease followed by a late pregnancy rise. High blood pressure in pregnancy is associated with adverse perinatal outcomes for the mother and offspring. We aimed to define normal ranges of blood pressure across gestation.

Methods: We used repeated antenatal blood pressure measurements [median (interquartile range) 10 (9-11) per woman] for 10,327 women. Multilevel models were used to derive longitudinal reference ranges for SBP and DBP from 12 to 40 weeks gestation for the whole cohort, for women with normal pregnancies (without essential hypertension or preeclampsia who delivered an appropriate-size-for-gestational age infant at term) and for subgroups of normal pregnancies defined by different levels of maternal prepregnancy BMI, smoking and parity.

Results: In normal pregnancies, the mean (95% reference range) SBP and DBP for iparous women at 12 weeks gestation were 112.1 (88.6-135.5) and 65.4 (48.9-81.9) mmHg, and at 37 weeks were 116.0 (92.3-139.7) and 70.0 (52.2-87.9) mmHg, respectively. For every additional 10  mm Hg of blood pressure at 12 weeks, normal ranges were 2-3 mm Hg higher across gestation. Reference ranges for multiparous women were 1-2  mm Hg lower throughout pregnancy. Stratified reference ranges were higher for women in higher prepregnancy BMI categories, and lower for smokers than for nonsmokers throughout pregnancy.

Conclusion: Normal ranges for blood pressure vary with gestation age and by maternal subgroups. Whole population and stratified normograms could be used as a reference to identify abnormal trajectories.

No MeSH data available.


Related in: MedlinePlus

Reference ranges for systolic and diastolic blood pressure between 12 and 40 weeks gestation in low-risk (iparous N = 1832; multiparous N = 2193) and high-risk (iparous N = 205; multiparous N = 285) normal pregnancies. Centiles are labelled. The low-risk group included women who had a normal prepregnancy BMI and did not smoke either immediately prior to or during pregnancy. The high-risk group included overweight or obese women who smoked either immediately prior to pregnancy, in the first trimester or throughout pregnancy.
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Figure 2: Reference ranges for systolic and diastolic blood pressure between 12 and 40 weeks gestation in low-risk (iparous N = 1832; multiparous N = 2193) and high-risk (iparous N = 205; multiparous N = 285) normal pregnancies. Centiles are labelled. The low-risk group included women who had a normal prepregnancy BMI and did not smoke either immediately prior to or during pregnancy. The high-risk group included overweight or obese women who smoked either immediately prior to pregnancy, in the first trimester or throughout pregnancy.

Mentions: The reference ranges of SBP and DBP across gestation in the low-risk group (normal prepregnancy BMI; never smoked) and in the high-risk group (overweight/obese; smoked at any time either immediately prior to or during pregnancy) of women who had normal pregnancies are shown in Fig. 2. Supplementary Table 2 summarizes the predicted values and 95% reference ranges of SBP and DBP at 12, 20 and 37 weeks gestation. Reference ranges in the high-risk group were generally around 4 mmHg higher than in the low-risk group across pregnancy for both iparous and multiparous women. SBP for iparous women in the high-risk group did not show a mid-pregnancy dip, but increased throughout pregnancy.


Gestational-age-specific reference ranges for blood pressure in pregnancy: findings from a prospective cohort.

Macdonald-Wallis C, Silverwood RJ, Fraser A, Nelson SM, Tilling K, Lawlor DA, de Stavola BL - J. Hypertens. (2015)

Reference ranges for systolic and diastolic blood pressure between 12 and 40 weeks gestation in low-risk (iparous N = 1832; multiparous N = 2193) and high-risk (iparous N = 205; multiparous N = 285) normal pregnancies. Centiles are labelled. The low-risk group included women who had a normal prepregnancy BMI and did not smoke either immediately prior to or during pregnancy. The high-risk group included overweight or obese women who smoked either immediately prior to pregnancy, in the first trimester or throughout pregnancy.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4255761&req=5

Figure 2: Reference ranges for systolic and diastolic blood pressure between 12 and 40 weeks gestation in low-risk (iparous N = 1832; multiparous N = 2193) and high-risk (iparous N = 205; multiparous N = 285) normal pregnancies. Centiles are labelled. The low-risk group included women who had a normal prepregnancy BMI and did not smoke either immediately prior to or during pregnancy. The high-risk group included overweight or obese women who smoked either immediately prior to pregnancy, in the first trimester or throughout pregnancy.
Mentions: The reference ranges of SBP and DBP across gestation in the low-risk group (normal prepregnancy BMI; never smoked) and in the high-risk group (overweight/obese; smoked at any time either immediately prior to or during pregnancy) of women who had normal pregnancies are shown in Fig. 2. Supplementary Table 2 summarizes the predicted values and 95% reference ranges of SBP and DBP at 12, 20 and 37 weeks gestation. Reference ranges in the high-risk group were generally around 4 mmHg higher than in the low-risk group across pregnancy for both iparous and multiparous women. SBP for iparous women in the high-risk group did not show a mid-pregnancy dip, but increased throughout pregnancy.

Bottom Line: Stratified reference ranges were higher for women in higher prepregnancy BMI categories, and lower for smokers than for nonsmokers throughout pregnancy.Normal ranges for blood pressure vary with gestation age and by maternal subgroups.Whole population and stratified normograms could be used as a reference to identify abnormal trajectories.

View Article: PubMed Central - PubMed

Affiliation: aMRC Integrative Epidemiology Unit at the University of Bristol bSchool of Social and Community Medicine, University of Bristol, Bristol cCentre for Statistical Methodology dDepartment of Medical Statistics, London School of Hygiene and Tropical Medicine, London eSchool of Medicine, University of Glasgow, Glasgow, UK.

ABSTRACT

Objective: Pregnancy is a period of considerable change in blood pressure, with an early pregnancy decrease followed by a late pregnancy rise. High blood pressure in pregnancy is associated with adverse perinatal outcomes for the mother and offspring. We aimed to define normal ranges of blood pressure across gestation.

Methods: We used repeated antenatal blood pressure measurements [median (interquartile range) 10 (9-11) per woman] for 10,327 women. Multilevel models were used to derive longitudinal reference ranges for SBP and DBP from 12 to 40 weeks gestation for the whole cohort, for women with normal pregnancies (without essential hypertension or preeclampsia who delivered an appropriate-size-for-gestational age infant at term) and for subgroups of normal pregnancies defined by different levels of maternal prepregnancy BMI, smoking and parity.

Results: In normal pregnancies, the mean (95% reference range) SBP and DBP for iparous women at 12 weeks gestation were 112.1 (88.6-135.5) and 65.4 (48.9-81.9) mmHg, and at 37 weeks were 116.0 (92.3-139.7) and 70.0 (52.2-87.9) mmHg, respectively. For every additional 10  mm Hg of blood pressure at 12 weeks, normal ranges were 2-3 mm Hg higher across gestation. Reference ranges for multiparous women were 1-2  mm Hg lower throughout pregnancy. Stratified reference ranges were higher for women in higher prepregnancy BMI categories, and lower for smokers than for nonsmokers throughout pregnancy.

Conclusion: Normal ranges for blood pressure vary with gestation age and by maternal subgroups. Whole population and stratified normograms could be used as a reference to identify abnormal trajectories.

No MeSH data available.


Related in: MedlinePlus