Changes In Blood Pressure During Different Periods In Normal Pregnancy And Its Related Determinants

Objective:To study the longitudinal changes of blood pressure(BP)during different perilds in normal pregnancy and its related determinants.Methods:14townships were randomly selected by cluster random sampling method from37townships in Liuyang city,Hunan province.Subjects are all women at childbearing age in these14townships registered from April2008to December2011. When the subjects visited to the local maternity and child-care agencies for pre-marital check,they were face-to-face interviewed and asked to fill out the questionnaire and finish the medical examination. Following-up program was carried out until delivery, with BP and other pregnancy information checked and collected. Analysis on variance of data regarding repeated measurements were used to investigate the changes of BP and related determinants.Results:1.General condition:642normal-conception women were investigated in our study. Age between20with42, BMI in pre-pregnancy is between14.02and20.26kg/m2, Waist circumference in pre-pregnancy is between49and99cm.2.Blood pressure of three periods after pregnancy are lower than that of pre-pregnancy, BP of third trimester is higher than that of first trimester and second trimester, the difference was statistically significant. SBP and DBP both indicated statistically significant change in four time points, also the linear trend test was statistically significant.3.Pre-pregnancy BMI, pre-pregnancy WC,pre-pregnancy Glu, pre-pregnancy TG,pregnancy history and annual per capita income were determinants which affect the changes of blood pressure during normal pregnnacy. Higher pre-pregnancy BMI,wider pre-pregnancy waist circumference and higher annual per capita income are associated with higher blood pressure, and annual per capita income mainly affect the pre-pregnancy blood pressure.Conclusion:1.Blood pressure of three periods after pregnancy are lower than that of pre-pregnancy, BP of third trimester is higher than that of first trimester and second trimester.2. Pre-pregnancy BMI,pre-pregnancy WC,pre-pregnancy Glu, pre-pregnancy TG,pregnancy history and annual per capita income were determinants which affect the changes of blood pressure.