Study on the regularity of blood pressure changes in pregnant women and its influencing factors

Abstract

Objective

To explore the patterns and influencing factors of blood pressure changes in pregnant women at different stages of pregnancy.

Method

A retrospective analysis of 445 pregnant women who underwent prenatal examination and delivered at the First Hospital of Hebei Medical University between December 2016 and November 2017. A questionnaire survey was conducted on pre-pregnancy information, and data was collected from pre-pregnancy blood routines, blood lipids, cortisol levels, and other biochemical indicators, as well as blood pressure measurements taken before pregnancy, in early pregnancy, mid-pregnancy, and late pregnancy. High-normal blood pressure (HNBP) during pregnancy and abnormal blood pressure variability (ABPV) were examined. Logistic regression and chi-square tests were used to identify risk factors and analyze the impact of ABPV on delivery outcomes.

Results

Blood pressure was significantly higher before pregnancy, decreased after conception, and gradually increased during mid- and late pregnancy (P < 0.001). Logistic regression identified pre-pregnancy systolic blood pressure (SBP), body mass index (BMI), and cortisol levels as high-risk factors for high systolic blood pressure during pregnancy (P < 0.05). Pre-pregnancy diastolic blood pressure (DBP) and occupation type were high-risk factors for high diastolic blood pressure (P < 0.05). SBP before pregnancy, family annual income, and total cholesterol levels were associated with abnormal blood pressure variability (ABPV) during pregnancy (P < 0.01). However, neither HNBP nor ABPV had a significant impact on gestational age, delivery method, delivery complications, or neonatal outcomes (all P > 0.05).

Conclusion

Blood pressure in pregnant women typically decreases in early pregnancy, then gradually rises during mid- and late pregnancy. The duration of HNBP is generally short, with most cases resolving on their own. Pre-pregnancy hypertension, BMI, cortisol levels, and occupational type are risk factors for gestational hypertension. However, normal blood pressure variability during pregnancy has little effect on maternal and neonatal outcomes.