Associations Between Trajectory of Different Blood Pressure Components in Pregnancy and Risk of Adverse Birth Outcomes – A Real World Study

Abstract

Background: High blood pressure during pregnancy has been suggested to be associated with adverse birth outcomes (ABO), but it is unclear how different blood pressure changes and the extent of the effect. Therefore, we aimed to investigate the association between blood pressure trajectories (systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP)) of pregnant women and ABO in a real-world study. Material and Methods: Leveraging 28,679 pregnant women and their fetuses from a register-based cohort from January 1, 2010, to December 31, 2019. Blood pressure trajectories were estimated by package "traj" in R software using real-world blood pressure data of routine antenatal care examinations. Logistic regression models were applied to examine the association between trajectories of different blood pressure components (SBP, DBP, MAP, and PP) during pregnancy and the risk of ABO. Results: Trajectories of all blood pressure components were identically labeled as lowstable, moderate-increasing, moderate-decreasing and high-stable. After adjusting for confounding factors, compared with pregnant women with the low-stable pattern, pregnant women with a high-stable or moderate-increasing pattern had a significantly increased risk of developing adverse birth outcomes. Pregnant women with a moderate-decreasing pattern had no significant increased risk of ABO but had a lower risk of adverse birth outcomes than those with a moderate-increasing pattern. The trajectories crossed at 17-20 weeks of gestation for all blood pressure components. Conclusion:Our study results indicated that reduction and maintenance of blood pressure to a low level of less than 110 mmHg for SBP and 65 mmHg for DBP after 20 weeks of gestation would benefit prevention of adverse birth outcomes, regardless of the level of blood pressure at early pregnancy.

Associations of prenatal blood pressure trajectory and variability with child neurodevelopment at 2 years old

“…Pregnant women in the other three trajectory groups experienced considerable changes during pregnancy. Our findings are consistent with previous researches conducted in Suzhou, China [19], and Japan [5], which identified similar patterns of Table 5 Associations between blood pressure variability and child neurodevelopment Each parameter was categorized into tertiles, with tertile 1, tertile 2, and tertile 3 considered as low, intermediate, and high BP variability, respectively. The models were adjusted for maternal age, educational level, pre-pregnancy BMI, passive smoking status, small for gestational age, infant sex, the number of BP measurements, gestational diabetes mellitus, and mean SBP or DBP BSID Bayley Scale of Infant Development, PDI psychomotor development index, MDI mental development index, SBP systolic blood pressure, DBP diastolic blood pressure, SD standard deviation, CV coefficient of variation, ARV average real variability BP trajectory in pregnant women.…”

“…Notably, even though BP changes in different trajectories fall within the physiological range of normal BP, pregnant women with a low-increasing, moderateincreasing, and moderate-decreasing pattern had an increased risk of delayed psychomotor neurodevelopment in children at 2 years. Previous researches have also found an association between several BP long-term patterns and lower birth weight and other adverse birth outcomes even when the BP values throughout pregnancy were below the diagnostic threshold for hypertension [5,6]. These results suggest that BP fluctuations within the normal range during pregnancy were associated with neurodevelopment of offspring.…”

“…Generalized linear models and multivariate logistic regressions were used to assess the relationship between BP trajectories/variability and BSID scores as well as the occurrence of delayed neurodevelopment, respectively. Covariates were ascertained according to prior published literature and the change in estimate method (if the estimate changed by > 10%, the variable was entered in the model), including maternal age, prepregnancy BMI, educational level, passive smoking status, SGA, infant sex, the number of BP measurements, and GDM [5,14,21]. Additionally mean BP levels were also adjusted for in the models when assessing the association of BP variability and neurodevelopment.…”

“…Previous research has examined the patterns of BP change during pregnancy. For example, a study conducted in Suzhou, China, analyzed the BP trajectories in 28,679 pregnant women and found that the trajectories of both SBP and DBP followed the same trend throughout pregnancy, labeled as low-stable, moderate-increasing, moderate-decreasing, and high-stable [5]. In another study from Japan, 755 pregnant women used home monitoring to track their BP, leading to the identification of six trajectory groups for both SBP and DBP during pregnancy: low-J-curve, low-steep J-curve, moderate J-curve, moderate-reverse J-curve, little high J-curve, and high J-curve [6].…”

Prevalence of adverse birth outcomes and associated factors in Jazan, Saudi Arabia: A cross-sectional study

“…[39] Similarly, a higher risk of adverse birth outcomes was reported among pregnant women with elevated blood pressure. [40] The identified similarity of findings in the current investigation to other national or international efforts suggests a possible generalization of the findings to similar community-based settings.…”