Effect of premature birth on long-term systolic blood pressure variability in women.

Objective: To investigate the effect of premature birth (PTB) on long-term systolic blood pressure (SBP) variability (SBPV) in women.

Methods: A total of 1974 pregnant women were divided into PTB group and non-PTB (NPTB) group. The SBP standard deviation (SSD) was calculated by four annual SBP values measured in 2006-2007, 2008-2009, 2010-2011, and 2012-2013. SBP coefficient of variation (SCV) was calculated by dividing SSD with mean SBP. Multivariate logistic regression analysis was used to analyze the influence of PTB on long-time SSD and SCV in women.

Results: SSD and SCV of the PTB group (10.95 mm Hg and 9.05%, respectively) were higher than those of the NPTB group (9.81 mm Hg and 8.23%, respectively), but there were no significant differences (p>0.05). The number of patients with SSD >9.87 mm Hg and SCV >8.28% in the PTB and NPTB groups was 57 (51.40%) and 62 (55.90%) and 747 (40.10%) and 841 (45.10%), respectively. The number of patients with SSD >9.87 mm Hg and SCV >8.28% in the PTB group was significantly higher than that in the NPTB group (p<0.05). Multiple logistic regression analysis showed that after adjusting other risk factors, the PTB group was at a risk of SSD and SCV elevations with OR values of 1.60 (95% CI: 1.06-2.40) and 1.64 (95% CI: 1.10-2.45), respectively.

Conclusion: PTB is a risk factor of long-time SBPV in women, which might be a potential reason for cardiovascular events. Pregnancy may be an important opportunity for early identification of women at an increased risk of cardiovascular disease later in life.