Analyse The Change Of Maternal Cardiac Reserve In Various Stages Of Pregnancy And The Risk Factors

Pregnant women's heart function and hemodynamics changed largly from early pregnancy to delivery compared with non-pregnancy.cardiac output, heart rate and blood volume increase,all of this make the pregnant women with poor cardiac reserve capacity can't tolerate,especially in the late preiod of pregnancy.When a heart begins to fail,the earliest indicator is the loss of cardiac reserve.The basis of a high level of cardiac reserve can withstand the impact of pregnancy on the heart.ObjectiveStudy on the change of maternal cardiac reserve in various stages of pregancy and the risk factors,in order to provide a theoretical basis to prevent pregnant women's heart failure and to improve cardiac reserve.Materials and methods1 Objects of researchAccording to the inclusion criteria and exclusion criteria,we selected 688 cases who had measurement cardiac reserve from Jul 2008 to Apr 2009 in the department of women's health care of the Third Affiliated Clinical College of Zhengzhou University. Statistical analysis carried on these monitor results and the questionnaires.Take the ratio of diastolic to systolic duration (D/S) as the indicator to study on the change of pregnant women's cardiac reserve and to find the risk factors for cardiac reserve depressed.Predetermined exclusion criteria for the selection of the study population were:Diabetes, maternal cardiovsdcular diserse,hypertensive disorders complicating pregnancy,multiple pregnancy. 2 Methods of research2.1 Groups of objectsThe age groups:<30 years old,30 to 34 years old and≥35 years old.Gestational age groups:～20+6 weeks,～29+6 weeks,30～31+6 weeks,32～34+6 weeks, and≥35 weeks.Education levels groups:elementary, junior high, high school and college and above.Residency groups:the country group and the city group.Gravidity groups:<3 times,3～5 times and>5 times.Anemia groups:anemia group and non-anemia group2.2 Statistical methodsThese data were analyzed by the software of SPSS 13.0.The statistical description to reveal the subjects general condition;t-test was used to compare the two groups means;One-way analysis of variance adopted to compare the means of multigroup,if these means can't meet the conditions of Homogeneity of variance,then use Non-parametric test;when we analied the risk factors,we use Univariate linear regression analysis at first,and then use Multiple linear stepwise regression analysis.The significant level is 0.05.Results1 The D/S of the pre-pregnancy and pregnancy groups compared had statisical significance. The D/S of the pre-pregnancy, gestational age group were:1.58±0.10, 1.48±0.13,1.38±0.10,1.31±0.14,1.20±0.12 and 1.31±0.14. The six groups' D/S distribution are not same(χ2=322.50,P=0.001).And statistically significant showed in every two groups(P<0.05).2 The D/S are different between the age groups.The D/S of the three groups werel.3±0.18,1.33±0.15 and 1.30±0.15.The difference were significant(χ2=8.16, P=0.02).In the groups, D/S compared has statistically significant only in the<30 years old and≥35-year-old group(P=0.001).3 The D/S of the different education levels groups compared had statisical significance(F=5.23,P=0.001).The D/S of the four groups were 1.31±0.15. 1.31±0.15,1.32±0.16 and 1.35±0.17.And statistically significant in the groups:junior high group and high school group, junior high group and college and above group, high schoolgroup and college and above group(P<0.05).4 The D/S of the different residency groups compared had no statisical significance(t=0.69, P=0.49).The D/S of the country group and the city group were 1.33±0.16 and.1.34±0.17.5 The D/S are different between the different gravidity (F=7.14,P=0.001).The D/S of the gravidity groups werel.35±0.17,1.26±0.15 and 1.24±0.13.The<3 times group compared with 3～5 times group showd a statistically significant difference(P=0.001).6 Anemia group and non-anemia group had statistically significant (t=-14.22, P=0.001),the D/S were 1.20±0.13 and 1.39±0.16.7 Regression analysis showed that the important risk factors were gestational age and gravidity times.Conclusions1 Pregnant women's cardiac reserve are lower than the pre-pregnancy group;2 With gestational age increased, cardiac reserve in a downward trend;3 Gestational age and gravidity are the major risk factors of cardiac reserve depression.