Background: Pre-eclampsia (PE) is associated with maternal cardiac remodelling and biventricular diastolic dysfunction. Preterm PE alone can also be associated with severe left ventricular hypertrophy and biventricular systolic dysfunction.
Aim & Objectives of the study: The aim of this study was to assess whether the maternal cardiovascular profile at mid-gestation in nulliparous normotensive women differs in women destined to develop preterm PE versus those who will develop PE at term.
Results: The study includes only nulliparous women with singleton pregnancy and at increased risk of developing PE. Risk for developing PE is determined by uterine artery Doppler assessment at the routine ultrasound assessment at 20-23 weeks of gestation. In order to achieve the aims and objective of study, 115 cases of mid gestational pregnant women were taken in the sample for study. These cases were classified into 4 groups i) low risk women with uneventful outcome (59 No’s), ii) high risk women with uneventful outcome (35 No’s), iii) high risk women who developed Term PE (13 No’s) and iv) high risk women who developed preterm PE (8 No’s). As per the protocol of the study data were collected on demographic profile, clinical profile and analyzed following appropriate statistical tools and techniques. The distribution of age among the four groups of patients were found to be more or less homogeneous as per the chi square test of association (p=0.411). Among the low risk women with uneventful outcome, all were having normal BMI. Among the high risk women with uneventful outcome 11.4% were overweight. The pair wise comparison of MAP by groups with the help of Mann-Whitney U test. It was clearly revealed that high risk women irrespective of status of event were having more or less the same MAP value with p=0.727, p=0.731, p=0.8 respectively. High risk women with or without uneventful outcome have clearly higher value of MAP than the low risk women with uneventful outcome (p=0.000). The Kruskal Wallis test revealed no significant difference in heart rate of the 4 groups of pregnant women (p=0.224). The stroke volume of each of the 3 groups of HRW with uneventful outcome, term PE and preterm PE was significantly lower than LRW with uneventful outcome with p value=0.000 for each of them. HRW with preterm PE have significantly lower stroke volume index than HRW with uneventful outcome (p=0.003). HRW with preterm PE and term PE do not differs significantly in stroke volume index (p=0.638). The comparison of cardiac output by groups is presented in table 10. The lowest median value of 3.79 L/min (3.67 L/min-3.96 L/min) was observed among HRW with preterm PE which gradually increased to 4.9 L/min (4.6 L/min-5.12 L/min) among LRW with uneventful outcome and the difference was found to be significant (p=0.000). The frequency distribution of cardiac index gradually shift to right from HRW with preterm PE to LRW with uneventful outcome signifying lower stroke volume index for HRW with uneventful outcome, with term PE and preterm PE in descending order. The frequency distribution of LVMi depicted that the distribution of LRW with uneventful outcome is more or less symmetrical whereas in case of 3 HRW groups the distribution is right screwed. The frequency distribution of left ventricular wall thickness, It clearly emerged that the distribution of LRW with uneventful outcome is relatively towards the left of the axis than the other three HRW groups. There is a significantly higher prevalence of LV remodelling /hypertrophy at mid-gestation in both preterm PE and term PE women. Asymptomatic cardiac diastolic dysfunction, impaired relaxation, altered geometry at mid gestation is only seen in high risk pregnant women with pre term preeclampsia but not in those with term preeclampsia.
Conclusion: It is now evident that women who developed preterm PE in pregnancy have a much higher incidence of developing symptomatic heart failure many years after delivery. Although it is not possible to distinguish pre-existing cardiac dysfunction from that acquired as a result of pregnancy, these cardiac findings may be useful in understanding the cardiovascular pathophysiology of PE.