Risk factors and perinatal outcomes for early and late onset preeclampsia, Pakistan : an observational study

Date of Award


Document Type


Degree Name

Master of Science in Epidemiology & Biostatistics (MSc Epidemiology & Biostats)


Community Health Sciences


Preeclampsia has two clinical entities: Early onset preeclampsia (EOP) and late onset preeclampsia (LOP). The two clinical entities may be distinct with respect to risk factors and perinatal outcomes in our setting. We aimed to compared risk factors for EOP and LOP and their perinatal outcomes. Methods: A case control study was conducted comprising of 535 preeclampsia cases (index group) in singleton pregnancies delivered at Aga Khan University Hospital, Karachi (AKUHK), Pakistan (2000 — 2016) and same number of controls (reference group). Preeclampsia was defined as blood pressure of? 140/90 mm Hg (taken twice, 6 h apart). Subjects were classified as EOP if the disease manifested before 34 weeks of gestation and LOP when manifestation was at > 34 weeks of gestation. Maternal characteristics and perinatal outcomes were compared by Multinomial Logistic Regression and Cox Proportional. Results: All of the 12 variables identified during the bivariate analysis were used in model building for risk factors of EOP and LOP. Six variables turned out to be significant in the final model namely pre-pregnancy BMI (PBMI), presence of IUGR, family history of hypertension (FHH) and history of hypertensive disorders during pregnancy (I IDP) still births in immediate previous pregnancy (SBIP) and booking status of pregnancy (BSP), (Table No 2).The adjusted odds(AO) of overweight (BMI 25-29.9 Kg/m2) relative to women with normal BMI (<24.9 kg/n.)2) is 5.02 (95% CI: 2.16, 11.64)titnes and 2.12( 95% CI:1.16, 3.87) times in FOP and LOP respectively as compared to the odds in to pregnant ladies without preeclampsia(PLW) adjusting for IUGR, FHI I, lack of utilization of antenna! services, HDP and SBIP. Similarly the AO of obesity (BMI above 30 Kg/m2 is.7I (95% CI: 3.36, 17.75) and 3.65 (95% Cl: 2.02, 6.58) times in PLP, EOP and LOP respectively as compared to PLW in adjusted model. The AO of IUGR relative to no IUGR in EOP and LOP is.47 (95% CI: 2.06, 9.71) and 3.31 (95% CI: 1.72, 6.36) times respectively as compared to PLW in adjusted model. The AO of lack of utilization of antenatal care services was 5.17 (95% CI: 1.68, 15.92) times among EOP as compared to PLW in adjusted model. While the AO of lack of utilization of antenatal care services was non-significant among women with LOP as compared to PLW in adjusted model.The AO of I IDP in parous women with prior history 4.5(95% CI: 2.46, 8.25) and 2.8(95% CI: 1.72, 4.60) times in EOP and LOP respectively as compared to PLW. The AO SBIP was 10.37(95% Cl: 2.60, 41.44) times in the EOP group as compared to PLW. Similarly the AO of SBIP in LOP are 5.48(95% CI: 1.52, 19.81) times compared to PLW in adjusted model. The AO of FBI I is 2.27(95% Cl: 1.20, 4.30) among EOP comparing to PLW in adjusted model.While the odds of FHB is insignificant in LOP as compared to PLW in adjusted model (table no 2). The adjusted risk of admission to NICU is 3.09(95% CI: 1.49, 6.41) in EOP relative to mothers with PLW adjusting for IUGR (table no: 4.3). Similarly the risk for is Apgar score at I minute less than 8 (Al L8) is more in EOP as compared to LOP when adjusted for IUGR (5.2). In this model IUGR was identified as potential confounder and the change in beta coefficient was more than 19% and 20% for EOP and LOP (Table no: 8).Conclusion: Within the preeclampsia cohorts, the odds of risk factors are comparatively high in EOP as compared to LOP. The EOP is different from LOP with respect to EHH. Furthermore, the risk of perinatal outcomes, that AI L8 and admission to NICU were significantly associated with FOP.

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