Hospital based study of risk factors for preeclampsia in nulliporous and porous women : a matched case control study

Date of Award


Document Type


Degree Name

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


Community Health Sciences


Preeclampsia is a serious and poorly understood complication of pregnancy, which can progress to eclampsia and maternal death, is an important cause of maternal and infant mortality and morbidity. Preeclampsia is a disease with worldwide health related significance to mothers and infants. It is diagnosed by new-onset increased blood pressure and proteinuria during second or third trimester of gestation. Preeclampsia is a major cause of maternal mortality (15-20% in developed countries) and morbidities (acute and long-term), perinatal deaths, preterm birth, and intrauterine growth restriction. Its greatest impact is in developing countries, where it accounts for the strikingly increased maternal mortality. This is the first report of a hospital based case control study to identify preeclampsia risk factors among women in Karachi and Rawalpindi. A matched case control study design was used to assess the factors associated with preeclampsia among women in maternity hospitals, in Karachi and Rawalpindi. We selected hospital-reported cases of preeclampsia within 3 days of delivery who met the American College of Obstetrician & Gynecologists criteria for case definition; New hypertension with blood pressure of 140 mm Hg systolic or diastolic B.P of 90 mm Hg diastolic or greater arising after 20 weeks of gestation in a woman who was normotensive before 20 weeks gestation on two occasions at least 4 -6 hours apart along with proteinuria. 113 cases and 226 controls without a history of chronic hypertension were matched (1 case: 2controls) on hospital, day of delivery and parity. This study has come up with some important risk factors among our women population which need to be interpreted with caution and evaluated by further research studies, increasing our knowledge of preeclampsia and its risk factors and improve our understanding of its complicated pathogenesis. In our study of risk factors for preeclampsia, gestational diabetes, pregestational diabetes, urinary tract infection during pregnancy and family history of hypertension were associated with preeclampsia risk. Cases were more likely to have a positive family history of hypertension as compared to controls (OR= 2.39, CI; 1.4-4.1). Women with gestational diabetes were at greater odds of having preeclampsia as compared to those who had no gestational diabetes (OR= 9.026, CI; 3.0-27). Women with a history of pregestational diabetes were at greater odds of having preeclampsia as compared to women without pregestational diabetes (OR =21.5, CI; 2.0-270). Urinary tract infection during pregnancy was also an important risk factor for preeclampsia. Cases were more likely to have a history of urinary tract infection during pregnancy as compared to controls (OR= 2.6; CI; 1.4- 5.1). However, high body mass index, maternal age, inter birth interval, past history of preeclampsia and sociodemographic factors were not associated with higher risk for preeclampsia. The association of family history of hypertension with preeclampsia risk is an important finding of our study. Though it is not a modifiable risk factor but in our context it is an important and easy to acquire clinical risk marker of preeclampsia compared to the biochemical markers that are invasive, require expensive techniques or special expertise that precludes their utility in routine screening. The family history of hypertension questions can be used as screening tool to identify pregnant women who need closer monitoring for the signs of preeclampsia during early pregnancy. Based on history, the screening should begin early to detect and treat the condition before it threatens the survival of mother and fetus. If greater awareness of the associated risk factors leads to earlier diagnosis and improved management, there may be scope for reducing a proportion of the morbidity and mortality from preeclampsia.

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