A population-based cross sectional survey wasrnconducted from April 1990 to March 1991, to measure thernmagnitude of high risk pregnancies, and to examine therndeterminant factors for pre-eclampsia and gestationalrnhypertension, in Ada-a district. 13 urban kebeles and 13rnrural villages were randomly chosen and a house to housernsurvey was conducted based on a pre tested questionnairernand relevant measurements. Information was collected onrndemographic, socioeconomic, the exposure status for riskrnfactors prior and during the current pregnancy, the usualrndietary intake and the usual physical activities duringrnthe early months of the current pregnancy, and measurementrnfindings for height, blood pressure and proteinuria.rnA total of 567 pregnant women were included in the study.rnOf the 567 pregnant women 28.6% were younger thanrn20 or older than 34 years. Early marriage below the agernof 20 were reported by 85%. 21.7% and 22.2% were Nulliparousrnand multiparous women respectively. 39.2% werernilliterate and 42.9% with a very low income. 14.6% gaverna history of abortion, 13.1% of infant deaths, 6.3% ofrnpostpartum hemorrhage and 1.1% of antepartum hemorrhage.rnAbnormal height was recorded in 18.5%, Albuminuria inrn11.5% and abnormal diastolic blood pressure in 12.2%,rnwhere 2.9% and 9.2% were classified as pre-eclamptic andrngestational hypertensive women. 52.3% were not receivingrnantenatal care services in the district.rnIt was found that pregnant women in the very lowrncategory of income had a reduced risk of pre-eclampsiarn(RR =0.3, 95% CI 0.06, 1.07). And Nulliparous women hadrna higher risk (RR =5.6, 95% CI 1.83, 15.92 ) . High energyrnexpenditure was observed to be a risk factor for gestationalrnhypertension (RR =5.3,95% CI 1.35 , 45.77). Amongrnthe studied pregnant women, those who had at least one ofrnthe risk factors were very high (85%) . Antenatal carernservices were not received by the majority of thernpregnant women, especially in the rural area. Relativelyrnyoung women, with a better education, a better income, inrntheir first pregnancy were at high risk of pre-eclampsiarnand gestational hypertension. strenuous physical exertionrnand low dietary protein intake during the early months ofrnpregnancy also increased the risk of both pre-eclampsiarnand gestational hypertension. A high dietary calciumrnintake during the early months of pregnancy increased thernrisk of pre-eclampsia but not gestational hypertension.rnThe results from this study indicate to increasernFamily Planning services and appropriate training, andrnuse of community health workers in Ada-a district.