Hypertensive disorders of pregnancy (HDP) are common and form one of the deadly triad, along with hemorrhage and infection, which contribute greatly to maternal morbidity and mortality, fetal, and neonatal jeopardy . In our study, the prevalence of hypertensive disorders of pregnancy was 25.4%, of which severe pre-eclampsia was 52.5% and eclampsia accounted for 2.6% of the total cases of hypertensive disorders. The present prevalence is comparable to some of the previous studies in Ethiopa; 18.25% of preclampsia in Arbaminch  and 25.1% in Derashie, SNNP  and also findings in other countries [26, 27]. However, it is higher than some of the overall global reports [13, 23] as well as some studies in Ethiopia; 2.4% at Mettu Referral Hospital , 5.7%in Debrebrhan Referral Hospital , and 8.5% at Jimma Specialized Hospital . The exaggerated prevalence of HDP in the current study is not surprising as the Hospital receives referrals of complicated pregnancies from 16 Health centers with catchment area of over 1.5 million populations. Therefore, the current prevalence might be the effect of the aggregate rates from a number of primary care facilities in the catchment area with large denominator population. Studies also show that the increased prevalence is common in centers that serve as a referral medical facility for an extended number of primary care units . The low socioeconomic status, young age, primiparity and urban residency are known risk factors for the development of preeclampsia  and could also be another contributing factors for increased prevalence of HDP in the present study. As the study was a retrospective type, measurement bias and errors could also have played a role. Severe pre-eclampsia accounted for the majority of HDP (52.5%) in this study. This is comparable to other studies in Ethiopia; 51.8% in Jimma, 60.7% in Mettu but less than the 78% in Addis Ababa. The prevalence of eclampsia in our study was only 2.6% which is comparable to the study in Jimma but much less than the 19% report of eclampsiain Mettu, 27.8% in Debrebrhan and Addis Ababa . The decreased proportion of eclampsia in the present study could partly be attributed to early diagnosis of preeclampsia, stringent medical management and termination of pregnancy after ascertaining fetal maturity before sequelae of preeclampsia ensued but still risking fetal prematurity. The increased awareness towards the complication of HDP coupled with the increasing trend in the ANC utilization by the urban residents in the recent years due to massive work by the Ethiopian government might have also contributed for the lower proportion eclampsia in the current urban study.
Majority of the women affected by the hypertensive disorders were nullipara(55.8%) and 91% of mothers had at most 34 years of age. This is similar with the findings of other studies conducted in Ethiopia [10, 25, 28]. However, there was no statistically significant association between age of mothers and severity of hypertensive disorders (p=0.15). In 53.2% of women with HDP, onset of labor was by induction and the likelihood of induced labor was significantly higher with severity of HDP (p<0.001). Almost all inductions were for women with preeclampsia, eclampsia and superimposed preeclampsia; which is less than the finding from studies in Debrebrhan (60.9%), but greater than studies in Jimma(36.6%) , and Mettu(44.6%). The mode of delivery was significantly associated with severity of HDP(p=0.009). The rate of cesarean section was 42.5% and instrumental delivery contributed for 3.9% of all deliveries of mothers with HDP. The current cesarean rate was higher than the study in Jimma (34%), Mettu (16.2%), and Debrebrhan (6.3%). On the contrary, the rate of instrumental delivery was slightly lower than the study in Jimma (7.8%)  and Mettu (6.9%) , but much lower than the study in debrebrhan (34.7%) . The presence of appropriate professionals in better number in the urban setting might have contributed to the higher cesarean delivery in the present study area contributing to the increased rate of prematurity. Most of the women (76.3%) with hypertensive disorders had the highest systolic blood pressure record of at least 160mmHg and 83% had the highest diastolic blood pressure of at least 110mmHg. This finding is in agreement to the study in Mettu.
Headache refractory to the ordinary analgesics was among the chief complaints in 30.8% of all mothers with HDP and in 58.5% of pre-eclamptic and eclamptic mothers combined. This is in agreement with the 48.9% incidence of headache among mothers with severe preeclampsia and superimposed preeclampsia from Debrebrhan and studies done in other countries; 46.2% in Iran , 42.22% in India . Blurring of vision was observed in 22.5% of subjects with HDP and in 42.7% with pre-eclampsia and eclampsia combined. This is also in agreement with other reports [28, 29, 31]. In our study, all the eclamptic mothers had preceding complaints of headache and blurring of vision before they were progressed to develop the abnormal body movement and loss of consciousness. Therefore, early detection and subsequent intervention of severe preeclampsia including termination of the pregnancy could have paramount importance in averting the sequelae. In developed countries pregnancy related acute renal failure (AKI) has decreased, with current estimates are around 1–2.8%, where as in developing countries it is 4.5-15% and responsible for both maternal and fetal morbidity and mortality . Some setups showed an alarmingly high value to a 36% with HDP. Our study indicated the prevalence of AKI (Cr>1.2mg/dl) to be 10.9% among mothers with HDP which is relatively higher than the reports in Mettu (6.6%). This could partly be attributed to the increased prevalence of the HDP in the present study. However, the rate of AKI (10.9%) and thrombocytopenia (7.7%) are less than similar studies in other countries .
Pre-eclampsia/eclampsia is responsible for an estimated 16% of global maternal mortality annually  and according to ACOG the HDP is responsible for 17.6% of direct maternal deathes. The risk of maternal death is much more common in settings in which prenatal and intrapartum care is not routinely available to pregnant women [8, 24]. Surprisingly, maternal mortality associated with HDP or ICU admission in the present study was non-existent even if the HDP is rampant in the study area. This is uncommon finding even compared to the other Ethiopian report of maternal mortality of 2.5% in Debrebrhan, 1.2% in Jimma, and also the national cause-specific case fatality rate of 3.6% . It is in agreement to the zero mortality rate of the study in Mettu. This could be attributed partly to the fact that our hospital having improved care facilities, well- staffed with appropriate professionals, giving services for 24 hours a day-7days a week, early presentation of the mothers to the hospital and/or health centers in the catchment area, vibrant referral system to the hospital from the health centers, and stringent interventions in the hospital including the termination of pregnancy might have contribute to no maternal death. WHO study also showed that the availability of basic and comprehensive EmOC 24 hours per day, 7 days per week—in conjunction with a functioning referral system—is thought to prevent most maternal deaths with direct causes .The low institutional delivery in the country  could be another contributing factor for the low maternal mortality observed in this study.
Hypertensive disorders of pregnancy are known to be associated with a number of perinatal complications which can be measured in terms of prevalence of preterm delivery, low birth weight, low Apgar score, intrauterine growth restriction, the need for resuscitation and/or admission to a neonatal intensive care unit (NICU), and stillbirths. In the present study, there was statistically significant association of preterm delivery with severity of HDP (p<0.001). The rate of preterm delivery was 29.5%, out of which severe pre-eclampsia and eclampsia accounted for over 80% of preterm deliveries. This finding is comparable with the study from Jimma (31.6%)  and Mettu (28.1%) but less than reports of 35.4% in Debrebrhan, and 48.6% in Addis Ababa . The study also showed increased likelihood of low birth weight with increasing severity of HDP (p<0.001). The rate of low Apgar at the first minute and 5th minute has statistically significant association with the severity of HDP (p<0.001). This is in agreement with other reports [10, 25]. Preeclampsia-eclampsia can also lead to higher frequency of neonatal respiratory difficulties, and increased frequency of admission to neonatal intensive care unit .Those infants born small and premature may experience low Apgar, prolonged stays in neonatal intensive care units and often face developmental delays . In our study, the need for resuscitational support was 15%, of which 87% were neonates born to mothers with severe pre-eclampsia and eclampsia. Similarly, 11.5% of neonates required referral to NICU, of which 89% were neonates born to severe pre-eclamptic and eclamptic mothers. The rate of NICU admission is comparable to the study from Jimma(16.4%) , but much less than the 40.1% of the Debrebrhan study .
The WHO multicountry survey has shown that there were about 3- and 5-fold increased risk of perinatal death in women with preeclampsia and eclampsia, respectively . In Ethiopia, hypertensive disorders of pregnancy account for perinatal mortality rate of 290/1000 total births . There were 4 still births in our study yielding still birth rate of 2.6%. This rate is much less than other studies in Ethiopia; 10.7% in Mettu, 27.5% in Jimma, 30.8% in Debrebrhan. This contracted prevalence of still birth in Yekatit-12 teaching hospital could be partly due to the extensively coordinated and commendable effort by every stakeholder and the efficient referral system from health centers to the hospital for every woman with the risk factor. The other very important contributing factor why the incidence of still birth is so low in the present study area could be associated with the low prevalence of eclampsia (2.6%) as compared to other studies in Ethiopia[10, 25, 28]. Eclampsia accounts for 5-fold increased risk perinatal death . The limited sample size could also have partly contributed to the low stillbirth rate.