Prevalence and factors associated with pregnancy-induced hypertension in public general hospitals, central zone, Tigray Region Ethiopia: a cross-sectional study

¹Department of Public Health Nutrition, College of Medicine and Health Sciences, Axum University, Tigray, Ethiopia, ²Department of Adult Health Nursing, School of Nursing, Aksum University, Aksum, Ethiopia, ³Department of Epidemiology and Biostatistics, College of Health Sciences, Aksum University, Aksum, Ethiopia, ⁴School of Nursing, College of Health Sciences, Axum University, Tigray, Ethiopia

^&Corresponding author
Ebud Ayele, Department of Public Health Nutrition, College of Medicine and Health Sciences, Axum University, Tigray, Ethiopia

Introduction    

Pregnancy-induced Hypertension is a high blood pressure and one of the leading causes of mortality and morbidity among pregnant women in the globe today [1]. It is characterized by either blood pressure levels of 140/90 mm Hg or higher after 20 weeks of gestation, or a blood pressure rise greater than 30/15 from early. Such mild forms of Pregnancy-induced Hypertension require close monitoring. The Severe forms of Pregnancy-induced Hypertension are reflected through blood pressure levels of 160/100 taken on two separate occasions, 6 hours apart after bed rest [2]. About 350,000 women die every year from pregnancy-related causes globally and more than half of deaths occur in Sub-Saharan Africa (SSA), and approximately 12% of maternal deaths are associated with pregnancy-induced hypertension (PIH) disorders Pregnancy-induced hypertension complicates 10% of all pregnancies, around 40,000 women, mostly from developing countries, die each year due to preeclampsia or eclampsia [3]. Hypertensive disorder of pregnancy is associated with adverse maternal and prenatal outcomes increased maternal mortality, increased risk of Cerebro-vascular accidents, renal failure, and pulmonary edema, increased risk of placental abruption [4].

Pregnancy-induced hypertension is associated with adverse maternal and prenatal outcomes increased maternal mortality, increased risk of cerebrovascular accidents, renal failure, and pulmonary edema, and increased risk of placental abruption [4,5]. Maternal mortality in Ethiopia due to Pregnancy-induced hypertension between 1980 and 2012 increased from 4%-29% at different health facilities [6]. And preeclampsia contributed to the complication of approximately 1% of all deliveries and 5% of all pregnancies. Moreover, 16% of direct maternal mortality and 10% of indirect maternal mortality were due to preeclampsia/eclampsia [7]. Even though many studies have been done elsewhere in the world, there is limited data on the prevalence of pregnancy-induced hypertension and its associated factors in resource-poor countries like Ethiopia especially in Tigray region. This study aimed to know the prevalence and associated factors of pregnancy-induced hypertension, so Providing information that exists on the ground has paramount importance to the central zone General Hospital, District Health Offices, patients, and health care professionals who are working in Hospitals. Also, this study raises awareness among healthcare professionals about the prevalence of hypertension and contributing factors, pregnant women who are at risk of developing pregnancy-induced hypertension also benefited indirectly. In addition, the information generated from this study helps as a source of information for other researchers to conduct similar studies in different study areas.

Methods     

Study design and settings: a retrospective cross-sectional study design was conducted in public general hospitals of Ethiopia, Tigray, and Central Zone from Aug 8, 2018- Jul 7, 2019. Central Zone of Tigray is one of the seven zones of Tigray Region which contains three general Hospital called Abyi-Adi, Aksum, and Adwa general hospital. Based on the 2007 census conducted by the Central Statistical Agency of Ethiopia, the total population was 1,245,824, of which 14.2% were living in the urban area. According to this census, 613,797 were men and 632,027 were women.

Study population: all pregnant women who were delivered at public general Hospital of central zone were the source population. Whereas, the study population were all selected pregnant women who were delivered in public general hospitals central zone. Women who were incompetent their document was excluded where as. The required sample size was determined using single population proportion formula with the assumption by taking prevalence of previous study done in Mizan-Tip pregnancy-induced hypertension 7.9% [8], 95% level of confidence and 2% marginal error. By adding 10% contingency the sample size was 769. Cards for each mother were selected using systematic random sampling technique. The sample size was distributed into each hospital in accordance with the magnitude of the population.

Data collection: after providing three-day training to the data collectors five percent Pretested was conducted in Shire general hospital to check the completes and consistency of the developed form and revision and edition takes place. The data was collected by three trained BSc in midwives and one BSc midwife as supervisor for a total of ten days. The required data was filed from the selected charts by using a structured data entry format prepared for this purpose. Information about patients' demographic data, past medical history, past obstetric history and laboratory investigations was collected. The required data which was missed from the client's chart was searched and filled into the data entry format from registration books, anesthesia room registrations and operation log books. Meanwhile the completeness of the data was checked every day by the principal investigator and supervisor. Regular supervision and follow up was made by principal investigator. In addition, regular checkup for completeness and consistency of the data was made on daily basis.

Operational definition:

Pregnancy induced hypertension disorder: hypertension with or without protein urea or edema two readings of diastolic blood pressure 90/110 mmHg, 4-6 hours apart which develops after 20 weeks of gestation [4].

Mild pre-eclampsia: two readings of diastolic blood pressure 90-109mmHg, 4-6 hours apart, after 20 weeks of gestation and with protein urea of 300mg/dl in 24 hours or up to 2+ and with/without edema [4].

Pre-eclampsia: Diastolic blood pressure is equal or greater than 110mmHg after 20 weeks of gestation. Associated with severe headache, blurred vision, epigastria pain, hyper-reflexia, oliguria, proteinuria (protein equal or greater than 5g/24 hours; dipstick +) and the patient is conscious [9].

Eclampsia: is signs and symptoms of severe preeclampsia and convulsions or coma [9].

Statistical analysis: the data collected from the charts was edited and entered, by Epi-Data version 3.02. Then it was exported and analyzed by SPSS version 22. Data cleaning was performed to check for frequencies, accuracy, and consistencies and missed values and variables. Any error identified during data entry was corrected after revision of the original completed data entry format. All the data obtained from the study population was entered, cleaned and analyzed by the investigator. To explain the study population in relation to relevant variables descriptive statistics was used. Independent variables with a p-value of = 0.25 in Uni-variate analysis were included in the multivariable analysis to control confounding factors. Multi-co linearity was checked to see the linear correlation among the independent variables by using standard error. The fitness of the model was tested by Hosmer-Lemeshow's goodness-of-fit test model coefficient with an enter method was found to be insignificant with a large P-value (P=0.05). Adjusted odds ratio along with 95% CI was estimate to identify the factors associated with Pregnant-induced hypertension disorder using multivariable logistic regression analysis. Level of statistical significance was declared at a p-value less or equal to 0.05.

Ethical consideration: clearance was obtained from Institutional Health Research Ethical Review board (IHRERC) of Aksum University College of Health and Medical science and a formal letter was written to central zone General Hospitals ensuring the approval of the proposal. All Hospital medical directors were permit to as to conduct the study. The data was collected by review of the registration books using structured checklists.

Results     

Socio-demographic characteristic of the respondents: a total of 769 women delivered were included in the study with a response rate of 100%. The mean age of the mothers was 36(SD ± 1.3) years. And seven hundred forty-two (96.5%) of them were married, 424 (55.1%) of them were women urban residence, and about 614 (79.9%), of women were multi-para (Table 1).

Maternal health history and health characteristics

Out of 769 about 39(5.1%) were have been pregnancy-induced hypertension, about 713 (92.7%) pregnant women have been single type pregnancy, and 732 (95.2%) out of women´s were haven't history of previous surgery, in addition to that 721(93.8%) women were haven't history of abortion, and 649(84.4%) women's were haven't history of low birth weight, and women 725(94.3%) were haven't previous family history of pregnancy-induced hypertension, and about 606(78.8%) women´s were two times antenatal care follow up , about 766(99.6%) were haven't diabetes mullets, about 736(95.7%) women's were haven't previous history of hypertension, and 726(94.4%) doesn't have been history of cardiovascular disease , about 690((89.7%) women were haven't renal disease during pregnancy, and 724(94.1%) women during pregnancy were haven't any substance abuse, about 434(56.4%) women during pregnancy were have planned and wanted pregnancy, and about 705(91.7%) women were haven't family history of diabetes mullets, about 501(65.1%) women were spontaneous vaginal delivery and 660(85.8%) mothers were with optimal nutrition states (Table 2).

Factor associated with pregnancy-induced hypertension

All 769(100%) the document was included in the study. The prevalence of pregnancy- induced hypertension were found to be 5.1% (95% CI, 4.74%-5.25%). Variables associated in adjusted analysis: previous history of gestational hypertension were more likely [(AOR=7.16, 95% CI: (1.16, 43.9)] to have pregnancy induced hypertension, substance abuse were more likely [(AOR=7.24, 95% CI:(1.42, 36.7)] to have pregnancy-induced hypertension, family history of hypertension where more likely [(AOR=5.43, 95% CI: (1.16, 25.45)], to have pregnancy-induced hypertension, multiple type of pregnancy where more likely [(AOR=37.09, 95% CI: (8.7, 158.06)] to implement pregnancy-induced hypertension (Table 3).

Discussion     

This study was assessed the Prevalence and factors associated with pregnancy-induced hypertension in public general hospitals, central zone, Tigray region Ethiopia. the prevalence of pregnancy-induced hypertension was 5.1% with 95% CI of (67%, 73%); Magnitude of pre-eclampsia, mild-eclampsia and eclampsia was 16(2.1%), 12(1.6%) and 12(1.6%) respectively. which is lower than the study conducted in India was 5.4% while preeclampsia and eclampsia accounts 44% and 40% respectively [10], In African-Americans it accounts 6.4% of deliveries [3], In Brazil (2008) study 14.5% of pregnant women were diagnosed [11], India 2006 was 5.38% [10]. A study employed in Jimma hospital prevalence of hypertensive disorders of pregnancy was 8.5% [12]. Dessie referral hospital is found to be 8.4% [13], Mizan-Tepi university teaching hospital, Tepi and Gebretsadik shawo hospitals, the prevalence of pregnancy-induced hypertension were (7.9%) [14], Dilla University Referral Hospital is found to be 2.2% [15] and south Africa was 12% [16] respectively. however , this finding is higher than the studies conducted in Nepal 4.4% were diagnosed as pre-eclampsia /eclampsia with proportion of 3.9%, 0.4%, 0.1% mild pre-eclampsia, severe pre-eclampsia and eclampsia respectively [17]. Another study indicates that the prevalence of preeclampsia in developing countries ranges from 1.8% to 16.7% [18]. In South Africa from 22,711 deliveries in Dora Nginza hospital over the two year period (2007 & 2008), showed that the prevalence of hypertension in pregnancy as 6.7% (66.9 per 1000 deliveries) and the incidence of pre-eclampsia is 35.4% and chronic hypertension 2.8% [19]. Studies in Ethiopia 5% [20]. Study in southern part of Brazil in (2011) gestational hypertension was (4.3%) [21]. The possible reason for this difference might be due to social-demographic characteristics and promotion differences facility to the maternal health. Furthermore, this discrepancy might be also due to difference in life style and safe health service environment.

In this study, mothers with previous hypertension, substance abuse, family history of pregnancy-induced hypertension and type of pregnancy were found to be significantly associated with pregnancy-induced hypertension. In this regard mothers with previous hypertension were 47.067 times more likely (AOR=47.07, 95% CI: (20.92, 105.88)] to have gestational hypertension than those who haven't before. This finding is similar to the study done in different area [22-25]. The reason might be almost mothers with having history of previous induced hypertension can have with their life span due to physiological genetic factor problem.

This study revealed that substance abuse women 7.2 times [(AOR=7.24, 95% CI: (1.17, 43.97)] to have pregnancy-induced hypertension than those counterparts. This was similar to the systematic review done from different literatures [26]. This is because of substance abuse causes social, psychological and economical problem on pregnant women's that can leads to increase stress, and also some substance can cause for physiological regulation problem led to increase the blood pressure on pregnant women. Family history of pregnancy-induced hypertension where 5.43 times more likely [(AOR=5.43, 95% CI: (1.159, 25.45)] to have gestational hypertension than those counterparts. this finding was similar to the study done in Amhara and others [13,22]. This might be occurred due to the genetic factor that can develop for the physiological predisposition pregnancy-induced hypertension to their off-springs.

The study showed that mothers with multiple type of pregnancy 37.09 times more likely [(AOR=37.09, 95%: (8.70, 158.06)] to have gestational hypertension than single type pregnancy. This finding was similar to the study done in Dessia referral hospital [27]. This is because of mothers having exposure towards multiple pregnancy can deferrer in physiological and mental states compares to the single type pregnancy.

Strengths of this study: even though this study was conducted from secondary data resource. Information about patients' demographic data, past medical history, past obstetric history and laboratory investigations was collected. The required data which was missed from the client's chart was searched and filled into the data entry format from registration books, anesthesia room registrations and operation log books. This study also didn't expose to recalling bias.

Weakness of the study: the study was conducted in three health facility, and this affects the representativeness of the study results. Involving more health facilities at different levels could have produced better generalizable results. Our study is a retrospective study based on secondary data, so it was not possible to determine all factors such as occupation, educational level, and economic status of pregnant women were missed that could affect pregnant-induced hypertension.

Conclusion     

This study indicated that the prevalence of pregnancy-induced hypertension was slightly lower, and those pregnant women with previous hypertension, substance abuse, family history of pregnancy-induced hypertension and multiple pregnancies had significant association with pregnancy-induced hypertension. Based on the finding of this study the following recommendations are forwarded: attendance of anti-natal care should give special focus on early treatment and prevention for those women's having family history pregnancy-induced hypertension, pregnant women with previous history pregnancy-induced hypertension and multiple pregnancies. Community health workers, anti-natal care attendance should work on the behavioral change of substance abuse women.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Ebud Ayele: conceived and designed the study, analyzed the data and wrote the manuscript. Kinfe Tsehaye, Kidane Zereabruk and Teklewoiyni Mariye: data analysis, drafting of the manuscript and advising the whole research paper. Tsgehana Gebregyorgis, Tsiyon Birhanu, Teklemariam Gebregziabher: interpretation of the data. Woldu Aberhe, Teklemariam Gebregziabher, Teklehaimanot Gereziher Haile and Shewit Engdashet contributed to manuscript preparation. All authors have read and approved the final version of the manuscript.

Acknowledgments     

We thank all the subjects of the study and the data collectors for their genuine contribution to the success of our work.

Tables     

Table 1: socio-demographic profile of study population of a study conducted on magnitude of pregnancy induced hypertension and associated factors among delivered women in public hospitals, Tigray, Ethiopia, 2019

Table 2: health profile of study population of participants of a study conducted on magnitude of pregnancy induced hypertension and associated factors among delivered women in public hospitals, Tigray, Ethiopia, 2019

Table 3: logistic regression analysis on association with pregnancy induced hypertension among deliverd women in public hospitals, Tigray, Ethiopia, 2019

References