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Prevalence and Associated Factors of Pregnancy-induced Hypertension amongst Pregnant Women Attending Antenatal Care: A Cross-sectional Study
*Corresponding author: Zerai Hagos, School of Global Health and Bioethics, Euclid University, Banjul, Gambia. hagos@euclidfaculty.net
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Received: ,
Accepted: ,
How to cite this article: Hagos Z. Prevalence and Associated Factors of Pregnancy-induced Hypertension amongst Pregnant Women Attending Antenatal Care: A Cross-sectional Study. Glob J Med Stud. 2025;5:27-30. doi: 10.25259/GJMS_64_2025
Abstract
Objectives:
Pregnancy-induced hypertension (PIH) is a major contributor to maternal and perinatal morbidity and mortality worldwide, particularly in low- and middle-income countries such as Ethiopia. Despite its significance, data on PIH prevalence and risk factors in Hawassa, a rapidly urbanising centre in southern Ethiopia, remain limited.
Material and Methods:
An institution-based cross-sectional study was conducted from January to June 2024 amongst 384 pregnant women attending antenatal care (ANC) at two government hospitals in Hawassa: Hawassa University Comprehensive Specialised Hospital and Adare General Hospital. Systematic random sampling was used to select participants. Data were collected through structured interviewer-administered questionnaires, anthropometric measurements, and medical record reviews. PIH was defined as systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg after 20 weeks of gestation in previously normotensive women, without proteinuria. Binary logistic regression was used to identify associated factors, with statistical significance set at p < 0.05.
Results:
The prevalence of PIH was 8.3% (95% confidence interval [CI]: 5.7–11.5). Significant associated factors included maternal age >35 years (adjusted odds ratio [AOR] = 2.45, 95% CI: 1.12–5.36), pre-pregnancy obesity (body mass index [BMI] ≥25 kg/m2; AOR = 3.12, 95% CI: 1.45–6.72), family history of hypertension (AOR = 4.08, 95% CI: 1.89–8.81) and primigravidity (AOR = 2.18, 95% CI: 1.02–4.65). Multiparity ≥3 was protective (AOR = 0.42, 95% CI: 0.19–0.94).
Conclusion:
The prevalence of PIH in Hawassa government hospitals aligns with national estimates but underscores the need for targeted screening of high-risk groups. Enhanced ANC counselling on modifiable risks, such as weight management, could mitigate PIH burden. Limitations include a cross-sectional design and potential bias from self-reported BMI.
Keywords
Antenatal care
Ethiopia
Hawassa
Pregnancy-induced hypertension
Prevalence
Risk factors
INTRODUCTION
Hypertensive disorders of pregnancy, encompassing gestational hypertension, preeclampsia, and eclampsia, affect 5–10% of pregnancies globally and are the second leading cause of maternal mortality, contributing to 14% of such deaths.1 In sub-Saharan Africa, these disorders account for 16% of maternal deaths, with Ethiopia reporting a 16.9% attribution to maternal mortality.2 The pooled national prevalence of hypertensive disorders in Ethiopia is approximately 6.8% (95% confidence interval [CI]: 5.9–7.7), though regional variations exist, ranging from 1.2% to 18.3%.2,3
Pregnancy-induced hypertension (PIH), defined as new-onset hypertension after 20 weeks of gestation without proteinuria, poses risks including preterm birth, low birth weight, and maternal complications such as stroke and organ failure.4 In Ethiopia, pooled PIH prevalence amongst delivery attendees is 7.9%, with higher rates in urban settings due to lifestyle factors.5 Risk factors include advanced maternal age, obesity, family history of hypertension, primigravidity, and inadequate attending antenatal care (ANC) utilisation.6,7
Hawassa, the capital of Sidama Region in southern Ethiopia, is a rapidly urbanising city experiencing dietary shifts, lifestyle changes, and migration. These factors may elevate PIH risk, yet local epidemiological data are scarce, hindering tailored interventions. This study aimed to determine PIH prevalence and associated factors amongst ANC attendees in Hawassa government hospitals, informing evidence-based maternal health strategies in an urbanising Ethiopian context.
MATERIAL AND METHODS
Study design and setting
This institution-based cross-sectional study was conducted from 1 January to 30 June 2024, at two government hospitals in Hawassa: Hawassa University Comprehensive Specialised Hospital, a tertiary referral center with approximately 5,000 annual deliveries, and Adare General Hospital, a secondary facility handling approximately 2,500 deliveries yearly. These hospitals provide free ANC services to about 80% of local pregnant women.
Study population and sampling
The source population comprised pregnant women ≥20 weeks of gestation attending ANC. Exclusion criteria included chronic hypertension, multiple gestation, or incomplete records. The sample size was calculated using the single population proportion formula, assuming 6.8% prevalence,3 95% confidence level, 5% margin of error, and 10% non-response rate, yielding 384 participants. Systematic random sampling was applied: Every 3rd eligible woman (based on average daily ANC attendance of ~50) was selected until quotas were met (192 per hospital).
Data collection tools and procedures
A pre-tested, structured questionnaire adapted from the World Health Organization STEP wise approach to noncommunicable disease risk factor surveillance (STEPS) and the Ethiopian demographic and health survey tools assessed socio-demographics, obstetric history, lifestyle (diet, physical activity, alcohol use) and family history of hypertension.8 Blood pressure was measured 3 times at 5-min intervals using calibrated digital sphygmomanometers (Omron HEM-7120) with appropriate cuff sizes after a 5-min rest, with the mean used for analysis. Hypertension was defined as ≥140/90 mmHg. Anthropometrics included height (to 0.1 cm) and weight (to 0.1 kg) for body mass index (BMI) calculation (kg/m2). Pre-pregnancy BMI was self-reported or estimated through early antenatal records; self-reports were cross-checked with records where available.
Four trained BSc midwives collected data over 20–25 min per participant. Medical records were used to verify gestational age (last menstrual period or ultrasound). Supervision ensured quality and completeness.
Missing data were minimal (<2%) and handled using listwise deletion in regression analyses.
Data analysis
Data were entered into EpiData 3.1 and analysed in the Statistical Package for Social Sciences 26. Descriptive statistics summarised the variables. Prevalence was calculated with 95% CI. Bivariable logistic regression screened associations (p < 0.25); multivariable analysis (backward stepwise regression) identified independent factors (p < 0.05). Adjusted odds ratios (AOR) with 95% CI were reported. Multicollinearity was assessed using the variance inflation factor <10 for all predictors. Model fit was checked using Hosmer–Lemeshow test (p > 0.05).
Ethical considerations
Ethical approval was obtained from Hawassa Health Department (Ref. No. HHD/2023/045; Date: 10 December, 2023). Written informed consent was obtained from all participants.
RESULTS
Socio-demographic and obstetric characteristics
Of 384 participants, the mean age was 27.4 ± 5.2 years;
52.6% were aged 25–34. Most (68.2%) were Sidama ethnicity, urban residents (62.5%) and homemakers (54.7%). The mean gestational age was 28.6 ± 6.1 weeks. Primigravidae comprised 41.1%; 22.4% had ≥3 prior pregnancies. Family history of hypertension was reported by 18.5%; 9.1% reported alcohol use during pregnancy. Pre-pregnancy obesity (BMI ≥25 kg/m2) was present in 24.0% of participants [Table 1].
| Characteristic | Frequency (n=384) | Percentage |
|---|---|---|
| Age (years) | ||
| <25 | 128 | 33.3 |
| 25–34 | 202 | 52.6 |
| >35 | 54 | 14.1 |
| Residence | ||
| Urban | 240 | 62.5 |
| Rural | 144 | 37.5 |
| Gravidity | ||
| 1 | 158 | 41.1 |
| 2–3 | 140 | 36.5 |
| ≥4 | 86 | 22.4 |
| Body mass index category | ||
| Underweight (<18.5) | 48 | 12.5 |
| Normal (18.5–24.9) | 244 | 63.5 |
| Overweight/Obese (≥25) | 92 | 24.0 |
| Family history of hypertension | 71 | 18.5 |
| Alcohol use | 35 | 9.1 |
Prevalence of PIH
PIH prevalence was 8.3% (32/384; 95% CI: 5.7–11.5). Of these cases, 68.8% had gestational hypertension alone; 31.2% had preeclampsia.
Associated factors
In bivariable analysis, age >35, obesity, family history of hypertension, primigravidity and alcohol use were significant (p < 0.05). Multivariable analysis retained age >35 (AOR = 2.45, 95% CI: 1.12–5.36), obesity (AOR = 3.12, 95% CI: 1.45–6.72), family history (AOR = 4.08, 95% CI: 1.89–8.81) and primigravidity (AOR = 2.18, 95% CI: 1.02–4.65). Multiparity ≥3 was protective (AOR = 0.42, 95% CI: 0.19–0.94). Alcohol use was not significant in the final model [Table 2].
| Factor | COR (95% CI) | AOR (95% CI) | P-value |
|---|---|---|---|
| Age >35 years | 2.78 (1.35–5.72) | 2.45 (1.12–5.36) | 0.025 |
| Pre-pregnancy obesity | 3.45 (1.68–7.09) | 3.12 (1.45–6.72) | 0.004 |
| Family history of hypertension | 4.56 (2.18–9.54) | 4.08 (1.89–8.81) | <0.001 |
| Primigravidity | 2.32 (1.15–4.68) | 2.18 (1.02–4.65) | 0.044 |
| Multiparity ≥3 | 0.48 (0.22–1.05) | 0.42 (0.19–0.94) | 0.036 |
COR: Crude odds ratio, AOR: Adjusted odds ratio, CI: Confidence interval, PIH: Pregnancy-induced hypertension
DISCUSSION
This study found an 8.3% prevalence of PIH amongst ANC attendees in Hawassa, slightly higher than the national pooled estimate of 6.8% but consistent with the southern Ethiopia regional rate of 10.1%.3,4 Urbanisation in Hawassa may contribute to this elevated prevalence through dietary shifts and sedentary lifestyles.5
Advanced maternal age (>35 years) was associated with a 2.45-fold increased risk, aligning with meta-analyses showing a 2.9-fold risk, likely due to vascular ageing.6,9 Pre-pregnancy obesity conferred a 3.12-fold risk, reflecting endothelial dysfunction and consistent with Ethiopian studies reporting 3.9-fold odds.6 Family history of hypertension showed the strongest association (AOR = 4.08), underscoring genetic predisposition. Primigravidity doubled the risk (AOR = 2.18), consistent with known nulliparous susceptibility.7 Multiparity ≥3 was protective (AOR = 0.42), suggesting parity-induced vascular adaptation.
Alcohol use was significant in bivariable but not multivariable analysis, likely due to confounding with other lifestyle factors. Comparison with other East African urban studies (e.g., Addis Ababa, Nairobi) shows similar risk patterns, reinforcing the urban risk profile.
Limitations
The cross-sectional design precludes causal inference. Self-reported pre-pregnancy BMI may introduce recall bias. Proteinuria assessment was not consistently available, though PIH was defined without it. Strengths include multi-hospital sampling, systematic measurement and robust statistical adjustment.
CONCLUSION
PIH prevalence in Hawassa is substantial, driven by modifiable (obesity) and non-modifiable (age, family history) factors. Public health implications include integrating risk screening into ANC, promoting pre-pregnancy weight management and early monitoring of high-risk women. Future longitudinal studies should evaluate targeted interventions in urban Ethiopian settings.
Ethical approval:
The research/study was approved by the Institutional Review Board at Regional Health Department, Reference No. RHD/2023/045, dated 10 December 2023.
Declaration of patient consent:
The authors certify that they have obtained all appropriate patient consent.
Conflicts of interest:
There are no conflicts of interest.
Use of artificial intelligence (AI)-assisted technology for manuscript preparation:
The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.
Financial support and sponsorship: Nil.
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