Background: Preeclampsia (PE) is a significant multi-organ system disorder of pregnancy and is responsible for global maternal morbidity and mortality. In Zanzibar, it affects approximately 26.3% of postnatal women. However, there is limited knowledge regarding the maternal risk factors and birth outcomes associated with PE. This study aimed to examine the maternal risk factors and adverse birth outcomes related to preeclampsia among pregnant women in Zanzibar. Methods: A prospective cohort study was conducted in 2021 across public health facilities on Unguja, Zanzibar. A total of 728 pregnant women at ≥20 weeks gestation with or without preeclampsia were enrolled and followed through three phases: during antenatal care (ANC), within 24 hours of delivery, and up to 28 days postpartum. Data were analyzed using SPSS version 26.0. Chi-square and regression analyses were conducted, with statistical significance set at p < 0.05. Results: The incidence of preeclampsia was 7.7%. The median age of women diagnosed with preeclampsia was 28 years (IQR: 24 - 33). Women with a family history of hypertension were significantly more likely to develop preeclampsia (adjusted odds ratio [aOR] = 1.92, 95% CI: 1.05 - 3.51, p = 0.033). Women with a history of chronic hypertension (aOR 3.69, 95% CI: 1.01-13.54, p = 0.049) and those with a previous history of preeclampsia or eclampsia were likely to develop preeclampsia in their subsequent pregnancies (aOR = 3.11, 95% CI: 1.11 - 8.71, p = 0.031). Additionally, women who delivered low-birth-weight infants according to certain criteria had greater odds of developing preeclampsia compared to women who delivered infants weighing 2.5 - 3.9 kg (aOR = 0.35, 95% CI: 0.15 - 0.82, p = 0.016). Conclusion: Preeclampsia affects a significant proportion of pregnant women in Unguja, Zanzibar. A family history of hypertension is significantly associated with an increased risk of developing preeclampsia. Early detection and effective management of preeclampsia, along with targeted health promotion during routine ANC services, through identifying and assessing potential risks to the mother and the baby, such as maternal conditions, family history, and lifestyle factors, may reduce the burden of preeclampsia and the associated maternal and neonatal outcomes in Unguja Zanzibar.
References
[1]
Jikamo, B., Adefris, M., Azale, T. and Alemu, K. (2022) Risk Factors for Preeclampsia and Eclampsia in Sidama Region: A Nested Case-Control Study. PAMJ—OneHealth, 9, Article No. 3. https://doi.org/10.11604/pamj-oh.2022.9.3.34409
[2]
Cresswell, J.A. (2025) Global and Regional Causes of Maternal Deaths 2009-20: A WHO Systematic Analysis. Lancet Global Health, 13, E626-E634. https://doi.org/10.1016/S2214-109X(24)00560-6
[3]
Sun, S., et al. (2025) Trends in Global and Regional Incidence and Prevalence of Hypertensive Disorders in Pregnancy (1990-2021): An Age-Period-Cohort Analysis. Scientific Reports, 15, Article No. 1513.
[4]
Mou, A.D., Barman, Z., Hasan, M., Miah, R., Hafsa, J.M., Das Trisha, A., et al. (2021) Prevalence of Preeclampsia and the Associated Risk Factors among Pregnant Women in Bangladesh. ScientificReports, 11, Article No. 21339. https://doi.org/10.1038/s41598-021-00839-w
[5]
Jikamo, B., Adefris, M., Azale, T. and Alemu, K. (2023) Incidence, Trends and Risk Factors of Preeclampsia in Sub-Saharan Africa: A Systematic Review and Meta-Analysis. PAMJ—OneHealth, 11, Article No. 1. https://doi.org/10.11604/pamj-oh.2023.11.1.39297
[6]
Tesfahun, E., Tadesse, S., Hailu, A., Minda, A., Ekubay, M., Tariku, B., et al. (2023) Prevalence of Preeclampsia and Associated Factors among Antenatal Care Attending Mothers at Tirunesh Beijing General Hospital, Addis Ababa, Ethiopia. AdvancesinPublicHealth, 2023, Article ID: 1132497. https://doi.org/10.1155/2023/1132497
[7]
Khan, B., Allah Yar, R., Khakwani, A.K., Karim, S. and Arslan Ali, H. (2022) Preeclampsia Incidence and Its Maternal and Neonatal Outcomes with Associated Risk Factors. Cureus, 14, e31143. https://doi.org/10.7759/cureus.31143
[8]
Tabacco, S., Ambrosii, S., Polsinelli, V., Fantasia, I., D’Alfonso, A., Ludovisi, M., et al. (2023) Pre-Eclampsia: From Etiology and Molecular Mechanisms to Clinical Tools—A Review of the Literature. CurrentIssuesinMolecularBiology, 45, 6202-6215. https://doi.org/10.3390/cimb45080391
[9]
Chang, K., Seow, K. and Chen, K. (2023) Preeclampsia: Recent Advances in Predicting, Preventing, and Managing the Maternal and Fetal Life-Threatening Condition. InternationalJournalofEnvironmentalResearchandPublicHealth, 20, Article No. 2994. https://doi.org/10.3390/ijerph20042994
[10]
Khan, B., Allah Yar, R., Khakwani, A.K., Karim, S. and Arslan Ali, H. (2022) Preeclampsia Incidence and Its Maternal and Neonatal Outcomes with Associated Risk Factors. Cureus, 14, e31143. https://doi.org/10.7759/cureus.31143
[11]
Respati, L.L.W., Indasah, I. and Puspitasari, Y. (2024) Qualitative Analysis of Pregnant Women with Preeclampsia at Muhammadiyah Ahmad Dahlan Hospital, Kediri. JournalofMaternalandChildHealth, 9, 674-681. https://doi.org/10.26911/thejmch.2024.09.04.05
[12]
Belay, A.S. and Wudad, T. (2019) Prevalence and Associated Factors of Pre-Eclampsia among Pregnant Women Attending Anti-Natal Care at Mettu Karl Referal Hospital, Ethiopia: Cross-Sectional Study. ClinicalHypertension, 25, Article No. 14. https://doi.org/10.1186/s40885-019-0120-1
[13]
WHO (2019) Maternal Mortality: Evidence Brief. 1-4.
[14]
Musarandega, R., Nyakura, M., Machekano, R., Pattinson, R. and Munjanja, S.P. (2021) Causes of Maternal Mortality in Sub-Saharan Africa: A Systematic Review of Studies Published from 2015 to 2020. JournalofGlobalHealth, 11, Article No. 04048. https://doi.org/10.7189/jogh.11.04048
[15]
World Health Organization (2025) Trends in Maternal Mortality Estimates 2000 to 2023: Estimates by WHO, UNICEF, UNFPA, World Bank Group, and UNDESA/Population Division.
[16]
Frank, I.O., Michael, J.M., Jenny, R. and Joseph, O. (2020) Prevalence and Risk Factors for Pre-Eclampsia/eclampsia in Northern Tanzania. JournalofPublicHealthandEpidemiology, 12, 78-85. https://doi.org/10.5897/jphe2019.1143
[17]
Rashid, S.A., Seif, S.A. and Omar, R.B. (2024) Prevalence, Predictors and Management of Pre-Eclampsia among Pregnant Women Attending Antenatal Clinics in Zanzibar. TanzaniaJournalofHealthResearch, 25, 1132-1149. https://doi.org/10.4314/thrb.v25i3.12
[18]
USAID C WHO, UNICEF (2022) Demographic and Health Survey and Malaria Indicator Survey. Paper Knowledge. Toward a Media History of Documents. 12-26.
[19]
Machano, M.M. and Joho, A.A. (2020) Prevalence and Risk Factors Associated with Severe Pre-Eclampsia among Postpartum Women in Zanzibar: A Cross-Sectional Study. BMCPublicHealth, 20, Article No. 1347. https://doi.org/10.1186/s12889-020-09384-z
[20]
Nyirenda, J., Kasonka, L. and Vwalika, B. (2019) Maternal Complications of Severe Pre-Eclampsia at a Tertiary Level Hospital in Zambia. MedicalJournalofZambia, 46, 117-123. https://doi.org/10.55320/mjz.46.2.116
[21]
Asseffa, N.A. and Demissie, B.W. (2019) Perinatal Outcomes of Hypertensive Disorders in Pregnancy at a Referral Hospital, Southern Ethiopia. PLOS ONE, 14, e0213240. https://doi.org/10.1371/journal.pone.0213240
[22]
Burton, G.J., Redman, C.W., Roberts, J.M. and Moffett, A. (2019) Pre-Eclampsia: Pathophysiology and Clinical Implications. BMJ, 366, l2381. https://doi.org/10.1136/bmj.l2381
[23]
Melese, M.F., Badi, M.B. and Aynalem, G.L. (2019) Perinatal Outcomes of Severe Preeclampsia/Eclampsia and Associated Factors among Mothers Admitted in Amhara Region Referral Hospitals, North-West Ethiopia, 2018. BMCResearchNotes, 12, Article No. 147. https://doi.org/10.1186/s13104-019-4161-z
[24]
Walle, T.A. and Azagew, A.W. (2019) Hypertensive Disorder of Pregnancy Prevalence and Associated Factors among Pregnant Women Attending Ante Natal Care at Gondar Town Health Institutions, North-West Ethiopia 2017. PregnancyHypertension, 16, 79-84. https://doi.org/10.1016/j.preghy.2019.03.007
[25]
Anto, E.O., Boadu, W.I.O., Ansah, E., Tawiah, A., Frimpong, J., Tamakloe, V.C.K.T., et al. (2023) Prevalence of Preeclampsia and Algorithm of Adverse Foeto-Maternal Risk Factors among Pregnant Women in the Central Region of Ghana: A Multicentre Prospective Cross-Sectional Study. PLOSONE, 18, e0288079. https://doi.org/10.1371/journal.pone.0288079
[26]
Mathew, R., Devanesan, B.P., Srijana, and Sreedevi, N.S. (2023) Prevalence of Hypertensive Disorders of Pregnancy, Associated Factors and Pregnancy Complications in a Primigravida Population. GynecologyandObstetricsClinicalMedicine, 3, 119-123. https://doi.org/10.1016/j.gocm.2023.01.002
[27]
Mtali, Y.S., Lyimo, M.A., Luzzatto, L. and Massawe, S.N. (2019) Hypertensive Disorders of Pregnancy Are Associated with an Inflammatory State: Evidence from Hematological Findings and Cytokine Levels. BMCPregnancyandChildbirth, 19, Article No. 237. https://doi.org/10.1186/s12884-019-2383-7
[28]
Noubiap, J.J., Bigna, J.J., Nyaga, U.F., Jingi, A.M., Kaze, A.D., Nansseu, J.R., et al. (2019) The Burden of Hypertensive Disorders of Pregnancy in Africa: A Systematic Review and Meta‐Analysis. TheJournalofClinicalHypertension, 21, 479-488. https://doi.org/10.1111/jch.13514
[29]
Obi, C.N., Obi, V.O., Nwafor, J.I., Onwe, B.I., Onuchukwu, V.U., Ugoji, D.C., et al. (2019) A Comparative Study of Pregnancy Outcome among Women with Preeclampsia and Normotensive at the Alex Ekwueme Federal University Teaching Hospital Abakaliki, Nigeria. InternationalJournalofResearchinMedicalSciences, 7, Article No. 3789. https://doi.org/10.18203/2320-6012.ijrms20194311
[30]
Lugobe, H.M., Muhindo, R., Kayondo, M., Wilkinson, I., Agaba, D.C., McEniery, C., et al. (2020) Risks of Adverse Perinatal and Maternal Outcomes among Women with Hypertensive Disorders of Pregnancy in Southwestern Uganda. PLOSONE, 15, e0241207. https://doi.org/10.1371/journal.pone.0241207
[31]
Masembe, S., Migisha, R., Turyasingura, G., Aheisibwe, H., Nzabandora, E. and Lule, J.C. (2024) Adverse Maternal Outcomes and Associated Factors among Mothers of Advanced Age Delivering at a Tertiary Hospital, Southwestern Uganda: A Cross-Sectional Study. BMCPregnancyandChildbirth, 24, Article No. 348. https://doi.org/10.1186/s12884-024-06557-1
[32]
Bakar, R.R., Mmbaga, B.T., Nielsen, B.B. and Manongi, R.N. (2019) Awareness of Danger Signs during Pregnancy and Post-Delivery Period among Women of Reproductive Age in Unguja Island, Zanzibar: A Qualitative Study. African Journal of Reproductive Health, 23, 27-36.
[33]
Mapunda, O.E., Msuya, S.E., A. Kapologwe, N., John, B., Damian, D.J. and Mahande, M.J. (2016) Assessment of Maternal Mortality and Its Associated Causes at Shinyanga Regional Hospital in Tanzania. Women’sHealthBulletin, 4, 1-7.
[34]
Obas, M., et al. (2018) Neonatal and Fetal Outcomes of Pregnant Mothers with Hypertensive Disorder of Pregnancy at Hospitals in Wolaita Zone, Southern Ethiopia. Journal of Midwifery and Reproductive Health, 7, 1636-1640.
[35]
Devane, D., Barrett, N., Gallen, A., O’Reilly, M.F., Nadin, M., Conway, G., et al. (2019) Identifying and Prioritising Midwifery Care Process Metrics and Indicators: A Delphi Survey and Stakeholder Consensus Process. BMCPregnancyandChildbirth, 19, Article No. 198. https://doi.org/10.1186/s12884-019-2346-z
[36]
Soomro, S., Shaikh, A.A. and Kumar, R. (2019) Maternal and Fetal Outcomes of Pregnancy-Related Hypertensive Disorders in a Tertiary Care Hospital in Sukkur, Pakistan. Cureus, 11, e5507.
[37]
Zhang, N., Tan, J., Yang, H. and Khalil, R.A. (2020) Comparative Risks and Predictors of Preeclamptic Pregnancy in the Eastern, Western and Developing World. BiochemicalPharmacology, 182, Article ID: 114247. https://doi.org/10.1016/j.bcp.2020.114247
[38]
Lisonkova, S., Bone, J.N., Muraca, G.M., Razaz, N., Wang, L.Q., Sabr, Y., et al. (2021) Incidence and Risk Factors for Severe Preeclampsia, Hemolysis, Elevated Liver Enzymes, and Low Platelet Count Syndrome, and Eclampsia at Preterm and Term Gestation: A Population-Based Study. AmericanJournalofObstetricsandGynecology, 225, 538.e1-538.e19. https://doi.org/10.1016/j.ajog.2021.04.261
[39]
Wolie Asres, A., Tilahun, A.W. and Addissie, A. (2023) Factors Associated with Preeclampsia among Pregnant Women in Gojjam Zones, Amhara Region, Ethiopia: A Case-Control Study. BloodPressure, 32, Article ID: 2255687. https://doi.org/10.1080/08037051.2023.2255687
[40]
Moungmaithong, S., Shen, L., Poon, L.C., Payne, B., Côté, A.M., Hoodbhoy, Z., et al. (2022) Risk Factors and Predictors for Pre-Eclampsia. In: Moungmaithong, S., Shen, L., et al., Eds., TheGlobalLibraryofWomen’sMedicine, Vol. 2, 1-32. https://doi.org/10.3843/glowm.416333
[41]
Yushida, Y. and Zahara, E. (2020) The Risk Factors toward Preeclampsia Events of Pregnant Women in Meureubo and Johan Pahlawan Community Health Center West Aceh. OpenAccessMacedonianJournalofMedicalSciences, 8, 670-673. https://doi.org/10.3889/oamjms.2020.5531
[42]
Sutan, R., Aminuddin, N.A. and Mahdy, Z.A. (2022) Prevalence, Maternal Characteristics, and Birth Outcomes of Preeclampsia: A Cross-Sectional Study in a Single Tertiary Healthcare Center in Greater Kuala Lumpur Malaysia. FrontiersinPublicHealth, 10, Article ID: 973271. https://doi.org/10.3389/fpubh.2022.973271
[43]
Nie, X., Xu, Z. and Ren, H. (2024) Analysis of Risk Factors of Preeclampsia in Pregnant Women with Chronic Hypertension and Its Impact on Pregnancy Outcomes. BMCPregnancyandChildbirth, 24, Article No. 307. https://doi.org/10.1186/s12884-024-06476-1
[44]
Ayala-Ramírez, P., Serrano, N., Barrera, V., Bejarano, J.P., Silva, J.L., Martínez, R., et al. (2020) Risk Factors and Fetal Outcomes for Preeclampsia in a Colombian Cohort. Heliyon, 6, e05079. https://doi.org/10.1016/j.heliyon.2020.e05079
[45]
Stitterich, N., Shepherd, J., Koroma, M.M. and Theuring, S. (2021) Risk Factors for Preeclampsia and Eclampsia at a Main Referral Maternity Hospital in Freetown, Sierra Leone: A Case-Control Study. BMCPregnancyandChildbirth, 21, Article No. 413. https://doi.org/10.1186/s12884-021-03874-7
[46]
Awor, S., Abola, B., Byanyima, R., Orach, C.G., Kiondo, P., Kaye, D.K., et al. (2023) Prediction of Pre-Eclampsia at St. Mary’s Hospital Lacor, a Low-Resource Setting in Northern Uganda, a Prospective Cohort Study. BMCPregnancyandChildbirth, 23, Article No. 101. https://doi.org/10.1186/s12884-023-05420-z
[47]
Ayala-Ramírez, P., Serrano, N., Barrera, V., Bejarano, J.P., Silva, J.L., Martínez, R., et al. (2020) Risk Factors and Fetal Outcomes for Preeclampsia in a Colombian Cohort. Heliyon, 6, e05079. https://doi.org/10.1016/j.heliyon.2020.e05079
[48]
Khanum, H. (2021) Prevalance of Pre-Eclampsia and Factors Responsible among Third Trimester Pregnant Women in Hospital of Dhaka. BiomedicalJournalofScientific&TechnicalResearch, 33, 26089-26097. https://doi.org/10.26717/bjstr.2021.33.005445
[49]
Kumsa, H. and Mergiyaw, D. (2024) Obstetrical and Perinatal Outcomes of Women with Preeclampsia at Woldia Comprehensive Specialized Hospital, Northeast Ethiopia. FrontiersinMedicine, 11, Article ID: 1326333. https://doi.org/10.3389/fmed.2024.1326333
[50]
Nkwabong, E., Djientcheu Deugoue, F. and Fouedjio, J. (2022) Pre-Eclampsia in a Sub-Saharan African Country and Maternal-Perinatal Outcome. TropicalDoctor, 53, 61-65. https://doi.org/10.1177/00494755221113155
[51]
Chai, L., Li, S., Yin, B., Zhu, X., Zhu, B. and Wu, K. (2025) Prevalence, Risk Factors, and Adverse Perinatal Outcomes in Chinese Women with Preeclampsia: A Large Retrospective Cohort Study. JournalofHealth, PopulationandNutrition, 44, Article No. 32. https://doi.org/10.1186/s41043-025-00778-6
[52]
Chasekwa, B., Ntozini, R., Church, J.A., Majo, F.D., Tavengwa, N., Mutasa, B., et al. (2021) Prevalence, Risk Factors and Short-Term Consequences of Adverse Birth Outcomes in Zimbabwean Pregnant Women: A Secondary Analysis of a Cluster-Randomized Trial. InternationalJournalofEpidemiology, 51, 1785-1799. https://doi.org/10.1093/ije/dyab248
[53]
Syoum, F.H., Abreha, G.F., Teklemichael, D.M. and Chekole, M.K. (2022) Fetomaternal Outcomes and Associated Factors among Mothers with Hypertensive Disorders of Pregnancy in Suhul Hospital, Northwest Tigray, Ethiopia. JournalofPregnancy, 2022, Article ID: 6917009. https://doi.org/10.1155/2022/6917009
