Case Control Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Methodol. Jun 20, 2023; 13(3): 98-117
Published online Jun 20, 2023. doi: 10.5662/wjm.v13.i3.98
Characterization and risk factors for unexplained female infertility in Sudan: A case-control study
Abdullah Abdulslam Abdullah, Musa Ahmed, Adesina Oladokun
Abdullah Abdulslam Abdullah, Musa Ahmed, Reproductive Health Sciences Program, Pan African University Life and Earth Sciences Institute, University of Ibadan, Ibadan 119, Oyo state, Nigeria
Abdullah Abdulslam Abdullah, Musa Ahmed, Adesina Oladokun, Department of Obstetrics and Gynecology, College of Medicine, University of Ibadan, Ibadan 119, Oyo state, Nigeria
Abdullah Abdulslam Abdullah, Department of Biomedical Sciences, Faculty of Veterinary Sciences, University of Gadarif, Al-Gadarif 32211, Sudan
Musa Ahmed, Department of Veterinary Surgery, Faculty of Veterinary Medicine, AL-Salam University, Al-fula 120, West Kordofan, Sudan
Author contributions: Abdullah AA, Ahmed M, and Oladokun A analyzed and interpreted the data, and drafted the manuscript; Abdullah AA and AO designed the study and directed implementation and data collection; Abdullah AA, Ahmed M, and Oladokun A edited the manuscript for intellectual content and provided critical comments on the manuscript; All authors gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agreed to be accountable for all aspects of the work.
Institutional review board statement: The study protocol and procedures were approved by the University of Ibadan/University College Hospital (UI/UCH) Ethics Committee (Ref. No; UI/EC/20/0438), and the Federal Ministry of Health, Sudan republic (Ref. No; 4-12-20).
Informed consent statement: Informed consent was obtained from all the study participants, and all necessary information regarding the study (objectives, requirements of the participants, and duration of the study) was given to the prospective study participants on an information sheet in Arabic to ensure an informed decision to participate in the study. Then, the full case histories of the participants were obtained through clinical examinations and laboratory investigations. Ethical principles such as discretion and confidentiality, the interviewees' free consent, and beneficence and nonmaleficence to participants were strictly adhered to.
Conflict-of-interest statement: The authors declared no potential conflict of interest concerning the research, authorship, and/or publication of this article.
Data sharing statement: The datasets used during this study are available from the principal investigator upon reasonable request.
STROBE statement: The authors have read the STROBE Statement – checklist of items, and the manuscript was prepared and revised according to the STROBE Statement – checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Abdullah Abdulslam Abdullah, MSc, Academic Research, Reproductive Health Sciences Program, Pan African University Life and Earth Sciences Institute, University of Ibadan, Ajibode Road, 200132, Ibadan 119, Oyo state, Nigeria. bahlol32029@gmail.com
Received: December 25, 2022
Peer-review started: December 25, 2022
First decision: February 8, 2023
Revised: February 8, 2023
Accepted: March 15, 2023
Article in press: March 15, 2023
Published online: June 20, 2023
Processing time: 176 Days and 23.2 Hours
ARTICLE HIGHLIGHTS
Research background

Unexplained infertility remains one of the mysteries in the reproductive health field, where the diagnostic evidence is still weak and the proposed treatments still work with unknown methods.

Research motivation

Unexplained infertility remains one of the mysteries in the reproductive health field, where the diagnostic evidence is still weak and the proposed treatments still work with unknown methods.

Research objectives

The objective of this study was to characterize and identify factors associated with unexplained infertility in Sudanese women.

Research methods

A matched (age and body mass index) case-control study was conducted from March 2021 to February 2022. The study samples were 210 women with unexplained infertility and 190 fertile women of reproductive age who were attending the maternity hospitals and fertility clinics in Khartoum, Sudan. The risk factors for unexplained infertility were identified using a structured, pre-tested questionnaire.

Research results

Infertile women had a significantly higher proportion of family history of infertility (explained and unexplained) compared with controls. Also, only marital status, family history of infertility, use of modern contraceptives, smoking, caffeine consumption, physical activity level, meals consumed, other vitamin-A-rich fruits and vegetables, and other vegetables were found to be significant (P < 0.05) factors associated with unexplained infertility among Sudanese women.

Research conclusions

Married women with a family history of infertility who smoke and consume a high amount of caffeine, who live a sedentary lifestyle, and who consume more than two meals free of vitamin-A-rich fruits and/or vegetables and/or other vegetables per day are at the highest risk of developing unexplained infertility.

Research perspectives

More interventional studies regarding the main factors, such as physical activity and dietary intake, for infertile women with unexplained causes, need to be done.