Influence of COVID-19 Infection/vaccination on Menstrual Regularity and Hormonal Function in Saudi Females of Reproductive Age

Objectives: This study aimed to examine the impact of COVID-19 infection and vaccination on menstrual regularity in Saudi women of childbearing age. Additionally, it sought to explore the potential effects of COVID-19 vaccination on serum hormonal levels during the follicular phase of the menstrual cycle, along with their relationship with Vit.D.

Methods: This case‒control study investigated the impact of COVID-19 infection and vaccination on menstrual regularity and hormonal function in Saudi women of reproductive age. Data were collected from 79 women who attended the Outpatient Department of Obstetrics and Gynaecology at King Faisal Medical Complex in Taif, Saudi Arabia. All participants had received COVID-19 vaccines. The data collection process was comprehensive, encompassing various participant characteristics, such as demographic information, history of COVID-19 infection, and details about menstrual patterns before and after infection and vaccination. Furthermore, hormonal measurements, including follicle-stimulating hormone (FSH), luteinizing hormone (LH), oestradiol, prolactin, thyroid-stimulating hormone (TSH), and vitamin D (Vit.D) levels, were extracted from the participants' medical records.

Results: Among the participants, 39.24 % had a history of COVID-19 infection, and following the infection, there was a significant increase in the proportion of women experiencing irregular menstruation. After receiving the COVID-19 vaccine, 72.15 % of the participants continued to have irregular menstrual cycles. The study found that a considerable number of participants had menstrual cycles outside the normal range, with 43.80 % having cycles shorter than 21 days and 35.10 % having cycles longer than 35 days. Comparing participants with regular and irregular cycles after COVID-19 vaccination, no significant changes were observed in most hormonal levels. However, the prolactin hormone showed a significant increase in participants with irregular cycles, while Vit.D levels were significantly decreased in this group.

Conclusion: The study findings indicate a higher prevalence of irregular menstruation among participants, particularly after vaccination. Notably, irregular menstrual cycles were found to be associated with elevated levels of prolactin hormone and decreased levels of Vit.D.