ASSESSMENT OF ENDOMETRIAL THICKNESS AND VASCULARITY BY TRANSVAGINAL DOPPLER ULTRASOUND AND THEIR RELATIONSHIP WITH ENDOMETRIAL MICROBIAL INFECTION IN REPRODUCTIVE-AGED WOMEN WITH SUBCLINICAL HYPOTHYROIDISM: A COMPARATIVE STUDY

Abstract

Background: Subclinical hypothyroidism is a mild thyroid disorder that involves having a high level of TSH and a normal level of free T4. It is not always clinically obvious but can influence reproductive function, menstruation, uterine development and blood flow. A further disruption of endometrial receptivity and fertility may be caused by endometrial microbial infection. TV-Doppler ultrasound is a non-invasive technique for evaluating vascularity and thickness of the endometrium.

Objective: To assess endometrial thickness and vascularity by transvaginal Doppler ultrasound and determine their relationship with endometrial microbial infection in reproductive-aged women with subclinical hypothyroidism.

Methods: This comparative study was carried out at Muhammad College of Medicine Peshawar, between January 2025 and June 2025. There were 73 women of reproductive age included and divided into subclinical hypothyroidism and euthyroid control groups. Demographic, clinical, thyroid profile, transvaginal ultrasound, Doppler vascularity and microbiological results were collected. The following parameters were compared between the groups: endometrial thickness, Doppler indices of uterine arteries, vascularity grade and microbial culture results. Data were analysed statistically with SPSS version 26 and p value ≤ 0.05 was taken as statistically significant.

Results: Women with subclinical hypothyroidism had significantly higher mean endometrial thickness than controls. Thickened endometrium, heterogeneous endometrial pattern, intrauterine fluid, and increased vascularity were more frequent in the subclinical hypothyroidism group. Uterine artery pulsatility index and resistance index were higher, while peak systolic velocity was lower among women with subclinical hypothyroidism. Endometrial microbial infection was detected more frequently in the subclinical hypothyroidism group than in controls. Infection was significantly associated with greater endometrial thickness, heterogeneous endometrium, intrauterine fluid, increased vascularity, and raised uterine artery resistance. TSH showed a positive correlation with endometrial thickness, pulsatility index, and resistance index.

Conclusion: Subclinical hypothyroidism was associated with increased endometrial thickness, altered Doppler vascularity, and higher frequency of endometrial microbial infection. Transvaginal Doppler ultrasound may be useful for identifying endometrial abnormalities in reproductive-aged women with subclinical hypothyroidism, particularly when symptoms of infection or infertility are present.