High Insulin Resistance in Saudi Women with Unexplained Recurrent Pregnancy Loss: A Case–control Study

Background: Unexplained recurrent pregnancy loss (RPL) accounts for >50% of the patients with RPL. Insulin resistance (IR) is a potential cause of unexplained RPL. Objectives: To evaluate the relationship between insulin resistance (IR) and unexplained RPL among Saudi women. Methods: This is a single-center, case–control study conducted at a tertiary hospital in the Eastern Province of Saudi Arabia. The study group comprised Saudi women with unexplained RPL, while the control group had Saudi women with at least one live birth and no RPL. Blood samples were taken to determine the fasting glucose (FG) and fasting insulin (FI) levels. Women with diabetes mellitus and polycystic ovarian syndrome were excluded. A homeostatic model assessment of insulin resistance index (HOMA‑IR) value ≥3 was considered as IR. Results: The study and control groups comprised 43 and 56 women, respectively. Between the groups, there was a significant difference in the mean age (case: 37.9 ± 5.4 years; control: 32.2 ± 5.9 years; P < 0.0001) and the mean BMI (case: 31.5 ± 6.0; control: 26.1 ± 2.8; P < 0.0001). FG level was slightly higher in the control group (90.9 mg/dL vs 88.7 mg/dL; P = 0.068). FI level was significantly higher in the study group (16.33 µU/ mL vs. 6.17 µU/mL; P < 0.0001). HOMA‑IR of ≥3 was significantly more common in the study group (n = 22; 51.2%) than the control group (4; 7.1%) (P < 0.0001). After adjusting for age and BMI, IR ≥3 was found to be independently associated with unexplained RPL (aOR: 13.2; 95% CI: 3.77–46.36). Conclusions: This study showed that Saudi women with unexplained RPL had significantly higher levels of fasting insulin and insulin resistance than those without a history of RPL. Therefore, it is recommended to assess IR in women with RPL.