PRL and immune system disorder: Our findings were supported by another hospital-based case control study, which found that hypothyroidism was reported significantly higher among women with infertility (19.1%), compared to controls (11.0%).22 Hypothyroidism can cause anovulatory cycles, luteal phase defects, high prolactin levels, and sex hormone imbalances.5 Immunity disorders were associated with a 3.66 increase in odds of infertility in Qatari females with a statistically significant p-value of 0.025; however, further research is needed to support this association.