LE + CC vs. LE for Ovulation Induction

Inclusion Criteria: * Women 18-40 years of age * Having ovulation disorder (length of cycle \< 21 or \> 35 days or having \< 8 cycles per year) * FSH ≥5 IU/L and ≤25 IU/L, or LH ≥5 IU/L and AMH ≥1.2 ng/mL * Progressive motility (PR) ≥ 32% OR total progressive motility sperm count \> 5 million; and sperm concentration ≥ 5 million/ml, (World Health Organization, 2021) * Agreeing to take part in study. * Not participating in other studies. Exclusion Criteria: * Untreated thyroid disease; Thyroid disease is suspected if patients have one of these (Bednarczuk et al., 2021); TSH ≥4 mIU/L or TSH ≥2.5mIU/L and TPOAb (+) or TSH \<0.1mIU/L * Untreated hyper-prolactinemia; Hyperprolactinemia is suspected if patients have prolactinemia concentration \>50 ng/mL (The sample is collected after an overnight fast, at least 2 hours after waking up, ensuring that venipuncture does not cause excessive stress.) * Allergy or having contraindications to LE or CC; * Unilateral or Bilateral fallopian tube blockage (HSG, HyFoSy or surgery confirmation) * Untreated endometrial abnormalities include endometrial hyperplasia, intrauterine adhesions, endometrial polyp, or chronic endometritis. * Uterine abnormalities include leiomyomas L0, L1, or L2; severe adenomyosis; congenital uterine abnormalities, include didelphus, arcuate, unicornuate, bicornuate, septate.