In a prospective observational study at a university teaching hospital, blood flow indices and serum hormone levels were compared between spontaneous and stimulated cycles in the same group of 50 patients with unexplained delayed conception.

In a prospective observational study at a university teaching hospital, the mid-luteal (peri-implantation) endometrial thickness and volume, uterine artery pulsatility index (PI) and resistance index (RI), endometrial and subendometrial vascularization index, flow index, and vascularization flow index, and serum estradiol and progesterone levels were compared between spontaneous and clomiphene citrate stimulated cycles in the same group of 50 patients with unexplained infertility.

Inclusion Criteria:

• Unexplained infertility
• Body mass index less than 30
• Regular menstruation
• Normal pelvic examination and ultrasonography

Exclusion Criteria:

• History of pelvic operations including cesarean section
• History of pelvic inflammatory disease
• Endometriosis
• Pelvic pathology including uterine fibroids
• General disease or medication that could potentially affect pelvic blood flow
• Smoking

Patients who had unexplained infertility