The research aims to compare diagnosis of ovulation and anovulation in 2D and 3D ultrasonography.

Thirty healthy participants will be enrolled. When their dominant ovarian follicle has a diameter of 16 mm or more, an anti-prostaglandin medication, indomethacin 30 mg, will be administered three times daily for 1-7 days. Anti-prostaglandins are known to cause anovulation. Daily 2D and 3D ultrasound scans, and urine and finger prick blood tests for reproductive hormonal assays will be performed. The medication will be discontinued once ultrasound features of anovulation are observed. These study procedures will also be carried out on days 1, 3 and 7 after anovulation.

A second cohort of 30 participants who had 2D and 3D ultrasound scans and hormonal assays in a natural cycle in a previous study (Bio 2080; NCT05531357) will also be evaluated.

These two groups represent the anovulatory and ovulatory groups, respectively, and their 2D and 3D ultrasound features will be compared. With 2D ultrasonography as a gold standard, the study aims to determine if 3D ultrasonography improves ovulation assessment and improves the recognition of anovulatory follicles in infertility treatment

Inclusion Criteria:

• Healthy biological females
• Regular menstrual cycles (21-35 days)

Exclusion Criteria:

• BMI <18 or >30
• Pregnancy
• Breastfeeding mothers
• History of infertility
• History of hysterectomy or oophorectomy
• Reproductive health issues that can interfere with study outcomes
• Smoking
• Not on any hormonal medication that affects reproduction (including hormonal contraception)
• History of metabolic syndrome or untreated thyroid disease
• Contra-indication to non-steroidal anti-inflammatory drug (NSAID) use. These include:
• Gastric ulcers or gastro-intestinal bleeding
• History of myocardial infarction or a coronary artery bypass
• Cerebrovascular disease
• Hypertension
• Chronic or acute renal failure
• Severe liver disease
• Nasal polyp syndrome