What initial investigations should I consider for a couple presenting with infertility after one year of unprotected intercourse?

Initial investigations for a couple presenting with infertility after one year of unprotected intercourse should include simultaneous assessment of both partners.

For the male partner, a semen analysis is the first-line investigation. Clear instructions should be given regarding sample collection, including abstinence for 2 to 7 days before collection, collection by masturbation into a non-toxic container, and prompt delivery to the laboratory. If the first semen analysis is abnormal, a repeat test should be done ideally after 3 months, or sooner if there is severe abnormality. Men with two abnormal semen analyses should be referred for further assessment.

For the female partner, initial investigations include measurement of mid-luteal phase serum progesterone (around day 21 of a 28-day cycle) to confirm ovulation, even if menstrual cycles are regular. Women with irregular or prolonged cycles may require repeated progesterone measurements and gonadotrophin (FSH and LH) levels to identify ovulatory disorders.

Screening for Chlamydia trachomatis should be offered to women before any uterine instrumentation, with appropriate treatment and contact tracing if positive.

Assessment of tubal patency is recommended, typically by hysterosalpingography (HSG) or hysterosalpingo-contrast ultrasonography in women without known comorbidities. Women with suspected pelvic pathology (e.g., pelvic inflammatory disease, endometriosis, previous ectopic pregnancy) should be offered diagnostic laparoscopy with dye to assess tubal and pelvic abnormalities simultaneously.

Routine measurement of prolactin and thyroid function tests should only be done if there are clinical indications such as symptoms of ovulatory disorder, galactorrhoea, pituitary tumour, or thyroid disease.