Pelvic Ultrasound

A pelvic ultrasound images the uterus, ovaries, fallopian tubes (if abnormal), and surrounding pelvic structures. In fertility it shows: endometrial thickness and pattern (lining), antral follicle count (AFC — egg reserve indicator), fibroids, polyps, ovarian cysts (simple, endometrioma, dermoid), hydrosalpinx (blocked tube with fluid — reduces IVF success 50%), and early pregnancy. Transvaginal (TVS) provides far superior resolution than transabdominal USS.

No — they are different routes to the same type of examination. A pelvic ultrasound can be performed transabdominally (probe on abdomen, full bladder needed) or transvaginally (probe inserted vaginally, better resolution, empty bladder). For fertility purposes, transvaginal ultrasound (TVS) is always preferred — it provides significantly higher resolution and can detect small follicles (2mm+), polyps, and early pregnancy that transabdominal misses.

Transabdominal pelvic ultrasound is painless — only mild discomfort from a full bladder is needed. Transvaginal ultrasound (TVS) involves gently inserting a probe into the vagina — it is mildly uncomfortable but not painful for most women; similar to a routine gynaecological examination. The procedure takes 5–15 minutes. If there is significant discomfort, inform the sonographer to adjust probe position.

Standard pelvic ultrasound cannot assess tubal patency (open vs blocked). Normal fallopian tubes are not visible on ultrasound. Blocked tubes become visible only when fluid-filled (hydrosalpinx). To test tubal patency, a separate investigation is needed: HSG (hysterosalpingography — X-ray dye test), HyCoSy (ultrasound contrast), or laparoscopy with dye (gold standard).

A pelvic ultrasound is performed at multiple fertility milestones: (1) Initial fertility workup — baseline TVS + AFC for ovarian reserve; (2) Before any treatment cycle — baseline scan on Day 2–4 to confirm no cysts and check endometrium; (3) During IVF/OI — serial follicle monitoring scans every 1–3 days; (4) Before embryo transfer — endometrial thickness check; (5) Post-transfer — early pregnancy scan at 6–7 weeks. It is the most frequently repeated investigation in fertility medicine.