Serial ultrasound monitoring of follicle growth and ovulation to optimise the timing of conception — whether trying naturally or undergoing fertility treatment.
For many women, knowing exactly when ovulation occurs is the key to maximising their chances of conception. Follicle tracking — a series of ultrasound scans performed across your menstrual cycle — removes the guesswork by showing exactly when your dominant follicle is ready to release an egg. Whether you are trying naturally, using ovulation induction medication, or undergoing IUI, follicle tracking gives you precise, actionable information. Located at 29 Weymouth Street, Marylebone, our clinic provides same-day diagnostic ultrasound with written reports.
Follicle tracking is a series of transvaginal or transabdominal ultrasound scans performed at specific points in your menstrual cycle to monitor the development of ovarian follicles. Each follicle contains a developing egg; as the dominant follicle grows (typically to 18–25mm), it indicates that ovulation is imminent. The scan also assesses the endometrial lining thickness and pattern, which is important for embryo implantation. Most women require 2–4 scans per cycle.
The first scan is performed early in your cycle to establish a baseline antral follicle count and check for any cysts before treatment or monitoring begins.
A second scan assesses follicle development. If a dominant follicle is identified, the timing of subsequent scans is planned accordingly.
When the dominant follicle reaches 16–18mm, a further scan is arranged to confirm readiness for ovulation and assess the endometrial lining.
If you are using an hCG trigger injection, your sonographer will advise on the optimal timing based on follicle size and endometrial appearance.
An optional final scan confirms that ovulation has occurred, providing reassurance that the cycle has been successful.
After each scan, your sonographer will explain the follicle measurements, endometrial thickness, and what they mean for your cycle timing. You will receive clear guidance on when to have intercourse or insemination, whether to take a trigger injection, and when to return for your next scan. A written report is provided at each visit.
Our HCPC-registered sonographers are available Monday to Saturday. Results discussed immediately, written report within 24 hours.