Follicular monitoring is the simple technique of monitoring and assessing ovarian follicles at regular intervals. The follicles are assessed by the doctor at regular intervals, especially on day 10, day 12 and day 14 of the menstrual cycle. Sometimes an ultrasound scan is performed 2-3 days later to confirm ovulation. Timed intercourse at the time of ovulation is the basic infertility test that is recommended for every couple.
Physiology procedure for development of follicles
Generally the ovulation journey starts at the late luteal phase of the earlier menstrual cycle. In this phase a 2.5 mm sized follicles are formed and a healthy follicle is selected from the formed ones and used for the next cycle. The number decreases with the age in women and the common number of follicles are 3-11. The second step in this process is the selection of the follicle starts at 1-5 day of the menstrual cycle. Among all the follicles, a size of approximately 5-10 mm is chosen and the rest of the follicle regresses. Dominance process begins at 5-7 day of the menstrual cycle. In this phase 10mm size is selected and suppresses the growth of the rest of the follicle and intended to ovulation. The growth will start in the follicle at the rate of 2-3mm a day and almost reaches to 17-27 mm.
At the time near to the ovulation, the follicle growth takes place rapidly and the follicle starts protruding from the ovarian cortex attains a crenate border. The tube explodes to discharge the ovum, along with some antral fluid.
Ultrasound for monitoring follicular study
Transvaginal ultrasound is recommended at this time for follicular study. This generally starts at the day 3 of the cycle. Size of the base line, monitoring of any cysts remaining from previous hyper stimulation were checked. The count of the developed follicle, size and shape of the follicle and antral edges were noted with the help of ultrasound. Once the size of the follicle reaches to 16 mm, ovulation needs to be monitored daily.
Most of the IVF processes are conducted after ovulation induction with the help of external injections and drugs like Clomiphene citrate. The success factors at this time are:
- Ovarian volume: good predictor of successful IVF outcome
- Antral follicle number: If this number is less than three, possible failure of ART procedures.
- Ovarian stromal blood flow: This is also a good predictor of ART success and it should be >10cm/sec for successful treatment.