Follicular Monitoring – What Should You Expect In One? (Part 2)

In part-1 of this article, the basics of Follicular Monitoring was outlined. In this article, we discuss more! For which you first need to understand the ovarian cycle.

In a normal menstrual cycle, you have 3 phases:

  • follicular phase
  • ovulation
  • luteal phase (which is again sub-divided into)
    • menstruation
    • proliferative phase
    • secretory phase

Why is ovulation so significant?

The normal female menstrual cycle lasts for 28-31 days. Mid-cycle (15-20 days from your period), a hormone known as the luteinizing hormone (LH) surges! Then, 24–36 hours after the release of LH, the dominant follicle (Graffian follicle) releases the oocyte (this here is ovulation!)

The reason why ovulation is important is that:

  • The oocyte only lives for 24 hours or less!  If fertilization fails, the dominant follicle then becomes corpus luteum (which decreases progesterone production, causing shedding and eventually bleeding).
  • The most fertile time which leads to conception is 5 days before and 1 to 2 days after ovulation.

During ovulation, the ovum undergoes physical changes, this is best assessed by follicular monitoring!

So, how does Follicular Monitoring work?

The whole purpose of follicular monitoring is to understand ovulation (release of ovum/egg from the ovary) and is deemed the most reliable method.

In most instances, a follicular monitoring/follicular ultrasound scan is generally done by an endovaginal scan, as the visualization of the uterus, the lining of the uterus and the ovaries are seen very clearly. When we look at the ovaries, we will be able to see the follicles inside the ovaries and these follicles are those which had eggs inside them.

What is looked for in a follicular ultrasound scan:

By now we know that every follicle is supposed to have one egg within it and every month there is one follicle that grows big and in the midcycle, this follicle grows to an appropriate size of about 20mm. Then it ruptures and the egg comes out of the ovary and travels up to the fallopian tube and there it is alive for about 48 hours ( if sexual intercourse occurs during this timeframe there is a chance of pregnancy to happen).

When we do a follicular scan we will be able to see the follicles very clearly and we will be able to assess if the follicle is growing or not. If the follicle is growing, then we know that yes, the follicle is growing and there is a good chance that ovulation also might happen and at the same time we get the added advantage of looking at the lining of the uterus and making sure your womb is also getting prepared for pregnancy to happen. If not, there are some hormonal supplements which can be given to make sure the womb lining also is good enough to support a pregnancy. That’s the reason why a follicular tracking ultrasound scan would be the best time to understand when the ovulation happens so as to make sure you are trying for pregnancy effectively.

In women with polycystic ovaries/PCOD, ovulation might not occur midcycle because these cycles are irregular. They might have delayed cycles with a length of 45 days, their ovulation might even happen on the 29th day or 30th day of the menstrual cycle. So, follicular monitoring is more beneficial in such cases.

Is Follicular Monitoring indicated in IUI?

IUI (intrauterine insemination) is the assisted transfer of sperms mainly done when there is an issue with the male sperms in terms of:

  • Quantity: sperm counts is lesser
  • Quality: sperms motility is on the lower end.

In any infertility treatment, where ovulation induction (by giving an injection) is done to the female partner in order to grow the follicles (which release the egg from the ovary), an IUI is done at the time of the release of the ovary.

The growth of the follicles needs to monitored by serial ultrasound. This is where follicular monitoring comes to play.




Dr. Aishwarya Rajeev has completed her MDS degree and is currently pursuing her PhD. She is an avid reader and loves to teach and write!

Leave a Reply

Your email address will not be published. Required fields are marked *