Using Follicular Scans to Maximise the Success of Ovulation Induction

If you are trying to get pregnant, chances are that you or your fertility doctor are tracking your menstrual cycle to know the ovulation dates. If you are planning to undergo ovulation induction to increase your chances of pregnancy, you may need follicular scans to maximise your success rate. Read on to know what these scans are and how they can help you.

What are Follicles?

Follicles are small fluid-filled sacs in the ovaries that contain eggs. A woman is born with a fixed number of follicles, meaning the number of eggs she can produce throughout her fertile period is determined even before her birth. These follicles contain immature eggs. 

Every menstrual cycle, one follicle will grow in size due to the development of the egg on the inside. Once the egg reaches its optimal size, the follicle will rupture, releasing the egg. This is known as ovulation. Only if ovulation occurs can a sperm fertilise the egg to result in pregnancy. 

What is a Follicular Scan?

A follicular scan, also known as follicle monitoring, consists of numerous transvaginal ultrasound scans that help monitor the follicles. The first follicular scan may be taken as early as the 6^th day of the menstrual cycle. The fertility specialist will perform multiple scans and increase the frequency closer to ovulation time. When the follicle is big enough, indicating the egg inside is ready for ovulation, it is the ideal time to try conceiving.

How Does Follicular Scan Help in Pregnancy?

Follicular scan closely monitors the follicles in the ovaries that are developing. Though all follicles contain immature eggs inside, only one dominant follicle will release an egg per cycle. So, the scans first help identify the dominant follicle. Next, they will close track its growth. Once the follicle reaches a size of approximately 18-24 mm, it is an indication that the egg inside is mature and ready for release.

For couples who are trying to get pregnant naturally, these follicular scans can help identify the fertile window to have unprotected sex for conception. In the case of fertility treatments, these scans can help doctors determine when to trigger the follicle for egg extraction. Once the follicle is triggered, ovulation will occur, and the egg will be safely retrieved. This egg is then fertilised under clinical conditions for IVF or inserted into the uterus for IUI, where insemination takes place inside the uterus. 

What is Ovulation Induction?

Ovulation generally occurs around the 14^th day of the menstrual cycle. For some women, it can be a day or two earlier or later. Ovulation mostly lasts just around 12-24 hours, after which the egg will start descending the fallopian tube. Once the descent begins, fertilisation is close to impossible, thus drastically reducing the chances of pregnancy for the month.

When a couple is having difficulty conceiving, the doctor will first track the ovulation dates. In the case of irregular periods, tracking ovulation becomes very challenging. For women with irregular ovulation or no ovulation at all, fertility drugs can stimulate the ovaries to release the eggs. Ovulation induction is a fertility treatment that stimulates the follicles to release the mature eggs, using certain medications.

Follicular Scan – Ovulation Induction

Fertility medications are given in specific doses at regular intervals to stimulate the follicles containing eggs to develop. These drugs will trigger the dominant follicle to release the mature egg for fertilisation. 

Now, different bodies react differently to various medications. Since it is all based on hormones, one can never be too sure about the impact of the fertility medicines on the follicles. This is where the follicular scans come in to help.

Through regular ultrasounds of the ovaries' follicles, doctors can monitor the impact of fertility medicines on the follicles. They will adjust the dosage accordingly, increasing or decreasing it based on the follicles' reaction. Follicular scans also help assess the uterine lining to determine if it is thick enough for implantation. If the uterine lining is not thick enough, the fertilised egg cannot implant, and pregnancy is not possible.

Follicular scans help assess the effectiveness of fertility medicines by tracking follicular development. They indicate the precise timing of ovulation, which is valuable information for achieving a successful conception. The scan can also confirm the release of the egg following the rupture of the follicle. This information confirms that a successful ovulation did occur. 

Follicular Tracking For Fertility Treatment

If you are undergoing a fertility treatment and the doctor has asked you to take follicular scans, here are some points you need to be aware of:

• Follicular scans are primarily performed transvaginally by inserting a probe in the vaginal opening. This is harmless but can be uncomfortable for many.
• These scans can only help in determining if the fertility drugs are indeed working and if ovulation can occur. 
• Follicular scans do not directly increase the chances of pregnancy. They only help identify the exact ovulation period, which in turn can drastically improve the chances of a successful conception.
• These scans can only help determine if the uterine lining is thick enough for implantation. They cannot influence the uterine lining in any way.
• The number of follicular scans required can vary from woman to woman and from cycle to cycle. Typically, 3-5 scans per cycle are considered normal.
• Ultrasounds are performed every 2-3 days until the dominant follicle is large enough for ovulation. Once it nears full size, you may require an ultrasound daily until ovulation occurs. 
• Follicular scans cannot determine or influence the outcome of the pregnancy. Various factors influence pregnancy outcomes, and follicular scans are not one of them.
• These scans can be very helpful for couples who have been trying to conceive for a long time but are unable to, or for women suffering from irregular ovulation or anovulation. 
• Follicular monitoring helps identify overstimulation of the ovaries, inadequate stimulation, or a less-than-expected impact of the drugs.

Steps Involved

If undergoing follicular ultrasounds, you may go through the following steps:

• The first scan will be taken on day 3 or 4 of the cycle. This will be marked as the starting point of monitoring. 
• Depending on the doctor, medications, and reaction, further scans may be required every 1-3 days until the dominant follicle is evident.
• Once the dominant follicle reaches the desired size, a trigger shot – an hCG injection is given to induce ovulation.
• A final scan may be taken to confirm ovulation.

Book an online appointment with Dr. Mangala Gowri M for fertility related issues.

Conclusion

Follicular scans are a great help in fertility medicine. It not only helps track follicular growth but also determines the exact timing of ovulation, which is important information for pregnancy planning. Since medications can be adjusted according to the follicular response, the risk of overdosing or underdosing is reduced by these scans.