For those who have difficulty detecting ovulation, a useful tool that can be employed is serial ultrasound. But what is serial ultrasound? How is it performed and why is it so important? It all starts when a couple has trouble conceiving naturally.
When the time trying to conceive exceeds 12 cycles or a year (with regular cycles), it is best to seek medical help to find out what is happening. The ultrasound is done to accurately detect the day of ovulation and also to check if the follicles are growing properly, with or without the use of stimulating medications.
In some cases, simple induction procedures, such as timed intercourse, become more effective when this resource is used. In fact, serial ultrasound is the same exam we are used to having. It can be pelvic or transvaginal. The difference is that the ultrasound is performed on consecutive days, in series! That’s why it’s called serial ultrasound.
Doctors may recommend starting the ultrasound in the last days of menstruation to check for any cysts from the previous cycle or to ensure all have resolved. Depending on the treatment the woman is undergoing, between 5 and 8 sessions may be needed, but the average is 3 to 4 ultrasounds on days determined by the doctor.
If the woman is taking ovulation inducers1, she should finish her medication treatment and wait a few days to see if they are effective. For clomiphene-based medications, it is generally advised to begin the series of exams on the 5th day after finishing the medication.
With stronger ovulating medications, such as injectables, it may begin as soon as the 3rd day after injections. If the patient is not taking anything, then the best time for the first ultrasound is very close to the beginning of the fertile period. The issue is with women who have irregular cycles and are not on medications to induce ovulation. The beginning of the fertile period should be indicated by the doctor by averaging the last three menstrual cycles.
What Are the Cases for Serial Ultrasound?
Timed intercourse is one of the treatments that require serial ultrasounds. In vitro fertilization as well as artificial insemination. Women undergoing these types of treatments have ultrasounds to assess whether the prescribed medication is working or if the doctor needs to prescribe more doses of ovulatory stimulators such as Menopur, Clomid, Indux, Serophene or any other medication proven to be effective. Typically, the follicles should already be larger around the 10th day after induction.
Follicles are ready to rupture when they reach a size of 19, 20mm, but they may still be viable up to a size of 30mm. It all depends on how quickly they grow and how many dominant follicles there are in each ovary or in one of them. After the follicles’ growth peak, the doctor will likely advise the couple on the best day to have intercourse. If needed, the doctor will prescribe an appropriate medication to help them rupture and facilitate fertilization, such as Choragon, for example.
But serial ultrasound is not just for checking eggs and ovaries! It also monitors endometrial growth. The endometrial thickness is crucial for pregnancy to occur2. If the endometrium is trilaminar, implantation chances are higher if fertilization occurs. To address any need for further growth, if necessary, the doctor in charge will prescribe supplements to help the endometrium become larger and thicker to receive the baby.
All in all, serial ultrasound is a real lifesaver! The best advice for those unsure if they are ovulating is to have it done for at least one cycle. With serial ultrasound, it is possible to detect problems such as luteinized unruptured follicle syndrome (LUF), for example3, and shorten the wait time to achieve pregnancy.
See also: Timed Intercourse – Extra Help to Conceive
Photo: John Watson
