Ultrasound scans are very essential for the assessment of fertility in women, who face difficulty in conceiving naturally. It helps a doctor diagnose possible causes for infertility such as evaluating the ovaries, endometrium, uterus, and the fallopian tubes. Based on the diagnosis, the doctor recommends a suitable fertility treatment.
What is the Use of Ultrasound Scan for Fertility?
An ultrasound probe emits high-frequency sound waves, which bounces off the organs and tissues in the body and reflect on the probe. When attached to a computer, these reflections are reconstructed into images on the monitor. A doctor uses the ultrasound for fertility testing and assesses reproductive organs and the pelvic areas to rule out any possible pathological or structural reasons of infertility, described as follows.
If you are facing difficulty in conceiving, your doctor will examine your ovaries, their shape and size, and check for the occurrence of any normal or abnormal cysts. Presence of numerous small cysts, appearing like a pearl necklace can indicate the possibility of a polycystic ovarian syndrome, whereas, a larger endometrioma cyst can mean endometriosis.
2. Antral Follicles
Antral follicles measure between 2 and 10 mm in diameter and consist of a fluid-filled cavity known as antrum. These follicles become visible through a transvaginal ultrasound on day 2, 3, or 5 of your cycle. Measuring the antral follicle count helps in:
- Evaluating ovarian reserve.
- Diagnosing the primary ovarian insufficiency.
- Determining your fertility potential with respect to your age (a low count indicates poor reserve and high count may indicate PCOS).
3. The Uterus
The technician takes note of the shape, size, and the position of your uterus. He may look for possible indications of uterine masses such as polyps, fibroids or adenomyosis in the uterus using a hysteroscopy or sonohysterogram, if required.
4. Endometrium Thickness
The doctor will also keep a check on the endometrium, the uterine lining as your menstrual cycle progresses. He will examine whether the lining at a stage is as thick as it should be.
5. Fallopian Tubes
Your doctor can see the fallopian tubes through 2D scan only if it is filled with fluid or is swollen. He may use an HSG test or HyCoSy to check if your fallopian tubes are clear or blocked, and the condition hydrosalpinx.
Adhesions can occur as a result of prior pelvic infection or endometriosis, and they block the free motion of the reproductive organs. It can be diagnosed by gentle pressing of the transvaginal probe on the ovaries, to see how they move in the pelvic cavity and whether they adhere to each other.
7. Blood Flow to Reproductive Organs
Using a colour Doppler scan, the doctor evaluates the blood flow around a mass or cyst. It is beneficial in distinguishing between a healthy cyst, an ovarian tumour, or an endometrial cyst.
8. Conception Check
An early pregnancy scan after you have been tested positive can help rule out the risk for ectopic pregnancy or a blighted ovum. It can also help detect the foetal heartbeat indicating an ongoing pregnancy.
Types of Ultrasound Scan for Infertility
Ultrasound scans play a significant role in investigating complex issues concerning the fertility of a woman. The type of ultrasound performed depends on the stage of your pregnancy or fertility treatment at a given moment. For women in their mid to late pregnancies, abdominal ultrasounds are more common, whereas, for women undergoing fertility testing or infertility treatment, a majority of the scans are carried out are transvaginal. The different kinds of ultrasound scans are described in brief as follows.
1. Abdominal Ultrasound
An abdominal ultrasound is the most commonly performed scan to monitor a woman’s pregnancy. In this scan, you will be asked to keep your bladder full for the procedure. The full bladder pushes the intestines away a bit, so the image appears clear. In an abdominal scan, a gel will be applied over your abdomen, which will make it smooth and easy for the ultrasound probe to be slid over your skin.
2. Transvaginal Ultrasound
In this case, the ultrasound is performed vaginally so that the doctor can assess the reproductive organs more closely. Here the transducer is shaped in the form of a slender and long wand. A condom is pulled over the wand, and a lubricating gel is applied on the tip before placing it inside the vagina, right before the cervix.
3. Antral Follicle Count
This test is performed through the transvaginal ultrasound device and requires specialization by the technician. It helps in determining your ovarian reserve and diagnosing polycystic ovarian syndrome (PCOS).
4. 3D Ultrasound
The ultrasound scans usually produce 2D images, but with the help of advanced technologies, it is possible to generate three-dimensional images. It helps detect the problems in fallopian tubes and uterine abnormalities which are not easily visible in two-dimensional ultrasound scans.
In this scan, the doctor transfers a saline solution through a catheter into the uterus. As the saline fills the uterus, it gets easier to visualize the shape of the uterus and check for any existing adhesions within the uterus.
6. Hysterosalpingo – Contrast Sonography (HyCoSy)
Here the doctor sends a mixture of dye or saline along with air bubbles, via a catheter, through the fallopian tubes, to determine if the tubes are open or blocked. The test was earlier done by hysterosalpingogram (HSG), a special x-ray. But HyCoSy is preferred over HSG because:
- There is less discomfort as compared to HSG.
- No exposure to iodine or radiation.
- Can be performed simultaneously with an ultrasound scan.
What Can an Ultrasound Not Diagnose?
A basic ultrasound for fertility check often falls short of diagnosing certain serious issues. Some of them are listed as follows.
1. Blocked Fallopian Tubes
The doctor can examine the fallopian tubes only through the help of hysterosalpingo-contrast sonography (HyCoSy). However, a basic ultrasound scan won’t be able to diagnose the fallopian tubes.
An ultrasound may indicate severe cases of endometriosis. It is recommended to use the laparoscopic surgery to detect moderate and less severe cases of endometriosis.
3. Uterine Abnormalities
Certain uterine abnormalities are unlikely to be diagnosed through a simple ultrasound scan. You require hysteroscopy or a sonohysterogram for complete uterus evaluation.
Ultrasound Scan during Infertility Treatment
Ultrasound scans prove vital for infertility treatment, as the doctor can examine the pelvic organs, to check for the growth of ovarian follicles, intrafollicular structures, and endometrial changes during the menstrual cycles. Using ultrasound for infertility problems become more frequent in case of hormone-stimulated cycles as they are required to be performed during ovulation, induction, and at later dates.
1. Baseline Ultrasound Scan
Your doctor may call you to schedule blood work and ultrasound within the first few days of your menstrual cycle. It is the baseline pelvic ultrasound for fertility, which is done to check for the presence of any unusual cysts on the ovaries to determine if fertility drugs could be started for the cycle or should be delayed till the next one.
2. Follicle Growth
You shall be required to frequently visit the clinic for ultrasound scans for follicle monitoring. The fertility medications prescribed to you largely depend on the follicle growth. Based on your treatment and number of mature follicles, you may be scheduled an egg-retrieval, or the cycle may be cancelled if the number is huge.
3. Endometrial Thickness
It is very important to check the uterine endometrial changes during your treatment cycle. The technician will also check for your endometrial thickness because after checking your endometrial thickness, the doctor will be able to alter your medication dosages to ensure a successful cycle.
4. Ultrasound-Guided Procedures
Apart from monitoring purposes, ultrasound is also used to guide some of the treatment, which includes embryo transfer and egg retrieval for IVF where a needle is used to retrieve eggs from the ovaries.
Ultrasound scans play a very important role in your fertility treatment. These scans are performed to monitor your ovulation, thickness, and pattern of the uterine lining, and perform diagnosis for conditions like endometriosis, ectopic pregnancy or presence of pelvic masses. These scans are important to perform as they can ensure a successful pregnancy.