Infertility is defined as the inability for a couple to conceive after at least 12 months of trying. About 10% of couples have difficulty falling pregnant and are diagnosed as infertile.
The cause of the infertility may be due to a male problem, a female problem or both. It is estimated that around 30% of all infertility is the result of a male problem. This is most often related to the quality and volume of the male partner’s sperm. An infertility specialist will be able to arrange the necessary investigations to try and find a cause for the infertility.
Part of the investigative work-up involves a pelvic ultrasound.
Women have two ovaries and these are located in the pelvis lying adjacent to the uterus(womb). Their main function is to release eggs and produce hormones. At birth, there are thousands of eggs in each ovary. As the woman matures and has menstrual periods, an egg will develop into a follicle measuring up to 20mm.The development of the follicles in the ovary can be seen on ultrasound and give information about egg production. The endometrium or lining of the uterus is a good reflector of ovarian function and will respond to the hormones and will have a specific appearance at different stages of the menstrual cycle. Normally during menstruation, the endometrium is typically thin. As the cycle progresses, the endometrium gets thicker and oedematous and is called the proliferative phase endometrium. In the later part of the cycle, the endometrium becomes its thickest during the secretory phase.
Normal Cycle Ultrasound Ovary & Endometrium
Sometimes problems that can affect fertility are found and can be treated. Some examples of causes of infertility include:
Polycystic ovaries (PCOS)
Polycystic ovaries contain many small cysts, usually more than 10. Typically these cysts are small, measuring ~8mm, which are clearly visible on transvaginal ultrasound. Your doctor will usually also arrange some blood tests to determine changes in hormone levels that are characteristic of PCOS. However, these levels vary considerably from one woman to another.
The cause of PCOS is related to the inability of the ovaries to produce hormones in appropriate proportions. Within the brain, the pituitary gland senses that the ovary is not functioning properly and releases abnormal amounts of LH (luteinising hormone) and FSH (follicle stimulating hormone). There are unusually high levels of LH and FSH that can be detected on blood tests.
The symptoms of PCOS include
- Menstrual irregularities: Patients have either irregular ovulation or no ovulation (anovulation). This reflects on irregular periods with long gaps between them (ammenorrhoea)
- Reduced fertility
- Skin problems
- Body Mass Index (BMI)
The American Society for Reproductive Medicine agreed to strict diagnostic guidelines at the 2003 Rotterdam concensus workshop.
Congenital anatomic variations
Congenital uterine anomalies have been estimated to occur in up to 5% of all women. They are a result of an abnormal development of the pelvic organs and may be associated with renal anomalies such as a single kidney or a variety of normal anatomic variations of the renal system. Congenital uterine anomalies can be seen with 2D and 3D gynaecological ultrasound. There may be a spectrum of changes, ranging from double uterine cavity, cervix and vagina to a single-sided uterine cavity to a rare situation where there may be absence of the pelvic organs.
Uterine structural lesions
There may be an overgrowth of tissue in the endometrial lining giving rise to an endometrial polyp, or in the muscle of the uterus, giving rise to uterine fibroid (leiomyoma). These lesions can sometimes affect implantation of a fertilized egg and prevent pregnancy. These may be diagnosed with pelvic ultrasound usually requiring a vaginal scan. Sometimes the lesions can be so subtle that they are not readily visible on vaginal ultrasound. Your doctor may request further investigation of the internal structure of the uterus (endometrial cavity) by sonohysterography.
Blocked fallopian tubes
The fallopian tubes serve as the site of fertilization and passage of the embryo into the uterine cavity. Structural abnormalities in the tube that cause obstruction or interfere with the transport of the embryo along the tube accounts for 25-40% of infertility in women. A normal pelvic ultrasound does not exclude the possibility of tubal problems and the fallopian tubes are best assessed by Hysterosalpingo-contrast-sonography (HyCoSy).
Some treatments of infertility include ovarian stimulation and induction of ovulation by fertility drugs. Vaginal ultrasound is necessary to monitor growth of the ovarian follicles, to assist with the infertility management.
Ovarian hyperstimulated ovarian syndrome (OHSS) is a rare complication of ovulation induction. The ovaries are enlarged with multiple enlarged cysts.
Tubal patency study
Hysterosalpingo-contrast-sonography (HyCoSy)is a transvaginal ultrasound technique used in the investigation of infertility. Its primary aim is to establish whether or not the woman’s fallopian tubes are patent or whether one or both is blocked.
The technique involves introducing an ultrasound contrast agent (Ex Em Foam) injected into the uterine cavity, which is then observed as it flows through the fallopian tubes to assess tubal patency. The contrast generates bright echoes that make visualisation of the tubes easier. The examination is optimised by the use of colour Doppler imaging. HyCoSy has increasingly been used as a first line investigation for infertility because it is convenient and safe. The procedure is a dynamic study that gives valuable information about tubal function and also allows examination of other pelvic organs.
A sterile speculum is placed in the vagina, and a thin catheter is then inserted into the uterine cavity through the cervical canal. The speculum is then replaced by a transvaginal ultrasound probe. Ultrasound is performed while contrast is injected into the uterine cavity and fallopian tubes.
There can be some mild discomfort associated with this procedure, particularly if the tubes are blocked. A simple analgesic such as Nurofen (2 tablets) taken half an hour before the procedure is recommended.
The procedure should not be performed during pregnancy, and is ideally performed at the completion of a period, on approximately day 10 of the menstrual cycle. This ensures that the procedure does not interfere with implantation of an embryo.