HyCoSy

Hystero-salpingo sonography (HyCoSy) is a non-invasive diagnostic method of tubal patency (fallopian tubes), which is key in evaluating the causes of infertility in women.

The HyCoSy test is performed by inserting a catheter into the cervix, which first injects a saline solution into the uterine cavity, and then a contrast liquid, which then enters the fallopian tubes.

The path of the contrast liquid is recorded and monitored with an ultrasound machine. When the contrast liquid fills the uterine cavity, passes through the fallopian tubes into the abdominal cavity and the fallopian tubes filled with saline solution or contrast are visualized by ultrasound, it is concluded that the fallopian tubes are transient.

HSS and HSSG are also used as abbreviations for hystero-salpingo sonography.

What is HyCoSy for?

Pathological changes in the fallopian tubes are the cause of infertility in about 25-30% of cases.

Passable and functional fallopian tubes are necessary for pregnancy to occur, and that is why examination of fallopian tubes patency is an integral part of infertility testing and one of the first diagnostic steps.

HyCoSy is advised after 12 months of unsuccessful pregnancy attempts in women under 35 years of age.

For women over 35 years of age, HyCoSy is recommended if pregnancy does not occur after 6 months of actively trying to conceive.

The fallopian tubes are a pair of tubular organs that connect the uterus to the ovaries. The length of the fallopian tube is 10-12 cm, and the inner diameter varies from 0.2-4 mm.

Immediately after ovulation, the egg cell "enters" the fallopian tube, more precisely, the fimbriae, which are the final part of the fallopian tubes, "catch" the egg cell "pull" it into the fallopian tubes. In the fallopian tubes, the egg cell meets the spermatozoa that come from the vagina through the uterus, and fertilization takes place in the fallopian tube. The fertilized egg cell then "travels" through the fallopian tube and after a few days is implanted in the uterine cavity, where the pregnancy develops. Any anatomical or functional change that represents an obstacle for the egg cell, sperm or fertilized egg cell, that is, the embryo, prevents pregnancy from occurring. These changes can be complete "blocking" of the fallopian tubes, narrowing, expansion, damage to the inside of the fallopian tubes as well as adhesions or some other mechanical factor on the outside of the fallopian tubes. The mentioned pathological changes are the most common consequences of the fallopian tubes infection, primarily inflammation caused by chlamydia and gonococcus. Adhesions, i.e. the newly formed scar tissue, can be the result of surgical treatments in the small pelvis or endometriosis.

What does the HyCoSy test look like?

The process itself, from preparation to procedure, is as follows:

Potencijalne komplikacije tokom i posle HycoSy procedure

Potential complications during and after the HycoSy procedure

Complications during and after the HyCoSy procedure are very rare.

• Pain similar to menstrual pain, which is often described as a feeling of pressure and discomfort in the lower abdomen, occurs in 5-8% of cases.
• Intervention is rarely interrupted due to pain. Considering that the injected saline solution and contrast remain in the abdominal cavity and "irritate" the peritoneum, a slight feeling of pain and nausea may be present for a day or two after the intervention.
• Infection, high fever, nausea and vomiting occur in about 0.5-0.8% of cases. In case of nausea and vomiting, metoklopramid is recommended, tablets 10 mg up to 3 times a day.

Interpretation of HyCoSy test results

• The finding is considered normal if, after injecting a saline solution or contrast into the uterus, the normal shape of the uterine cavity is diagnosed and the fluid passes through both fallopian tubes, and the fallopian tubes appear as thin curved lines.
• If a myoma, polyp, adhesions, deviation in the shape of the uterine cavity or septum in the uterine cavity (cavum) is diagnosed after injecting a saline solution or contrast into the uterine cavity, hysteroscopy is advised;
• If the saline solution and contrast do not enter the fallopian tube(s), there is a "blockage" in the initial part of the fallopian tubes. In that case, a laparoscopy is advised  (to confirm the findings) or in vitro fertilization (IVF) depending on the age of the patient, the duration of infertility and the characteristics of the semen analysis;
• If the saline solution and contrast enter the fallopian tube/tubes, and then remain in the fallopian tube and do not reach the abdominal cavity, there is a “blockage" at the other end of the fallopian tubes (toward the ovary). This condition is called hydrlosalpinx/sactosalpinx. In that case, laparoscopy is advised.
• If hydrosalpinx is confirmed, the fallopian tube should be removed before IVF. Hydrosalpinx reduces the chance of IVF success by allowing fluid from the blocked fallopian tube back into the uterine cavity and hindering implantation (reinforcement) and development of the embryo.

Reliability of the HyCoSy procedure

HyCoSy has about 5-10% false positive and 5-10% false negative results. A false positive result is understood when the ultrasound examination does not show that the contrast enters the fallopian tubes or it is seen that the contrast remains in the fallopian tubes. A false negative result means that the ultrasound examination does not show the pathological change of the fallopian tube, but it does exist. 

The percentage of false positive and false negative results is similar to that of hysterosalpingography (HSG) and laparoscopy.

Advantages of HyCoSy over HSG and laparoscopy

HSG is a fallopian tube patency test based on the same principle as HyCoSy, except that instead of an ultrasound machine, an X-ray machine is used to control the contrast flow. HSG is painful when metal instruments are used instead of a silicone or rubber catheter. HSG is most often performed under general anesthesia. Reliability  is similar to HyCoSy, that is, the percentage of false positive and false negative results is around 5-10%.

Laparoscopy is an operation performed under general anesthesia by inserting a camera and instruments into the stomach through small incisions in the front abdominal wall. Before that, in the same way as with the HyCoSy and HSG methods, a catheter or metal instruments are inserted into the cervix. Methylene blue dye is inserted through the cervix and the passage of the dye through the fallopian tubes is monitored. This method is done if there is another reason for surgery, but not as the first choice of tubal patency test. There are about 5% false positive results.

The advantage of the HyCoSy method compared to HSG and laparoscopy is that it is performed on an outpatient basis, anesthesia is not required, radiation is avoided and the risk of allergic reactions to the iodine-based contrast used in HSG is avoided. In Milenković Clinic, HyCoSy is performed as the first choice, and laparoscopy is performed as needed.

Expert advice: frequently asked questions

Answers by: Milan Milenković MD, PhD