Embryoscopy: A superior method for the evaluation of miscarriage
Problems with D&C for evaluation of miscarriage
During a D&C, a woman is given anesthesia in a hospital or surgical center. While laying on her back, the legs are placed in stirrups and a speculum is placed in the vagina. The cervix is grasped and the opening (the cervical canal) is dilated using metal rods of increasing diameter. Once the cervical canal has been opened sufficiently, a long plastic tube attached to a suction machine is placed into the uterus. The suction machine is turned on and the contents of the uterus are aspirated. The tissue obtained has traditionally been sent to a lab that specializes in growing cells and extracting and identifying the chromosomes. Depending on a number of factors, this method took a few to several weeks to grow the cells obtained.
One of the problems with D&C is that when the tissue is aspirated from the uterus, it contains a mixture of cells. There are cells from the fetus itself, cells of the placenta and gestational sac and cells from the mother’s uterine lining. The mother’s cells are typically healthy and grow well whereas the fetal cells can often be barely viable.
In the past, when the genetics lab grows the cells from a D&C, there was no way to ensure that only the fetal cells grew. Consequently, the results of a chromosome analysis often reflected the mother’s chromosomes and not that of the fetus.
In general, the results of a chromosome analysis from a D&C returned one of four results:
- The cells did not grow and no chromosome result could be obtained
- A normal female
- A normal male
- A fetus with a chromosome abnormality either male or female
A chromosome result indicating a normal female is not a helpful result. It cannot be determined if this came from the fetal cells, as desired, or the mother’s cells. Unfortunately, a large number of chromosome analyses from miscarriages return a result showing a normal female. Studies have shown that 30-80% of the results obtained from a D&C may come from the mother’s cells. Until recently, there was nothing that could be done about this.
Embryoscopy for evaluation of the cause of miscarriage
Recently, a new technique has been used by a few highly skilled physicians. This new technique uses fiber optics to look inside the uterus (hysteroscopy) and has been called embryoscopy or fetoscopy.Like a D&C, a hysteroscopy is usually performed in a hospital or surgical center under anesthesia. The cervix is dilated large enough to allow passage of a fiber optic telescope. Salt water (saline) is used under high pressure to hold the uterine cavity open to allow adequate visualization.
With direct visualization, the implantation site of the pregnancy can be located in the uterus. The fetus grows inside of a spherical structure called the gestational sac. The sac can be opened and the placental tissue and sometimes the fetus can be identified inside.
The hysteroscope has multiple channels. These channels allow for the insertion and removal of fluid to keep the uterine cavity clear to the observer. Another channel transmits the optics and yet another provides the light. A final channel allows for the passage of instruments into the uterus. Using grasping instruments, the placental tissue or fetus can be removed.
This is a great advantage over the D&C because the tissue removed is essentially “pure”. That is, only the tissue of interest is obtained. There is little or no chance for the mother’s uterine cells to “contaminate” the specimen. Thus, when a result indicating a normal female is obtained, it can be relied upon as easily as when a normal male result is returned.
There are several benefits of the hysteroscopy approach for the evaluation of the causes for miscarriage. In some cases, when a fetus is present, abnormalities in the development of the fetus can be seen. Collecting the fetal tissue in this way, the specimen is kept sterile and so the chances for the cells to be grown by the genetics lab is enhanced. As stated above, the mixing of the mother’s cells with the fetal cells does not occur, so there is much better reliability.
Another advantage occurs when there is loss of a twin pregnancy. During a D&C, the tissue from both twins gets mixed together. A result may indicate one, both or neither of the fetuses. With the hysteroscopy method, each fetus and its respective placenta can be removed separately.
A recent study compared the results obtained with D&C with that obtained using the the embryoscopy technique. The researchers found that overall, chromosome abnormalities were responsible for miscarriage in 67% of the cases studied. In a significant number of cases, the D&C technique would have provided an incorrect result. This occurred when the D&C result indicated a “normal female” where in reality, the fetus was abnormal.
Microarray for chromosome analysis
Recently, a new technology has become available to evalute the chromsomes called microarray. Microarray has several advantages over the older method of cell culture.
- It is not necessary to grow the cells for several weeks in the laboratory
- This dramatically reduces the chance of getting “no result”
- Results are available in 7-10 days instead of 4-6 weeks
- Sophisticated software algorithms can determine if contamination by the mother’s uterine cells have occurred
- It is possible to get results even on non-viable cells
Who is a candidate for Embryoscopy?
Any woman who has been diagnosed with a non viable pregnancy and who wants to try to determine the cause for the miscarriage can have embryoscopy performed instead of a D&C. Women for whom this is especially important are:
- Women who have a history of recurrent miscarriage
- Women who have lost a pregnancy after a heartbeat was seen on ultrasound
- Women who were receiving treatment to prevent miscarriage but were diagnosed with a non-viable pregnancy
If I am not currently a patient of IVF1, how do I arrange to have an embryoscopy with Dr. Morris?
- Call our office and state you have a nonviable pregnancy and would like to arrange for an embryoscopy
- Email of fax a copy of your medical records for this pregnancy, including ultrasound results
- You will need to electronically complete your medical history online through our patient portal
- Schedule an appointment in our office for an ultrasound followed by a brief consultation with Dr. Morris