Women with Turner Syndrome (TS) are a distinctive group of women who require specialized medical and obstetrical/gynecological care. TS is found in approximately 1 in 2,500 pregnancies and is the result of the loss or partial loss of an X chromosome. Normally women’s chromosomes are 45XX and with TS it will be 45X. Because of this missing chromosome women with TS can look slightly different and can have an array of possible medical conditions such as:
cardiovascular disease which could be the result of a congenital anomaly
Pediatricians and pediatric endocrinologists usually follow these patients closely during childhood and adolescence, initiating estrogen to begin puberty and normal development. Conception and pregnancy offer unique conditions which will require individualized intense care by a team of specialists and preconception counseling is a must. Because of the higher risks for various medical conditions, TS patients need to be followed carefully throughout their lives.
…..Let us return to our review of non-invasive prenatal testing for abnormalities of the fetal chromosomes.
…..This testing is supported by the professional societies, including the American College of Obstetrics and Gynecology. It is not a testing program that is offered to all pregnant women at this time, and there are certain indications for considering this program. Now in what circumstances should it be considered? Here are some:
If the mother’s age will be 35 years or older at the baby’s birth
Abnormal sonographic findings of the fetus that may point to an increased risk of fetal chromosome abnormalities
History of a past pregnancy with chromosomal abnormalities
Abnormal testing results in the current pregnancy that suggest chromosomal problems
…..The testing is a simple blood test of the mother, and it can be taken in the first or second trimester and as early as 10 weeks gestation. It does not replace chorionic villus sampling (CVS) or amniocentesis, and these are the tests to consider if there is a positive non-invasive test result.
…..If there is a positive result, genetic counseling is the next step, and probably the invasive tests will be offered. Also, remember that this test is intended to detect trisomy 21, 18, and 13, and to give information about the X and Y chromosome. It does not eliminate the chance of other chromosome problems that may be present.
…..Prenatal genetic testing is used to determine the risk of a fetus having an abnormal chromosome. Finding the fetus with an abnormality at the 21, 13, or 18th chromosome at an early fetal age and with a non-invasive technique has been the quest of many investigators over the past 50 years. Every decade seems to bring a new and exciting way to help the pregnant woman determine the health of the baby she is carrying.
Now the pace of new developments in the science of prenatal genetic testing is moving at a rate that was unimaginable just a few short years ago. A non-invasive fetal diagnosis now appears to be practical because cell-free fetal DNA can be found in the mother’s blood and can be used for genetic testing. These new techniques will gradually replace the invasive procedures such as chorionic villus sampling or amniocentesis.
…..With all the new advances, the testing and counseling for genetic fetal evaluation is evolving, so it is important to discuss these new frontiers with your medical team.