Chorionic villous sample in Jordan

Chorionic villus sampling is a diagnostic test in which a small amount of chorionic villus tissue — placental tissue that carries the same genetic make-up as the fetus — is drawn with a fine needle under ultrasound guidance so that the fetal chromosomes or a specific gene can be examined. It is performed early in pregnancy, usually between about the eleventh and fourteenth weeks, which is precisely why it is chosen when an early answer is needed. The test is usually offered after a high-risk screening result (cell-free fetal DNA or combined first-trimester screening), when an ultrasound finding raises concern, when a known inherited condition runs in the family, after a previous pregnancy affected by a chromosomal condition, or in consanguineous couples with a specific testable genetic disease. The essential difference is that screening tests give a probability, whereas villus sampling gives a diagnosis on the sample obtained. Its limits deserve to be stated plainly. It answers the specific questions that were requested; it does not screen for every disease and cannot promise a healthy baby. It does not measure intellectual ability, and it does not show structural malformations — that is the job of the second-trimester anatomy scan. It does not replace the rest of antenatal care, and it is not used for social sex selection. In a small number of cases the result is inconclusive, or a chromosomal mosaicism confined to the placenta appears, and amniocentesis is then requested later for confirmation. Risks include cramping and light spotting in many women, and rarely fluid leakage or infection, along with a small additional risk of miscarriage that your doctor should explain using the figures of the centre performing it rather than generic numbers. The test is not performed before about the tenth to eleventh week, because sampling earlier than that was linked with limb development problems. The decision is ultimately yours, taken after genetic counselling that makes clear what would change in the management of the pregnancy after each possible result, and suitability is determined by clinical and ultrasound assessment rather than by reading.