This is because chorionic villus sampling (CVS) is a prenatal test that involves taking a sample of tissue from the placenta to test for chromosomal abnormalities and certain other genetic problems.There are two types of CVS procedures: transcervical and transabdominal.In the transcervical procedure, a catheter is inserted through the cervix into the placenta to obtain the tissue sample.In the transabdominal procedure, a needle is inserted through the abdomen and uterus into the placenta to obtain the tissue sample.

Choice A is wrong because it describes the transabdominal procedure, not the transcervical one.

Choice B is wrong because it describes the transabdominal procedure, but with a catheter instead of a needle.

Choice D is wrong because it describes the transcervical procedure, but with a needle instead of a catheter.

The normal ranges for CVS are between 10 and 12+6 weeks of gestation.CVS does not provide information on neural tube defects, so women who undergo CVS also need a follow-up blood test between 16 to 18 weeks of their pregnancy to screen for neural tube defects.

This is because chorionic villus sampling (CVS) involves taking a small sample of tissue from the placenta, which may cause some discomfort and bleeding.

Choice B is wrong because you may not experience leaking of amniotic fluid after the procedure.CVS does not involve puncturing the amniotic sac, unlike amniocentesis.

Choice C is wrong because you may not experience Rh sensitization after the procedure.

Rh sensitization is a condition where the mother’s immune system attacks the baby’s blood cells if they have different Rh factors.CVS can prevent this by testing the baby’s blood type and giving an injection of anti-D immunoglobulin to the mother if needed.

Choice D is wrong because you may not experience neural tube defects after the procedure.

Neural tube defects are birth defects that affect the brain and spinal cord of the baby.CVS cannot detect these conditions, but amniocentesis can.Therefore, women who undergo CVS also need a follow-up blood test between 16 to 18 weeks of their pregnancy to screen for neural tube defects.

The procedure can detect chromosomal abnormalities such as Down syndrome.This is because CVS involves taking a sample of tissue from the placenta, which contains the same genetic material as the fetus.By analyzing the chromosomes in the tissue sample, CVS can identify conditions caused by missing or extra chromosomes, such as Down syndrome.

Choice B is wrong because CVS cannot detect neural tube defects such as spina bifida.Neural tube defects are problems with the development of the brain and spinal cord that occur early in pregnancy.CVS does not provide information on neural tube defects, so women who undergo CVS also need a follow-up blood test between 16 to 18 weeks of their pregnancy to screen for these conditions.

Choice C is wrong because CVS can only detect some genetic disorders such as cystic fibrosis, not all of them.Genetic disorders are caused by changes in the DNA sequence of a gene, which affect how the gene works.CVS can test for some genetic disorders that are inherited in a simple pattern, such as cystic fibrosis, sickle cell disease, thalassaemia and muscular dystrophy.However, CVS cannot test for all genetic disorders, especially those that are complex or rare.

Choice D is wrong because CVS cannot detect neural tube defects such as anencephaly.Anencephaly is a severe condition where the baby is born without parts of the brain and skull.As mentioned above, CVS does not provide information on neural tube defects, so women who undergo CVS also need a follow-up blood test between 16 to 18 weeks of their pregnancy to screen for these conditions.

“The procedure is usually performed between 10 and 13 weeks of gestation.”This is because CVS can provide early diagnosis of chromosomal abnormalities and genetic disorders in the first trimester of pregnancy.

Choice B is wrong because the procedure has a risk of miscarriage of about 0.5% to 1%.This is higher than the risk of amniocentesis, which is another prenatal diagnostic test.

Choice C is wrong because the procedure has a risk of infection of about 0.5%.This is due to the insertion of a needle or a catheter through the abdomen or the cervix to obtain a sample of chorionic villi.

Choice D is wrong because the procedure has a risk of bleeding of about 1% to 2%.This is caused by the disruption of blood vessels in the placenta during the sampling.

The correct answer is choice B. Results are usually available within 24 hours.This is known as the rapid CVS result.A more detailed set of CVS results will be available within 10 to 14 days, but may take up to 3 weeks in some cases.

Choice A is wrong because results are not usually available within 10 to 14 days.

This is the time frame for the final result, not the preliminary one.

Choice C is wrong because results are not usually available within 7 days.

This is too long for the rapid result and too short for the final result.

Choice D is wrong because results are not usually available within 30 days.

This is much longer than the usual time frame for both the rapid and the final result.