A nurse is reviewing the contraindications for a Contraction Stress Test (CST) with a pregnant client.

Which condition would be a contraindication for the test?

This test can detect genetic disorders.

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.

The placenta is a structure in the uterus that provides blood and nutrients from the mother to the fetus.

Choice A is wrong because CVS does not provide information on neural tube defects, such as spina bifida.

For this reason, 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.

Choice C is wrong because CVS can detect chromosomal abnormalities, but not all chromosomal abnormalities are genetic disorders.

For example, Down syndrome is a chromosomal abnormality that occurs randomly and is not inherited from the parents.

Choice D is wrong because CVS cannot detect Rh sensitization, which is a condition where the mother’s immune system produces antibodies against the fetus’s blood cells.

Rh sensitization can be detected by a blood test that measures the level of antibodies in the mother’s blood.

This is a contraindication for the Contraction Stress Test (CST) because it increases the risk of infection and umbilical cord prolapse.

A CST is a test that measures the baby’s heart rate during uterine contractions induced by oxytocin or nipple stimulation.

Choice A is wrong because gestational diabetes is not a contraindication for the CST.

It is a condition that affects how the body processes glucose during pregnancy and may cause complications such as macrosomia (large baby), hypoglycemia (low blood sugar) or preeclampsia (high blood pressure and protein in urine).

Choice B is wrong because mild preeclampsia is not a contraindication for the CST.

It is a condition that causes high blood pressure and protein in urine after 20 weeks of pregnancy and may affect the placenta, kidneys, liver or brain.

Choice C is wrong because preterm labor is a relative contraindication for the CST, not an absolute one.

It means that the test may be performed if the benefits outweigh the risks, but it should be avoided if possible because it may trigger early labor or delivery.

Preterm labor is defined as regular uterine contractions with cervical changes before 37 weeks of pregnancy.

Normal ranges for blood pressure are below 120/80 mmHg, for glucose are 70-100 mg/dL (fasting) or below 140 mg/dL (2 hours after eating), and for protein in urine are less than 300 mg/24 hours.