Chorionic villus sampling and amniocentesis

Chorionic villus sampling takes placental tissue, whereas amniocentesis takes amniotic fluid. A fetal medicine specialist or genetic counsellor can explain which test fits the pregnancy timing and the condition being investigated.

Both procedures use ultrasound guidance. Chorionic villus sampling may be performed through the abdomen or cervix to reach placental tissue. Amniocentesis uses a fine needle through the abdomen to withdraw fluid surrounding the baby.

These tests can answer specific chromosome or genetic questions, but the laboratory analysis must be chosen for the concern. A normal result for one test panel does not rule out every possible fetal or pregnancy condition.

Before the appointment, clarify the test being offered, the route of the procedure, whether your bladder should be full, and when results are expected. Tell the team about blood-thinning medicine, allergies, your blood group and any current bleeding or infection symptoms.

Mild cramping or light spotting can occur afterward. Follow the unit's guidance on activity, pain relief and bathing, and keep its contact number available. Arrange practical support if you expect to rest after returning home.

Seek prompt advice for increasing or severe abdominal pain, heavy bleeding, leaking clear fluid, fever, chills, contractions or feeling generally unwell after either procedure. Report reduced fetal movement if you are at a stage when movement is normally felt.

Call emergency services for collapse, severe breathing difficulty or uncontrolled bleeding. Use the aftercare number for any symptom the procedure team specifically told you to report.

Ask exactly what condition is being tested, which sample offers the clearest answer, what results are possible, whether further testing could follow, and who will explain the findings. Discuss the procedure-related risks and alternatives in the context of your pregnancy.