prenatal diagnosis

Prenatal diagnosis is the practice of finding out about a baby’s genetic or chromosomal condition before birth. It answers a question many expectant families ask — is the pregnancy affected by a particular disorder? — using information gathered while the fetus is still developing.

The methods range from non-invasive blood tests that screen for risk, to procedures that sample fetal or placental material directly for a definitive answer. Sampling the amniotic fluid or the placenta gives cells whose chromosomes and genes can be analyzed, while ultrasound adds structural information.

Prenatal diagnosis is informative, not prescriptive. It tells a family what is, so they can prepare medically and emotionally, seek specialist care, or make personal decisions in line with their own values. Because some procedures carry a small risk and results can be weighty, this work is closely tied to counseling.