Name of the Procedure:

Fetal aneuploidy DNA sequence analysis using maternal plasma, also known as Non-Invasive Prenatal Testing (NIPT) for trisomy 21, 18, and 13.

Summary

This procedure involves analyzing fragments of fetal DNA present in the mother's blood to screen for chromosomal abnormalities such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13). The results are reported as risk scores for each condition.

Purpose

The primary goal is to detect the likelihood of common chromosomal abnormalities in the fetus early in pregnancy. This helps expecting parents and healthcare providers make informed decisions about further diagnostic testing or management.

Indications

• Expecting mothers, typically after 10 weeks of gestation.
• Particularly indicated for pregnant women of advanced maternal age (35 years or older).
• Women with a family history of chromosomal abnormalities.
• Positive results from other prenatal screening tests.
• Couples with a history of previous pregnancies affected by trisomies.

Preparation

• No fasting or special preparations required.
• An initial ultrasound may be done to confirm gestational age.
• A blood sample is taken from the mother, usually without the need for any other prior diagnostic tests.

Procedure Description

1. A healthcare professional draws a blood sample from the mother.
2. The sample is sent to a specialized lab where fetal DNA is extracted from maternal plasma.
3. Advanced DNA sequencing techniques are used to analyze selected regions of the fetal genome.
4. An algorithm calculates the risk score for trisomy 21, 18, and 13.
5. Results are sent to the healthcare provider, who will discuss them with the expecting parents.

Duration

The blood draw takes about 10-15 minutes. Results are typically available within 7-10 days.

Setting

This procedure is performed in an outpatient clinic or prenatal care facility.

Personnel

• Qualified nurses or phlebotomists to draw the blood.
• Laboratory technicians and geneticists to handle and analyze the blood sample.
• Obstetricians or genetic counselors to interpret the results and discuss them with the patient.

Risks and Complications

• Mild discomfort or bruising at the blood draw site.
• Very rare risk of incorrect results, such as false positives or negatives.
• Psychological stress while waiting for results or following a high-risk result.

Benefits

• Early, non-invasive screening for serious chromosomal abnormalities.
• Reduces the need for invasive diagnostic procedures like amniocentesis.
• Quick results that allow for early decision-making and planning.

Recovery

• No specific recovery period is needed.
• Patients can resume normal activities immediately after the blood draw.
• Follow-up appointments may be scheduled to discuss results and next steps.

Alternatives

• First-trimester combined screening (blood test and ultrasound).
• Second-trimester maternal serum screening.
• Invasive diagnostic procedures such as amniocentesis or chorionic villus sampling (CVS), which provide definitive diagnosis but carry a small risk of miscarriage.

Patient Experience

• Mild discomfort during the blood draw, similar to any routine blood test.
• Anxiety or anticipation while awaiting results.
• Counseling and support are offered to help manage any emotional stress associated with the screening outcomes.