Prenatal genetic testing in Japan

Area of Science:

• Medical Genetics
• Obstetrics and Gynecology
• Public Health

Background:

• Prenatal diagnosis and maternal serum marker tests (MSMTs) are crucial for identifying fetal abnormalities.
• Understanding the utilization rates of these tests is important for improving prenatal care.
• In 1997, the landscape of prenatal testing in Japan required examination.

Purpose of the Study:

• To assess the utilization of prenatal diagnosis and MSMTs in Japan during 1997.
• To evaluate the rates of amniocentesis and chorionic villus sampling.
• To determine the uptake of MSMTs across different age groups.

Main Methods:

• A survey was conducted using questionnaires sent to medical facilities providing prenatal diagnosis, representing approximately 80% of such facilities.
• Data on prenatal diagnoses, including amniocentesis and chorionic villus sampling, were collected.
• Maternal serum marker tests (MSMTs) data were gathered, including patient age and follow-up results for chromosomal abnormalities like trisomy 21.

Main Results:

• Prenatal diagnosis was performed on 5,748 women, with 96.3% undergoing screening for chromosomal abnormalities.
• Maternal serum marker tests (MSMTs) were performed on 14,682 women; only 4% of pregnant women over 35 underwent amniocentesis.
• Pregnancy termination occurred in 89.1% of cases diagnosed with fetal abnormalities. Informed consent policies varied, with only 34.5% of facilities obtaining written consent before MSMTs.

Conclusions:

• The study revealed low rates of amniocentesis among pregnant women over 35 and limited offering of MSMTs in Japan in 1997.
• Prenatal testing should be voluntary, emphasizing the need for adequate patient information.
• Improving informed consent procedures is essential for ethical and effective prenatal screening programs.