On September 19, 2022, the California Prenatal Screening (PNS) Program launched its revised program. Cell-free DNA (cfDNA) is now the primary screening test for trisomy 21, trisomy 18, and trisomy 13, replacing biochemical screening for trisomies 21 and 18.
cfDNA screening is available starting at 10 weeks 0 days and can be done throughout pregnancy. However, the PNS Program recommends that cfDNA screening take place from 10 weeks 0 days through 21 weeks 0 days so that all follow-up services can be available to individuals determined to be high risk. cfDNA screening also gives patients the option to find out the sex of the fetus. Providers can choose this option by checking a box when ordering screening. There is no additional cost for finding out the fetal sex.
In addition to cfDNA, maternal serum alpha fetoprotein (MSAFP) screening for neural tube defects is still offered, now from 15 weeks 0 days through 21 weeks 0 days of gestational age.
The PNS Program continue to provide follow-up genetic counseling and diagnostic services for participants with screen-positive results for the three trisomies or neural tube defects at state-approved Prenatal Diagnosis Centers.
Within the PNS Program, providers choose to work with one of the three state-contracted labs. They are Natera, Quest Diagnostics, and Revvity. They screen for trisomy 21, trisomy 18, and trisomy 13 and neural tube defects (what is on the state’s screening panel). The revised PNS Program screening panel does not currently include sex chromosome anomalies or microdeletions. See questions and answers below for more details on this.
Another change is the expanded use of the CalGenetic Portal for ordering screening and getting results. See questions and answers below for more details on this.
An additional change is regarding nuchal transluchency ultrasound. Nuchal translucency ultrasounds are still recommended as the most accurate dating method of gestational age. However, the PNS Program no longer requires a nuchal translucency measurement to receive a preliminary risk assessment for fetal chromosomal abnormalities with a first trimester biochemical screening test. The previous policy to authorize follow-up services at a state-contracted Prenatal Diagnosis Center with a large NT > 3.0 mm, regardless of the biochemical screening result, has ended.
However, if the cfDNA or MSAFP screening result is positive, and the patient goes to a state-contracted Prenatal Diagnosis Center and the fetus is identified to have a large NT > 3.0 mm, and the patient chooses to have an amniocentesis, the patient can choose to have a karyotype or microarray.