A genetics evaluation should be offered to all women interested in prenatal genetic screening or testing. Women who are pregnant or planning to become pregnant who meet any of the following guidelines may be at an increased risk and a genetics referral should be considered:
A personal or family history of a known pathogenic variant/mutation
A personal or family history of a known or suspected genetic disorder, birth defect, or chromosomal abnormality
Consanguinity (mother and father are related by blood)
Women who will be 35 years of age or older at the time of delivery
Women with positive or abnormal results following maternal serum screening
Women with abnormal results following a CVS or amniocentesis
Fetal anomalies identified via ultrasound
Exposure to potential teratogens during pregnancy, including certain prescription medications, maternal infections, recreational drugs, or radiation
A history of stillbirth, SIDs, or 3 or more recurrent miscarriages
Carrier screening may be appropriate for individuals or couples who are interested in learning if they carry a gene for certain genetic conditions. In some cases, it takes two genetic variants for a person to develop a disorder, and through carrier screening, couples who are carriers can be counseled about their risk of having a child with that genetic condition.
Carrier screening for Cystic Fibrosis (CF) and Spinal Muscular Atrophy (SMA) should be offered to all pregnant women.
Carrier screening is recommended for individuals from certain ethnic backgrounds that are associated with a higher carrier frequency. This includes individuals with Ashkenazi Jewish, African American, French-Canadian, Mediterranean, and/or Asian ancestry.
Full referral guidelines are referenced on the back of this handout and are periodically updated. If you are concerned about a patient’s personal or family history, a genetics professional can help determine if further risk assessment and/or genetic testing is indicated.
Genetic testing performed in one or both parents in order to determine risk for child to be affected with certain recessive or x-linked genetic conditions.
Maternal Serum Screening Screening Test
First Trimester: 10 to 13 weeks Second Trimester: 15 to 22 weeks
First trimester: Maternal blood test paired with ultrasound exam to screen for trisomy 21 and trisomy 18. Second trimester: Maternal blood test to screen for trisomy 21, trisomy 18, and neural tube defects.
Non-Invasive Prenatal Screening/ Testing (NIPS/NIPT) Screening Test
10 weeks and beyond
Maternal blood test to screen for trisomy 21, trisomy 18, trisomy 13, and sex chromosome abnormalities.
Chorionic Villus Sampling (CVS) Diagnostic Test
10 to 13 weeks
Analysis of fetal cells from chorionic villi sample which can diagnose chromosomal abnormalities and other genetic conditions.
Amniocentesis Diagnostic Test
15 to 20 weeks
Analysis of fetal cells from an amniotic fluid sample which can diagnose chromosomal abnormalities, neural tube defects, and other genetic conditions.