What if I miss the Down syndrome screening?
Jul 21, 2025
Source: Cainiu Health
Dr. Zhang Lu
Introduction
The appropriate time for non-invasive DNA testing is between 12 to 22 weeks of pregnancy. If the Down syndrome screening was missed and the pregnancy is within this gestational period, this test can be performed to assess the risk of common fetal chromosomal trisomy syndromes by analyzing fetal cell-free DNA. Amniocentesis can be conducted between 16 to 22 weeks of pregnancy if the Down syndrome screening was missed and the gestational age is appropriate.
Generally, if the Down syndrome screening is missed, alternative approaches may include opting for non-invasive DNA testing, undergoing amniocentesis, enhancing other fetal anomaly screenings, monitoring fetal development, and seeking consultation at a genetic counseling clinic. Detailed explanations are as follows:
1. Opt for non-invasive DNA testing: The optimal time for non-invasive DNA testing is between 12 and 22 weeks of pregnancy. If the Down syndrome screening was missed and the pregnancy is within this gestational window, this test can be performed to assess the risk of common fetal chromosomal trisomies by analyzing fetal cell-free DNA.
2. Undergo amniocentesis: Amniocentesis can be performed between 16 and 22 weeks of pregnancy. If the Down syndrome screening was missed and the gestational age is appropriate, this procedure can directly obtain fetal cells to determine whether the number and structure of chromosomes are normal, offering a high level of accuracy.
3. Enhance other fetal anomaly screenings: Timely undergo ultrasound examinations such as four-dimensional color Doppler ultrasound to carefully observe the development of each fetal organ and detect any structural malformations. While these cannot directly identify chromosomal abnormalities, they can assist in assessing fetal health.
4. Monitor fetal development: Regularly track fetal growth indicators such as head circumference, abdominal circumference, and femur length, comparing them with standard developmental benchmarks. If any abnormalities are detected, timely further investigations should be conducted to rule out developmental delays caused by chromosomal issues.
5. Consult a genetic counseling clinic: Visit a genetic counseling clinic and provide the doctor with information regarding gestational age and previous pregnancy and childbirth history. Based on this information, the doctor can assess the risk of fetal abnormalities and provide personalized testing recommendations and guidance.
There is no need for excessive anxiety after missing the Down syndrome screening. It is important to seek medical attention promptly and choose appropriate testing methods according to gestational age and individual circumstances. Follow the doctor's instructions during the testing process. If test results are abnormal, timely cooperation with further diagnostic procedures and management is essential to ensure maternal safety during pregnancy.
