Do I need to fast for the Down syndrome screening test?

Generally, "Down syndrome screening" refers to prenatal screening for Down syndrome, which mainly consists of two parts: blood tests and ultrasound examinations. Fasting is usually not required before undergoing the screening.

Prenatal screening for Down syndrome primarily involves taking a blood sample from the pregnant woman to measure specific biochemical markers such as human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP), and unconjugated estriol (uE3). These results are combined with maternal factors including age, weight, and gestational age to assess the risk of fetal chromosomal abnormalities such as Down syndrome. Since these biochemical markers are generally unaffected by food intake, fasting is typically not necessary. However, some hospitals may require fasting to minimize measurement errors or to coordinate with other concurrent tests. It should be noted that prenatal screening results serve only as a reference for assessing the risk of chromosomal abnormalities and cannot be used as a definitive diagnosis. If abnormal results are detected, further diagnostic testing—such as amniocentesis or non-invasive prenatal DNA testing (NIPT)—should be performed to confirm the fetus's health status.

Pregnant women are advised to maintain regular作息 (daily routines), ensure adequate sleep, follow a healthy diet, engage in moderate exercise, wear loose, breathable, cotton clothing and comfortable footwear, practice good personal hygiene, and maintain stable emotional well-being.