Non-invasive trisomy 13 high risk

The fetus may also encounter various risks in the mother's womb, such as congenital diseases. Through maternal examination, it is possible to effectively infer whether there are any abnormalities in the fetus in the mother's belly. Non-invasive DNA testing is a method of examining the fetal genes. However, non-invasive DNA testing is a relatively complex testing method, so what does it mean if the non-invasive DNA test shows a high risk of trisomy 13?

The high risk of trisomy 13 is due to the nondisjunction of the 13th pair of chromosomes during meiosis due to some reasons. As the mother's age increases, the risk of newborns developing the disease also increases (the average maternal age of the affected children is 32.4 years old, significantly higher than that of ordinary children). Some people have found that cases related to maternal age often occur during winter pregnancy, and the reason is unknown. What are the symptoms of a high-risk fetus with trisomy 13?

There are no abnormalities in the fetus before birth, but the developmental deformity is very serious and the degree varies. After birth, common malformations include cleft lip, cleft palate, small eyes or no eyeballs, deformed and low-positioned auricles, poor development of the prothorax, undifferentiated frontal lobes, lack of external olfactory lobes, deafness, severe mental retardation, inconsistent muscle tone, minor convulsions, polydactyly, syndactyly, narrow and convex nails, and flexor fingers. Male children often have hypospadias and cryptorchidism, while female children often have bicornuate uterus.

More than 80% have congenital cardiovascular malformations. The most common ones are dextrocardia (65%), ventricular septal defect (60%), patent ductus arteriosus (48%), atrial septal defect (44%), transposition of the great arteries (11%) and aortic valve stenosis (10%). In addition, there are rare aortic arch abnormalities, aortic co-rotation, coronary artery abnormalities, pulmonary artery stenosis and atrioventricular channel.

The most important prevention method is to conduct prenatal screening among high-risk pregnant women, and perform amniocentesis and chromosome karyotype analysis to screen and prevent the birth of affected children.