Abstract
Objective: To present the prenatal diagnosis of trisomy 18 and to review of the literature. Case: A 29-year-old pregnant woman was showed high risk of trisomy 18 by maternal serum screening at 16 weeks' of gestation, showing elevated AFP(125 U/mL, 3.25 MoM), low free β-hCG (3.29 ng/mL,0.11MoM), low PAPP-A (1120 mU/L, 0.31MoM). She asked for an amniocentesis because the risk value for trisomy 18 was 1/5 and trisomy 21 was 1/77121. Results: The results of amniocentesis on Prenatal BoBs revealed a fetus with trisomy 18, whose karyotype of amniotic fluid cells was 47, XY, +18. Ultrasonography demonstrated intrauterine pregnancy, single live fetus, multiple abnormalities including "strawberry head ", bilateral multiple choroid plexus cysts, cleft lip and palate, and atrioventricular septal defect. The pregnancy was terminated subsequently. Conclusion: Trisomy 18 can be identified in prenatal screening with advanced maternal age, abnormal maternal serum screen results, and multi-structural abnormal ultrasonography results. Fetuses with trisomy 18 may be associated with congenital heart disease, neural tube malformation, abdominal valgus, omphalocele, multiple cysts in bilateral choroid plexus, cleft lip and palate, elevated AFP, and decreased free β-hCG and PAPP-A.
Second-trimester prenatal diagnosis of trisomy 18 associated with elevated maternal serum alpha-fetoprotein level, bilateral multiple choroid plexus cysts, cleft lip and palate, and atrioventricular septal defect, and review of the literature
