Abstract
Second trimester MSAFP screening for low values is proving valuable in the detection of fetal chromosome defects in women < 35 yrs. of age. Detection prior to 16 wks. would be desirable. To determine whether low MSAFP values also occur in the first trimester in association with a fetal chromosomal abnormality, we used a “simultaneous-sandwich” radioimmunoassay with polystyrene beads coated with anti-AFP monoclonal antibodies, using solid phase support. The coefficient of variation was<5% for this assay which is about 10 x more sensitive than conventional RIAs. Blood was sampled in 359 cases just before CVS (chorionic villus sampling) in Milan. Fetal age was usually assessed by 2 ultrasound studies± 1 wk. apart, and chromosomes of the villi analysed. Sera were sent blind & only after AFP assay results were sent to Milan were karyotypes released. MSAFP≤0.6 MOM occurred in 5/17 (45.5%) significant fetal chromosome defects (trisomy 21, 18 [2], 13 & unbal. 13/14 translocation) while 2 (18.2%) were<0.5 MOM. 11/17 (64.7%) affected fetuses had MSAFP<median. 1/5 trisomy 21 fetuses had MSAFP< 0.5 MOM. About 75% of trisomy 21 offspring are delivered by women< 35 yrs. of age. These results suggest that first trimester MSAFP screening could identify a significant number of these pregnancies early enough for CVS. Further study is necessary to determine the optimum week for efficient screening.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
