The application of maternal pregnancy-associated plasma protein-A in prenatal screening

Abstract

Objective To establish the normal referential data of maternal serum pregnancy-associated plasma protein-A (PAPP-A) level in singleton pregnancy in Kunming region by reviewing the relationship of maternal serum PAPP-A level and pregnant outcome in prenatal screening program. Method To detect the PAPP-A levels of serum samples from 2 585 cases of normal singleton pregnancy from 6 gestational weeks to 40 weeks using dissociation enhanced lanthanide fluoroimmunoassay(DELFIA). Results The medians of maternal serum PAPP-A of Chinese population in Kunming region were significantly higher than those of the Caucasian population in 9〜13 gestational weeks, respectively. The average median of PAPP-A in twin pregnancy was 1. 79 times compared to the median of singleton pregnancy in Kunming region (P<0. 01). In 8 cases of trisomy pregnancy, the mean PAPP-A MoM in the second trimester was 0. 72 MoM. Conclusion It is necessary to establish local referential normal PAPP-A median of local region to improve the veracity of prenatal screening. The maternal serum PAPP-A level of trisomy pregnancy in 15〜20 gestational weeks intended to close the normal level, but significantly reduced as the pregnancy progress. The PAPP-A level in 18 trisomy pregnancies was much lower than that of Down's syndrome pregnancies. Key words: pregnancy-associated plasma protein-A (PAPP-A); prenatal screening; trisomy syndrome