The relationship between CRL and PAPP-A measurements in first trimester fetuses with low birth weight

Recent studies have suggested that impaired fetal growth are indicators that may be present in the first trimester. The aim of this study was to investigate the relationship between crown-rump length (CRL) and pregnancy associated plasma protein-A (PAPP-A) measurements in first trimester for low birth weight (LBW).

This prospective cohort study were on 120 pregnant women in first pregnan-cy trimester، in Women''s Hospital Mirza Kochak Khan in 2011-2012. Gestational age according to crown-rump length and gestational age according to last menstrual period (LMP)، neonatal weight، small for gestational age، pregnancy associated plasma protein-A and low birth weight were recorded. Main outcome measures was weight and gestational age at birth. Statistical tests used included descriptive statistics، t-test، χ² and all tests were two-tailed and differences with P<0. 05 were considered to be statistically significant.

Our findings showed that a total of 120 cases were included CRL Z-score and log 10 (MOM PAPP-A) were positively correlated with fetal birth weight. The mean Crown-rump length Z-score was significantly can be reduced in LBW in first trimester pregnancy. (P<0. 001) Mean PAPP-A in low birth weight was (0. 4±0. 11 MOM)، but in normal weight infants was (1. 04±0. 7 MOM). (P=0. 011) also mean PAPP-A in pregnant women with SGA infants is significantly less than other pregnant women (0. 5±0. 2 versus 1. 1±0. 7) (P<0. 001).

Our data suggest that crown-rump length and maternal levels of PAPP-A measured during the first trimester are independent factors that influence fetal birth weight. But their predictive powers are not sufficiently good for them to be used alone for low birth weight screening.