Publication:

Pregnancy associated plasma protein A: an early predictor of fetal growth restriction

Background The aim of our study was to determine the association of low levels of pregnancy associated plasma protein-A (PAPP-A) levels estimated at 11-13+6weeks of gestation with fetal growth restriction (FGR).

Methods A prospective observational study of a total of 203 pregnant women with PAPP-A levels were followed up and the outcome data were collected at childbirth.

Results The incidence of FGR was 7.3%. A significant association was found between low levels of PAPP-A MoM (≤0.49) with FGR (p=0.000) with unadjusted odds ratio of 11.6. At PAPP-A multiples of median (MoM) ≤0.49, FGR had a median (Q1, Q3) of 0.46 (0.42, 1.54) versus 1.87 (0.59, 3.11) which was statistically significant (p=0.05) with moderate strength of prediction [minus 0.58 (95% CI, minus 1.113, minus 0.055), p=0.03]. At the cut-off considered in our study i.e., ≤0.49 MoM, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 73%, 81%, 23%, and 97% respectively with a positive LR of 3.82 and negative LR of 0.32. Karl Pearson’s correlation showed positive correlation (r=0.308, p<0.001) between PAPP-A MoM and birthweight and showed that for every unit increase in PAPP-A MoM, birthweight increased by 0.082 times (approximately 90 gm). We also found an association of low PAPP-A with pre-eclampsia, preterm delivery and increased caesarean delivery births.

Conclusions We conclude that low PAPP-A MoM levels are good reflectors of placental function and adverse outcomes. PAPP-A, a part of the dual marker, may be extrapolated for suspecting FGR. This could guide in instituting appropriate feto-maternal surveillance.