Measurement of maternal serum amyloid A as a novel marker of preterm birth

To study the association between maternal serum amyloid A (mSAA) levels and preterm birth (PTB).

This prospective observational nested case control study was conducted at Ain Shams University Maternity Hospital, Cairo, Egypt, between May 2017 and December 2017. The study recruited pregnant women at 26-34 weeks presented with threatened preterm labor (PTL). Women with PTB were included in cases group while control group included women who continued pregnancy and delivered at term. Serum samples were collected to measure mSAA levels. The main outcome of the study was the association between mSAA levels and PTB. Secondary outcomes included neonatal intensive care unit admissions and neonatal mortality.

Fifty-eight women were included in the final analysis (29 in each group). Women with PTB had a statistically significant higher mSAA levels [5.1 (4.5-7.7) vs. 1.2 (0.0-2.5) mg/l, for cases and controls respectively, p < .001]. Higher mSAA levels were also observed among women whose babies were admitted to NICU, but there was no significant relation between mSAA level and neonatal death. A statistically significant negative correlation was found between mSAA and gestational age at delivery and neonatal birth weight. mSAA had an excellent value to predict PTB (AUC = 0.972 [95% CI, 0.891-0.998], p < .0001), fair value to predict admission to NICU and a poor value to predict neonatal death.

mSAA level was found to be elevated among women with threatened PTL who end with PTB; mSAA is a potentially useful predictive marker of PTB that warrant further study. CLINICALTRIALS.GOV: NCT01639027.