The Mean AFOD and echogenic AFPS in all pregnancies at onset of labor was found to be 0.99 and 4.9 mm respectively.
We hypothesise that AFOD is definite marker for labor as well as fetal lung maturity.
The mean AFOD and AFPS at onset of labor was found to be 1.03 [+ or -] 0.31 (0.35 - 1.69 CI 95%) and 5.14 [+ or -] 0.69 mm (3.67 - 6.7 CI 95%) respectively in 116 women who delivered normal babies.
The snowstorm appearance, blizzard patterns and dense clusters of AFPs are seen usually at a higher AFOD values (> 0.80) and more appreciated with fetal movements on ultrasonography.
Based on the results of our study we observed that an AFOD value of < 0.40 and AFPS < 4 mm at labor increases the risk for RDS of varying degrees.
Within this range, 18 women (AFOD ranged from 0.19 to 1.25) delivered having AFOD ranged from 0.19 to 1.25.
Our results confirm the hypothesis that lung maturity progresses with the AFOD surge culminating in onset of normal labor.
The Degeneracy of AFPS in determining AFOD makes the association only an approximation and not an equivalent to gold standard (AFOD).