Strengths and limitations
In our study, the Hadlock and the FMF growth charts were not accurate predictors of severe neonatal outcomes. However, we recognize the lack of power to detect such difference.
Other limitations of our study include that we only assessed the ability of two of the many fetal growth standards described in the literature,(32-34) nevertheless, we included the Hadlock chart, as is the one utilized in our institution and similar studies have also compared two standards.
We also acknowledge that our study participant number is inferior to other studies(11, 15, 16)and it was carry out in a single institution. Therefore, our results may not generalizable to other populations. However, we evaluated the accuracy of these growth charts only in pregnancies complicated by PPROM that only complicates 2-3% of the obstetrical population.(35)
Our strengths include that for our first outcome we included the detection SGA in a population where this diagnosis has been associated with an increased risk for infant morbidity and mortality.(36, 37) In addition, the evaluated adverse neonatal outcomes in our secondary outcomes have been previously validated and known to cause severe morbidity and mortality in premature infants.(36, 38). In our cohort we did not appreciate an association with SGA and SNO.