Strengths and limitations
One of the main strengths of the study includes the prospective
enrolment of patients. Additionally, this study was performed within the
context of routine clinical practice and patients were seen by their
usual physicians, making the results more reliable and applicable in
routine care settings. Furthermore, this is the first study assessing
the performance of the FMF algorithm exclusively in a Spanish cohort and
in a clinical setting where MAP was measured once and only in one arm,
showing comparable results to those reported in the original study.
Despite a previous study showed that prediction of PE is similar when
biomarkers are measured before or after 11 weeks6, the
FMF algorithm was designed with biomarkers assessed between 11+0 and
13+6 weeks. In this study biomarkers were measured before 11+0 weeks in
1,675 (63.4%) women. Therefore, another remarkable strength of our work
is that it provides evidence of the applicability of the FMF and
Gaussian algorithms before and after 11 weeks for predicting PE and SGA.
The main limitation of our study is the low number of cases with
early-onset SGA and early-onset PE, and the relatively low number of
cases with preterm SGA and preterm PE. Additionally, indication for
elective delivery of SGA fetuses based on Doppler and cardiotocogram
findings may be different when using other fetal growth restriction
protocols. However, Doppler and cardiotocogram classification is rather
uniform in Spain, where the Gaussian algorithm is widely used. Another
limitation to be noted is that the technique for MAP measurements may
potentially reduce the FMF algorithm’s performance and could explain its
lower AUC versus the Gaussian algorithm for some marker combinations.