Table 6.

Comparison of our method with previously reported methods

Method	Size of training set	Test set
		bACC	SENS	SPEC	PPV	NPV
TDxII [5]	-	0.82	0.86	0.78	0.29	0.99
Bonet [25]	N = 390 (NRM: -)	0.85	0.84	0.86	0.63	0.94
quantusFLM [5]	N = 730 (NRM: 13.8%)	0.82	0.74	0.89	0.51	0.96
Our method (irregular ROI)	N = 167 (NRM: 24.0%)	0.83	0.82	0.84	0.64	0.93
Our method (square ROI)	N = 167 (NRM: 24.0%)	0.87	0.91	0.82	0.63	0.96

The best results of each metric are shown in bold, and the worst results are shown in italics

TDxII, surfactant/albumin ratio, the best index in the report of amniocentesis results

In Bonet's work, SENS, SPEC, PPV, and NPV were calculated at different gestational week groups, and the table shows the mean values