Table 3 The comparison between our study and previous studies.

From: Automated interpretation of cardiotocography using deep learning in a nationwide multicenter study

Study ID

Pre-processing method

Type of features extracted

Part of CTG used

Clinicians as author(s)

Hold-out-validation

Cross validation method

ML classifier(s) used

Model interpretability

Performance measure(s)

Oversampling

Our study

Excluded records with missing data (e.g., maternal age, Apgar scores) or incomplete twin signals (> 1-min discontinuity)

From 0.5 Hz time-point signals, 7 statistical features (max, min, median, mean, number of peaks, variance, standard deviation) were extracted for the final model

FHR and UC

Both

Yes

None

1D-SEResNet50

No

SEResNet50:

No

Specificity = 81%

NPV = 94.7%

AUPRC = 62.5%

AUROC = 88%

20

Linear interpolation

FHR FIGO features and UC

FHR and UC

Non-clinician

Yes

k-fold

LG

Yes

LG:

No

AUROC = 74%

21

Did not specify

Morphological

FHR and UC

Non-clinician

No

k-fold

MLP, bagging, RF ands SVM

Partially

RF

Yes

Sensitivity = 96.4%

Specificity = 98.4% Accuracy = 96.7%

Precision = 96.8%

22

Remove spikes, interpolate, and segment into 20 min

Wavelet packet decomposition image

FHR

Non-clinician

No

k-fold

2DCNN

No

CNN:

No

Accuracy = 95.24% Sensitivity = 90.4% Specificity = 100%

23

Smoothing

Morphological and statistical

FHR and UC

Non-clinician

No

k-fold

NN, RF, clustering and SVM

Partially

Ensemble combination- NN, RF, k-means and SVM: Accuracy = 92.30%

No

24

Processing outliers and removing spike using moving average

Image

FHR and UC

Non-clinician

Yes

Did not specify

1D-CNN and bidirectional Gate

No

Accuracy = 95.15%

No

Sensitivity = 96.20% Specificity = 94.09%, Precision = 94.21%

Recurrent Unit (BiGRU)

F measure = 95.20%

AUROC = 99.29%

25

Outlier detection and linear interpolation

Linear and nonlinear, extract feature using CNN & LSTM

FHR

Non-clinician

No

k-fold

SVM and CNN-BiLSTM

Partially

SVM:

No

Sensitivity = 56.97% Specificity = 73.35%

QI = 63.91%

26

Did not specify

Image based and text

FHR

Non-clinician

Yes

Stratified k-fold

CNN

No

MMIF-1 (ViT-B/16): Accuracy = 96.3%

No

F measure = 96.3%

AUROC = 96.2%

27

Did not specify

Image

FHR

Non-clinician

Yes

k-fold

KNN, NB, SVM, DT, RF, ADABOOST, XGBOOST

No

XGBOOST:

No

Accuracy = 96.3%

Precision = 95.4%

Recall = 97.3%

F measure = 96.4%

AUROC = 95.9%

28

Lagrange interpolation

Image

FHR

Non-clinician

No

Did not specify

Double Trend Accumulation Former CNN

No

Accuracy = 90.6%

No

29

Lagrange interpolation

Curve classification

FHR

Non-clinician

Yes

k-fold

Trend-Guided Long CNN

No

Accuracy = 89.80%

No