Evaluating Fundal Dominant Contractions on Spatiotemporal Electrohysterography as a Marker for Effective Labor Contractions.

OBJECTIVE: To evaluate if fundal (F) dominance of the electrohysterogram is associated with vaginal delivery and lack of F dominance is associated with cesarean for labor dystocia. STUDY DESIGN: We conducted a prospective cohort study of nulliparous women in spontaneous labor at ≥36 weeks. Clinicians were blinded to electrohysterography data which were in addition to standard cardiotocography. All contractions in the hour preceding diagnosis of complete cervical dilation (for women delivering vaginally) or the hour preceding the decision for cesarean were analyzed. RESULTS: Of 224 patients, 167 had evaluable data. The proportion of F dominant contractions was not different for women undergoing cesarean for labor dystocia (n = 11) compared with all others (n = 156)-88.7 ± 10.2 versus 86.0 ± 11.4%; p = 0.44. Results were similar when comparing the cesarean for labor dystocia group to those undergoing cesarean for other indications (n = 10) and vaginal deliveries (n = 146)-88.7 ± 10.2 versus 86.5 ± 10.0 versus 85.9 ± 11.5%; p = 0.74. CONCLUSION: We were unable to confirm our earlier finding that F dominance of the electrohysterogram is associated with vaginal delivery and lack of F dominance is associated with cesarean for dystocia.

Photoplethysmography and Heart Rate Variability for the Diagnosis of Preeclampsia.

BACKGROUND: The goal of this study was to determine a set of timing, shape, and statistical features available through noninvasive monitoring of maternal electrocardiogram and photoplethysmography that identifies preeclamptic patients. METHODS: Pregnant women admitted to Labor and Delivery were monitored with pulse oximetry and electrocardiogram for 30 minutes. Photoplethysmogram features and heart rate variability were extracted from each data set and applied to a sequential feature selection algorithm to discriminate women with preeclampsia with severe features, from normotensive and hypertensive controls. The classification boundary was chosen to minimize the expected misclassification cost. The prior probabilities of the misclassification costs were assumed to be equal. RESULTS: Thirty-seven patients with clinically diagnosed preeclampsia with severe features were compared with 43 normotensive controls; all were in early labor or beginning induction. Six variables were used in the final model. The area under the receiver operating characteristic curve was 0.907 (standard error [SE] = 0.004) (sensitivity 78.2% [SE = 0.3%], specificity 89.9% [SE = 0.1%]) with a positive predictive value of 0.883 (SE = 0.001). Twenty-eight subjects with chronic or gestational hypertension were compared with the same preeclampsia group, generating a model with 5 features with an area under the curve of 0.795 (SE = 0.007; sensitivity 79.0% [SE = 0.2%], specificity 68.7% [SE = 0.4%]), and a positive predictive value of 0.799 (SE = 0.002). CONCLUSIONS: Vascular parameters, as assessed noninvasively by photoplethysmography and heart rate variability, may have a role in screening women suspected of having preeclampsia, particularly in areas with limited resources.