A novel technique for prediction of preterm birth: fetal nasal flow Doppler.

Objectives: Absence of fetal breathing movements (FBM) has been found to be a good predictor of preterm delivery in symptomatic patients. However, analysis of FBM patterns and Doppler measurement of them for preterm birth prediction have not been performed before. In this study, we aimed to investigate and analyze FBM patterns in symptomatic preterm labor patients by fetal ultrasonography and nasal Doppler.

Methods: This was a multicenter, prospective cohort study. Singleton pregnant patients between 24 and 37 gestational weeks diagnosed with preterm labor were included in the study. Patients were evaluated in three groups: no FBM (Group 1), regular FBM (Group 2), irregular FBM (Group3).

Results: Seventy-three patients were available for the final analysis after exclusion. Preterm delivery rate in 24 h in groups were 91.7, 32.7 and 100%, respectively. The absence of FBM (Group 1) was statistically significant for preterm delivery in for both 24 (91.7 vs. 42.6%, p=0.002) and 48 h (91.7 vs. 49.2%, p=0.006) when compared with fetal breathing positive Group 2 and 3. In fetal nasal Doppler analyses in Group 2, the inspiration/expiration number rate was significantly lower in the patients who delivered in 24 h (0.98±0.2 vs. 1.25±0.57, p=0.015). By using fetal nasal Doppler, combination of absence of FBM or irregular FBM or regular FBM with inspiration number/expiration number (I/E) <1.25 detects 94.6% of patients who will eventually deliver in the first 24 h after admission.

Conclusions: Examining FBM patterns and using nasal Doppler may help the clinician to differentiate those who will deliver preterm and may be an invaluable tool for managing preterm labor patients.