Fetal Nasal Flow Doppler and Breathing Patterns for Prediction of Preterm Labor: A Prospective Cohort Study

Background: Expectation of preterm birth is very hard for obstetricians although there are various ways such as fetal fibronectin, different cytokines, cervical length measurement and elastography was implemented for this reason. Doppler might be used to evaluate fetal nasal fluid flow but this test was not made in expecting preterm labour til now. Aim: To study the value of fetal breathing movement patterns and nasal flow Doppler in women with symptomatic preterm labor. Patients and Methods: This prospective study was conducted at tertiary care hospital at Helwan University Hospital from April 2022 till October 2022 and performed on a total of 81 pregnant women at 28 to 37 weeks gestation with symptomatic preterm labor. Results: During this study, 100 patients were assessed for eligibility and 81 patients were included in the study. Of all eligible patients, 12 patients were excluded from the study based on the inclusion criteria and 7 patients refused to participate in of the study. Ultimately, the analysis was based on the data of 81 pregnant women at 24 to 37 weeks gestation with symptomatic preterm labor. The current study revealed that the age, Body mass index, Gestational age, Cervical dilation and Cervical length was 27.4 ± 4.8 years, 29.4 ± 2.5 kg/m2 , 31.2 ± 2.3 weeks, 3.3 ± 0.6 cm and 15.6 ± 2.2 mm respectively and 25.9% of cases were nulli parous. Our study results revealed that breath movement was not detected in (14.8%) of cases, was irregular in (17.3%), while it was regular in more than two thirds (67.9%) of cases and 44.4% of the studied cases had delivery within day 1 (24 hours). Conclusion: Adding Doppler study to the upper respiratory tract tests could help in assessment of fetal nasal fluid flow. Inspiration/ expiration number ratio ≤1.12 had highest sensitivity and PPV in predicting delivery in day-1. As a result, only inspiration/expiration number ratio was related to higher possibility for preterm delivery.