Assessment of airway parameters in obstetric patients and comparing them at different phases in the perinatal period: A prospective observational study

Abstract

Background and Aims: Airway changes occur in different stages of pregnancy. We aimed to evaluate the changes in the upper airway in obstetric patients during pregnancy, labour and after delivery using multiple airway indices and identify the predictive factors of these changes. Methods: This observational study was conducted on 90 parturients aged >20 years, having monofoetal pregnancy. The patient's weight was noted, airway assessment including Mallampati grading (MPG), and thyromental distance (TMD), sternomental distance (SMD), neck circumference (NC) and Wilson's risk score were measured in the second trimester of pregnancy (T0), between 32 and 34 weeks of gestation (T1), at the time of admission for safe confinement, between 38 and 40 weeks of gestation (T2), 2 h after delivery of baby (T3) and, 24 h after delivery (T4). Unpaired t-test and analysis of variance test were applied. Results: Changes in mean (standard deviation [SD]) weight, recorded from T0 to T2, were from 56.96 (10.77) to 65.322 (11.49) kg (P = 0.001). A rise of one or two grades in MPG was detected as the pregnancy progressed, and a decrease of one grade was noted after delivery. A significant decrease in mean (SD) TMD was noted from 6.88 (0.65) to 6.36 (0.62) cm from T0 to T2 (P = 0.001). SMD also decreased in a similar manner as TMD. NC increased from T0 to T3 and then decreased at T4 (P = 0.004). Conclusion: Following the second trimester of pregnancy, MPG increased by either one or two grades, with a decrease in TMD and SMD and an increase in NC.

Keywords

• airway changes
• delivery
• labour
• mallampati grading
• neck circumference
• pregnancy
• sternomental distance
• thyromental distance