Investigation of risk factors of transient tachypnea of the newborn in our hospital and trial for early diagnosis

Background: Transient tachypnea of the newborn (TTN) is one of the most common respiratory disorders in newborns. Risk factors for TTN include cesarean section, male sex, and premature delivery. Here, we examined the risk factors of TTN in our hospital in order to find a tool for early diagnosis.<br>Methods: We performed a retrospective review of 444 babies who were born in our hospital between April 2012 and March 2013. TTN was diagnosed in 34 babies (TTN group). Eighty-seven babies had tachypnea or grunting, but improved upon routine care within 12 hours (non-TTN group). Two hundred and sixty-five babies had no symptoms or problems (control group). Fifty-eight babies suffered from infectious diseases, among others (other disease group). We compared the sex, gestational age, birth weight, vaginal delivery or cesarean section, and Apgar score among the TTN group, the non-TTN group, and the control group.<br>Results: The percentage of the TTN group was 7.7% among all newborn babies, making it the most common disease of newborn babies in our hospital. In the comparison among these 3 groups, there were no significant differences in sex or maternal age, but the average gestational days were 269.6 in the TTN group, 274.3 in the non-TTN group, and 274.1 in the control group, which was significantly lower in the TTN group than in the other 2 groups. The average birth weights were 2,795.7 g in the TTN group, 2,951.5 g in the non-TTN group, and 2,989.8 g in the control group; the birth weight was significantly lower in the TTN group than in the control group. The proportions of cesarean section were 24% in the TTN group, 14% in the non-TTN group, and 10% in the control group; this rate was significantly higher in the TTN group than in the control group. The proportions of premature rupture of membrane were 21% in the TTN group, 31% in the non-TTN group, and 14% in the control group; this rate was significantly higher in the non-TTN group than in the control group. There was no significant difference in fetal distress among these 3 groups. The median Apgar scores at 1 min were 8 in the TTN group, and 9 in the non-TTN group and the control group, which were significantly different; the score was the lowest in the TTN group, intermediate in the non-TTN group, and the highest in the control group. The median Apgar scores at 5 min were 9 in the TTN group and 10 in the non-TTN and control groups; it was the lowest in the TTN group.<br> When the conditions of gestational week ≤38 weeks (gestational day ≤272), Apgar score at 1 min ≤8, and Apgar score at 5 min ≤9 were combined, the prevalence of TTN was 59% (10 out of 17 babies); otherwise, it was 7% (24 out of 369 babies), which was significantly different.<br>Conclusion: Gestational age, birth weight, cesarean section, and Apgar score were related to TTN in our study. When gestational week ≤38 weeks, Apgar score at 1 min ≤8, and Apgar score at 5 min ≤ 9 were combined, the prevalence of TTN was more than 50%.