Respiratory distress (RD) in newborns is recognized as one or more signs of increased work of breathing, such as tachypnea, nasal flaring, chest retractions, or grunting [1]. Normally, a newborn’s respiratory rate ranges from 30 to 60 breaths per minute. Tachypnea is defined as a respiratory rate greater than 60 breaths per minute. Tachypnea is a compensatory mechanism for hypercarbia, hypoxemia, or acidosis (both metabolic and respiratory) [2]. In developed countries, the incidence of RD varies from 2% to 3.9%, whereas Indian studies reported an incidence ranging from 0.69% to 8.3% [3, 4, 5].

The commonest cause of RD in term babies is transient tachypnea of the newborn (TTNB), whereas in preterm babies, it is hyaline membrane disease. Transient tachypnea of the newborn is also known as Type II Respiratory Distress Syndrome or Wet Lung. It is the commonest cause of RD, accounting for 40-45% of cases. The known risk factors for TTNB are maternal asthma, male sex, macrosomia, maternal diabetes, and cesarean delivery [6, 7]. Following TTNB, meconium aspiration syndrome (MAS) is the second most common cause of RD. In term newborns, MAS is caused by the aspiration of meconium during the birth process. The pathophysiology of MAS involves intrauterine passage of meconium, aspiration, and pulmonary disease, resulting in hypoxemia and acidosis. Persistent pulmonary hypertension of the newborn (PPHN) frequently accompanies severe MAS and contributes to hypoxemia [8]. The other known common causes of RD are respiratory infections in newborns. Various co-morbidities are associated with newborns experiencing RD, including sepsis, neonatal seizures, hypoglycemia, air leaks, mostly related to mechanical ventilation, patent ductus arteriosus (PDA), hypothermia, intracranial hemorrhage (ICH), persistent pulmonary hypertension (PPHTN), metabolic alterations, and pulmonary hemorrhage [9].

Moreover, the treatment of neonatal RD can be supportive and disease-specific, including oxygen therapy, nutrition, mechanical ventilation, and antibiotics [10]. The prognosis of newborn babies with respiratory distress is disease-specific and depends upon newborn care. Newborns with TTNB, mild, and moderate MAS usually have an excellent prognosis. Continued efforts in preventing premature birth, early recognition of fetal distress, identification of maternal risk factors, and prenatal disease diagnosis have further improved neonatal outcomes. Early detection and management can decrease the duration of the disease course [11].

This study will help us understand the etiology of the disease and the various risk factors associated with respiratory distress, aiding in early diagnosis and management, thereby reducing morbidity and mortality. Additionally, it may contribute to preventing the risk factors associated with respiratory distress in term newborns. Furthermore, there is a paucity of data regarding the clinic-demographic profile of term newborns admitted with respiratory distress. This study may fill this gap.

This analytical cross-sectional study was conducted in 250 term newborns (37 to 42 weeks) with respiratory distress admitted to the Department of Pediatrics at Santosh Medical College and Hospital, Ghaziabad, Uttar Pradesh, during a one-year period from June 2018 to June 2019. Purposive sampling technique was used, involving alternate days of the week. Preterm and post-term babies, as well as patients who did not provide consent, were excluded from the study. Ethical clearance was obtained from the Institutional Review Committee, and written consent was obtained from the guardians after explaining the study’s objectives.

A detailed maternal history was obtained to ascertain the clinical-demographic profile and etiology of respiratory distress. Maternal risk factors such as Antepartum Hemorrhage (APH), placenta previa, Pregnancy-Induced Hypertension (PIH), eclampsia, smoking, gestational diabetes (GD), oligohydramnios, and history of Premature Rupture of Membranes (PROM) were recorded. Fetal heart rate was constantly monitored, and variations (fetal tachycardia, fetal bradycardia, decelerations, and decreased variability) were observed and noted after consultation with an obstetrician. Natal history was obtained to determine the mode of delivery and indications for interventions, if any. Complications during and prior to labor (obstructed or prolonged labor, fetal distress) were noted. Gestational age in completed weeks was assessed based on the mother’s last menstrual period and confirmed, where necessary, by routine early antenatal ultrasound (USG) examination and Ballard scoring. Postnatal history was obtained regarding birth asphyxia, cyanosis, or any other complications, as well as details of resuscitation measures performed at birth. The Apgar score at 5 minutes was assessed. For babies who were vigorous at birth, routine care was provided according to NRP guidelines 2015. However, in non-vigorous babies (defined as absence of respiratory effort, decreased muscle tone, and heart rate below 100 beats per minute), resuscitative measures were carried out as per NRP guidelines 2015. A detailed clinical examination was conducted, and respiratory distress was monitored throughout the hospital stay using Downe’s scoring system for term babies (0-3 = No respiratory distress; 4-6 = Respiratory distress; 7-10 = Impending respiratory failure). SpO2 was constantly measured using pulse oximetry.

The collected data was analyzed using the Statistical Package for the Social Sciences (SPSS) version 11.5. Descriptive statistics including frequencies, percentages, proportions, mean, and standard deviation were calculated, along with graphical and tabular presentation. For inferential statistics, associations were calculated at a 95% confidence interval, where p < 0.05 was considered significant, using the chi-square test. Data analysis included descriptive statistics such as mean, standard deviation, median, range, and percentage. Comparisons were made using the Chi-square test. Significance was assessed at a 5% level of significance (p < 0.05).

A total of 250 term newborns aged between 0-28 days of life, admitted with respiratory distress over a one-year period from June 2018 to June 2019, were included, with a Male:Female ratio of 1.7:1. The gestational age distribution showed that 65% were term pregnancies and 35% were late-term pregnancies upon admission (Table 1). Among these newborns, 10% exhibited severe respiratory distress, while 35% experienced moderate respiratory distress.

In Table 1, Upper Class=UC, Upper Middle=UM, Lower Middle=LM, Upper Lower=UL.

The oxygen requirements for newborns admitted with respiratory distress were categorized into three groups. The majority of babies, 137 (55%), only required oxygen via a hood-box. Approximately 30% (75) of newborns needed oxygen through bubble c-pap, while 15% (38) received oxygen via mechanical ventilation. Only 13% (32) of the newborns required inotropes after admission.

The most common maternal risk factor associated with respiratory distress in newborns was meconium-stained liquor (MSL) (25%), followed by premature rupture of membranes (PROM) (14

The most common associated co-morbidity was sepsis (58 cases, 23%), followed by hypothermia (12%) and neonatal seizures (9

Approximately 32% of newborns with respiratory distress did not develop any co-morbidities.

Transient Tachypnea of the Newborn (TTNB) was identified as the most common cause of respiratory distress, accounting for 47%, followed by Meconium Aspiration Syndrome (MAS) contributing to approximately 23%, as illustrated in Figure 3. The maternal risk factors associated with respiratory distress were not found to have a significant difference with the causes of respiratory distress.

Newborns born to mothers with a gestational age between 37 and 40 weeks had a significantly higher rate of respiratory distress (RD) with a p-value of 0.024. Other maternal factors such as residence, socioeconomic status, maternal age, parity, mode of delivery, and color of liquor did not show a statistically significant association with the severity of RD. Additionally, newborn factors including birth weight, gender, and Apgar score at 5 minutes did not exhibit a significant association with the severity of RD. Similarly, requirements for oxygen, inotropes, and antibiotics were not significantly associated with the severity of RD.

Newborns who experienced severe respiratory distress required a statistically longer hospital stay. Out of the 250 babies with respiratory distress, 213 were discharged, 25 left against medical advice (LAMA), and 12 sadly passed away, as indicated in Table 2. Among the 250 newborns, 35 were delivered with pre-rupture of membranes (PROM). It was observed that PROM was not significantly associated with the severity of respiratory distress (p = 0.558).

The total number of deliveries during the study period in our setting was 12,096, out of which 325 (2.5%) term newborns were admitted with respiratory distress (RD). This observation is similar to that made by Numan et al. [12], where 2.16% of term newborns were noted to have RD. The most common cause of RD in the current study was Transient Tachypnea of the Newborn (TTNB) (47%), which is comparable with the studies conducted by Numan et al. [12] and Kumar et al. [13]. As noted by various researchers, TTN followed by Meconium Aspiration Syndrome (MAS) and congenital pneumonia are the most common causes of RD in term newborns [14].

The period of gestation was found to differ significantly with the severity of RD. Among the newborns born between 37 to 40 weeks, 65% developed RD, whereas only 35% of newborns born between the gestational age of 40 to 42 weeks developed RD. These results are similar to a study conducted by Dani et al. [15]. There is strong evidence revealing an inverse relationship between gestational age and respiratory morbidity. As the gestational age decreases, there are higher chances of the development of RD in full-term newborns [15]. Neonates born by cesarean section have a larger residual volume of lung fluid, secrete less surfactant to the alveolar surface, and have a delayed clearance of the lung. Thus, they are at a higher risk of developing Respiratory Distress Syndrome (RDS). Hence, expert opinions recommend careful consideration of elective delivery without labor at less than 39 weeks’ gestation. In the current study, 62% of babies born through cesarean section developed RD, which was not statistically significant and is comparable with the study done by Joel et al. [16]. Similar to the observation made by Condo et al. [17], we also did not find a statistically significant association between maternal age and the severity of RD. Almost 74% of the babies with RD were born to multigravida mothers, which correlates with the study done by Joel et al. [16]. The type of amniotic fluid and the severity of RD showed no statistically significant association. Among newborns born with clear amniotic fluid, 55% developed RD, while 45% of newborns born with meconium-stained amniotic fluid developed RD. This finding is similar to the study done by Rijal et al. [18].

Out of the 250 newborns, 63% were males and 37% were females. It is believed that female fetal lungs produce pulmonary surfactant earlier in gestation than male lungs, probably due to the different hormonal profile of male infants. Earlier studies noted that RD is more common in male gender [19, 20]. Although a low Apgar score was noted in 45% of the babies, and 55% of the newborns had normal Apgar scores, 35% developed moderate depression, while 10% experienced severe depression at 5 minutes. These Apgar scores showed no statistically significant association with the severity of RD. Birth weight of newborns was not found to have a significant difference with the severity of RD. Among newborns admitted with respiratory distress, 65% were Appropriate for Gestational Age (AGA), 21% were Small for Gestational Age (SGA), and 14% were Large for Gestational Age (LGA). These results are comparable with the study done by Kommawar et al. [21]. However, earlier studies had noted a significantly higher risk of development of RD among low birth weight (LBW) term newborns, which was one of the main risk factors for RDS [15, 17, 22].

The current study revealed absence of significant maternal characteristics with development of RD. Recognition of risk factors for RD in neonates is crucial for development of preventive and early treatment strategies.35% of babies with RD had no known risk factors in mother. The 25% newborns were delivered with meconium stained liquor, 14% had PROM, 8% had PIH, 05% had anemia, 4% were oligohydromnious, 4% were delivered via obstructed labour, 04% were GDM and 2% had APH. These findings are correlated with the previous studies [23, 24, 25]. However, predicting which infants will become symptomatic is not always possible before birth. Regardless of the cause, if not recognized and managed quickly, respiratory distress can escalate to respiratory failure and cardiopulmonary arrest. Therefore, it is important that any health care practitioner caring for newborn infants can readily recognize the signs and symptoms of respiratory distress, differentiate various causes, and initiate management strategies to prevent significant complications or death. There was no associated co-morbidities in 32% of newborns with RD. Co-morbidities associated with RD were sepsis in 23%, neonatal seizures in 9%, hypoglycemia in 5%, metabolic alteration in 5%, Persistent pulmonary hypertension in 5%, PDA 3% pulmonary hemorrhage3% and ICH in 2%. 4% of newborns with RD developed air leaks were on mechanical ventilation. These findings are correlated with the study conducted by Gouyon et al. [24]. We have only 4% of babies with pneumothorax in current study,other studies have noted to be in between 10.3% and 34% [26, 27]. Hospital stay was also found to have significant differ with the severity of RD with P-value of 0.001, which is comparable with the study done by Numan et al. [12]. Hence the increased severity of RD had lead to prolonged hospital stay but it did not change the outcome. The outcome of the newborn with RD in present study was not significantly higher.

In the present study, 2.5% of term newborn developed respiratory distress. The most common causes were TTNB followed by MAS and congenital pneumonia. Only lower gestational age was associated with higher respiratory distress. Though MSL, PROM, PIH were seen to be commonly seen in term babies with respiratory distress it did not affect the severity and outcome. Thorough clinical assessment and appropriate investigation is required for all infants presenting with signs of respiratory distress to ensure accurate diagnosis and correct treatment. Prompt recognition of the more serious underlying conditions is important to improve the outcomes.

Persistent pulmonary hypertension of the newborn (PPHN), Transient tachypnea of new born (TTNB), Respiratory distress (RD), Meconium Aspiration Syndrome (MAS), Patent Ductous Arteriosus (PDA), Intracranial Haemorrahge (ICH), Ante partum hemorrhage (APH), pregnancy induced hypertension (PIH), Gestational Diabetes Mellitus(GDM), Premature Rupture of Membranes (PROM), Large for Gestational Age (LGA), Appropriate for Gestational Age (AGA), Small for Gestational Age (SGA)

Ethics approval and consent to participate:- The study was submitted and approved by the institutional ethics committe of Santosh Medical College & Hospital Ghaziabad Uttarpradesh and written informed consent from parents to participate in study was taken.

Consent for publication from parent was taken.

The datasets used or analysed during the current study are available from the corresponding author on reasonable request

The authours declare that they have no competing interest.

Authors declare no conflict of interests.

JY data collection, SC data collection & idea of research, AA idea of research, writing and proof reading,VS analysed and interpreted data, all authors have read and approved the manuscript.

1. Warren, J. B., & Anderson, J. M. (2010). Mewborn respiratory disorder. Pediatrics in Review, 31(12), 487-496.
2. Edwards, M. O., Kotecha, S. J., & Kotecha, S. (2013). Respiratory distress of the term newborn infant. Paediatric Respiratory Reviewes, 14(1), 29-37.
3. Banerjee, C. K., Narang, A., Bhakoo, O. N., & Aikat, B. K. (1975). The causes of neonatal mortality: an analysis of 250 autopsies on newborn infants. Indian pediatrics, 12(12), 1247-1252.
4. Nagendra, K., Wilson, C. G., Ravichander, B., & Singh, S. P. (1999). Incidence and etiology of respiratory distress in newborn. Medical Journal Armed Forces India, 55(4), 331-333.
5. Singh, M., Deorari, A. K., Khajuria, R. C., & Paul, V. K. (1991). A four year study on neonatal morbidity in a New Delhi hospital. The Indian Journal of Medical Research, 94, 186-192.
6. Anastasiou, E., Alevizaki, M., Grigorakis, S. J., Philippou, G., Kyprianou, M., & Souvatzoglou, A. (1998). Decreased stature in gestational diabetes mellitus. Diabetologia, 41(9), 997-1001.
7. Demissie, K., Marcella, S. W., Breckenridge, M. B., & Rhoads, G. G. (1998). Maternal asthma and transient tachypnea of the newborn. Pediatrics, 102(1), 84-90.
8. PA, D. (2006). Australian and New Zealand Neonatal Network. The epidemiology of meconium aspiration syndrome: Incidence, risk factors, therapies, and outcome. Pediatrics, 117, 1712-1721.
9. Yadav, S., Lee, B., & Kamity, R. (2021). Neonatal respiratory distress syndrome. StatPearls.
10. Yu, W. L., Lu, Z. J., Wang, Y., Shi, L. P., Kuang, F. W., Qian, S. Y., ... & Collaborative Study Group of Pediatric Respiratory Failure. (2009). The epidemiology of acute respiratory distress syndrome in pediatric intensive care units in China. Intensive Care Medicine, 35, 136-143.
11. Chandrasekhar, R., Mohan, M. M., & Lakshmi, B. V. (2016). Clinical study of respiratory distress in newborn. International Journal of Contemporary Pediatrics, 10, 2349-2391.
12. Hameed, N. N., Al-Janabi, M. K., & AL-Reda, Y. I. (2007). Respiratory distress in full term newborns. Iraqi Postgraduate Medical Journal, 6(3), 233-39.
13. Kumar, A., & Vishnu Bhat, B. (1996). Epidemiology of respiratory distress of newborns. The Indian Journal of Pediatrics, 63, 93-98.
14. Reuter, S., Moser, C., & Baack, M. (2014). Respiratory distress in the newborn. Pediatrics in Review, 35(10), 417-429.
\
15. Dani, C., Reali, M. F., Bertini, G., Wiechmann, L., Spagnolo, A., Tangucci, M., & Rubaltelli, F. F. (1999). Risk factors for the development of respiratory distress syndrome and transient tachypnoea in newborn infants. Italian Group of Neonatal Pneumology. European Respiratory Journal, 14(1), 155-159.
16. Tochie, J. N., Choukem, S. P., Langmia, R. N., Barla, E., & Koki-Ndombo, P. (2016). Neonatal respiratory distress in a reference neonatal unit in Cameroon: an analysis of prevalence, predictors, etiologies and outcomes. Pan African Medical Journal, 24(1), 152.
17. Condo, V., Cipriani, S., Colnaghi, M., Bellu, R., Zanini, R., Bulfoni, C., ... & Mosca, F. (2017). Neonatal respiratory distress syndrome: are risk factors the same in preterm and term infants?. The Journal of Maternal-Fetal & Neonatal Medicine, 30(11), 1267-1272.
18. Rijal, P., & Shrestha, M. (2018). Analysis of neonatal respiratory distress in neonatal intensive care unit at Nepal medical college. Journal of Nepal Health Research Council, 16(2), 131-135.
19. Donald, I. (1954). Radiology in neonatal respiratory disorders. The British Journal of Radiology, 27(321), 500-503.
20. Nagendra, K., Wilson, C. G., Ravichander, B., & Singh, S. P. (1999). Incidence and etiology of respiratory distress in newborn. Medical Journal Armed Forces India, 55(4), 331-333.
21. Kommawar, A., Borkar, R., Vagha, J., Lakhkar, B., Meshram, R., & Taksandae, A. (2017). Study of respiratory distress in newborn. International Journal of Contemporary Pediatrics, 4(2), 490-494.
22. Alfarwati, T. W., Alamri, A. A., Alshahrani, M. A., & Al-Wassia, H. (2019). Incidence, risk factors and outcome of respiratory distress syndrome in term infants at Academic Centre, Jeddah, Saudi Arabia. Medical Archives, 73(3), 183-186.
23. Jobe, A. H. (2012). Effects of chorioamnionitis on the fetal lung. Clinics in Perinatology, 39(3), 441-457.
24. Gouyon, J. B., Ribakovsky, C., Ferdynus, C., Quantin, C., Sagot, P., Gouyon, B., & Burgundy Perinatal Network. (2008). Severe respiratory disorders in term neonates. Paediatric and Perinatal Epidemiology, 22(1), 22-30.
25. Williams, O., Hutchings, G., Hubinont, C., Debauche, C., & Greenough, A. (2012). Pulmonary effects of prolonged oligohydramnios following mid-trimester rupture of the membranes-antenatal and postnatal management. Neonatology, 101(2), 83-90.
26. Ayachi, A., Rigourd, V., Kieffer, F., Dommergues, M. A., Voyer, M., & Magny, J. F. (2005). Maladie des membranes hyalines chez le nouveau-ne a terme. Archives de Pediatrie, 12(2), 156-159.
27. Madar, J., Richmond, S., & Hey, E. (1999). Surfactant-deficient respiratory distress after elective delivery at 'term'. Acta Paediatrica, 88(11), 1244-1248.