A prospective study of the severity of early respiratory distress in late preterms compared to term infants

Characteristics and outcomes of respiratory distress among term infants born in a regional setting

INTRODUCTION

Respiratory distress is the leading cause of admission to neonatal units and is a common indication for medical retrieval. Whilst approximately 25% of births in NSW occur in regional centres, there is a paucity of neonatal research in these settings.

OBJECTIVE

To describe the characteristics and outcomes of term neonates admitted with respiratory distress to two regional special care nurseries (SCNs) and identify variables associated with the need for medical retrieval.

DESIGN

We describe a cohort of 629 term infants admitted to the SCN in two regional hospitals, 2015-2019. We describe the admission characteristics, level of respiratory support, biochemical investigations, diagnosis and outcomes.

FINDINGS

During the study period, 629 eligible term infants were admitted, retrieval occurred in 29 (4.6%). Those admitted were more often male (66.5%), with a mean gestational age of 39 + 1 weeks (±9 days) and birth weight of 3470 g (±500 g). Infants requiring medical retrieval had higher PaCO2 on blood gas analysis (59.8 mmHg vs. 53.3 mmHg, OR 1.03, p = 0.02). There was no association between maternal GBS status, meconium-stained liquor, gestational age, or raised inflammatory markers and medical retrieval. Transient tachypnoea of the newborn was the most common diagnosis of neonates admitted to SCN with respiratory distress.

DISCUSSION

Among term infants admitted to a SCN for respiratory distress most were male, of a normal birthweight and born in good condition. Within our cohort there was no association between retrieval and maternal GBS colonisation, meconium-stained liquor or raised infectious biomarkers. Medical retrieval was infrequent and was associated with higher PaCO2 on initial blood gas analysis.

CONCLUSION

We present a large cohort of term newborn infants managed for respiratory distress in a regional setting over a five-year period. Retrieval was infrequent, and outcomes for the cohort were excellent with no deaths during the study period.

Late preterm: a new high risk group in neonatology

Late preterm infants are those infants born between 34 0/7 weeks through 36 6/7 week of gestation. These are physiologically less mature and have limited compensatory responses to the extrauterine environment compared with term infants. Despite their increased risk for morbidity and mortality, late preterm newborns are often cared in the well-baby nurseries of hospital after birth and are discharged from the hospital by 2-3 days of postnatal age. They are usually treated like developmentally mature term infants because many of them are of same birth weight and same size as term infants. There is a steady increase in the late preterm birth rate in last decade because of either maternal, fetal, or placental/uterine causes. There has been shift in the distribution of births from term and post-term toward earlier gestations. Although late preterm infants are the largest subgroup of preterm infants, there has been little research on this group until recently. This is mainly because of labeling them as "near-term". Such infants were being looked upon as "almost mature", and were thought as neonate requiring either no or minimal concern. In the obstetric and pediatric practice, late preterm infants are often considered functionally and developmentally mature and often managed by protocols developed for full-term infants. Thus, limited efforts are taken to prolong pregnancy in cases of preterm labor beyond 34 weeks, moreover after 34 weeks most centers do not administer antenatal prophylactic steroids. These practices are based on previous studies reporting neonatal mortality and morbidity in the late preterm period to be only slightly higher in comparison with term infants and whereas in the current scenario the difference is significant. Late preterm infants have 2-3-fold increased risk of morbidities such as hypothermia, hypoglycemia, delayed lung fluid clearance, respiratory distress, poor feeding, jaundice, sepsis, and readmission rates after initial hospital discharge. This leads to huge impact on the overall health care resources. In this review, we cover various aspects of these late preterm infants like etiology, immediate and long-term outcome.

Impact of neonatal morbidity on the risk of developmental delay in late preterm infants

BACKGROUND

Late preterm infants (LPI) have a higher risk of developmental delay (DD) than term-born infants. The association of perinatal complications with specific morbidity is not clear.

AIM

(1) To compare the risk of DD at 4years of age between LPI who have presence or absence of any morbidity associated with the prematurity at birth, called complicated (cLPI) or uncomplicated (uLPI), and term-born infants, (2) to determine maternal and perinatal factors associated with risk of DD, and (3) to analyze, in LPI, the association between perinatal morbidity and risk of DD.

METHODS

A retrospective cohort study including 163 LPI - 47 cLPI and 116 uLPI - and 158 term-born infants (Terms) was conducted. Parents completed the Ages & Stages Questionnaires®3rd Spanish version (ASQ3). Risk of DD was defined as the presence of any ASQ3 domain scoring below the mean minus 2 SD. Association between risk of DD and maternal and perinatal factors was analysed using a multivariate logistic model. Incidence of risk of DD was analysed according to specific morbidity.

RESULTS

Compared to Terms, cLPI have a higher risk of DD in the communication domain. Respiratory pathology was associated with a higher risk in the communication domain. Caesarean delivery was the only maternal perinatal risk factor for DD, especially in gross motor domain.

CONCLUSIONS

At the age of 4years cLPI, especially those with respiratory morbidity, had a higher risk of communication delay. Caesarean delivery was the only perinatal risk factor associated with risk of DD.