The transition from intra to extra-uterine life in late preterm infant: a single-center study

De Carolis et al. Italian Journal of Pediatrics (2016) 42:87 DOI 10.1186/s13052-016-0293-0 RESEARCH Open Access The transition from intra to extra-uterine life in late preterm infant: a single-center study M. P. De Carolis1*, G. Pinna1, C. Cocca1, S. A. Rubortone1, C. Romagnoli1, I. Bersani1, S. Salvi2, A. Lanzone2 and S. De Carolis2 Abstract Background: Infants born at 34 to 36 weeks of gestation (late preterm) are at greater risk for adverse outcomes than those born at 37 weeks of gestation or later. Aim of this paper is to examine risk factors for late preterm births and to investigate the complications of the transition period in late preterm infants (LPIs). Methods: All consecutive late preterm deliveries, excluded stillbirths, were included. Maternal and neonatal data, need for delivery room resuscitative procedures, temperature at birth (T1) and two hours after the admission (T2) were analyzed in all LPIs stratified by Gestational Age (GA) and divided into three groups (34, 35 and 36 weeks). Results: Two hundred seventy-six LPIs were analyzed. Pregnancy complications were present in 72 mothers (26. 1 %), more frequently at 34 weeks of gestation respect to 35 and 36 weeks (p = 0.008, p = 0.006 respectively). Forty seven LPIs (17.1 %) needed for any resuscitation and 37 (13.4 %) were ventilated at birth. LPIs at 34 weeks were significantly more likely to receive ventilation respect to those at 35 and 36. At T1 the mean temperature resulted lower at 34 weeks respect to 36 weeks (p = 0.03). At T2 respect to T1, the rate of normothermic neonates increased at 35 and 36 weeks (p = 0.003, p = 0.005, respectively). Hypoglicemia rate was similar among the groups; 66.7 % of hypoglicemic neonates were hypothermic at T1. The rate of respiratory diseases and NICU admission decreased with increasing GA. Higher number of neonates ventilated at birth developed respiratory disorders respect to those unventilated (40.5 % vs 8.4 %; p < 0.001). Conclusions: Transition period in LPIs may become critical, as resuscitation strategies can be required and heat loss can occur. LPIs, especially at 34 gestational weeks, are higher-risk group needing adequate and targeted management at birth. Keywords: Late preterm infant, Transition, Birth, Cardiopulmonary resuscitation, Thermoregulation Background The fetal-to-neonatal transition at birth is characterized by major physiological changes in respiratory and hemodynamic function and in thermoregulation [1]. Late preterm infants (LPIs), defined as neonates born between 340/7 and 366/7 weeks of gestation [2], are physiologically and metabolically immature at birth, and can be lacking of the self-regulatory ability to appropriately * Correspondence: 1 Department of Paediatrics, Division of Neonatology, Catholic University of Sacred Heart, Universitary Hospital A. Gemelli, Largo Gemelli 8, 00168 Rome, Italy Full list of author information is available at the end of the article respond to the extra-uterine environment. Despite being considered as “near term”, LPIs have higher rates of morbidity and mortality respect to term neonates [3]. Specifically, hypothermia and respiratory morbidity have been found to be more common in this group compared with term neonates [4]. It is reported that LPIs may experience delayed or inadequate transition to the extra-uterine environment [5] and are considered at higher risk for developing respiratory distress [6]. The aim of the present study was to evaluate maternal risk factors for late preterm (LP) delivery and to investigate the complications during transition period in LPIs, © 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. De Carolis et al. Italian Journal of Pediatrics (2016) 42:87 particularly by evaluating the need for resuscitation and the risk of hypothermia. Methods A retrospective study of all the consecutive LP deliveries, identified from perinatal data base of the University Hospital “A.Gemelli”, Rome, Italy, from January 1 to December 31, 2013 was conducted. Maternal and neonatal informations were collected from medical records. The approval of the Ethics Committee of our Institution was obtained. Pregnancies complicated by stillbirths were excluded. The following maternal and obstetric factors were evaluated: age, ethnicity, parity, type of pregnancy (singleton or multiple gestations), pre-existing medical conditions, pregnancy complications, presence of labour, delivery mode and reasons for C-section [7], administration of antenatal steroid (ANCS) therapy. The pre-existing medical conditions considered were autoimmune, cardiovascular, infectious and neurological diseases, thyroid disorders, cancer, hematological conditions or thrombosis. Pregnancy complications included were: diabetes (gestational diabetes and diabetes types 1 and 2), hypertensive disorders (gestational hypertension and preeclampsia) [8] and intrahepatic cholestasis. Intrauterine growth restriction (IUGR) was defined as an estimated fetal weight < the 10th percentile for the gestational age (GA). ANCS therapy was considered when a complete course, consisting of two doses of 12 mg betamethasone 24-h apart, was administered. At the time of delivery, the presence of preterm premature rupture of membranes (pPROM), defined as rupture of membranes occurring before the onset of labour, spontaneous labour, defined by presence of uterine contractions leading to delivery, and placental accidents, including placental abruption and placenta praevia, were evaluated. Neonatal variables included: GA, birth weight (BW), small for gestational age (SGA) defined as BW < the 10th percentile, gender and presence of major malformations. GA was determined according to first-trimester crown– rump length. From the delivery room (DR), informations regarding the neonatal status at birth were recorded including the resuscitative procedure carried out according to the American Academy of Pediatrics guidelines [9]. Initial ventilation was provided with the NeoPuff device (Fisher & Paykel Healthcare Inc, Irvine, CA), by mask or endotracheal tube. Measurement of body temperature was performed, as part of routine quality assurance processes, at birth (T1) and two hours after the admission (T2). Measures to reduce the risk of hypothermia were adopted in all LPIs in DR [10]. Temperatures were classified as: Page 2 of 7 hyperthermia (>37.5°C), normothermia (36.5–37.5 °C), mild hypothermia (36.0–36.4 ° (...truncated)