Neonatal Outcome of the Late Preterm Infant (34 to 36 Weeks): The Singapore Story

Abstract

Introduction: Late preterm (LP) neonates (34 to 36 weeks gestation) are often managed like term neonates though current literature has identified them to have greater complications. The primary objective of our study was to evaluate and compare morbidity and resource utilisation in LPs especially in view of paucity of Asian studies in this regard. Materials and Methods: A retrospective audit was carried out on 12,459 neonates born in KK Women’s and Children’s Hospital (KKWCH). The chief outcome measures were hypoglycaemia, hypothermia, respiratory morbidity, feeding problems and neonatal jaundice. Resource utilisation included neonatal intensive care unit (NICU) admission, mechanical ventilation, parenteral nutrition and length of hospitalisation. Results: Of 12,459 deliveries, 1221 (10%) were LP deliveries with a significantly increasing trend of 8.6% to 10% from 2002 to 2008 (P = 0.001). Neonatal morbidity in the form of hypoglycaemia (34 weeks vs 35 to 36 weeks vs term: 26% vs 16% vs 1%); hypothermia (5% vs 1.7% vs 0.2%); feeding difficulties (30% vs 9% vs 1.4%); respiratory distress syndrome (RDS) (4% vs 1% vs 0.1%); transient tachypnea of the newborn (TTNB) (23% vs 8% vs 3%) and neonatal jaundice (NNJ) needing phototherapy (63% vs 24% vs 8%), were significantly different between the 3 groups, with highest incidence in 34-week-old infants. Resource utilisation including intermittent positive pressure ventilation (IPPV) (15% vs 3.5% vs 1%), total parenteral nutrition/intravenous (TPN/IV) (53% vs 17% vs 3%) and length of stay (14 ± 22 days vs 4 ± 4.7 days vs 2.6 ± 3.9 days) was also significantly higher (P <0.001) in LPs. Conclusion: LP neonates had significantly higher morbidity and resource utilisation compared to term infants. Among the LP group, 34-week-old infants had greater complications compared to infants born at 35 to 36 weeks. Key words: Morbidity, Mortality, Respiratory distress syndrome, Total parenteral nutrition

Feeding the Late and Moderately Preterm Infant

“…LPT infants have significantly more medical problems and are more likely to require specific medical support including intravenous infusions than term infants (26.7% vs 5.3%; OR: 6.48; 95% CI 2.27-22.91; P ¼ .0007) (23), resulting in a significantly longer duration of hospital stay compared with term infants (16,18,68). Furthermore, resource utilization including total parenteral nutrition (PN)/intravenous support (53% vs 17% vs 3%) and length of stay (14 AE 22 vs 4 AE 4.7 vs 2.6 AE 3.9 days) is significantly higher (P < 0.001) in MPT infants versus LPT and term infants (9).…”

“…Feeding difficulties are the primary reason for prolonged hospital admission of LPT infants and up to 3/4 of LPT infants require feeding support (46). These feeding difficulties are related to gestational age being more frequent in infants born at 34 weeks compared with those born at 35-36 weeks of gestation (30% vs 9%) (9). This is related to immaturity of multiple physiological processes including cardiorespiratory instability, metabolic disturbances, immaturity of state regulation, uncoordinated suck, swallow, breathe organization, and decreased oromotor tone (46,47).…”

“…Within the group of LMPT, those born at a lower gestational age are more likely to receive PN/intravenous support than those born at a higher gestational age (9,74,75). The need for central venous access remains a controversial issue in the nutritional care of LMPT infants.…”

“…The incidence of early hypoglycaemia (within the first 12 hours of life) was 3 to 4 times greater in the LPT infants as in the term infants, with 1 of 3 experiencing recurrent episodes of hypoglycaemia (22). The rate of hypoglycaemia ranged from 16 to 34% and was associated with lower GAs (9,22,23), the risk being further increased in infants born at 34 weeks compared with those born at 35 to 36 weeks of gestation (9,24). In a large retrospective cohort study from Australia, including 735 LMPT infants, the rate of hypoglycaemia was similar to the rates found in LPT infants: 22% in the LMPT appropriate for gestational age (AGA) infants, increasing to 32% in the LMPT small for gestational age (SGA) infants (25).…”

“…The incidence of preterm birth in different countries varies widely (5) as does that of LMPT infants with a rate less than 4% in Scandinavia and up to 10% in Korea (6–9). Interestingly, when moderate‐ and late‐preterm are combined, the LMPT population represents more than 80% of all preterm births and consume about one‐third of all hospital expenditures related to prematurity (10,11).…”