Understanding Prematurity in Infants

Prematurity

• Preterm infants are live births before 37 completed weeks from the first day of the LNMP.
• Prematurity is different from poor intrauterine growth (IUGR), but both can result in low birth weight infants and increased neonatal morbidity and mortality.
• Preterm infants are categorised into extremely preterm (<28 weeks GA), very preterm (28 to <32 weeks GA), moderate preterm (32 to <34 weeks GA), and late preterm (34 to <37 weeks GA).
• Preterm infants might be born with low birth weight (LBW, <2.5kg), very low birth weight (VLBW, <1.5kg), or extremely low birth weight (ELBW, <1kg).

Introduction to Prematurity

• Prematurity is a leading cause of death in children younger than 5 years globally.
• Approximately 15 million babies were born premature in 2018, which is 1 in 10 babies.
• Over 60% of global preterm births occur in Africa and South Asia.
• Nigeria has the third-highest number of preterm births globally, following India and China.
• Approximately 1 million babies die due to complications of preterm birth.
• Those who survive prematurity can experience lifetime disabilities such as visual, hearing, and learning disabilities.
• Survival is greatly related to birth weight.
• There are stark inequalities in preterm baby survival rates worldwide.
• Half of babies born below 32 weeks die in low-income settings; however, almost all survive in high-income settings.
• 90% of premature babies born in low-income settings die, while less than 10% of those born in high-income settings die.
• In Nigeria, prematurity accounts for 80% of the NMR.
• A positive correlation exists between prematurity and IUGR.

Intrauterine Growth Restriction (IUGR)

• IUGR occurs due to medical conditions that affect circulation and the efficiency of the placenta, which affects the growth of the fetus.
• It can be caused by conditions affecting the general health and nutrition of the mother.
• IUGR has connections with decreased inulin production and/or a decreased response to insulin-like growth factors (IGF) at the receptor level.
• It can be a natural response to fetal nutritional or oxygen deprivation.
• IUGR can be symmetric or asymmetric.
• Symmetric IUGR usually affects fetal cell number and anthropometry equally impacting head circumference, length, and weight.
• Asymmetric IUGR often occurs late in gestation with usually brain growth and OFC preserved
• Risk factors for IUGR involve fetal factors (chromosomal abnormality, intrauterine infection, multiple gestation, IGF deficiency), placental factors (abruptio placentae, villous placentitis, twin-twin transfusion), and maternal factors (toxemia, sickle cell, malnutrition, hypertension, CKD, narcotics).

Aetiology

• Prematurity occurs for a variety of reasons with many preterm births occurring spontaneously and idiopathic.
• Some follow early induction or Caesarean sections for medical and non-medical reasons.
• The increased incidence in preterm births has followed infertility treatments with IVF in mothers of increasing maternal ages, resulting in multiple gestations, and with improved NICU care abroad.
• Recognised causes also include fetal, placental, or maternal factors:
  • Placental: placenta previa, placenta abruption, placenta insufficiency, chorioamnionitis, villous placentitis.
  • Fetal: multiple gestation, genetic abnormalities, erythroblastosis, non-immune hydrops.
  • Maternal: infections (diarrhoeal dx, UTI), PROM, pre-eclampsia, uterine anomalies (bicornate uterus, incompetent cervix), chronic dx, extremes of emotions, drug abuse, under nutrition.
• Low socioeconomic families experience higher rates of preterm deliveries, connected with maternal nutritional anaemia, inadequate ANC, obstetric factors, teenage parents, and short birth intervals.

Problems with Prematurity

• The occurrences and severeness of prematurity problems directly relates to the extent of the prematurity.
• These problems are multisystemic, resulting from immature fetal organs or complicating treatment, or because of the conditions that triggered the labour and/or delivery.
• Respiratory issues:
  • Respiratory distress syndrome(RDS)
  • Bronchopulmonary dysplasia
  • Apnoea
  • Pulmonary hypoplasia
  • Congenital pneumonia
• Cardiovascular conditions:
  • Patent Ductus Arteriosus (PDA)
  • Bradycardia
  • Hypotension
• Haematological occurrences:
  • Anaemia of prematurity
  • Disseminated Intravascular Coagulation (DIC)
  • Hydrops fetalis
  • Hyperbilirubinemia
• Digestive conditions:
  • Necrotizing enterocolitis(NEC)
  • Spontaneous GI perforations
  • Poor suck
  • Poor gut motility
• Endocrine/Metabolic conditions:
  • Hypoglycaemia
  • Hypocalcaemia
  • Metabolic acidosis
  • Hypothermia
• Central nervous system conditions:
  • Intraventricular haemorrhage(IVH)
  • Periventricular leucomalacia
  • Hypoxic-ischemic encephalopathy (HIE)
  • Retinopathy of prematurity
  • Kernicterus
  • Hypotonia
• Renal conditions:
  • Renal tubular acidosis(RTA)
  • Hyponatremia
  • Hyperkalaemia
• Other issues:
  • Increased susceptibility to infections
  • Higher incidence of congenital malformations(PDA)
  • Hernias

Management of Prematurity

• Resuscitation must begin at birth, with a paediatrician or trained individual in neonatal resuscitation present at delivery.
• Provide gentle airway clearance, start resuscitation, and perform ventilation through Continuous Positive Airway Pressure (CPAP).
• Use a paediatric ventilator if very premature.
• Deliver intra-tracheal surfactant for infants under 32 weeks.
• Provide warmth by cleaning well, use a radiant warmer, and if weight is less than 1.5kg, place in a preheated incubator.
• Practice Kangaroo Mother Care and administer a Ballard score.
• Conduct minimal handling.
• Secure intravenous access through umbilical catheterization.
• Obtain samples for RBS, FBC, serum electrolytes, blood culture, and CRP.
• Start with IVF 10% dextrose free of electrolytes for 2-3 days to provide calories
• Start fluids at 70-80 ml/kg/day, gradually rising to 150 ml/kg/day.
• Begin trophic feeds with EBM cautiously, gradually by a NG-tube or gavage feeding.
• Intravenous antibiotics include:Amoxycillin, Ceftazidime, genticin, vancomycin.
• Intravenous Aminophylline is for apnoea and to prevent diaphragmatic fatigue.
• Use prophylactic phototherapy.
• Attach apnoea, thermal, and O2 saturation monitors.
• Provide quality nursing care.
• Carefully monitor both input and output, weight increase, and occipitofrontal circumference.