A preterm infant is formally defined as any baby born alive before 37 completed weeks of gestation are reached, calculated from the first day of the mother's last normal menstrual period. In busy Nigerian maternity units where mothers frequently present without dating scans or uncertain menstrual dates, midwives rely on alternative clinical tools. The New Ballard Score or the older Dubowitz examination can be performed within the first few days of life to estimate physical and neurological maturity. Additionally, early booking ultrasound scans done before 20 weeks remain the absolute gold standard for dating, though many women in resource-constrained settings book late. Misclassifying a term infant as preterm skews local statistics, just as missing true prematurity delays vital surveillance for organ immaturity.
Preterm birth is further sub-divided based on gestational age, because survival rates and physiological challenges change drastically with every week gained inside the womb:
Late preterm babies represent the largest volume of preterm admissions in most Nigerian tertiary hospitals. Midwives must remain vigilant with late preterm infants because they often look deceivingly mature and robust, yet they share many physiological vulnerabilities with smaller babies, particularly regarding feeding coordination and temperature control.
Preterm births occur via two main pathways: spontaneous onset following preterm labor or preterm premature rupture of membranes (PPROM), and provider-initiated delivery due to maternal or fetal medical complications. In Nigerian obstetric populations, a significant driver of spontaneous preterm birth is untreated reproductive tract infections, such as bacterial vaginosis and malaria in pregnancy. Provider-initiated deliveries often stem from severe conditions like pregnancy-induced hypertension, pre-eclampsia, and severe antepartum hemorrhage from placenta previa or abruptio placentae. Midwives play a key preventive role by treating urinary and genital infections early during routine antenatal clinic visits and monitoring blood pressure meticulously.
The extrauterine survival of a preterm infant is limited by the structural and functional immaturity of multiple organ systems:
Preterm newborns lose heat rapidly because they possess minimal subcutaneous fat, lack mature brown adipose tissue, have a large surface-area-to-weight ratio, and cannot mount an effective shivering response. Hypothermia in a preterm infant triggers hypoglycemia, metabolic acidosis, and pulmonary vasoconstriction, which worsens respiratory distress. Midwives must enforce the warm chain immediately upon delivery: drying the baby instantly with warm towels, discarding wet linen, placing the infant on skin-to-skin contact with the mother if stable, or utilizing a pre-warmed radiant warmer during emergency resuscitation. In resource-limited Nigerian delivery suites, avoiding drafts and using caps and socks are non-negotiable life-saving measures.
Kangaroo Mother Care (KMC) is a proven, cost-effective intervention consisting of continuous skin-to-skin contact between the mother and her preterm or low birth weight infant, exclusive breastfeeding, and early discharge. KMC stabilizes the infant's heart rate, normalizes body temperature just as effectively as an incubator, promotes bonding, and significantly reduces severe infections and mortality in low-resource settings. The infant is dressed only in a diaper, cap, and socks, and positioned upright between the mother's breasts in a sling or wrapper. Midwives play a crucial role in educating mothers and family members on proper positioning, breathing monitoring, and recognizing danger signs while practicing KMC.
Midwives must maintain high clinical suspicion for complications that threaten preterm infants during the first weeks of life. Neonatal sepsis presents subtly in preterms; instead of a classic fever, the baby may show temperature instability, lethargy, poor suck reflex, and abdominal distension. Jaundice requires prompt monitoring using visual inspection or a bilirubinometer, with phototherapy initiated before kernicterus develops. Apnea of prematurity—pauses in breathing lasting longer than 20 seconds accompanied by bradycardia—responds well to gentle tactile stimulation or prescribed oral caffeine citrate. Early recognition and immediate escalation of care save lives.