A baby born before 37 completed weeks of pregnancy is preterm. WHO describes preterm birth as a major global health issue and the leading cause of death among children under 5. Outcomes vary widely according to gestational age, health needs and access to effective care.
Preterm birth is not one uniform condition. Families may hear the same broad term used for babies born at very different stages, so the gestational-age category and the baby’s clinical condition matter.
How does WHO group preterm birth?
WHO uses three gestational-age categories: extremely preterm, before 28 weeks; very preterm, from 28 to less than 32 weeks; and moderate to late preterm, from 32 to 37 weeks. Babies may face different problems and require different levels of support within and across these groups.
These categories describe timing, not a guaranteed outcome. Birth weight, infection, breathing, feeding, congenital conditions, available neonatal care and other factors also affect an individual baby.
How common is preterm birth?
WHO estimates that 13.4 million babies were born preterm in 2020, more than 1 in 10 births. Estimated rates across countries ranged from 4% to 16%. Complications of preterm birth caused about 900,000 deaths in 2019.
WHO also states that three-quarters of these deaths could be prevented with current, cost-effective interventions. These figures describe populations; they cannot calculate a particular baby’s chance of survival or disability.
Why are survival differences so large?
WHO highlights a major inequality in access to care. In low-income settings, about half of babies born at or below 32 weeks die because feasible care is often unavailable. In high-income countries, almost all babies born at that gestation survive.
WHO also notes that use of technology may be suboptimal in some middle-income settings, increasing disability among preterm babies who survive the neonatal period. Skilled care, warmth, feeding support, infection management and safe respiratory support can all influence outcomes.
Why does preterm birth happen?
Preterm birth may occur spontaneously, or clinicians may recommend early induction of labour or caesarean birth for medical reasons. WHO lists multiple pregnancy, infection and chronic conditions such as diabetes and high blood pressure among common causes. Often, however, no cause is identified.
Because causes differ and may overlap, families should not assume that one action explains the birth. Clinical review can address medical questions, while emotional support can help parents who are coping with uncertainty or self-blame.
What does WHO say about antenatal care?
WHO identifies quality care before, between and during pregnancy as part of prevention. Its antenatal-care guidance includes counselling on a healthy diet and optimal nutrition, and on tobacco and substance use. It recommends an early ultrasound to help determine gestational age and identify multiple pregnancy.
WHO also recommends at least eight contacts with health professionals during pregnancy, beginning before 12 weeks. These contacts create opportunities to identify and manage risk factors and complications. The exact care plan belongs with the person’s maternity team.
What care can improve outcomes when early birth is likely?
WHO describes interventions that health professionals may use when preterm birth is imminent, including antenatal corticosteroids under defined conditions, antibiotics when the membranes have ruptured before labour, and magnesium sulphate for fetal neuroprotection at certain gestational ages. These are clinical interventions with eligibility criteria, timing requirements and possible risks.
They must not be started or requested solely from an article. The obstetric and neonatal team considers gestational age, infection, the mother’s condition and available newborn care.
What care does WHO describe after birth?
WHO recommends essential newborn care for every baby, including thermal care, support for breastfeeding, and infection prevention and management. For preterm or low-birth-weight babies, recommendations include kangaroo mother care, early breast milk feeding, continuous positive airway pressure for respiratory distress syndrome and medicines such as caffeine for breathing pauses when clinically appropriate.
Kangaroo mother care involves prolonged skin-to-skin contact with a parent or caregiver and feeding with breast milk. WHO recommends starting it immediately after birth for preterm or low-birth-weight babies unless the baby is critically ill and cannot receive it safely.
Should parents and babies remain together?
WHO emphasizes keeping mother and baby together from birth and caring for them as a unit whenever possible. Separation should occur only when the baby is critically ill. Family involvement, education and support are part of good care.
A neonatal unit may still need equipment, monitoring and procedures around the baby. Staff can explain how parents can participate safely through touch, skin-to-skin care, feeding or comfort according to the baby’s condition.
What may happen after discharge?
Some preterm babies need follow-up for feeding, growth, development, vision, hearing or respiratory concerns. Needs vary, and a discharge plan should state medicines, feeding arrangements, follow-up appointments and who to contact if concerns arise.
Seek urgent care for breathing difficulty, blue or grey colour, seizure, marked difficulty waking, inability to feed, or another sign of serious illness. Families should also follow the neonatal team’s specific instructions because very young or medically complex babies may need assessment for subtler changes.
What is the main message for families?
Gestational age is useful, but it is only part of the picture. Evidence-based maternity and newborn care, family participation and access to follow-up can substantially affect outcomes. Ask the care team to explain the baby’s current needs and plan in plain language.
References
- World Health Organization. Preterm birth. Source reviewed 4 October 2026.