Long Term Outcome Of Pemature Babies

Christoph Aring Christoph Aring

Prematurity is a signifikant challenge for parents and doctors. There are significant regional differences in the survival rate of very premature babys born at 22 – 24 weeks of gestation showing the highest survival rates in Japan and the lowest for example in France, speaking of the so-called developed countries.

This stunning difference is explained largely by the different medical approach to extreme prematurity – in Japan it is law to treat premature babies from 22 weeks onward and all available medical and social ressources are provided for the babies and their families, whereas in France and other countries medical treatment is initiated not until completed 24 weeks of gestation. From 24 weeks of gestation onward the survival rates differ far less in these countries. In less well developed countries many deaths of premature babies, whose need for advanced medical support decreases with each week, even day of gestation, could be prevented by a very cheap medical intervention antenatally (cortisone given to the mother before birth) and kangaroo mothers/fathers care after birth (warmth and body contact).

Talking about mortality rates of premature babies is one thing, talking about the overall long term outcome is another. Recent scientific studies have been published which adressed this issue based on observation and testing of former premature babies after up to 20 years.

Chronic lung problems (bronchopulmonary dysplasia) due to immaturity and vulnerability and the resulting need for medical interventions (cortisone, mechanical intervention, oxygen and others) in the first days of life emerge as the most important risk factor not only for long term survival without major health impairment but also for the impaired cognitive development of these children. One study concludes that chronic lung disease accounts for 65% of the lower IQ-results of these children later in life – at school age and afterwards. Another study concludes that prematurity, especially extreme prematurity, causes 10-15% of all cases of lowered cognitive capabilities of childhood. This study adresses the impact of specific medical interventions in early childhood on increasing the prevalence of later intellectual disability. Prematurity in general increases the need for specific medical interventions in early childhood.

Over the many years of neonatal intensive care medicine remarkable advances have been made: the application of surfactant facilitated the survival of more extreme premature children - nowadays a gestational age of 22 completed weeks seems to be the absolute limit of viability, when the lungs have reached the ability for adequate gas exchange. The use of corticoids, surfactant and more sophisticated methods of mechanical ventilation reduced the rate of cerebral palsy significantly, on the other hand the extensive use of corticoids after birth again increased the incidence of later neurological deficits. Despite these encouraging improvements of treatment and resulting survival rates without severe organ dysfunction the prevalence of later intellectual impairment remained more or less unchanged – the more premature, the higher the risk. Unfortunatly the extent of intellectual impairment cannot be disclosed before the child reaches an age, where age-specific intellectual capabilities are needed – a premature born baby that left hospital apparently healthy may be completely normal at 2 year follow-up and may show lower intellectual performance when going to school, may show additional behavioral problems like hyperactivity at age 10y or older, may show psychiatric disorders or may need persistant parental support at older age.

Besides gentle ventilatory treatment, Vitamin A, breastmilk feeding, Coffein, early enteral nutrition, combining cortison with surfactant seem to have a preventive impact. Prenatal factors like high blood pressure of the mother, smoking, pre- and postnatal infections as well as birth small for gestational age seem to increase the risk of later intellectual impairment.

These are the main results of recently published long-term follow-up studies of prematurity.

If you are shocked or in dispair reading this: consider that a premature baby is a wonderful human being, that it comes into our world through you, that prematurity most often happens by fate and that there are still some effective possibilities to diminish the long-term sequelae of prematurity of which I shall tell you soon.