Introduction
The World Health Organization defines a preterm birth as a birth that occurs before 37 weeks or 259 days gestation (Beck, Wojdyla, Say, Betran et al., 2010). Worldwide, the majority of preterm births occur in Africa and Asia, but the highest percentages of preterm births (preterm births as a percentage of all births) occur in North America. Almost half of preterm births are idiopathic (no known cause), 15 - 20 % are due to medical decisions or are elective (probably adding to the higher percentage of preterm births in North America), and about 30% are due to the rupture of preterm membranes. Of all early neonatal death rate causes, preterm birth accounts for about 28% of deaths not due to some type of congenital malformation (Beck et al., 2010). Low birth weight, sensory and motor problems, and cognitive problems are associated with preterm births.
Although preterm and low birth weight babies are born in all socioeconomic levels, the rates are highest among impoverished mothers and especially among members of ethnic minority groups (Beck et al., 2010). The effects of preterm births are compounded by the difficulties these caregivers experience in helping their children attain normal levels of health and to develop at a normal rate. Often the caregivers of preterm children live in less protective environments and have limited access to the medical and social support services and intervention programs that are aimed at reducing the negative and long-term consequences of premature births (Beck et al., 2010; Sagial & Doyle, 2008).
Preterm births are exceptional among all of the different adverse outcomes that can occur during pregnancy because they are determined by a time span and are not tied to any particular etiology or specific pathophysiology.
If an infant is born preterm, the actual physical signs displayed are often in reverse proportion to the child’s gestational age, which would be expected as preterm development occurs along a fairly predictable timeline. Thus, the research has indicated that there is little doubt concerning the notion that a child’s gestational age is the most significant factor accounting for the utmost influence on later outcomes that are associated with preterm births. In the 1970’s, prior to the prevalent use of hospital assisted ventilation for preterm infants, there were very few babies that survived if they were born before 28 weeks of gestation. However, with the earlier and increasing use of assisted ventilation, antenatal corticosteroids, and pulmonary surfactant as well as changing attitudes by both parents and physicians regarding the use of intensive care for preterm infants the survival rates for infants of very preterm births, particularly infants born before 28 weeks gestation, improved markedly during the mid-1990s (Saigal & Doyle, 2007). Even though preterm births at 32–36 weeks of gestation are actually five times more frequent than births before 32 weeks of gestation, their public health effects are not well documented. Moreover, in the United States in 2003 12.3% of the births were preterm. This is concerning because since 1981 the records indicate that there has been a 31% rise in the United States preterm birth. Two-thirds of these births were late preterm births defined as occurring between 34–36 weeks of gestation (Beck et al., 2010).
Therefore depending on the age of the preterm infant they are at risk for many different types of medical problems that can affect different organ systems. Preterm children have been shown to have significantly higher proportions of sensory deficits, cerebral palsy, learning disabilities, and other illnesses compared to children who are born at full term. The morbidity that is associated with preterm births will often extend well into the child’s later life. This can lead to massive physical and psychological effects on the child and family and enormous economic costs for both the family and society (Saigal & Doyle, 2008). In 2005 estimates that the total costs to the United States of the complications of preterm births with respect to medical, educational, and estimated loss of productivity were more than 26.2 billion dollars (Beck, et al., 2010).
Click here for Part II: Medical Issues Associated with Preterm Births
Rudy Hatfield - I am a clinical neuropsychologist with extensive experience in the assessment and treatment of neurological and psychiatric disorders. I ...
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