Birthweight & Gestation

Singletons

Low birthweight is a major determinant of infant mortality and morbidity. In addition, as it is associated with a variety of social and environmental factors, it is often used as a health status indicator. Low birthweight  may result from being born too soon (i.e. a preterm birth), from poor intratuterine growth or from a combination of the two. For more information on outcomes for these groups of babies see  Small Babies in Scotland .

A number of factors have been shown to be associated with low birthweight and/or preterm births. These include maternal smoking, maternal age (older and younger mothers are more likely to have a low birthweight baby), deprivation, previous obstetric history, low pre-pregnancy maternal weight, drug/alcohol use, hypertension and multiple births. Information on some of these factors is also recorded, and available on these web pages: maternal age; smoking at booking and maternal smoking recorded at public health nurse/health visitor's First Visit.  These show trends in opposing directions: the increase in the proportion of babies born to older mothers would tend to produce an increase in proportion of low birthweight babies. However, the decrease in maternal smoking, and in the proportion of babies born to younger mothers (under 25 years) would tend to produce a decrease in the proportion of low birthweight babies.

The chart below shows trends in the proportions of babies born of low (1500-2499g) and very low (under 1500g) birthweight at full term (at or after 37 weeks gestation) and pre-term (before 37 weeks gestation) for singleton births.

Click below for related data:

• Live Birth by Birthweight and Gestation Groups  [707KB]
• All Births by term and Birthweight Categories  [140KB]
• Live Births by Birthweight and Deprivation Category  [640KB]