The Meaning of Premature
While there is no single definition of the term, Katz et al. (2013) consider "premature" as something that happens too soon, especially prior to its suitable or natural time. In childhood development, Cook & Cook (2014), state that a premature birth is one that occurs more than three weeks prior to the estimated delivery date (EDD). Naturally, the gestation period for a mature baby is 36 weeks (Cook & Cook, 2014). Therefore, any baby born before the onset of the 37th week of pregnancy is premature (Cook & Cook, 2014). Naturally, premature births pose great dangers to both the mother and the baby.
As earlier stated, any birth that occurs within 37 weeks after conception or more than three weeks before the expected due date is a preterm birth.
Low Birth Weight
The term "low birth weight" is used to refer to a baby who weighs less than 2.5 kilograms at birth. On average, most babies weigh about 3.6 kilograms at birth, therefore, one weighing less than 2.5kgs has low birth weight. Notably, the number of babies with low birth weight has drastically increased in the U.S. 5.8% of newborns in the United States have low birth weight (Katz et al., 2013).
Very Low Birth Weight
One of the categories of low birth weight is very low birth weight (VLBW), which refers to babies born weighing less than 3 pounds 5 ounces or 1.5 kilograms (Katz et al., 2013). The other category is extremely low birth weight (ELBW) which is for babies weighing less than 1 kilogram at birth (Katz et al., 2013).
Small for Gestational Age
Small for gestation age (SGA) is a terminology for babies who are smaller than what is expected for babies in a similar gestation age. These babies may be shorter or weigh below the10th percentile compared to their peers in the same gestation age. For instance, at 30 weeks, a normal baby should be about 15.71 inches and 2.91 pounds (Katz et al., 2013). However, a zygote small for gestation age will be about 13.5 inches and 2.00 pounds in weight (Katz et al., 2013).
Risk Factors for Preterm Birth and Low Birth Weight
There are numerous factors that can cause preterm births and low birth weight among babies. These include race, mother's age, and mother's health. Firstly, studies have shown that the risk for preterm birth and low birth weight is twice as high among African-Americans as in Caucasians ((Katz et al., 2013). Secondly, young mothers, especially those below 15 years of age are at higher risk of preterm births ((Katz et al., 2013). Thirdly, multiple births such as twins or triplets further increase the risk. Finally, mothers who are exposed to cigarettes, alcohol, and illicit drugs are more likely to have preterm births and low weight births compared to their peers who live healthy lifestyles and regularly seek prenatal care.
Cook, J., L. & Cook, G. (2014). The world of children. London: Pearson Education.
Katz, J., Lee, A. C., Kozuki, N., Lawn, J. E., Cousens, S., Blencowe, H. & Adair, L. (2013). Mortality risk in preterm and small-for-gestational-age infants in low-income and middle-income countries: a pooled country analysis. The Lancet, 382(9890), 417-425.