After British researchers had studied birth records of more than 36,000 babies born in the north of the City of Birmingham for the period of four years, they discovered that dark skinned and colored women were more liable to have preterm delivery and birth of premature babies than white women. Three thousand births, meaning, 8 percent of premature infants, who were born at least three weeks ahead of their due birth date, were from mothers of African origins.

　　After determining factors of age and social status of mothers, researchers found that 22 percent of African women are more liable to give birth before the duration of pregnancy (which is almost 37 weeks) is complete; 78 percent give birth before the thirty-fourth week of pregnancy; ladies who give birth to premature babies before 28 weeks of pregnancy are fourfold.

　　The researchers, according to the International Journal of Gynecology & Obstetrics, see that social deprivation represents a factor that increases the danger of preterm delivery. They point out that black children grow faster than their white peers, something that causes shorter-term pregnancies in their mothers.