Size at Birth by Gestational Age

A 2006 study created growth curves and tables for length, weight, and head circumference at birth for Jamaican children (30-43 weeks gestation; 1).

The authors measured ~10,500 infants born in Jamaica in September and October 1986, or ~94% of all births on the island during the period. The vast majority of the infants were of West African descent: the authors estimated that 94% were in this group, with 7% being of mixed African descent, and less than 0.5% being Caucasian.

Sickle Cell Disease

Sickle Cell Disease is the name for a group of blood diseases that affect hemoglobin. Hemoglobin is a molecule in blood cells that carries oxygen. As blood moves through the body, hemoglobin releases oxygen and delivers it to muscles, the brain, and all tissues of the body. People with sickle cell disease have abnormally shaped hemoglobin molecules. This problem distorts their red blood cells, which can become sickle (crescent)-shaped.

Children with sickle cell disease tend to get more infections than other children, and they also grow more slowly. Puberty and growth spurts occur later, but adult height is usually normal. They often have anemia because their red blood cells break down quickly. Children with anemia can be short of breath and tired. Another problem is that sickle-shaped blood cells can get stuck inside blood vessels, a situation that leads to impaired circulation, oxygen deprivation, pain, and organ damage. The Mayo Clinic has information about managing sickle cell disease.

The curves here were made from a longitudinal study of 315 Jamaican infants and children with sickle cell disease. All children had been born at the Victoria Jubilee Hospital in Kingston between 1973 and 1981. They all attended the sickle cell clinic of the University of the West Indies. The weight curves here are based on non-smoothed data.

References

1. 1. Samms-Vaughan M et al. (2006) Growth curves for normal Jamaican neonates. West Indian Med 32(5):368-374. Full text on ResearchGate.
2. 2. Thomas PW et al. (2000) Height and weight reference curves for homozygous sickle cell disease. Arch Dis Child 82(5):3204-3208. Full text on PubMed.