Birthweight and placenta

The weight and shape of the placenta along with the baby’s birth weight are important measurements of how well the baby developed in the womb. The size and shape of the placenta are affected by environmental exposures the mother faces during pregnancy. Access to quality foods and a well-balanced diet, exposure to toxic stress and certain environmental chemicals all play a role in the development of the placenta.  The placenta serves as both protection and a nutritional provider for the developing baby. For mothers who lack access to quality food, the placenta increases in size in order to better protect the fetus and to better extract nutrients.

The circulation within the placenta is central to uterine and umbilical blood flows, is therefore an important player for the success of pregnancy. The foods the mother is able to eat during pregnancy will determine how well the placenta is able to transport nutrients and oxygen to the developing baby.

One extreme example is of children born after their mothers experienced famine conditions during pregnancy. When limited in nutrition access, the placenta increases in size to better absorb nutrients from the mother’s diet.  A larger placenta can better transfer nutrients and, for example, support brain growth; however, this diverted blood supply can threaten the development of other organs.  The developing organs that receive less blood within the womb are at a greater risk of developing a chronic disease later in life.  This increase in placental growth impacts future development.  Additionally, the placenta requires nutrition itself, and with its increased size some of the nutrition meant for the fetus will be used to sustain its larger size

While large placentas have been found to be associated with greater risk of chronic disease, small placentas and small or thin infants, indicate malnourishment and lack of oxygen supply during development in the womb. These are also associated with increased risk of later life chronic disease

Barker, & Thornburg. (2013). Placental programming of chronic diseases, cancer and lifespan: A review. Placenta, 34(10), 841-845.

Barker, D., Osmond, C., Thornburg, K., Kajantie, E., & Eriksson, J. (2013). The shape of the placental surface at birth and colorectal cancer in later life. American Journal of Human Biology, 25(4), 566-568.

Lane, R. (2014). Fetal programming, epigenetics, and adult onset disease. Clinics in Perinatology, 41(4), 815-831.

Chavatte-Palmer, P., Tarrade, A., & Rousseau-Ralliard, D. (2016). Diet before and during Pregnancy and Offspring Health: The Importance of Animal Models and What Can Be Learned from Them. International Journal of Environmental Research and Public Health,13(6), 586.

Tegethoff, M., Greene, N., Olsen, J., Schaffner, E., & Meinlschmidt, G. (2011). Stress during Pregnancy and Offspring Pediatric Disease: A National Cohort Study. Environmental Health Perspectives,119(11), 1647-1652.