A baby’s delivery weight is an important risk factor of infant mortality and childhood development disorders. That being the case, the prevailing wisdom has been that "bigger is better".
Now, researchers have determined baby's birth weight can also be an important determinate in the mother’s own health later on.
New mothers who give birth to large babies are more likely to get breast cancer in the future, University of Texas Medical Branch at Galveston researchers found.
Researchers believe delivering a baby’s whose birth weight is 8.25 pounds or larger increases the mother’s hormone production, and as a result creates a kind of "cancer incubator" that favors future breast cancer and progression.
“This means that they [the mothers] have high levels of estrogen, low levels of anti-estrogen and the presence of free insulin-like growth factors associated with breast cancer development and progression," said lead author Dr. Radek Bukowski, professor of obstetrics and gynecology in the Division of Maternal-Fetal Medicine.
Dr. Bukowski suggested breastfeeding, having more than one child, following a healthy diet high in fruits, vegetables and grains and regularly exercising, have been generally shown to reduce overall breast cancer risk.
"Women can't alter their pregnancy hormones, but [they] can take steps to increase their general protection against breast cancer,” he said.
Researchers have known that an association existed between giving birth to a chubby baby and the mother’s future breast health.
Previous studies, such as the famous Framingham Offspring Birth History Study and others, have looked at generations of women and pointed to such correlations.
Approximately 7.6 percent of the women from the Framingham cohort, who also participated in this study, were later diagnosed with breast cancer.
But Dr. Bukowski and his team wanted to know if this association existed independent of other breast cancer risk factors, such as the mother’s age, race, current weight, if she had ever used hormone replacement therapy or had diabetes.
In the Framingham study, the mother's own birth weight was found to be a determining factor.