University Park, Pa. -- Children born to teenage mothers who were iron deficient early in their pregnancies were less active at age 3 than the children of iron-sufficient moms, a Penn State study has shown.
"By being less active, the children may be missing out on exploring their environment and, consequently, missing out on opportunities for positive development," said Laura Murray-Kolb, National Institutes of Mental Health postdoctoral fellow in psychology and human development and family studies at Penn State who led the study.
"While many previous studies have shown that maternal nutrition affects the physical health and development of the child, this study adds to the growing evidence that a mother's nutritional status in pregnancy also affects the behavior and personality of the child as well," she added.
The study was detailed in a poster presented Sunday, April 2, at the Experimental Biology conference in San Francisco. The study authors are Murray-Kolb; John L. Beard, professor of nutritional sciences; and Elizabeth Susman, Jean Phillips Shibley professor of biobehavioral health.
Sixty teenage mothers, ages 14 through 19, from a mid-size town in Pennsylvania completed the study. Blood samples collected from the mothers at 16 weeks into their pregnancy showed that the majority, 58 percent, were iron deficient, including 10 percent who were actually anemic.
The mothers came from low to mid-level socio-economic backgrounds and had sought prenatal care. They had all been given iron-containing vitamin supplements by their health-care providers.
Murray-Kolb notes that the high rate of iron deficiency is fairly typical of adolescent women who often experiment with a variety of diets. She notes that the rate of iron deficiency among the women observed early on in pregnancy likely reflects their pre-pregnant iron status.
At the end of their pregnancies, only 7 percent of the study participants were iron-sufficient. Murray-Kolb notes that this very high rate of iron deficiency reflects the high demand that the combination of adolescence and pregnancy place on iron reserves and the fact that compliance with taking their vitamins may not have been high among the study participants.
When the children of the study participants were 3 years old, the mothers were asked to complete two questionnaires about their child's behavior. The answers to the questionnaires indicated that the children of the women who were iron-deficient early in their pregnancies had lower activity levels and were slower at responding to their environment than children of iron-sufficient mothers.
Murray-Kolb noted that her previous research had shown that new mothers who are mildly iron deficient are less emotionally available or in tune with their babies. Earlier Penn State research also had identified a connection between moderate iron deficiency and a slow-down in thinking and memory in women. She notes that the behavioral effects in the 3-year-olds that were observed in this new study could be the result of the mother's less emotionally available behavior toward the child as well as the effects of low iron availability to the child in the womb during early pregnancy.
"The results of this study reinforce the notion that prenatal vitamins are important for the health and well-being of both mother and child," she noted.
The study was supported by a grant from the Institute of Child Health and Development to Susman and Murray-Kolb's postdoctoral fellowship from the National Institute of Mental Health.