Ferritin concentration and pregnancy outcome: linear models for predicting birthweight and birth length

Iron-deficiency anemia can have negative consequences for pregnant women. Previous investigations conducted to explore the association between iron-related components of mothers' serum and the outcome of pregnancy have had diverse results.

This study aimed to investigate the correlation between ferritin concentration (as the index of stored iron) of mothers' serum during the last 24 hours of pregnancy and birth outcome.

Respondents were chosen from the list of all women who had given birth between January 1 and March 30, 2006, in a Rafsanjan county maternal hospital in southeast Iran. The study checklist was completed for 600 to 900 mothers (over a period of 30 days), and about 600 were eligible to participate. Blood samples were taken from 120 eligible women who were randomly selected after they had given their second consent. Data, including birthweight and birth length, were analyzed with SPSS; parametric (t-test, correlation, logistic regression) and nonparametric (chi-square, Mann-Whitney U) tests were used where appropriate.

No significant differences between different groups of respondents were found in birthweight, birth length, or the ferritin concentration of mothers' serum, indicating that the effect of confounder variables (e.g., baby's sex, mother' educational status, mother's age, gestational age, etc.) was controlled successfully. Significant positive correlations were found between the mother's ferritin concentration and the baby's birthweight (r = 0.434, N = 120, p < .001) and birth length (r = 0.396, N=120, p < .001). Linear models revealed that the ferritin concentration of mothers' serum during the last 24 hours of pregnancy could be suitable to predict both birthweight and birth length.

This study confirms that provision of sufficient amounts of iron-related components to pregnant women is necessary to improve pregnancy outcome.