Haptoglobin genotype and natural fertility in humans.

OBJECTIVE: To study the possible relation between human natural fertility and haptoglobin (Hp) genotype. DESIGN: Prospective study. SETTING: Maternity departments of local hospitals in two Italian localities. PATIENT(S): Healthy women who had just given birth in the maternity departments of two local hospitals (n = 679). INTERVENTION(S): Venous blood collection for determination of Hp genotype with the use of starch gel electrophoresis of hemoglobin-supplemented serum. MAIN OUTCOME MEASURE(S): Distribution of Hp genotypes in relation to age of puerperae. RESULT(S): In both populations, the proportion of young mothers was much higher among women who were homozygous for the Hp*1 allele (the Hp*1/*1 genotype) than among women who had other Hp genotypes. In addition, the proportion of multiparous women among the older mothers was higher among those with the Hp*1/*1 genotype than among those with other Hp genotypes. CONCLUSION(S): The data suggest that women with the Hp*1/*1 genotype reproduce at an earlier age and have higher natural fertility potential than women with other Hp genotypes.