2010 Volume 56 Issue 4 Pages 414-421
Placental/umbilical cord blood (CB) contains multipotent hematopoietic stem/progenitor cells and has been utilized worldwide both clinically and experimentally. Neonatal birth weight is positively correlated with CB volume and with the total number of nucleated cells associated with engraftment and survival after CB transplantation. Considering the recent increase in the frequency of low birth weight (<2500 g) and the decline in body mass index (BMI) among Japanese women of childbearing age, the present study investigated the combined impact of the prepregnancy BMI and the gestational weight gain on CB volume. From 1998 to 2007, CB samples were obtained from 579 healthy women with singleton vaginal deliveries. The prepregnancy BMI was classified into the underweight, normal, overweight, or obese groups. According to the current gestational weight gain recommendations or other new optimum recommendations, the gestational weight gain was classified into below, within, or above recommendations in each prepregnancy BMI group. The neonatal weight and placental weight had significantly positive effects on the CB volume. Underweight pregnant women demonstrated significantly lower neonatal and placental weight. According to the current recommendations, no significant difference in the CB volume was observed. According to the new optimum recommendations for underweight pregnant women, a significantly higher CB volume was obtained from the group within the recommended weight gain range than from the group below the recommended range. In the underweight group, a higher CB volume could be obtained if the upper limit of the gestational weight gain increases by a few kilograms more than the current gestational weight gain recommendations.
