Placental weight and birth characteristics of healthy singleton newborns.

To determine the relationship of placental weight and birth characteristics of healthy Chinese singleton newborns, 552 consecutive singleton near-term and uncomplicated pregnancies were enrolled in a retrospective study from October 2000 to April 2001. Maternal age, infants' gender, gestational age, placental weight (PW), birth weight (BW), birth length (BL), cord length, ponderal index, and appearance of meconium-stained amniotic fluid or a nuchal cord were recorded and analyzed. Our results show that the mean value of BW was 3235 +/- 17 g, birth length was 48.8 +/- 0.1 cm, PW was 646.2 +/- 0.3 g, BW/BL was 66.2 +/- 0.3, BW/PW was 5.1 +/- 0.1, and ponderal index was 2.8 +/- 0.0, respectively. Male neonates had significantly larger BWs (p<0.05) and BLs (p<0.01) than did female neonates. However, there was no significant difference in PW between male and female neonates. PW was positively correlated with BW (r=0.413, p<0.01), BL (r=0.305, p<0.01), BW/BL (r=0.397, p<0.01), and cord length (r=0.264, p<0.01). The PW of studied infants showed no significant difference when grouped by gestational age, maternal age, presence of meconium stained amniotic fluid, or presence of a nuchal cord. Of the studied healthy neonate, 81.9% and 69.4% had no meconium-stained amniotic fluid or nuchal cord, respectively. There were no significant differences in PW or BW/PW between neonates with the presence or absence of meconium-stained amniotic fluid or a nuchal cord. These results indicate that PW has a significant role in fetal growth in terms of weight, body length, and cord length. Furthermore, it has no significant role in the presence of meconium-stained fluid or a nuchal cord in healthy neonates.