Blood volume and its components were estimated during 126iodinated human serum albumin in 194 newborn infants with 26 to 41 weeks of gestation. Umbilical cords were ligated 15 seconds after vaginal delivery (n = 141) and within 5 seconds after delivery by cesarean section (n = 53). The infants were divided into four groups according to the mode of delivery and presence of prenatal complications: group I: vaginal deliveries (n = 96) and group II: cesarean section (n = 25) without preceding complications; group III: infants with intrauterine asphyxia (n = 56); group IV: infants with tight umbilical cord loops around neck (n = 17). Subgroups were established with respect to gestational age and to one-minute Apgar scores.
Significantly different blood volume (BV) and red cell mass (RCM) values between the subgroups were only found in group I with respect to different Apgar scores: la Apgar >5; BV 77.9 ± 6.2; RCM 37.5 ± 5.1 ml./kg.; lb Apgar <6: BV 70.0 ± 4.4; RCM 29.6 ± 2.9 ml./kg. (<0.005). Intrapartum asphyxia did not affect BV (71.3 ± 4.8 ml./kg.) and RCM (31.2 ± 3.6 ml./kg.) in group II. BV and RCM were significantly (P < 0.005) lower than in group la. In group III, BV (90.4 ± 7.0 ml./kg.) and RCM (46.9 ± 6.3 ml./kg.) were significantly (P < 0.005) higher than in group I, irrespective of the mode of delivery and Apgar scores. The infants of group IV had the lowest volumes (BV 67.5 ± 5.7; RCM 27.4 ± 2.7 ml./kg.). Values obtained in premature and full-term infants were similar in the respective groups.
These results indicate that infants with intrapartum asphyxia and with tight nuchal cords do not participate in placental transfusion or even lose some blood into the placenta. However, infants with intrauterine asphyxia (excepting those with tight nuchal cords) receive marked placental transfusion in utero.