<Li> <P> Newborn child and mother, postpartum umbilical nonseverance (with placenta). </P> </Li> <P> Newborn child and mother, postpartum umbilical nonseverance (with placenta). </P> <Li> <P> A newborn at 45 seconds, with umbilical cord clamped . </P> </Li> <P> A newborn at 45 seconds, with umbilical cord clamped . </P>

When do the placenta and umbilical cord develop