When an oxytocin injection has been administered before the placenta has detached, the baby's cord will need to be clamped within 30 seconds to a minute after the baby is born. This prevents the baby from receiving an oversupply of blood (known as 'over transfusing' the baby).
If the cord is not clamped the oxytocin drugs can stimulate strong uterine contractions that will almost 'squeeze' up to an extra 200 mls of blood from the placenta through the cord and to the baby. It can be compared to squeezing out a wet sponge - when you wring it out with force more liquid comes out - this is the same with oxytocin drugs and the placenta. The clamp acts like a dam, preventing the extra blood flow from reaching the baby.
An oversupply of blood can overload the baby's heart and lungs and give the baby too many red blood cells causing more severe cases of
jaundice. In the case of twins, the cord of the first twin usually needs to be clamped and cut immediately to prevent possible blood from the second twin being transferred to the first twin, if the placenta is being shared (although in most cases it is not, but it is a precaution taken anyway, just in case).
Once the cord is cut and the baby is separated from the mother, your caregiver may release the clamp that remains attached to the part of the cord leading to the placenta still inside the woman's uterus. This allows the cord to drain blood, usually into a receptacle. It has been shown that cord blood drainage decreases the length of the 3rd stage and can reduce the overall blood loss. This would also be done to collect a sample of cord blood if the mother has a
negative blood group. If you are
donating cord blood a needle may be inserted into one of cord's blood vessels to obtain the blood.
Waiting for signs of separation
As with a natural 3rd stage the caregiver should ideally wait until the signs of the placenta separating are evident before delivering the placenta.