Q. I am pregnant with my second child and planning a homebirth. However, after my first delivery, I lost around a litre of blood and suffered a retained placenta, which had to be manually removed. I am unsure exactly why this happened and haven`t been able to find out the risk of it happening again. I don`t want to give birth at home if I`m at high risk of another postpartum haemmorage, as my midwife has explained that it might be impossible for her to stop the bleeding. Do you know what my risk is? And can you explain why I passed several large clots of blood before the placenta came out?

A. Choosing the preferred location for your baby's birth is an important decision to make and in considering which option(s) is safest for you and your baby's well-being, you, your partner, the midwife and doctor will consider how your current pregnancy has progressed (ie whether there have been any concerns or problems), whilst also taking into account your past obstetric history. This relates to your previous pregnancy and birth, and any complications that arose around this time. In doing so, your health professionals are better able to identify any areas where there may be some concern, so they can make an informed suggestion as regards the safest place for your baby's birth. This involves balancing your personal wishes and preferences with any potential risks or disadvantages that have been identified for you and/or your baby.

You experienced a significant loss of blood (called a ‘postpartum haemorrhage') following your last birth; this is classified as an ‘obstetric emergency' and can be life-threatening where appropriate medical aid and facilities are not immediately available. The haemorrhage happened because your afterbirth (placenta) was left behind inside your womb (uterus) in the final stage (third stage) of labour. After the baby is born, the muscles of the uterus contract down, which causes a blood clot to form immediately behind the placenta (called a retro-placental clot); these two actions combined, help the placenta to peel away from the uterine wall and be delivered. This is likely to be why you passed some large blood clots while the placenta was still inside you.

However, sometimes this does not happen and either the placenta separates but cannot be expelled or the placenta fails to separate. If the placenta separated but could not be expelled, sometimes the retro-placental clot can escape, which might have been what you experienced. Where all or part of the placenta remains inside the uterus, this is referred to as a ‘retained placenta' and, as with your previous birth, often needs to be ‘manually' removed by a doctor. The incidence of retained placenta varies globally, but in developed countries such as the UK, tends to arise in around 3% of vaginal births. There are four main reasons why a retained placenta occurs:

• Your uterus stops contracting, or doesn't contract strongly enough to enable the placenta to separate from the uterine wall
• The placenta and membranes have separated from the uterine wall, but the neck of the womb (cervix) closes before they can be delivered; this can happen once the oxytocic injection - ‘syntometrine' has been given
• The placenta is so deeply embedded into the wall of the uterus that it remains attached - this is called ‘placenta accreta'
• The umbilical cord ‘snaps' during delivery of the third stage, leaving the placenta and membranes behind.

The research evidence available suggests that where a manual removal of placenta has been required in a previous pregnancy, there is an increased likelihood that this may happen again. For this reason, your midwife and doctor are likely to strongly advise that you have your baby in the maternity unit where there is easy access to the relevant facilities and obstetric expertise, should these be required.

If the cord snapped or your cervix closed before the placenta had been delivered at your last birth, your midwife may suggest considering a ‘physiological' third stage of labour. This is where the oxytocic injection is not given and your placenta is allowed to deliver naturally. However, if these circumstances do not apply, research shows that giving an oxytocic injection to manage the delivery of the placenta and membranes significantly reduces the risk of postpartum haemorrhage. Giving your baby a breastfeed soon after their birth has also been found to be effective in assisting the delivery of the placenta and membranes and reducing the risk of haemorrhage. This is because breastfeeding encourages the release of the hormone ‘oxytocin', which makes the uterus contract down more.

I would also suggest that you talk with your own midwife and/or doctor, who will have access to your maternity records and should be able to answer any questions about events surrounding your previous labour and birth.

Best regards

Vicky