I’ve written a few posts now in relation to HBAC, and I agree I have been quite harsh at times. I apologise if any of my posts have offended you. I wanted to write something to help explain why doctors in some cases prefer to do a repeat section rather than a VBAC/TOLAC.
Firstly we are very fortunate to be living in an age where medical technology has advanced to a point where we can successfully risk out mums who have a higher chance of complications during labour which could in turn lead to a higher mortality rate for their baby.
We hear so many stories about unnecessary caesareans, everywhere we look the NCB (Natural Child Birth) Movement are publishing stories about yet another woman who didn’t need their section. In this post I want to try and explain why these sections are performed, the benefits and the risks and try and overthrow the myths being thrown around in the NCB communities. If you are part of the NCB community please do stick around and read this post, you might be surprised at what you learn.
What is Risk Balancing?
Risk comes with pretty much everything we do on a daily basis. From peeling potatoes to crossing the road. Everything we do comes with a risk factor associated with it. Pregnancy and Labour as you saw above comes with its own risks. Some would say that your birthday is the most dangerous day of your life, and they may well be right. If we step back in time labour used to carry with it a neonatal mortality rate of between 1 in 10 and 1 in 20 and 1 in 25 maternal mortality rate. These days however thanks to advancements in modern medicine the risks are no longer that high. This is mostly down to a combination of the risk assessments doctors and midwives do on a daily basis, the preventative stance taken by OB’s and the knowledge we now have in knowing when to intervene. With Risk balancing they assess the risks, balance the risks and then offer the safest initial birth solution to the mother.
The entire concept behind balancing risk is to try and minimise the chance of death or injury as much as possible.
Let’s use a hypothetical situation to explain this fully:
So what quantifies a need for caesarean?
This is a question I am sure many of you will be asking. Especially if you have already had a caesarean that you feel was unwarranted, or you are faced with your OB telling you they would prefer you RCS than VBAC.
Firstly depending on where you are from you will have been ‘risked out’ This means that your midwife and OB will have looked through your previous medical history along with your current pregnancy to see if you are suitable for VBAC (Vaginal Birth After Caesarean)
Most doctors and midwives are fully VBAC supportive. Contrary to popular belief if a caesarean can be avoided then 99% of the time it will be. It is in the interest of the mum and baby to ensure that they have the safest birth possible, and it is in the doctors’ interest to ensure that this happens.
You may have been risked out for several reasons, some of the most common reasons for doctors suggesting a section over VBAC are as follows (information taken from the NHS website):
- You’ve already had a caesarean section, and there were complications during the procedure. If there were no complications, a vaginal birth after a caesarean (VBAC) may be possible, and is successful in 70 per cent of cases.
- Your baby is in a bottom-down (breech) position, and external cephalic version (ECV) isn’t recommended, or hasn’t been successful.
- You are expecting twins or more, and the first baby isn’t in a head-down position.
- Your baby is in a sideways (transverse) position, or keeps changing his position (unstable lie).
- You have severe pre-eclampsia or eclampsia, and having your baby by vagina will take too long to be safe.
- You have a low-lying placenta (placenta praevia).
- You have a medical condition, such as a certain type of heart disease.
- You’ve asked to have a caesarean, perhaps because of a previous traumatic vaginal birth.
- You caught genital herpes for the first time in your third trimester.
- You have HIV and are either not receiving retroviral therapy, have a high viral load, or also have hepatitis C. A vaginal birth is an option if your HIV is under control.
Sometimes, certain conditions go together, giving more than one reason to have a planned caesarean. For example, you may have a low-lying placenta that has contributed to your baby settling into a breech or transverse position.
There may also be other reasons your doctor might want to perform a RCS over a VBAC, if you have previously ruptured, if the size of your baby is extraordinarily large (common if mum has GD (Gestational diabetes) or has history of large babies resulting in emergency caesareans previously)
All of these can quantify a need for a repeat caesarean. This does not mean that you have to have another caesarean. It just means that ‘your’ risk of complications during labour has increased. If the risk is high then generally a doctor will prefer to re-section. They are not advising this for any other reason than the safety of you and your baby. Let’s look at this in a little more detail.
Let’s take a hypothetical situation to help explain why a repeat section may be recommended, and how you may feel about this:
Put yourself in this situation:
You are 37 weeks pregnant. Baby is measuring in at an estimated 9lbs. should you go to 40 weeks baby ‘may’ potentially grow to over 11lbs. You have 2 other children, both of which were large babies weighing in at 9lbs 7oz and 10lbs 6oz. The chances are this baby will be bigger again. Your previous babies ended up in emergency sections due to their size. You have been told by your OB that if you choose to VBAC you may end up in difficulty again, he would like to schedule an RCS at 39 weeks. You have also been told in one of your birth groups that you can do this, your body was made to birth any size baby. You want to experience birth. You feel sad that you have not been able to birth naturally. You feel like your body is broken. You also feel optimistic that this time around you can do this. You have lots of support in your birth groups and you have seen several success stories from mothers in your group. They have done it… you can too?
You have two choices. One choice is to follow your OBs advice and go in at 39 weeks for the section. Your other choice is to attempt a VBAC with the support of your group.
I don’t envy anyone who has to make this choice, it’s difficult and wrought with emotion. Let’s now look at the statistics, reasoning and logic behind the advice the OB has given you:
The average newborn weighs about 3.4kg (7lb 8oz). Babies weighing more than 4kg (8lb 13oz) at birth are considered larger than average, or macrosomic. If you have a very large baby, weighing 4.5kg (9lb 15oz) or more, it can put you and your baby at greater risk of certain complications.
About 11 per cent of babies in England are born at a weight of 4kg or more, with 1.6 per cent weighing 4.5kg or more.
If your baby is over 4.5kg, there is a one in 13 chance that he will experience shoulder dystocia during birth, increasing to a one in seven chance if your baby is over 5kg. This is when your baby’s shoulders become stuck after you’ve pushed his head out and is more likely to happen if your baby is very large. It’s a rare but serious situation that needs immediate attention from an obstetrician.
Shoulder dystocia can bring with it a whole host of other issues too. Cord compression being the most serious as this can result in the death of your baby. 20% of all babies involved in a shoulder dystocia deliver will experience injury, some temporary and some permanent. The most common of these injuries are damage to the brachial plexus nerves (16 in 100), fractured clavicles, fractured humeri, contusions and lacerations, and birth asphyxia.
When we look at the statistics for Shoulder Dystocia it starts to put things into perspective from the doctors point of view. Studies have shown Fetal Mortality rate at 29%, fetal morbidity as high as 48% and Neonatal morbidity also occurs in up to 42%. In addition to that are the risks to the mother. Maternal morbidity can be as high as 68% due to blood loss that includes post partum haemorrhage, cervical, vaginal and perineal lacerations, episiotomy extensions and uterine atony (Wagner et al, 1999).
It is understandable why a large baby would be a concern for your doctor, especially with previous history and the statistics involved.
This is only one example, but hopefully it gives you an insight as to why doctors may suggest a section over vaginal birth.
But why is the Caesarean rate so high?
The current rate of CS in the US stands at 32.7% (as per the CDC website) and 26.2% in the UK (as per the NCT website)
I know many people look at these figures and wonder why so many CS are performed. Its easy to see why so many people think that most of these must be unnecessary.
The answer is easy: OBs will often take a preventative stance when it comes to balancing risk and in addition due to their experience and knowledge have a better understanding on when it is necessary to intervene. It is far better to have a higher CS rate than a high mortality rate. Considering the current neonatal mortality rate for birth in general in the US is 18 in 100,000 (all types of birth) is this not a far cry from the 1 in 10 to 1 in 20 prior to modern medicine?
Neonatal Mortality: http://www.ncbi.nlm.nih.gov/pubmed/16948717
Shoulder Dystocia: http://shoulderdystociainfo.com/fetalinjuries.htm
Vaginal Delivery Maternal Mortality rates: http://scholar.google.co.uk/scholar_url?url=https://xa.yimg.com/kq/groups/23009980/1656081415/name/ARPH%2Bmorbidity%2Bcesarean%2BCanada%2B2007.pdf&hl=en&sa=X&scisig=AAGBfm1wJTrxvNxy1KmTMdWeUKBOrvhG_w&nossl=1&oi=scholarr&ved=0CCEQgAMoATAAahUKEwja-9HUzOTHAhXDZ9sKHY9sAPk
Neonatal and Maternal Mortality prior to the advancement in modern medicine (first chart neonatal, second chart maternal):
- So all 100 women have the CS in the first part and there are no adverse outcomes. Ask yourself what would happen if none of them had a CS and tried to birth vaginally. Now there are 5 dead babies on average. So in scenario 1, none are statistically likely because it would take over 1000 CS before you would see a baby death (1/1000), which is greater than 100. But in scenario 2, without the intervention of a CS for any of our 100 women, we’d have already had five dead babies on average. So without the intervention, it would only take 20 births on average to have a bad outcome. It would take 980 more births to see a baby die in a planned primary CS.