Planned caesareans increase breathing problems for babies
Publication Date:12/12/2007
Babies born by planned caesarean section are at higher risk of breathing difficulties immediately after birth, a new study shows. The risk is greater for babies born by caesarean at an earlier stage of pregnancy.
What do we know already?
Caesarean section, where the baby is taken out of the womb through a cut across the mother's abdomen, used to be done only for problems that stopped the mother from giving birth normally through the vagina. But because the operation has become safer, it's now used more often.
However, that doesn't mean it's safer than giving birth normally. A recent study showed normal birth is usually safer for mothers and babies.
Babies don't use their lungs while they're in the womb, because they get all the oxygen they need from the placenta. They only start breathing when they are born. That's why premature babies often have difficulties breathing - their lungs haven't developed enough to cope with breathing unaided.
Previous studies have suggested that caesarean section also increases the risk of breathing problems. But until now, we didn't know how big the extra risk was, or whether the risks were mainly for planned or emergency caesarean sections. An emergency caesarean is where the mother planned a normal birth but needed a caesarean for medical reasons, after labour had started.
This new study compared babies born by planned caesarean section with all planned normal births, even if the mother later needed an emergency caesarean. That should give us a more accurate picture of the risks of planned caesareans.
What does the new study say?
Babies born by planned caesarean section were much more likely to have breathing problems than the babies whose mothers had planned a normal birth. They were almost four times as likely to have problems.
Babies born by caesarean at 37 weeks of pregnancy had the biggest increased risk of breathing problems, including serious problems that needed several days of oxygen therapy. Early caesarean sections had a bigger risk than caesareans carried out later in pregnancy.
Tell me more about the study's findings
The study looked at 34,458 babies born between 37 and 41 weeks of pregnancy, in a hospital in Denmark, from 1998 to 2006.
Just over 4 in 100 of the babies delivered by planned caesarean section at any stage of pregnancy had breathing problems, compared to 1.5 in 100 of the babies whose mothers had planned a normal birth.
The problems were most likely for babies born earlier in pregnancy. The study found:
- At 37 weeks, 10 in 100 babies born by planned caesarean had breathing problems, compared to 3 in 100 planned normal births
- At 38 weeks, 5 in 100 babies born by planned caesarean had breathing problems, compared to 2 in 100 planned normal births
- At 39 weeks, 2 in 100 babies born by planned caesarean had breathing problems, compared to 1 in 100 planned normal births.
We still don't know exactly why babies born by caesarean section have more difficulties breathing. But researchers think it may be because changes to hormones in the woman's body, during or just before labour, help prepare the baby's lungs to start working. If the baby is born by planned caesarean section, without the woman going into labour, this doesn't happen.
Where does the study come from?
The study was carried out at Aarhus University Hospital in Aarhus, Denmark. It was published in the BMJ (British Medical Journal), which is owned by the British Medical Association.
How reliable are the findings?
This was a very big study, carried out over several years, and the figures are likely to be reliable, because they were all recorded in hospital records at the time.
Sometimes women have planned caesarean sections because they have an illness that might affect the health of their baby, for example diabetes or pre-eclampsia (very high blood pressure). This might affect the results, so the researchers looked at the figures again, taking out all the women who'd had caesareans for these reasons. The results stayed the same, which means we should be able to rely on them.
What does this mean for me?
If you are pregnant, there are lots of things to consider when planning how to have your baby.
For most women and their babies, a normal vaginal birth is the safest option. This study gives you more information about the risks to the baby of a caesarean birth. But there are medical reasons why a vaginal birth is not right for everyone.
The study suggests babies born by early caesarean sections (at 37 weeks) have the highest risk of problems. So later caesareans might be better for the baby. But there may be good reasons why your doctor wants you to have an early caesarean section, such as if you have dangerously high blood pressure.
What should I do now?
If you are thinking about a caesarean section, or if your doctor has recommended one, make sure you understand the reasons. Talk to your doctor or midwife about the risks and benefits of a caesarean section for you and your baby. It's your decision, so make sure you have all the information you need to make the choice that is right for you.
It's not possible to plan everything in life, and sometimes plans for childbirth have to change. But your midwives and doctors should respect your decisions and help you to have your baby in the way you have chosen, as far as is possible.
From:
Hansen AK, Wisborg K, Uldbjerg N, et al. Risk of respiratory morbidity in term infants delivered by elective caesarean section: cohort study. BMJ. Published online 12 December 2007.
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© BMJ Publishing Group Limited ("BMJ Group") 2007. All rights reserved
This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.
