After an epidural, there appeared to be three times as many emergency deliveries due to suspected oxygen deprivation of the baby compared to deliveries without analgesia. Compared to deliveries with other forms of pain relief, women had almost twice as many emergency deliveries. This appears from two studies conducted by obstetrician Dr Sanne Gordijn of the UMCG, together with her colleague Dr Wessel Ganzevoort of Amsterdam UMC and their research team. They publish about this this week in the scientific journal Ultrasound in Obstetrics and Gynecology.
Previous research already showed that the number of artificial deliveries, usually ventouse deliveries, increases after an epidural. Not much was known so far about the increase in caesarean sections due to suspected oxygen deprivation.
There are two main reasons for ventouse deliveries and caesareans (collectively referred to as 'emergency deliveries'): labour is not progressing or the gynaecologist estimates that the baby is suffering from oxygen deprivation. The latter is also known as 'foetal distress'. The current studies did not include emergency deliveries due to non-progress in labour.
The epidural is increasingly used in Dutch birth care. It is the most effective method of pain relief during childbirth. Its use is increasing every year. In 2021, almost a quarter of all pregnant women in the Netherlands received an epidural. Among women who give birth for the first time, almost 40 per cent use an epidural, and if labour is initiated in these women, the epidural is used by more than 50 per cent. The studies were done because the researchers noticed in daily practice that low-risk women who were referred for pain relief from the obstetrician still often had emergency deliveries after an epidural.
The researchers conducted two studies for this research. In the first study, they looked at the data of all births in the Netherlands from 2014 to 2018 with a gestational age of 36 to 42 weeks; a total of almost 630,000 deliveries. In addition, they analysed data from a previous randomised (lottery) study on the effectiveness of the epidural. The same pattern was seen in both studies: there is a significantly increased risk of emergency delivery due to the suspicion of oxygen deprivation in the baby after an epidural.
One of the main side effects of the epidural is a drop in blood pressure in women. A drop in blood pressure can also reduce blood flow to the placenta. This can lead to less oxygen for the baby; this can be seen in the baby's heart rate on the heart monitor during labour. Gordijn: 'So we think that reduced blood flow to the placenta is a possible explanation for the increased number of emergency deliveries after an epidural. This is also consistent with the fact that we see that the smaller the baby is and therefore the more likely that the placenta is already not working optimally, the higher the likelihood of such an emergency delivery based on suspected oxygen deprivation. The exact mechanism does not become clear from these studies.'
Gordijn is clear about the value of an epidural: 'An epidural is valuable and the most effective pain relief for women who need it.' According to her, it therefore remains true that women should be able to receive the epidural if they need it. 'However, it is important to make an informed choice of pain relief. Since until now there was no knowledge about a possible relationship with emergency birth due to expected oxygen deprivation of the baby, this was previously not included in the advice of gynaecologists and obstetricians and women's considerations.'
