Epidural: risks and benefits during labour

An epidural is an analgesic compound that reduces pain during labour. It is administered by an anaesthetist via a fine needle into the epidural space (between two lumbar vertebrae), providing local anaesthesia. A catheter is then placed and secured along your back. The anaesthetic is then injected, taking effect in approximately ten minutes. It is a highly effective pain relief technique. There are, however, certain contraindications and medical conditions that may prevent its use. Do not hesitate to discuss this with your healthcare professional and anaesthetist. 

In a large review published in 2018, researchers examined 40 studies involving more than 11,000 mothers. They compared those who had received an epidural, a spinal block, a caesarean, and those who received no medication, or who received painkiller injections, including opioids [2]. 

The epidural is an effective analgesic 

On average, it reduces perceived pain by 2 to 3 points on a scale of 0 to 10 (0: no pain and 10: extremely painful), and does so more effectively than opioids. Most mothers reported that with the epidural, pain management was "excellent or very good". This analgesic technique is therefore highly effective in providing relief for mothers. 

The epidural is preferable to opioids 

The previous study, showing the effect of the epidural as an analgesic, also demonstrated that mothers who received one experienced less nausea and vomiting than those who received opioids. They also had fewer breathing difficulties (need for oxygen). 

Children born following an epidural were also less likely to receive naloxone, a medication used to block the effects of opioids, compared with those born following a delivery with opioids. 

However, this practice can be accompanied by side effects and complications. 

Epidural and maternal health risks

Mothers who had an epidural experienced higher rates of hypotension, motor block, fever, and urinary retention (requiring insertion of a catheter into the bladder to drain urine) [3].

A review of 22 studies, covering more than 650,000 births, also showed that it doubled the likelihood of experiencing a perineal tear [4].

However, it would not increase long-term lower back pain [5].

Epidural and slowing of the second stage of labour

Women with an epidural experienced a longer first and second stage (i.e. the pushing phase) of labour, on average 13.66 minutes longer. These mothers were also more likely to receive synthetic oxytocin to increase contractions and induce labour [6].

However, the increase in labour duration would be most pronounced during the second stage. For example, a study of more than 62,000 births showed that the average duration of the second stage was twice as long for mothers with an epidural during their first birth (an average of 1h06 compared with 36 minutes without). For mothers giving birth for the second time, the duration was 24 minutes with an epidural compared with 12 minutes without [7].

Some studies show that the best pregnancy food supplement for the duration of the second stage of labour would be raspberry leaf. 

Epidural and risk of instrumental delivery with forceps

A mother with an epidural is also 1.4 times more likely to require the use of forceps and ventouse during the pushing phase [8].

But when researchers restricted the data to include only births from 2005 onwards, they no longer observed an increase in the use of forceps and ventouse. One hypothesis is that epidurals are administered at increasingly lower doses thanks to more advanced techniques, and that this improvement helps reduce instrumental delivery by forceps/ventouse.

This may be due to the fact that with an epidural, sensation in the legs is reduced or absent, making it difficult to move the lower body. They also observed that an epidural multiplies the likelihood of motor block by 30 [9]. 

Epidural and risk of caesarean section

Researchers found no significant difference in the caesarean section rate between women who had an epidural and those who did not. However, the rate in both groups was 11% and 13% respectively, which is considerably lower than the average [10].

Some studies show an increased likelihood of having a caesarean section, but the findings are not always reliable [11].

For example, another analysis of more than 200,000 women shows that it multiplies the likelihood of having this intervention by 2.5 [12].

This may be explained by the fact that an epidural can lead to a longer labour, particularly during the second stage. 

Your baby is not at greater risk if you have an epidural! Researchers were unable to identify any differences between women who received an epidural and those who did not in terms of the baby's condition (number of admissions to intensive care and APGAR score, which assesses a newborn's vitality based on empirical observation at the time of birth) [13]. 

Epidurals and the risk of abnormal foetal head position at delivery

An analysis of more than 15,000 epidurals showed that there was a 1.4 times greater likelihood of an abnormal foetal head position at delivery compared with births without an epidural [14]. 

Epidurals and the risk of autism

In October 2020, a study on births in California revealed that epidurals might in fact be associated with a 37% increase in subsequent autism diagnoses in children [15]. However, this data was widely criticised for failing to account for numerous factors — socioeconomic, genetic, and medical — related to autism that could be more prevalent among women who choose an epidural. Experts also noted that it was biologically implausible for epidurals to be associated with autism. 

Shortly after publication, several professional societies issued a statement asserting that the study did not provide credible scientific evidence of a link with autism [16].

Subsequent research showed that epidurals had no effect on autism.

The new research examined the use of epidurals during labour and subsequent autism diagnoses in Canada. It looked at 123,175 children born between 2005 and 2016 who were followed up until 2019. In reality, there was no statistically significant difference in autism rates between children whose mothers received an epidural during labour and those who did not [17].

Water birth generally helps to experience less pain according to studies. As a result, there is less need for analgesic medication, and almost no epidurals [18]. Researchers have shown that out of more than 700 mothers who gave birth in water, none of them required analgesics [19]. This method therefore appears to promote a natural birth.

The epidural is therefore effective in managing labour pain. However, it is not a minor procedure — in particular, an increase in the duration of the second stage of labour has been observed in women. That said, it does not appear to be associated with complications for your baby. 

Certain contraindications or medical conditions may, however, prevent an epidural from being an option. 

Water birth, for example, can be a good alternative for the mother. 

Do not hesitate to seek advice from your midwife, gynaecologist, doctor, etc.