According to researchers in Australia having an epidural to relieve labour pains may affect how successful breastfeeding will be.
The researchers say epidurals are associated with problems with breastfeeding, both in the short and long term.
They found that women who have the injections have problems in the first week after birth with breastfeeding and stop before six months, compared with women who had no analgesia.
A team at the University of Sydney looked at 1,300 women who gave birth in 1997 and they suggest that a chemical in epidurals could possibly affect the babies.
The other suggestion is that women are more likely to persist with breastfeeding, if they do not have the pain relieving injection.
Siranda Torvaldsen, from the University of Sydney, and colleagues from other institutions across Australia studied 1,280 women who had given birth between March and October 1997 in the Australian Capital Territory.
Of these women, 416 had an epidural during the birth of their baby, and 172 of this group also also had a caesarean section.
The researchers found that although 93% of women breastfed their baby in the first week, epidural anesthesia was significantly associated with difficulty breastfeeding in the few days after birth and with partial breastfeeding in the first week after delivery.
The women who had the epidurals were also found to be twice as likely to completely stop breastfeeding before six months compared with women who used no analgesia.
Seventy-two percent of women who had no analgesia were breastfeeding at 24 weeks compared with 53% who received pethidine or epidurals containing bupivacaine and fentanyl (an opioid).
An epidural is inserted into a space near the spinal cord to ease the pain of labour.