Fasting For Surgery

Why fast before surgery?

The reason for not eating or drinking for several hours before having a general anaesthetic is so that the stomach is empty. This reduces the risk of any stomach contents entering the lungs (pulmonary aspiration) while patients are relaxed and sleepy.

Not breastfeeding can be stressful for baby

While an adult or older child will understand why they must not eat or drink for a certain number of hours, a breastfed baby doesn’t understand why he can’t feed on demand, even if he isn’t especially hungry or thirsty— because he breastfeeds for many other reasons such as for comfort or to fall asleep. Expecting a breastfed baby not to breastfeed for enforced periods of time can be very stressful to mother and baby. This article looks at the recommendations for the minimum fasting time so that stress and upset can be reduced.

Breast milk is digested quickly

Breast milk is digested much more quickly than formula or solid food which has a bearing on the fasting interval for the breastfed baby 1

Guidelines for a baby fasting for surgery

Opinions vary slightly on the safest fasting time for a breastfed baby. Most organisations recommend fasting for four hours. The Royal College of Anaesthetists (RCoA), Association of Anaesthetists of Great Britain and Ireland (AAGBI) and Association of Paediatric Anaesthetists of Great Britain and Ireland (APAGBI) have produced a guide which states:

Children are much more comfortable if they do not have to wait longer than necessary without food and drink. The following are generally agreed timings for when you can give your child something to eat or drink before non-urgent surgery.

  • Six hours before, your child can have a light meal or a glass of milk. Bottle-fed babies can have formula feed.
  • Four hours before, babies can have breast milk.
  • Two hours before, children should have a drink of water or very dilute squash.

What do others say?

At the time of writing the Academy of Breastfeeding Medicine (ABM), American Society of Anesthesiologists (ASA) and the Royal College of Nursing (RCN) also recommend four hours as a recommended fasting time for a breastfed baby prior to surgery. See the links below for their policies:

Is a fasting interval less than four hours ever recommended?

A paper by Cook-Sather and Litman (2006) discussed whether shorter fasting periods for breast milk (three hours), formula (four hours) and light meals (six hours) may be possible:

…the relative safety and benefits of allowing clear liquids up to 2 hr prior to anesthesia for otherwise healthy children are well established. Shortened fasting periods for breast milk (3 hr), formula (4 hr) and light meals (6 hr) are supported by accumulated experience and an evolving literature that includes evidence of minimal gastric fluid volumes (GFVs) at the time of surgery. Ideal fasting intervals for children with disorders that may affect gastrointestinal transit have yet to be determined.

In Breastfeeding Answers Made Simple, 2010, p. 317 Nancy Mohrbacher states that breast milk can be given up to three hours before surgery, citing the above study 2 and one by Brady et al 3.

Paediatricians Lawrence and Lawrence 4 advocate limiting breastfeeding from four hours prior to surgery but permit feeding from a prepumped and empty breast for comfort—up to two hours before surgery. The decision on the safest and most appropriate fasting time for your baby will need to be discussed with your baby’s surgeon and anaesthetist.

Distraction from breastfeeding

Ideas to distract your baby during the fasting period include going for a drive or perhaps trying a pacifier. It may be helpful if someone other than the breastfeeding mother tries to comfort the baby so that the little one doesn’t expect to nurse. The timing of surgery can make a difference: later in the day may make distraction easier than if the fasting period is through the night.

After surgery

Unless your health professionals have any concerns, breastfeeding can continue as soon as your baby is ready to feed by mouth (Lawrence & Lawrence, 2016).


Breast milk is digested more quickly than formula which allows for shorter recommended fasting times for the breastfed baby prior to having an anaesthetic. Most organisations recommend the fasting period should be four hours. Some authors advocate comfort nursing on an prepumped and empty breast up to two hours before surgery. Discuss the safest fasting time for your baby with your baby’s health professionals.