Studies have not found that antenatal expression of colostrum improves breastfeeding outcomes

You might get the impression that expressing colostrum antenatally is important to support breastfeeding because it's become a popular practice, but in fact there's still no evidence to show that using antenatal colostrum improves breastfeeding outcomes.

The possible downside is that feeding baby your stored antenatal colostrum in the hours and days after birth, instead of baby taking colostrum directly from your breast, risks decreasing your milk production, which is definitely not the intended outcome! Tiny amounts of colostrum directly removed from your breast by your baby and swallowed down into her tummy is always best, for both you and baby.

Also,

• Some women, like my younger self, don't like the sensation of expressing colostrum before the birth, and for most of us, there's actually no reason to.

• One quarter of women find they simply can't express milk antenatally, but this is not related to capacity to make milk after baby is born.

But if you have medical problems which might delay your milk coming in, such as diabetes or gestational diabetes, the health professionals looking after you will advise you on safely expressing and storing your pre-birth colostrum, should you choose to do so, for use as a backup.

You can find out about these medical challenges further down this page.

How do you express colostrum antenatally?

From 36 weeks on, you might gently express colostrum for up to ten minutes twice a day, drawing up the little pearls from your duct orifices on your nipples into slender syringes provided by the maternity hospital. You'll need to stop expressing if you feel womb contractions or notice any vaginal bleeding. Your midwives or providers will tell you how to label the syringe, place it in the freezer, and take it with you up to the hospital in a cooler pack.

It's quite normal for women not to be able to express colostrum antenatally! The combined total amount of colostrum which women are able to express antenatally is highly variable, and varies from nothing to a few millilitres to twenty millilitres or even a lot more.

But even if you do have pre-existing or gestational diabetes or other medical conditions, the most important steps you can take to protect your milk production once your baby is born is to offer frequent flexible breastfeeds (or frequent colostrum removal if you are separated from your baby or have breastfeeding problems) in the days after birth, and to have help sorting out any fit and hold challenges. These are the most important steps you can take to protect your milk supply, regardless of whether or not you have a store of antenatal colostrum.

This is because

1. In my experience, the most common reasons for low milk production relate to either fit and hold problems or not feeding (or removing milk) frequently enough, and yet these are often not addressed, and

2. There's no evidence to show that even when you have medical conditions, the use of antenatal colostrum actually improves breastfeeding outcomes.

You can find out about fit and hold starting here.

You can find out about frequent flexible breastfeeds here.

When might antenatal expression of colostrum be most helpful?

Women sometimes tell me how glad they were to have some colostrum ready for their baby because the birth didn’t quite go to plan. They felt that their stored colostrum prevented the need to use formula, or at least exposed their baby’s gut to colostrum in addition to formula if it was required, because they'd been separated from their baby or because they'd had breastfeeding difficulties.

Antenatal expression of colostrum has been shown to delay the introduction of formula prior to a mother and her baby's discharge from hospital when the mother has diabetes. However, the research also shows that expressing antenatal colostrum doesn't impact on rates of newborn hypoglycaemia or average blood glucose levels for the baby, or breastfeeding outcomes.

It's possible the research linking antenatal colostrum expression with some delay in the use of formula in the first few days (without any other benefits shown for breastfeeding) is simply because women who express antenatally are committed to avoiding formula use if they can. Therefore, the staff might be more likely to adopt a 'wait and see' approach, delaying the use of formula as much as possible after the baby is born.

When not to express during pregnancy

Your own midwife or doctor is the best person to talk with you about the safety of antenatal expression of colostrum in your unique situation. Overall, antenatal expression of colostrum has been shown to be safe for most women, and doesn't bring on early labour.

However, there are some situations where it's best for women to avoid antenatal expression. These are

• A history of, or currently experiencing, threatened or actual preterm labour

• Cervix problems ('cervical incompetence')

• History of bleeding through a pregnancy or of a placenta praevia

• Vertical ('classic'), unknown, or multiple caesarean scars

• Any medical problems with your unborn baby.

Medical conditions for which some women consider expressing and storing colostrum in late pregnancy.

Remember, there's no evidence-based reason to express colostrum antenatally, if you find it unpleasant, can't express any drops, or don't wish to for any reason.

Mother

• Diabetes or gestational diabetes

• Previous breast surgery

• Polycystic ovary syndrome

• Hypothyroidism

• Previous experience of delay in your milk coming in

• Previous diagnosis of insufficient glandular tissue

• Multiple sclerosis

• Medical assistance to conceive

Baby

• Congenital conditions e.g. cardiovascular anomalies or Down's syndrome

• Cleft lip or palate

• Small for gestational age

• Planned premature delivery e.g. twins

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Selected references

1. East CE, Dolan WJ, Forster DA. Antenatal breast milk expression by women with diabetes for improving infant outcomes. Cochrane Database of Systematic Reviews. 2014;CD010408.

2. Casey JR, Banks J, Braniff K, Buettner P, Heal C. The effects of expressing antenatal colostrum in women with diabetes in pregnancy: a retrospective cohort study. Australian and New Zealand Journal of Obstetrics and Gynaecology. 2019;59:811-818.

3. Forster DA, Moorhead AM, Jacobs SE. Advising women with diabetes in pregnancy to express breastmilk in late pregnancy (Diabetes and Antenatal Milk Expressing [DAME]: a multicentre, unblinded, randomised controlled trial. Lancet. 2017;389:2204-2213.