During the first trimester of pregnancy, the breasts begin producing colostrum in small amounts. [i]
Sometimes colostrum ‘leaks’ onto the person’s bra or other clothing; others do not experience any outward signs that the breasts are preparing for lactation even as the pregnancy progresses. The fluid could be thin or thick, and is usually yellow-ish because of beta-carotene, one of the protective components of milk. At the time of the baby’s birth, more colostrum is being produced by the breasts than the baby will need. However, some fear that the baby ‘won’t get enough’ or that the ‘milk won’t come in,’ and want to express colostrum before the baby is born. According to research, the breasts make 10-100 ml of colostrum per day, averaging about 30 ml or an ounce per day – more than the baby needs.
Reasons to express and save colostrum prenatally:
- Out of curiosity. Many have wondered “what’s going on under my skin.”[ii]
- To practice hand-expression of milk for after the baby is born. Colostrum is thicker and made in smaller volume than later milk, but the technique for collecting milk is the same.
- If ‘milk coming in’ might be delayed. If the mother has diabetes or a complicated birth with Cesarean surgery or some other complication, the onset of full milk production may be a day or so later, and mothers’ own colostrum is the safest substance for her baby.[iii]
- To increase confidence that the breasts are preparing to make milk.
Concerns about prenatal expression of colostrum:
- Breast expression will trigger premature labor contractions. Prenatal (antenatal) expression of colostrum has not been shown to trigger labor contractions if the pregnancy is otherwise stable. In fact, ‘nipple stimulation’ is not especially effective in starting or enhancing labor contractions.
- I’ll hurt myself or my breasts. Nobody other than the mother should attempt to express colostrum. Some women have expressed difficulty, embarrassment or discomfort expressing colostrum.
How to store colostrum: Use small, food-safe storage containers with secure lids. Freeze the colostrum soon after expression. You can add more small amounts of colostrum to the frozen container, but not enough that would thaw the stored colostrum. Newborns will only need less than one ounce per feed, so don’t use large containers. Thaw under running warm water, not in a microwave oven. Use the thawed colostrum within 24 hours.
[i] Lawrence, R. A., & Lawrence, R. M. (2016). Breastfeeding: A Guide for the Medical Profession (Eighth ed.). Philadelphia: Elsevier.
[ii] Brisbane, J. M., & Giglia, R. C. (2015). Experiences of expressing and storing colostrum antenatally: A qualitative study of mothers in regional Western Australia. J Child Health Care, 19(2), 206-215.
[iii] Forster, D. A., Jacobs, S., Amir, L. H., Davis, et al. (2014). Safety and efficacy of antenatal milk expressing for women with diabetes in pregnancy: protocol for a randomized controlled trial. BMJ Open, 4(10), e006571.