Human colostrum, the nourishing first milk, plays a vital role in the health of newborn infants and is available from approximately week 20 of pregnancy. Current advice is to refrain from expressing colostrum before the 37th week of pregnancy unless indicated otherwise. A recent pilot study lead by researchers from the University of Southern Denmark, with a funding contribution from the Haakaa Foundation, has explored expressing colostrum before birth, specifically focusing on the safety of pregnant women starting expression earlier (from week 34 of pregnancy). The aim was to assess whether colostrum expression is feasible at lower gestational ages without inducing early labour, and to evaluate its impact on postnatal breastmilk availability and overall breastfeeding outcomes.
Description and Findings
Participants were randomly assigned to one of two groups. Starting at 34 weeks of pregnancy, one group was asked to express breastmilk by hand twice a day for 10 minutes, while the other group did not. Those in the expressing group received instruction on hand expression techniques and how to store the milk using special colostrum collectors. All participants were healthy first-time pregnant with uncomplicated pregnancies. Both groups received breastfeeding support and were followed for eight weeks after giving birth.
The results showed that early expression did not trigger preterm birth, with no difference in gestational age between the two groups. The average timing of birth was identical in both groups. Most of the women (82%) in the expressing group successfully expressed and had their own milk available at birth. Breastfeeding success after birth was similar in both groups, and no negative health issues were reported.
The study concluded that for healthy, low-risk first-time pregnant women, expressing breastmilk in short sessions from week 34 of pregnancy is safe and may help ensuring breastmilk availability immediately after birth. This is very helpful information when planning future studies involving women at high risk of premature birth, where early feeding with human colostrum is of particular importance for the infant.
Further Reading:
Mother’s own milk (MOM) is especially important as the first nutrition for preterm infants, but mothers often struggle to initiate milk production right after preterm birth. If antenatal breastmilk expression (aBME) does not induce preterm labor when performed before term age in healthy pregnant women, it could also improve nutrition with MOM right after preterm birth. We are planning to evaluate aBME in high risk pregnancies in a new study.
Simonsen, M. B., Bentzen, S. B., Möller, S., Holm, K. G., Vinter, C. A., & Zachariassen, G. (2025). Safety of antenatal breastmilk expression from week 34 of pregnancy: a randomized controlled pilot study (The Express-MOM study). Maternal health, neonatology and perinatology, 11(1), 2. https://doi.org/10.1186/s40748-024-00197-1