Collecting colostrum before birth gives you a ready supply of nutrient-rich first milk that can be used immediately after delivery, especially if your baby has trouble feeding or needs help stabilizing blood sugar. The practice, called antenatal colostrum harvesting, is typically started around 36 to 37 weeks of pregnancy using hand expression, and it’s now encouraged by maternity units across the UK, Australia, Ireland, and the US for pregnancies where early feeding challenges are expected.
What Makes Colostrum Worth Saving
Colostrum is the thick, concentrated milk your breasts produce in late pregnancy and the first days after birth. It’s nutritionally distinct from the mature milk that comes in later. Colostrum contains roughly 28 times more secretory IgA, the antibody that coats a newborn’s gut and protects against infection, compared to mature breast milk. It also carries two to eight times more lactoferrin, a protein that fights bacteria and helps with iron absorption.
These aren’t minor differences. Colostrum is essentially a first vaccine and a first meal rolled into one, and newborns only need tiny volumes of it. That’s what makes pre-collection practical: even a few milliliters stored in syringes can meaningfully supplement what your baby gets at the breast in those critical first hours.
Babies at Risk of Low Blood Sugar
The most common medical reason to harvest colostrum before birth is gestational diabetes or pre-existing diabetes in pregnancy. Diabetes during pregnancy increases the chance of neonatal hypoglycemia (dangerously low blood sugar after birth) significantly. While about 6% of newborns in general experience low blood sugar, that rate jumps to 25 to 50% in babies born to mothers with diabetes.
The standard treatment for neonatal hypoglycemia is early feeding, either at the breast or with supplemental colostrum or formula. Having your own frozen colostrum on hand means the medical team can give your baby a small feed of breast milk rather than formula if breastfeeding doesn’t happen immediately. Women who’ve done this describe it as a “safety net,” reporting that seeing syringes of colostrum in the freezer gave them confidence and reduced anxiety about potential complications. Even a tiny feed of colostrum can raise a baby’s blood sugar and encourage them to breastfeed well afterward.
It’s worth noting that while the largest trial on this topic (the DAME trial) confirmed that antenatal expression is safe for women with diabetes, it didn’t demonstrate specific measurable benefits to newborns in clinical outcomes. The value may be more practical than statistical: having colostrum available reduces reliance on formula and supports mothers who want to provide breast milk from the start.
Other Situations Where It Helps
Gestational diabetes isn’t the only reason to collect early. Antenatal harvesting is also recommended when you’re planning a cesarean section, since surgery can delay skin-to-skin contact and that first breastfeed. If your baby has a known condition diagnosed before birth, such as a cleft lip or palate, a heart defect, or Down syndrome, feeding at the breast may be difficult initially, and having stored colostrum bridges the gap.
Premature babies benefit too. Mothers who deliver preterm often experience delayed milk production, sometimes by several days. Research shows that mothers of very preterm babies who begin expressing within an hour of delivery produce nearly twice as much milk in the first week compared to those who start even a few hours later. Antenatal expression builds on this principle by getting the process started before birth, potentially accelerating the transition to full milk production. A 2015 randomized study of 200 pregnant women found that starting antenatal expression at term shortened the time it took to fully establish breastfeeding.
When and How to Start
Most guidelines recommend beginning at 36 to 37 weeks of pregnancy. Starting earlier is not advised because nipple stimulation releases oxytocin, which can trigger contractions. At 36 weeks, the pregnancy is far enough along that this is considered safe for most women.
The technique is hand expression only. Breast pumps are not recommended at this stage. You gently massage each breast, then use your fingers to compress the areola and express drops of colostrum into a small syringe. Sessions should be short: about 5 to 10 minutes once you get the hang of it, two to three times a day. Don’t be discouraged if you only get drops at first. Colostrum is produced in very small quantities, and even a fraction of a milliliter has value.
Each syringe should be labeled with your name, the date, and the time. Store them in the back of the fridge for up to five days, or move them to the freezer if you won’t use them within that window. Frozen colostrum keeps for up to six months at standard freezer temperature (-18°C). When it’s time to head to the hospital, pack the syringes in a cool bag with ice packs to keep them frozen during transport.
Who Should Not Express Early
Antenatal expression is well-supported as safe for most women from 36 weeks onward, but certain pregnancy complications rule it out. You should not express colostrum before birth if you:
- Are less than 36 weeks pregnant
- Have a cervical suture (cerclage) in place
- Have experienced threatened preterm labor before 36 weeks
- Have polyhydramnios (excess amniotic fluid)
- Have vaginal bleeding or premature rupture of membranes
- Have been diagnosed with placenta praevia
- Have a baby in an unstable lie (changing position late in pregnancy)
- Take medication that is not safe for breastfeeding
If any of these apply, the potential risks of stimulating contractions or complicating an already fragile pregnancy outweigh the benefits. For women without these risk factors, the evidence consistently supports the safety of starting at 36 to 37 weeks. Your midwife or maternity team can walk you through the technique and provide syringes and storage supplies.
The Psychological Benefit
Beyond the clinical reasons, many women report that colostrum harvesting gives them a sense of agency during a time that can feel uncertain. In interviews with mothers who had diabetes during pregnancy, women described the practice as empowering. They felt they were actively doing something for their baby before birth, providing “extra nutrients” and “immunity” rather than simply waiting for potential complications. The act of collecting and freezing colostrum turned an abstract worry about neonatal blood sugar into a concrete, manageable task. For mothers facing a planned cesarean or a baby with a known health condition, having that small stash of colostrum ready can make the first hours after birth feel less stressful and more within their control.