How Much Colostrum Should I Express Before Birth?

There is no set volume you need to hit. Most pregnant people who hand-express colostrum before birth collect only drops to a few milliliters per session, and that is completely normal. The practice, known as antenatal colostrum expression, is about building a small reserve and becoming comfortable with the skill, not about filling bottles. The amounts are so small that protocols are measured in minutes of effort rather than milliliters of output, and the research behind the practice focuses on safety and breastfeeding readiness rather than volume targets.

What Typical Volumes Actually Look Like

Colostrum before birth comes in surprisingly tiny quantities, and this catches many people off guard. In a trial comparing hand expression to pumping for mothers of term newborns, the median volume collected by hand expression was about half a milliliter per session, with a range from nothing at all up to around five milliliters.¹ That is not a disappointing result. That is what colostrum looks like before the hormonal cascade of birth triggers full milk production. A newborn’s stomach on day one holds roughly five to seven milliliters per feeding, so even a syringe or two of colostrum collected before birth can genuinely matter in those first hours.

Some sessions will produce nothing visible. Others might yield a bead of thick, golden or clear fluid. Volume tends to increase gradually with consistent practice over days and weeks, but the trajectory is not linear and varies enormously from person to person. The key point is that low volume does not predict poor milk production after delivery. Colostrum is being held back by high circulating levels of progesterone during pregnancy, and that hormonal brake lifts after the placenta is delivered, not before.²

When to Start and How Often

Most guidance suggests beginning antenatal colostrum expression somewhere between 34 and 37 completed weeks of pregnancy. One commonly referenced protocol has you express for about five minutes per breast, twice a day, starting at 37 weeks and continuing until birth.³ A pilot study looking at safety tested a similar schedule of ten minutes twice daily but started earlier, at 34 weeks.⁴ Some hospitals and midwifery programs begin instruction at 36 weeks as a general starting point.⁵

The variation in starting times mostly reflects local clinical practice and how well-studied the safety data is for a given gestational age. If your provider recommends a specific week, follow their advice, because they are accounting for your individual pregnancy. The twice-daily frequency and the five-minutes-per-breast structure are the most common pattern in the literature, but this is not rigid. Some people find a single daily session is all they can manage; others express three times a day. The goal is gentle, consistent stimulation, not marathon sessions. Colostrum at this stage responds to patience and repeated short efforts, not to prolonged or forceful squeezing.

Why Hand Expression Beats a Pump for This

Breast pumps are designed to move larger volumes of mature milk efficiently, and they are not well-suited to the thick, sticky, low-volume nature of colostrum. Hand expression lets you control pressure precisely and collect every drop into a small syringe, whereas a pump can lose those tiny amounts in its tubing and flange. A randomized trial that compared the two methods in term newborns found that mothers assigned to hand expression were more likely to still be breastfeeding at two months than those assigned to pumping.¹

A historical review of antenatal expression practices noted that the one major trial that used a breast pump rather than hand expression found no difference in formula use during the hospital stay compared to no intervention at all. The authors pointed out that one clear disadvantage of using a pump is that you miss the chance to practice hand expression itself, a skill that is useful in the early days after birth when you might need to express a small amount of colostrum to help your baby latch.⁶ In other words, the technique practice may be as valuable as the colostrum you collect.

Does Expressing Before Birth Help With Milk Coming In?

This is where the evidence gets genuinely mixed, and the answer depends on the population studied. In one trial of women without diabetes, those who had been expressing antenatally were far more likely to have sufficient milk flowing within half an hour of the first breastfeed after birth: about 94% in the expressing group compared to 70% in the control group.⁷ A separate trial found that roughly 89% of women who practiced antenatal expression established full lactation within six hours of delivery, compared to about 72% of those who did not.⁸

But in women with diabetes in pregnancy, the picture is less encouraging. A randomized trial specifically looking at whether antenatal expressing hastened the onset of copious milk production found no meaningful difference. Delayed onset of lactation, defined as milk not arriving until 72 hours or more after birth, occurred at similar rates in both the expressing and non-expressing groups.⁹ And the largest trial evidence summarized in a recent review concluded that while antenatal colostrum expression is safe, trials have not found measurable improvements in breastfeeding initiation, exclusivity, or long-term breastfeeding outcomes compared to standard care.⁵

This does not mean the practice is useless. It means its primary benefits may not show up in the metrics that clinical trials measure most easily, like exclusive breastfeeding rates at hospital discharge. Having a syringe of your own colostrum ready in the freezer can make a real practical difference in the first hours if your baby needs supplementation, because it means you can avoid formula if that matters to you. And the skill-building and confidence effects, while harder to quantify, show up consistently in qualitative research.

Safety and the Question of Preterm Labor

The most common worry about expressing before birth is whether nipple stimulation could trigger contractions or premature labor. The largest and most rigorous evidence on this comes from the DAME trial, which showed no difference in gestational age at birth between the expressing group and the control group. Babies in both groups arrived at the same average point, around 38.6 to 38.7 weeks. Neonatal intensive care admissions were also similar: about 15% in the expressing group versus 14% in the standard-care group.⁶ That trial included women with diabetes, a group already at higher risk for complications, so the safety finding is reasonably reassuring.

That said, this safety evidence applies to women with otherwise low-risk pregnancies who begin at 34 weeks or later. If you have a history of preterm labor, cervical insufficiency, placenta previa, or if you are carrying multiples, the risk calculation changes. Most clinicians will advise against antenatal expression in those situations, and the research has not specifically tested safety in those populations. This is one of those cases where the general evidence says “safe” but the individual answer depends heavily on your specific pregnancy.

Who Benefits the Most

Antenatal colostrum expression was originally promoted for pregnancies where the baby is at higher risk of needing supplemental feeding shortly after birth. The most common scenario is diabetes in pregnancy, whether gestational or pre-existing. Babies of diabetic mothers are more prone to low blood sugar in the first hours, and having colostrum on hand means you can offer it quickly without reaching for formula. A retrospective study found no significant differences in rates of neonatal low blood sugar between babies whose mothers expressed antenatally and those whose mothers did not, suggesting the colostrum is at least a safe substitute for formula in that situation even if it does not eliminate the problem.¹⁰

The practice has also expanded to pregnancies where the baby has a known congenital anomaly that may complicate feeding, such as cleft lip or palate, or heart conditions that require early surgery. In those cases, having a frozen stash of colostrum that can travel to the NICU with the baby can be both practically useful and emotionally meaningful for the parent. One observational study used a protocol of expression from 37 weeks specifically for this group of mothers.³

Beyond medical indications, some people choose to express antenatally simply because they want a small backup supply or want to practice the physical skill. There is nothing wrong with that approach as long as you are past the generally accepted starting point and your provider is aware.

The Confidence Factor

Something that comes through strongly in the qualitative research is how much the practice affects the way people feel about breastfeeding before the baby even arrives. A randomized trial of women with gestational diabetes found significantly higher prenatal breastfeeding self-efficacy scores in the group that practiced antenatal expression compared to the control group.¹¹ A qualitative study of women in Western Australia found that most reflected positively on the experience, reporting that it helped them become familiar with their breasts and gave them a sense of security knowing they had colostrum stored for after birth.¹²

But the confidence effect can cut both ways. A study of first-time U.S. mothers found that some women worried when they produced little or no colostrum antenatally, interpreting it as a sign that they would have problems producing milk after birth.¹³ That concern is understandable but misplaced. As discussed earlier, the volume you collect before birth is constrained by hormones that do not fully lift until after delivery. Getting almost nothing from a prenatal session says very little about what your body will do once those hormonal conditions change. If you decide to try antenatal expression, knowing this in advance can save you from unnecessary anxiety.

How to Store What You Collect

The practical mechanics of storage are simpler than you might expect. The standard approach is to express directly into a small sterile syringe, usually a one- or three-milliliter oral syringe. Cap the syringe, label it with the date, and freeze it. Most hospitals and birth centers will let you bring frozen syringes in a cooler bag when you come in to deliver, so the colostrum is available in the first hours.

Frozen colostrum keeps well for several months in a standard home freezer. When needed after birth, a syringe can be thawed quickly by holding it under warm running water or placing it in a cup of warm water. Some people collect over several sessions into a single syringe by refrigerating it between sessions and adding to it within 24 hours before freezing, though practices on this vary by hospital policy. Ask your midwife or lactation consultant what your facility recommends, since guidelines on combining expressed colostrum differ from place to place.

The Role of Professional Support

Learning to hand-express for the first time can be awkward and frustrating, especially when the volumes are tiny and the technique is unfamiliar. The qualitative literature consistently shows that support from a midwife or lactation consultant makes a significant difference in whether people persist with the practice. A study of women with gestational diabetes in Hong Kong found that support from partners and, crucially, from midwives and lactation consultants was fundamental to their persistence with antenatal expression.¹⁴ Another U.S.-based intervention involved demonstration and practice of the technique with a lactation consultant beginning at 37 weeks, with reinforcement at weekly study visits.¹³

The Western Australian qualitative study also noted that while most women found the experience positive, some reported embarrassment about expressing in front of another person, and one described physical pain.¹² If the process is painful, something about the technique is off. Colostrum expression should involve gentle compression, not forceful squeezing. A hands-on demonstration with a professional can make the difference between a productive, comfortable experience and a discouraging one.

Why the Hormone Story Matters for Expectations

Understanding a little about what is happening hormonally can save you from misreading your body’s signals. During pregnancy, your breasts begin producing colostrum roughly at the midpoint of gestation. The glands are ready, and the product is there, but high levels of progesterone act like a dam holding back full secretion.² This is why you can extract some colostrum by hand but not a large volume. The colostrum you express is what leaks past that hormonal block under physical pressure.

After delivery, when the placenta separates, progesterone levels drop sharply and prolactin rises. That is when the dam breaks and milk volume ramps up dramatically over the following two to four days. Animal studies confirm the same pattern: colostrum secretion coincides with plummeting progesterone and rising prolactin and cortisol levels around the time of birth.¹⁵ The practical takeaway is that prenatal volume and postnatal volume are governed by different conditions. You cannot judge one by the other. A person who collects almost nothing before birth can have a perfectly abundant supply afterward, and someone who collects several milliliters a day prenatally does not necessarily have an easier postpartum transition.

This is also why the evidence on whether antenatal expression speeds up full milk production is mixed. For women without diabetes, the repeated stimulation before birth may help prepare the tissue and give a head start. For women with diabetes, who often face delayed lactation onset for metabolic reasons unrelated to breast stimulation, the practice may not overcome that underlying hormonal hurdle. The value of the stored colostrum in the meantime, bridging that gap without formula, remains real regardless.

1
PubMed Central. Randomised trial comparing hand expression with breast pumping for mothers of term newborns feeding poorly
2
Pediatric Clinics of North America. Lactogenesis: The Transition from Pregnancy to Lactation
3
PubMed Central. A Longitudinal Observation of Antenatal Milk Expression in Mothers of Infants with Congenital Anomalies
4
PubMed Central. Safety of antenatal breastmilk expression from week 34 of pregnancy: a randomized controlled pilot study (The Express-MOM study)
5
PubMed Central. Antenatal colostrum expression: are we interfering with nature?
6
Proceedings of the Nutrition Society. A brief history of antenatal colostrum expression, and where to from here
7
PubMed Central. Effect of Antenatal Expression of Breast Milk at Term in Reducing Breast Feeding Failures
8
PubMed Central. Effect of Antenatal Breast Milk Expression at Term Pregnancy to Improve Post Natal Lactational Performance
9
PubMed Central. Does Antenatal Expressing Affect Onset of Lactogenesis for Women With Diabetes? Results From a Randomised Controlled Trial and Cohort Study
10
PubMed. The effects of expressing antenatal colostrum in women with diabetes in pregnancy: A retrospective cohort study
11
PubMed Central. Effect of antenatal milk expression on prenatal breastfeeding self-efficacy, lactogenesis onset, and early exclusive breastfeeding in pregnant women with gestational diabetes mellitus: a randomized controlled trial
12
PubMed. Experiences of expressing and storing colostrum antenatally: A qualitative study of mothers in regional Western Australia
13
PubMed Central. “It gave me so much confidence”: First-time U.S. mothers’ experiences with antenatal milk expression
14
Women and Birth. A qualitative exploration of antenatal milk expression experiences among Hong Kong Chinese women with gestational diabetes: insights from the GAME programme
15
PubMed. Physiology of colostrum production