The breasts produce their first milk, called colostrum, starting around the 16th week of pregnancy and continuing for the first few days after birth. This thick, often yellowish fluid is highly concentrated, providing nutrients and potent immune factors, which is why it is sometimes referred to as “liquid gold.” Antenatal Colostrum Expression (ACE), or harvesting, is the practice of manually collecting and storing this milk during the final weeks of pregnancy. The goal is to have a supply ready for the newborn if they require extra feeding support immediately after delivery or if initial breastfeeding is delayed.
Recommended Timing for Antenatal Colostrum Expression
For most individuals experiencing a healthy, low-risk pregnancy, the advised time to begin antenatal colostrum expression is around 36 or 37 weeks of gestation. This timing minimizes the risk of inadvertently stimulating the uterus to contract too early. Nipple stimulation naturally causes the body to release oxytocin, a hormone that triggers the “let-down” reflex for milk flow but also plays a role in initiating labor.
Starting expression in the late third trimester significantly reduces any theoretical risk of promoting premature delivery. Healthcare providers generally recommend that manual expression sessions be kept short, perhaps 5 to 10 minutes per session, and done only once or twice daily at the beginning. If any uterine tightening or cramping is felt during the process, stop expressing immediately and consult with a medical professional.
Medical Conditions That Prohibit Expression
While antenatal expression is generally safe for low-risk pregnancies, several medical conditions make the practice strongly discouraged or entirely prohibited. Any condition that predisposes the mother to premature labor means that the oxytocin released during breast stimulation could pose a risk. Individuals with a history of actual or threatened preterm labor in previous pregnancies should avoid expression.
Other high-risk scenarios include having a short cervix, a cervical stitch (cerclage) in place, or any instance of vaginal bleeding during the current pregnancy. Conditions such as placenta previa, where the placenta covers the cervix, also make expression unsafe due to the increased risk of hemorrhage triggered by uterine contractions. Anyone considering expression must first receive clearance from their obstetrician or midwife.
Practical Steps for Safe Harvesting and Storage
The most effective and safest way to harvest colostrum before birth is through hand expression, not by using a breast pump. Colostrum is produced in very small, thick droplets, and a pump’s suction tends to waste this fluid on the internal parts of the equipment. Hand expression allows for direct collection of the tiny amounts released, often just a few milliliters at a time.
Begin by washing hands thoroughly and ensuring sterile collection containers, such as small syringes, are ready. Applying a warm compress or expressing after a warm shower can help stimulate the milk-ejection reflex. The technique involves placing the thumb and forefinger in a “C” shape a few centimeters back from the base of the nipple, then gently pressing toward the chest wall and compressing the tissue behind the areola.
Collect the droplets directly into the sterile syringe or container, being careful not to touch the inside surfaces. Express from each breast until the flow slows, then switch sides, repeating the process on each side two or three times. Once collected, the colostrum should be clearly labeled with the date and time of expression.
Small volumes can be stored in the refrigerator for up to 24 hours to allow for multiple collections before freezing. For long-term storage, the collected colostrum should be placed in a deep freezer at -18°C or colder, where it can be kept for up to six months. When transporting the frozen supply to the hospital, it must be kept frozen using a cool bag and ice packs.
Reasons for Antenatal Colostrum Harvesting
Harvesting colostrum provides a banked supply of the infant’s first food, which can be invaluable in specific medical or logistical situations immediately after birth. One of the most common reasons for expression is for mothers with pre-existing or gestational diabetes. Babies born to diabetic mothers are at a higher risk of experiencing low blood sugar (hypoglycemia) after birth, and having colostrum readily available helps stabilize the infant’s glucose levels without needing formula supplementation.
A stored supply is beneficial in several scenarios, reducing stress on parents and supporting the goal of exclusive human milk feeding:
- If the baby is anticipated to have early feeding difficulties, such as those born with a cleft lip or palate or certain congenital conditions.
- If a planned Cesarean section is scheduled.
- If there is a known risk of the mother and baby being separated, such as if the infant requires a stay in the neonatal intensive care unit.
Having colostrum available ensures the baby receives the immunological and nutritional benefits immediately.