Antenatal expression, often called colostrum harvesting, is the practice of hand-expressing small amounts of breast milk during the final weeks of pregnancy. This initial milk, known as colostrum, is produced starting around the middle of pregnancy and continues for the first few days after birth. Many expectant parents consider beginning this process at 37 weeks gestation, which is considered early term. The primary reason for this practice is to build a small reserve of this nutrient-dense substance to use after the baby’s arrival, especially if feeding challenges arise.
Why Consider Pumping at 37 Weeks
Colostrum is packed with a concentrated blend of nutrients and immunological factors perfectly suited for a newborn. It is low in fat and high in carbohydrates, protein, and antibodies that protect the baby from infections and diseases. This early milk also acts as a laxative, helping the newborn pass meconium, the baby’s first dark stool, which helps reduce the risk of jaundice.
Banking a supply of colostrum is beneficial for infants who may face feeding difficulties or blood sugar regulation issues immediately after birth. This includes babies born to mothers with pre-existing or gestational diabetes, as they are prone to low blood sugar (hypoglycemia). A ready supply of colostrum allows medical staff to provide supplementation with human milk instead of formula if the baby’s glucose levels drop.
Storing colostrum is also helpful for mothers having an elective cesarean section or those with babies diagnosed antenatally with conditions like cleft lip or palate. Using expressed colostrum ensures the baby receives its mother’s milk and immunological protection during separation or delay in effective breastfeeding. Furthermore, learning to hand express before birth can boost a mother’s confidence and skill set for the breastfeeding journey ahead.
Understanding the Safety Concerns
The decision to begin antenatal expression at 37 weeks should be made in consultation with a healthcare provider. The main safety concern revolves around the potential for breast and nipple stimulation to trigger uterine contractions. This occurs because stimulation releases oxytocin, a hormone responsible for the milk let-down reflex, which is chemically identical to the hormone that causes labor contractions.
While 37 weeks is considered full term, the release of oxytocin can potentially initiate labor. Research indicates that hand expression is safe for women with low-risk pregnancies starting at this gestation. During expression, it is common to experience mild uterine tightening, known as Braxton Hicks contractions.
These mild contractions are non-painful and irregular, representing normal uterine activity. However, if the contractions become regular, painful, or feel like menstrual cramps, the expression session must be stopped immediately. Any progression toward labor-like symptoms, such as persistent pain or vaginal bleeding, requires immediate medical evaluation.
When Antenatal Expression is Contraindicated
For some individuals, the risk of stimulating uterine contractions outweighs the benefits, making antenatal expression unsafe. This applies to pregnancies with known risk factors for preterm labor or placental issues. Any history of threatened or actual premature labor in the current or previous pregnancies prohibits the practice.
Absolute contraindications include conditions involving the structure of the cervix, such as an incompetent cervix or the presence of a cervical suture. Placental issues, including known placenta previa or any unexplained vaginal bleeding in the current pregnancy, also make expression unsafe. Mothers carrying multiples are advised against antenatal expression due to their higher risk of early delivery.
Techniques for Colostrum Collection and Storage
Hand expression is the recommended technique for colostrum collection during the antenatal period, as the initial volume is typically very small and thick. Using a breast pump at this stage is generally ineffective and can cause discomfort or damage to the delicate breast tissue. Start by washing hands thoroughly and applying a warm compress or expressing after a warm shower to encourage milk flow.
The process begins with a gentle breast massage. Form a “C” shape with the thumb and forefinger a few centimeters behind the areola. Press the fingers back toward the chest wall, then compress the thumb and forefinger together, rolling them gently forward toward the nipple without sliding across the skin. This should be a rhythmic action of pressing and releasing.
Express for short, limited periods, such as five to ten minutes per breast, one to three times daily, switching sides when the flow slows. The drops of colostrum should be collected directly into sterile, one-milliliter syringes, which can be obtained from a healthcare provider. Colostrum collected throughout the day can be stored in the refrigerator, and the labeled, capped syringes should be transferred to the freezer. Frozen colostrum is safe to use for up to six months and must be transported to the hospital in a freezer bag or cooler with ice packs to maintain its frozen state.