Antenatal expression, also known as colostrum harvesting, involves stimulating the breasts to collect the first milk, or colostrum, before the baby is born. This practice is often discussed by expectant parents facing certain health considerations. It requires careful thought and medical consultation, as the timing and safety profile are the two most important factors to understand before deciding to begin.
Understanding Antenatal Colostrum Harvesting
Colostrum is the thick, yellowish first milk, highly concentrated in nutrients, antibodies, and growth factors, making it the perfect first food for a newborn.
Harvesting this milk before delivery provides an invaluable supply that can be stored and used if the baby experiences feeding difficulties in the initial days. This pre-stocked supply can help babies who are at risk for low blood sugar, such as those whose mothers have pre-existing or gestational diabetes. Colostrum availability is also beneficial if the baby is born with a congenital condition, like a cleft lip or palate, or if they are diagnosed with intrauterine growth restriction.
The small, concentrated amounts of colostrum help line the newborn’s gut with healthy bacteria, protecting against infection and disease. It also acts as a natural laxative, which helps the baby pass meconium, the first tarry stool, and reduces the risk of jaundice. For mothers, practicing antenatal expression can serve as a “warm-up,” increasing confidence in milk expression techniques and promoting the flow of milk once the baby arrives.
Safety Considerations and Timing at 37 Weeks
The recommended starting point for antenatal expression is often 37 weeks because nipple stimulation, whether through pumping or hand expression, causes the release of the hormone oxytocin. Oxytocin is responsible both for the milk ejection reflex and for triggering uterine contractions.
By 37 weeks, the pregnancy is considered full-term, and the risk associated with stimulating the uterus is significantly lower than earlier in gestation. While the small surges of oxytocin from expression are generally not enough to induce labor in a low-risk pregnancy, the possibility remains. If uterine cramping or painful contractions are felt during expression, the activity should be stopped immediately, and a healthcare provider should be contacted.
It is paramount to consult with an obstetrician or midwife before starting any expression routine. They can assess the pregnancy’s specific risk factors and confirm that the practice is safe for both the mother and the baby. Starting at 37 weeks is a general guideline, not a universal permission slip.
Practical Guidance for Expression and Storage
Hand expression is the preferred method over an electric pump because colostrum is produced in very small, thick amounts. Using a pump may cause the milk to stick to the equipment and can be less effective and potentially more uncomfortable at this stage. The technique involves gently massaging the breast and then compressing the tissue behind the areola to encourage the flow of milk droplets.
A common recommendation is to start by expressing once a day for about 5 to 10 minutes, gradually increasing to two or three sessions daily as comfort allows. The small drops of colostrum should be collected directly into a sterile container, such as a small syringe, which is usually provided by the healthcare team.
Once collected, the colostrum must be labeled with the date and time of expression and stored safely. Fresh colostrum can be kept in the refrigerator for a short period, but for long-term storage until delivery, it should be frozen immediately. Colostrum kept in a freezer at -18°C or lower can be stored for up to six months. When transporting the frozen syringes to the hospital, they should be kept in an insulated bag with a freezer block to maintain the cold chain.
When Pumping Before Delivery is NOT Recommended
Antenatal expression is advised against in high-risk pregnancies due to the potential for stimulating uterine contractions and prematurely triggering labor. This practice is contraindicated for anyone with a history of threatened or actual premature labor.
It should also be avoided if there are issues with the cervix, such as an incompetent cervix or if a cervical stitch is in place. Other contraindications include a diagnosis of placenta previa, which is a low-lying placenta covering the cervix, or any unexplained vaginal bleeding during the pregnancy. Always discuss your specific medical history with your doctor or midwife.