Antenatal expression (ANE) is the practice of gently hand-expressing and collecting colostrum, the first milk, during the final weeks of pregnancy. This nutrient-rich substance is naturally produced starting around the 16th week of gestation, but deliberate collection is typically considered around the 36-week mark. While 36 weeks is a common time to begin this practice, it is not a decision to be made in isolation. Before attempting any form of breast stimulation, consulting with a healthcare professional, such as an obstetrician or midwife, is necessary. This guidance ensures the practice is safe for your specific pregnancy and medical history.
Medical Clearance and Oxytocin Release
The primary safety concern surrounding antenatal expression centers on the physiological mechanism triggered by nipple stimulation. Expressing milk causes the release of the hormone oxytocin from the pituitary gland. Oxytocin is a powerful hormone involved in both the milk ejection reflex and uterine contractions.
This hormone acts on the uterine muscles, which can cause them to contract. While the uterus may already be experiencing mild, non-painful Braxton Hicks contractions, the introduction of oxytocin can potentially increase their frequency or intensity. For this reason, medical clearance from an OB-GYN or midwife is mandatory before beginning at 36 weeks, as this is still considered early term.
Starting at 36 weeks is considered safer than starting earlier in the third trimester because the pregnancy is closer to full term. However, the risk of stimulating labor is still present. A healthcare provider must confirm there are no underlying risk factors that would make uterine stimulation a concern. If any painful or regular contractions begin during expression, the activity must be stopped immediately and a medical professional contacted.
Benefits of Antenatal Colostrum Harvesting
The motivation behind antenatal expression is to create a reserve of colostrum, often referred to as “liquid gold,” which is concentrated with beneficial components. Colostrum is a unique first food, distinguished by high levels of proteins, antibodies, and growth factors. It is designed to provide newborns with immediate immunological support and to help their digestive system start functioning.
The collected colostrum serves as a readily available supplement in specific scenarios where the newborn may require immediate feeding support. A primary benefit is stabilizing the baby’s blood sugar levels, which is important if the mother has pre-existing or gestational diabetes. Babies born to mothers with diabetes are at an increased risk of neonatal hypoglycemia, and stored colostrum can be administered instead of formula to manage this condition.
Pre-collected colostrum is also useful if the baby is expected to have feeding difficulties, such as those with a cleft lip or palate, or if there is a known complication like intrauterine growth restriction. Having a supply on hand can prevent the need for artificial milk supplementation if the baby is separated from the mother after birth or if the mother’s mature milk supply is delayed. It also acts as a natural laxative, which helps the baby pass meconium, their first dark stool, reducing the risk of developing jaundice.
Practical Technique for Expression at Home
Antenatal expression is best performed using the manual hand expression technique, rather than a mechanical pump. Colostrum is produced in very small amounts—often just a few drops—and its thick, sticky consistency makes it difficult to collect efficiently with a pump. Manual expression ensures every drop can be carefully collected. To begin, wash your hands thoroughly and find a comfortable, relaxed position, possibly after a warm shower to encourage milk flow.
The technique involves forming a “C” shape with your thumb and forefinger a few centimeters behind the areola. Gently press your fingers back towards your chest wall, then compress the breast tissue to express the colostrum. Do not slide your fingers over the skin or pinch the nipple itself. Rotate the position of your fingers around the areola, similar to moving around a clock face, to express from all the milk ducts.
The expressed colostrum is collected directly into small, sterile syringes, typically 1ml or 2ml in size, which may be provided by a healthcare provider. Once collected, the syringe must be clearly labeled with the date and time of expression. It should be stored in the refrigerator between sessions on the same day. At the end of the day, transfer it to a freezer for long-term storage, which can be up to six months. Sessions should be kept short, around three to five minutes per breast, and repeated only one to three times per day to start.
Medical Conditions Where Pumping is Prohibited
While antenatal expression is safe for most low-risk pregnancies after 36 weeks, specific medical conditions make the practice absolutely contraindicated. The risk of stimulating uterine activity is too significant in pregnancies already deemed high-risk for preterm labor.
Individuals with a history of threatened or actual premature labor should not attempt any form of breast stimulation. The practice is also prohibited by the presence of certain complications, such as placenta previa or any unexplained vaginal bleeding during the current pregnancy.
Other contraindications include having a cervical suture (a stitch placed to prevent preterm birth) or a diagnosis of a short cervix. Multiple gestation pregnancies, like twins or triplets, are also advised against antenatal expression unless specifically cleared by a specialist due to the increased risk of early delivery. These conditions require avoiding any activity that could potentially trigger oxytocin release and subsequent uterine contractions.