Pregnant individuals often question the safety of manipulating their breasts, whether through massage or intentional expression, due to the fear of inadvertently triggering labor. The safety depends heavily on the timing in the pregnancy and the individual’s underlying health status. For most people with a low-risk pregnancy, occasional, non-aggressive breast manipulation is unlikely to cause a problem. However, caution and medical consultation are always warranted before engaging in deliberate stimulation, especially in the later stages of pregnancy.
The Physiological Link Between Nipple Stimulation and Uterine Activity
Stimulation of the nipple and the surrounding areola triggers the neuroendocrine reflex. Sensory nerve endings send signals to the brain, prompting the release of the hormone oxytocin into the bloodstream.
Oxytocin is recognized for its dual function in the reproductive system. It is the primary hormone responsible for triggering uterine contractions and is routinely used in synthetic form to induce or augment labor.
The oxytocin released also causes the milk ejection reflex, or “let-down.” While nipple stimulation can cause uterine activity, this effect is highly variable and depends on the stage of gestation. Studies show that stimulation can cause uterine contractions in full-term women, with oxytocin levels rising in short bursts during these contractions.
The release of oxytocin in response to stimulation is typically pulsatile, contrasting with the continuous infusion used during medical induction. Although nipple stimulation can increase uterine contractions, whether it causes a sustained increase in circulating oxytocin is still being studied.
Safety Guidelines and Contraindications for Breast Manipulation
The primary safety concern regarding breast manipulation is the risk of unintentionally initiating preterm labor. For individuals with an uncomplicated, low-risk pregnancy, gentle and brief stimulation, such as during hygiene or sexual activity, is generally considered safe. However, the risk profile changes significantly as a person approaches full-term or if certain medical conditions are present.
Healthcare providers advise against intentional or prolonged stimulation if the individual is at risk for early delivery, including those with a history of preterm labor. Specific medical conditions are considered absolute contraindications to intentional stimulation.
Conditions requiring complete avoidance of breast and nipple manipulation include:
- A short cervix or an incompetent cervix.
- A low-lying placenta or placenta previa, where the placenta covers the cervix.
- Multiple gestation, such as being pregnant with twins or triplets.
It is strongly advised to consult with a healthcare provider before attempting any intentional nipple stimulation. If uterine cramping or bleeding occurs during or after breast manipulation, stop the activity immediately and contact a doctor or midwife. For low-risk individuals, intentional stimulation, such as for colostrum expression, is generally not recommended until after 36 weeks of gestation.
Purposeful Antenatal Colostrum Expression
Pregnant individuals may purposefully “squeeze” their breasts for Antenatal Colostrum Expression (ACE), also known as colostrum harvesting. Colostrum is the initial, antibody-rich milk produced by the breasts, often starting around the 16th week of pregnancy. Collecting and storing this colostrum before birth benefits newborns who may need extra feeds or supplementation.
Benefits of Antenatal Colostrum Expression
A pre-prepared supply of colostrum is particularly beneficial for babies who may experience low blood sugar levels, such as those born to individuals with diabetes in pregnancy. It is also helpful for babies who might have difficulty feeding initially due to conditions like a cleft lip or palate. Expressing colostrum antenatally can also increase a parent’s confidence in their ability to hand express, which is a useful skill for establishing feeding after delivery.
Manual expression is the recommended technique, as breast pumps are impractical for the small amounts of colostrum produced prenatally. The technique involves washing hands, gently massaging the breast, and then using the thumb and forefinger to compress the tissue a few centimeters back from the areola. The colostrum droplets are collected into a sterile syringe, labeled with the date, and then frozen.
It is advised to begin hand expression around 36 or 37 weeks of pregnancy, and only after receiving explicit medical approval. Sessions should start gently, perhaps for only three to five minutes on each breast, two to three times a day. If no colostrum is expressed, this does not indicate future milk supply issues, as hormonal changes after birth trigger full milk production.