Can Pregnancy Reduce Breast Milk Supply? What to Expect
Posted on April 20, 2026
Posted on April 20, 2026
Finding out you are pregnant while still breastfeeding can bring up a whirlwind of emotions. You might feel excited about the new addition but also concerned about how this changes things for your nursing child. One of the most common questions we hear is whether pregnancy will cause a dip in milk production. Many parents notice changes in their supply quite early in the first or second trimester.
At Milky Mama, we know how much you value your breastfeeding relationship. It is completely normal to feel a bit anxious when you notice your output decreasing or your child acting differently at the breast. Understanding the science behind these changes can help you feel more in control of your journey, and our virtual lactation consultations can help if you want personalized breastfeeding help. This post covers why supply changes happen, when to expect them, and how you can navigate breastfeeding while pregnant. We will explore the hormonal shifts and practical steps you can take to support your body during this time.
The simple answer is yes, pregnancy can and often does reduce breast milk supply for the majority of people. Research suggests that up to 70% of breastfeeding parents notice a significant decrease in their milk volume during pregnancy. This change is usually due to the complex hormonal shifts required to support a growing fetus.
While some parents are able to maintain a partial supply throughout their entire pregnancy, others find their milk dries up almost completely. This change is usually out of your direct control. It is not a reflection of your effort or your body "failing" to provide. Instead, it is a physiological response as your body prioritizes the needs of the new pregnancy.
To understand why your supply might dip, we have to look at the hormones involved in lactation. The two main players in milk production are prolactin and oxytocin. Prolactin helps your body make the milk, and oxytocin helps release it during a "let-down." A let-down is the reflex that moves milk from the back of the breast to the nipple.
When you become pregnant, your body begins producing high levels of progesterone. Progesterone is essential for maintaining a healthy pregnancy, but it has a specific effect on lactation. It acts as an inhibitor to prolactin. This means that even if you are nursing or pumping frequently, the rising progesterone levels tell your breasts to slow down milk production.
Around the midpoint of your pregnancy, usually between weeks 16 and 20, your breasts begin a process called lactogenesis I. This is when your body starts producing colostrum. Colostrum is the thick, yellowish "first milk" that is incredibly rich in antibodies and nutrients for a newborn.
This shift from mature milk to colostrum often results in a lower total volume of fluid. Colostrum is produced in smaller amounts because a newborn baby's stomach is only about the size of a marble. For an older baby or toddler who is used to a high volume of mature milk, this transition can be a big adjustment.
Usually, breastfeeding works on a "supply and demand" basis. The more milk is removed, the more your body makes. However, during pregnancy, the hormonal signals are often stronger than the physical demand. You might find that even with "power pumping" or extra nursing sessions, your supply does not return to its previous levels. This is one of the few times when the supply and demand rule does not work perfectly.
Key Takeaway: Progesterone levels rise during pregnancy to support the fetus, but this hormone naturally suppresses milk production. This is a normal biological process that happens regardless of how often you nurse.
Every person is different, but there are common patterns for when supply starts to shift. Some parents notice a change as early as the first few weeks after conception. For others, the drop is more gradual and becomes noticeable in the second trimester.
During the first few months, you might not notice a huge drop in volume yet. Instead, you might experience physical symptoms that make nursing more difficult. Nipple tenderness is a very common early pregnancy symptom. This can make the "latch" (how the baby attaches to the breast) feel painful, even if it was comfortable before.
Most parents see the most significant decrease in milk supply during the second trimester. This is when progesterone levels climb steadily. By the end of the second trimester, most of the mature milk has been replaced by colostrum. If you are pumping, you may see your ounces drop significantly during this window.
By the third trimester, your supply will likely remain at a low, steady level of colostrum. Some toddlers continue to nurse for comfort during this time, even if they are not getting much volume. This is often when "dry nursing" occurs, where the child latches and sucks even though very little milk is being produced.
If you aren't sure if your supply is changing, there are several signs to look for. These signs vary depending on the age of the child you are currently nursing.
It is important to have realistic expectations here. Because the drop is caused by hormones rather than a lack of stimulation, it is very difficult to "boost" supply back to pre-pregnancy levels. For a deeper dive, our guide on how to support your milk supply while pregnant is a helpful next step. However, you can focus on maintenance and ensuring your body has what it needs to function at its best.
Your body is doing two very big jobs at once: growing a human and making milk. This requires a significant amount of energy. Most healthcare providers recommend adding about 300 to 500 extra calories per day for breastfeeding, plus the additional calories needed for the stage of your pregnancy.
Focus on nutrient-dense foods like:
Our Emergency Lactation Brownies are a favorite for many moms because they contain oats and flaxseed, which are traditional ingredients used to support lactation. While they may not override pregnancy hormones, they provide a delicious way to get extra nutrients.
Dehydration can make a low supply even worse. Pregnancy already increases your blood volume, which requires more water. Adding breastfeeding on top of that means you need to be very proactive about your fluid intake. If you find plain water boring, our Pumpin' Punch™ or Lactation LeMOOnade™ can be a great way to stay hydrated while enjoying a treat. These drinks are designed to support hydration with a boost of flavor.
A common worry for many parents is whether nursing will cause a miscarriage or early labor. For most healthy, low-risk pregnancies, breastfeeding is considered safe. While nipple stimulation can cause mild uterine contractions (due to oxytocin), these are generally not strong enough to trigger labor in a healthy pregnancy.
However, there are certain situations where your doctor or midwife might advise you to wean. These include:
Always talk to your healthcare provider about your specific situation. They can help you determine if nursing is the right choice for you and your growing baby.
One of the hardest parts of nursing while pregnant isn't always the supply drop—it’s the physical and emotional sensation. Many parents experience "nursing aversion." This is a feeling of intense irritation, agitation, or a "skin-crawling" sensation when the older child latches.
Combined with nipple sensitivity, this can make breastfeeding feel like a chore rather than a bonding experience. If you are struggling with this, you are not alone. It is a very common biological response to the high levels of hormones in your system.
Tips for managing sensitivity:
If your supply drops significantly, you may need to make some changes to how you feed your older child. The decision depends largely on the child's age.
If you are pregnant and nursing an infant under six months, a supply drop is a medical concern. Infants this young rely entirely on breast milk or formula for nutrition. If your supply decreases, you must work closely with a pediatrician and a lactation consultant. You will likely need to supplement with donor milk or formula to ensure your baby continues to grow and stay hydrated.
At this age, babies are starting solids but still get most of their nutrition from milk. You may need to increase their intake of solid foods or offer a supplement if they are not gaining weight or have fewer wet diapers.
For children over one year old, milk is often more about comfort than primary nutrition. As long as they are eating a balanced diet of solid foods and drinking water, a drop in milk supply is usually not a nutritional emergency. This is a personal choice. You may choose to continue "tandem nursing" (nursing both the toddler and the new baby later) or use the supply drop as a natural time to wean.
When you are looking for ways to support your supply, be careful with herbal supplements. Some herbs that are commonly used in lactation products may not be recommended during pregnancy. For example, some herbs can cause uterine stimulation.
At Milky Mama, we prioritize safety and education. We always recommend that pregnant parents consult with their OB-GYN or midwife before starting any herbal lactation supplement, such as our Pumping Queen™. Your provider can help you weigh the benefits and ensure the ingredients are safe for your specific pregnancy.
Safety Note: This product is not intended to diagnose, treat, cure, or prevent any disease. Consult with your healthcare provider for medical advice.
It is okay to have mixed feelings about your supply dropping. You might feel guilty that your older child is getting less milk, or you might feel relieved if you were already considering weaning. Every drop counts, and the bond you have with your child is about much more than just the volume of milk you produce.
If you choose to continue nursing, remember that your body is doing an incredible thing. You are nourishing one child while literally building another from scratch. You're doing an amazing job, and it is important to give yourself grace during this transition.
If your goal is to tandem nurse (breastfeed both children once the new baby arrives), the supply drop during pregnancy is just a temporary hurdle.
At Milky Mama, we believe that breastfeeding support should feel compassionate and empowering. Whether you are navigating a supply drop during pregnancy or preparing for tandem nursing, we are here for you. We offer more than just products; we offer a community.
Our Breastfeeding 101 course can be a lifesaver when you are trying to figure out a supplementation plan or dealing with nursing aversion. We can help you navigate the transition from mature milk to colostrum and prepare you for the arrival of your new baby. Remember, breastfeeding is natural, but it doesn't always come naturally—especially when pregnancy is added to the mix.
Pregnancy is one of the few times when your breast milk supply may decrease despite your best efforts. The rise in progesterone is a powerful signal that shifts your body's focus toward the new life growing inside you. While this can be a challenging transition, it is a normal part of the biological process. Focus on staying hydrated, eating well, and listening to your body's needs.
You deserve support, not judgment, as you navigate this dual journey. Whether you continue nursing, decide to wean, or find a middle ground, your well-being matters just as much as your children's.
Final Thought: Your worth as a parent is not measured in ounces. Whether you nurse through your pregnancy or choose a different path, you are providing exactly what your family needs.
For more support and resources, explore our online breastfeeding classes or reach out for a personalized consultation. We are here to help you every step of the way.
While not everyone loses their supply completely, the vast majority (around 70%) will see a significant decrease. This usually happens between the fourth and fifth months of pregnancy. Some people continue to produce a small amount of colostrum, while others may experience a total "dry up" until the new baby is born.
You should always consult with your healthcare provider before taking any herbal supplements while pregnant. Some ingredients found in lactation supplements may not be recommended during pregnancy. Even with supplements, the hormonal shift of pregnancy is often strong enough to override the effects of galactagogues (milk-boosting ingredients).
Yes, your milk will likely undergo a taste change as it transitions from mature milk to colostrum. Colostrum is higher in sodium and lower in lactose, making it taste saltier and less sweet. Some toddlers may notice this change and choose to wean themselves because they no longer like the flavor.
"Dry nursing" occurs when a child continues to nurse for comfort even though very little or no milk is being produced. This is generally safe and will not harm your pregnancy as long as you are not experiencing pain or contractions. It can be a helpful way to maintain the nursing relationship if you plan to continue tandem nursing later.
Disclaimer: This product is not intended to diagnose, treat, cure, or prevent any disease. Consult with your healthcare provider for medical advice. The information provided is for educational purposes only and should not replace professional medical guidance.