Can Pregnancy Reduce Breast Milk Supply? What to Expect

Posted on April 20, 2026

Introduction
The Role of Hormones in Milk Production
When Does Milk Supply Typically Decrease?
Common Signs Your Supply is Changing
Managing the Physical Challenges of Nursing While Pregnant
Nutritional Demands for Tandem Support
Can You Increase Your Supply While Pregnant?
Nursing Through the Transition to Tandem Feeding
When to Seek Professional Support
Understanding the "Nursing Strike" During Pregnancy
Supporting Your Mental Wellness
Conclusion
FAQ

Introduction

Finding out you are pregnant while still breastfeeding your older child can bring up a mix of excitement and uncertainty. Many parents wonder if their bodies can handle the demands of growing a new baby while continuing to provide milk for their current nursling. At Milky Mama, we understand that this season of life requires extra grace and a lot of reliable information to help you navigate the changes ahead.

This post will cover why milk supply often decreases during pregnancy, the timeline for these changes, and how you can support your body during this transition. We will also discuss the signs of a supply drop and how to manage the needs of both your baby and your growing pregnancy. For additional guidance, read our related guide to breastfeeding while pregnant and supporting milk supply.

The short answer is that for most people, pregnancy will cause a noticeable decrease in milk volume due to significant hormonal shifts.

The Role of Hormones in Milk Production

To understand why pregnancy impacts your milk supply, it helps to look at the hormones that control lactation. Usually, milk production is a "supply and demand" system. This means the more often your baby nurses or you pump, the more milk your body makes. However, during pregnancy, your body enters a different hormonal state that prioritizes the developing fetus.

The primary hormone responsible for maintaining a pregnancy is progesterone. While progesterone is vital for a healthy pregnancy, it acts as a natural inhibitor to milk production. It essentially tells your mammary glands to slow down. During your first and second trimesters, progesterone levels rise steadily, which often leads to a drop in the amount of milk you can produce.

Understanding Prolactin and Progesterone

Prolactin is the hormone that signals your breasts to make milk. In a typical breastfeeding relationship, every time your baby latches, your prolactin levels spike. During pregnancy, however, the high levels of progesterone can block the "message" prolactin sends to your milk-making cells. This is why many moms notice a decrease in supply even if they are nursing just as frequently as before.

When Does Milk Supply Typically Decrease?

For many parents, the drop in supply happens much earlier than they expect. Some notice a change as early as the first few weeks of pregnancy, often before they even see a positive test. For others, the shift is more gradual.

Statistics and clinical observations show that about 70% of breastfeeding parents experience a decrease in milk volume during pregnancy. This most commonly occurs between the end of the first trimester and the middle of the second trimester. Our guide to supporting your milk supply while pregnant explores this natural change in greater detail.

The Colostrum Transition

Around the fourth or fifth month of pregnancy, your body undergoes another major shift. It begins to transition from mature breast milk back to colostrum. Colostrum is the thick, yellowish "first milk" that is incredibly rich in antibodies and nutrients. It is specifically designed to meet the needs of a newborn.

This transition is a biological preparation for the arrival of your new baby. Because colostrum is produced in much smaller quantities than mature milk, your older child may notice the change in volume. They might also notice a change in flavor, as colostrum tends to be saltier and less sweet than mature milk.

Key Takeaway: The drop in milk supply during pregnancy is primarily hormonal and usually occurs between the first and second trimesters.

Common Signs Your Supply is Changing

If you are concerned about your supply, there are several signs you can look for. Because the change is often gradual, you might notice behavioral shifts in your nursing child before you notice physical changes in your breasts.

Increased Nursing Frequency: Your child may want to nurse more often because they are not getting as much milk per session. This is their way of trying to "place an order" for more milk.
Frustration at the Breast: Some toddlers or older babies may pull away, cry, or act frustrated during a nursing session when the milk doesn't flow as quickly as it used to.
Longer Nursing Sessions: If the flow is slower, your child may stay latched for a longer period to feel satisfied.
Weight Gain Changes: If your nursling is under six months old and still relies on breast milk as their primary source of nutrition, it is vital to monitor their weight gain and wet diaper count closely.
Pumping Output: If you use a breast pump, you may notice that the amount you collect in each session begins to dwindle, despite your best efforts.

If you need help evaluating pumping output, weight gain, or other breastfeeding concerns, Milky Mama's breastfeeding help and virtual lactation consultations can provide personalized support.

Managing the Physical Challenges of Nursing While Pregnant

Beyond the supply drop, nursing during pregnancy can be physically demanding. It is important to listen to your body and make adjustments as needed.

Nipple Sensitivity and Soreness

One of the most common early signs of pregnancy is breast and nipple tenderness. This sensitivity can make breastfeeding feel uncomfortable or even painful for some moms. This is caused by the increase in estrogen and progesterone. If nursing becomes painful, you might try changing positions or using a nipple balm to provide some relief.

Nursing Aversion (Agitation)

Some parents experience a phenomenon called "nursing aversion" or "nursing agitation" during pregnancy. This is a sudden feeling of irritation, skin-crawling, or an intense desire to have the child unlatch. It is a biological response that is more common than many people realize. If you experience this, know that you are not alone and it is not a reflection of your love for your child. Taking deep breaths, staying hydrated, or setting gentle boundaries on nursing time can help.

Increased Fatigue

Your body is working overtime. It is growing a human, producing milk, and caring for a child. This can lead to extreme exhaustion. To support your energy levels, we recommend staying on top of your hydration. Our Pumpin' Punch™ drink mix is a great way to stay hydrated while also getting a boost of lactation-supporting ingredients like electrolytes and vitamins.

Nutritional Demands for Tandem Support

When you are pregnant and breastfeeding, your nutritional needs are significantly higher than average. You are essentially "eating for three." Your body will prioritize the developing fetus first, then the needs of your own body, and finally the production of milk.

To maintain your energy and support what supply you have, you may need to increase your caloric intake. Many experts suggest adding an additional 500 calories for breastfeeding and another 300 to 500 calories for the pregnancy, depending on which trimester you are in.

Focus on Protein: Protein is the building block for your baby’s growth and helps keep you feeling full.
Healthy Fats: Incorporate avocados, nuts, and seeds to support brain development for the baby and hormone health for you.
Iron-Rich Foods: Pregnancy can often lead to anemia, which can further impact your energy and milk supply.
Whole Grains: Oats are a classic galactagogue (a substance that may help support milk supply) and provide sustained energy.

Our Emergency Lactation Brownies are a favorite for many moms in this situation. They are packed with oats, brewer's yeast, and flaxseed, providing a tasty way to get extra nutrients and support your lactation goals during this demanding time.

Can You Increase Your Supply While Pregnant?

This is the question most moms ask when they see the numbers on the pump start to drop. It is important to have realistic expectations. Because the supply drop is driven by pregnancy hormones, traditional methods like power pumping or nursing more frequently may not have the same effect they would if you weren't pregnant.

While you may not be able to "force" your body to produce more milk against the tide of progesterone, you can support the supply you do have.

Focus on Hand Expression

Sometimes, as the milk becomes thicker and transitions to colostrum, a pump may not be as effective at removing it. Hand expression (using your hands to manually compress the breast and express milk) can sometimes be more effective during the later stages of pregnancy.

Supplementing When Necessary

If your nursing child is under a year old, their primary nutrition must come from breast milk or formula. If your supply drops significantly, you must work with your pediatrician to ensure your child is getting enough calories. You may need to supplement with expressed milk (if you have a freezer stash) or formula to bridge the gap.

What to do next:

Monitor your child's wet diapers and weight gain.

Consult a pediatric nutritionist or your doctor if you are concerned about your child's intake.

Increase your own water and calorie intake to support your energy.

For more foundational education about milk production, pumping, and recognizing low supply, consider the Breastfeeding 101 online course.

Nursing Through the Transition to Tandem Feeding

If you choose to continue nursing throughout your pregnancy, you may eventually transition into "tandem feeding." Tandem feeding is when you breastfeed both your newborn and your older child.

For many families, this is a beautiful way to help the older sibling bond with the new baby. Once the baby is born and the placenta is delivered, your progesterone levels will drop sharply. This triggers the "milk coming in" phase (Lactogenesis II), and your supply will typically increase significantly to meet the needs of both children. Learn more about this transition in our guide to tandem breastfeeding.

Will There Be Enough for the Newborn?

A common worry is that the older child will "take all the milk" from the new baby. Rest assured, the body is designed to prioritize the newborn. Your body will produce colostrum for the first few days after birth, which is exactly what the newborn needs. Most lactation consultants recommend letting the newborn nurse first to ensure they get the colostrum they need, followed by the older sibling.

When to Seek Professional Support

Breastfeeding while pregnant is a complex journey. If you are feeling overwhelmed, it is always a good idea to reach out for professional help. An International Board Certified Lactation Consultant (IBCLC) can help you create a plan that works for your specific situation.

You should consider seeking support if:

You are experiencing significant pain during nursing.
Your child is not gaining weight or is showing signs of dehydration.
You are feeling intense nursing aversion that is impacting your mental health.
You have questions about the safety of nursing with a high-risk pregnancy.

At Milky Mama, we offer virtual lactation consultations to provide you with expert guidance from the comfort of your home. We are here to support you through every stage, from the first positive test to tandem nursing and beyond.

Understanding the "Nursing Strike" During Pregnancy

Sometimes, the child is the one who decides to stop nursing during pregnancy. This is often referred to as a nursing strike or self-weaning. Because the taste and volume of the milk change, some children simply lose interest.

If your child suddenly refuses to nurse, try not to take it personally. It is often a result of the saltier taste of colostrum or the slower flow. You can try nursing in different positions or offering the breast when they are sleepy and more likely to latch out of habit. However, if they continue to refuse, they may be ready to move on to the next stage of their feeding journey.

Supporting Your Mental Wellness

Being a "milky mama" while pregnant is no small feat. The physical and emotional toll can be heavy. It is okay to set boundaries. If you find that nursing once a day is all you can handle, that is okay. If you decide that weaning is the best choice for your mental health, that is also okay.

Your well-being matters just as much as your children's nutrition. A healthy, happy parent is the best gift you can give your babies. Surround yourself with a supportive community, whether that is online or in person, and don't be afraid to ask for help with household chores so you can get the rest you need.

Conclusion

Can pregnancy reduce breast milk supply? Yes, for the majority of people, the hormonal shifts of pregnancy will cause a decrease in milk volume and a change in composition. While this can be a challenging adjustment, understanding the biological "why" behind these changes can help you navigate them with more peace of mind. Remember to prioritize your nutrition, stay hydrated with drinks like our Lactation LeMOOnade™, and listen to your body's cues.

Hormonal changes (progesterone) are the main cause of supply drops.
The transition to colostrum usually happens in the second trimester.
Increased caloric and hydration needs are essential for nursing while pregnant.
Every drop counts, and your well-being is a priority.

"You're doing an amazing job. Growing a baby while nourishing another is a testament to the incredible strength of your body."

If you need extra support or want to explore products designed to help you on this journey, our lactation snacks collection offers options to explore. Whether you choose to tandem nurse or transition to weaning, we support your decision and are honored to be part of your story.

This product is not intended to diagnose, treat, cure, or prevent any disease. Consult with your healthcare provider for medical advice. This information is for educational purposes and does not replace professional medical guidance.

FAQ

Does every woman lose her milk supply when she gets pregnant?

While not everyone loses their supply completely, about 70% of breastfeeding parents notice a significant decrease in milk volume. This is primarily due to rising progesterone levels, which naturally inhibit milk production to support the pregnancy.

Is it safe to continue breastfeeding while I am pregnant?

For most people with a healthy, low-risk pregnancy, breastfeeding is perfectly safe and does not increase the risk of miscarriage or preterm labor. However, if you have a history of preterm labor or are carrying multiples, you should discuss your breastfeeding plan with your healthcare provider.

Why does my toddler seem frustrated when nursing now that I'm pregnant?

Your toddler may be frustrated because the milk flow has slowed down or the taste has changed. As your body transitions to producing colostrum, the milk becomes thicker, saltier, and is produced in much smaller quantities, which can be a big change for a child used to a faster flow.

Can I use lactation supplements to bring my supply back while pregnant?

Subscribe & Save: 10% off

SHOP NOW

Your cart is empty

Your cart

Estimated total

About Milky Mama

Support

Stay Connected

Can Pregnancy Reduce Breast Milk Supply? What to Expect

Table of Contents

Introduction