When Do Pregnant Women Start Lactating? Early Signs and What to Expect

Wondering when your breasts will start producing milk? The lactation process begins earlier than most expecting mothers realize, and understanding this natural process can help you feel more confident about your upcoming breastfeeding journey. Lactation typically begins around the middle of pregnancy, between 16 to 20 weeks (Source: GetBoober).

Through my years of supporting new mothers, I’ve noticed that many are surprised to learn that their bodies start preparing for breastfeeding long before their baby arrives (honestly, before you even thought about getting pregnant). This early preparation is actually a beautiful example of how our bodies instinctively know what to do to nourish our little ones.

The process begins with subtle changes in your breast tissue during early pregnancy, progressing to the production of colostrum (your first milk) by mid-pregnancy. While some mothers notice signs of lactation early on, others might not experience any noticeable changes until after birth – and both scenarios are completely normal.

Your breasts are actually preparing for milk production from birth and as you go through puberty and each of your menstrual cycles – and the process ramps up significantly when you become pregnant. The hormonal changes that sustain your pregnancy also trigger the development of milk-producing glandular tissue. This gradual process ensures that your body will be ready to nourish your baby when the time comes.

Throughout this article, you’ll learn about each stage of the lactation process during pregnancy, helping you understand:

• The timeline of lactation development during each trimester
• Early signs that your body is preparing for breastfeeding
• What to expect with colostrum production
• How milk production changes after birth
• Normal variations in the lactation process

Remember, while there’s a typical timeline for lactation development, every mother’s experience is unique. Some women may notice breast changes and even leak colostrum during pregnancy, while others won’t experience any leaking until after birth. Both scenarios are perfectly normal and don’t indicate how successful your breastfeeding journey will be. If you don’t notice any breast changes during pregnancy, make sure to reach out to a lactation professional before you give birth.

Throughout this article, I’ll share both evidence-based information and practical insights from my experience supporting countless mothers through their breastfeeding journeys. Understanding these changes can help you feel more prepared and confident about your body’s amazing capabilities, whether you’re in your first trimester or approaching your due date.

The Lactation Timeline During Pregnancy

The development of your milk-producing system follows a carefully orchestrated timeline throughout pregnancy. This process, known as lactogenesis, begins during early pregnancy and continues through the postpartum period. Stage I lactogenesis occurs throughout pregnancy, with significant developments in breast tissue and hormone levels preparing your body for milk production (Source: NCBI).

First Trimester Changes

During these early weeks, your body is already laying the groundwork for milk supply development. The most noticeable changes typically include:

Your breasts begin their transformation almost immediately after conception. The rising levels of estrogen and progesterone trigger the development of additional milk ducts and the growth of milk-producing cells. You might notice your breasts becoming tender and more sensitive – this is a sign that these important changes are taking place.

While you won’t produce milk during this time, your breast tissue is undergoing crucial developmental changes. The network of milk ducts is expanding, and blood flow to your breasts increases significantly. Some women may notice their veins becoming more visible through their skin – this is completely normal and helps support the developing milk-producing system.

Second Trimester Development

The second trimester marks a significant milestone in your lactation journey. Around 16-20 weeks into pregnancy, your breasts begin producing colostrum, the nutrient-rich first milk that will nourish your baby immediately after birth. This early milk production is normal during pregnancy, though not everyone will notice it.

During this time, your breasts continue to grow and develop. The areolas (the dark area around your nipples) typically become larger and darker, and small bumps called Montgomery’s tubercles may become more prominent. These changes help prepare your breasts for their upcoming role in breastfeeding your newborn baby.

Some key developments during this period include:

• Formation of mature milk-producing cells
• Development of additional milk ducts
• Beginning of colostrum production
• Continued growth and changes in breast tissue

Third Trimester Preparation

The final months of pregnancy are crucial for completing your breast tissue development. Your body maintains high levels of progesterone, which prevents significant milk production while allowing colostrum production to continue. This hormonal balance ensures your body will be ready to produce mature milk after your baby’s birth.

During these last weeks, you might experience:

It’s important to understand that while these changes happen internally, you may not notice all of them externally. Some mothers experience obvious signs like leaking colostrum, while others don’t notice any leaking at all. Some believe more leakage occurs due to weaker nipple muscles. Both scenarios are normal and don’t predict your ability to produce milk after birth.

Throughout this entire process, your body prepares for immediate feeding after birth and your whole breastfeeding journey. The complex hormonal changes and physical developments during pregnancy create the foundation for successful milk production once your baby arrives.

Remember that while this timeline represents the typical progression of lactation development, every woman’s body follows its unique pattern. The absence of any particular sign doesn’t indicate a problem with your milk-producing capability. What matters most is that your body naturally prepares itself, even if you can’t see all the changes.

Early Signs of Lactation

Recognizing the early signs of lactation can help you understand how your body prepares for breastfeeding. Some mothers may notice these changes as early as the 12th or 14th week of pregnancy (Source: Flo Health). Let me walk you through the most common signs I see in my practice as a lactation consultant.

Physical Breast Changes

Your breasts will undergo several noticeable changes as they prepare for milk production. These changes are essential indicators that your body is developing its milk-making capabilities, though it’s important to remember that the degree of change doesn’t predict your future milk supply.

The most common physical changes include:

• Increased breast size and fullness
• Greater breast sensitivity or tenderness
• Darkening of the areolas
• More prominent Montgomery’s tubercles (small bumps on the areola)
• More visible veins under the breast skin

These changes occur gradually throughout your pregnancy, and you might notice some more than others. Each person’s experience is unique, and all variations are expected as long as the changes are happening progressively rather than suddenly.

If you don’t notice any changes, especially by the third trimester, be sure to book a prenatal consult with a member of my team so we can help support your breastfeeding journey by identifying any potential hurdles.

Colostrum Production

One of the most significant signs of lactation is the production of colostrum. This thick, yellowish fluid is often called “liquid gold” because of its rich concentration of antibodies and nutrients. While some women notice colostrum production during pregnancy, others won’t see any until after birth.

If you do notice colostrum, you might experience:

I want to emphasize that not leaking colostrum during pregnancy is entirely normal. I’ve worked with countless mothers who didn’t notice any leaking during pregnancy yet went on to have an abundant milk supply after birth. Even with my own pregnancies, I only noticed colostrum leakage with my first and second babies and none with my third – and I made the most milk with my third child. Your body is still preparing for breastfeeding even if you don’t see visible signs.

For those interested in learning more about the early stages of breastfeeding, I’ve compiled some helpful breastfeeding tips for new moms that can help you prepare for your journey.

While these early signs are exciting indicators of your body’s preparation for breastfeeding, remember that every pregnancy is different. Some mothers prominently experience these signs, while others might notice very few changes. What matters most is that your body is naturally preparing for breastfeeding, even if you can’t see all the changes happening externally.

Postpartum Milk Production

The transition from pregnancy to postpartum brings significant changes in milk production. After the placenta is delivered, it signals to your body to ramp up milk production, and you’ll produce more colostrum. Within 24-72 hours, your milk will start to transition to more mature milk, which is made in higher quantities. Some people refer to this as when “your milk comes in“, though this can cause some confusion – because colostrum is milk, making some moms worry that they don’t have any milk until several days postpartum.

Let me explain what happens during this crucial transition period in a little more detail.

The Hormonal Shift

The birth of your baby and delivery of the placenta trigger dramatic hormonal changes that signal your body to begin copious milk production. This process involves several key hormones:

Understanding these hormonal changes can be particularly important if you’re breastfeeding after a c-section, as the recovery process might affect your early breastfeeding experience. However, rest assured that your body is designed to initiate milk production regardless of the delivery method.

When Your Milk Comes In

The transition from colostrum to mature milk, often called milk “coming in,” typically follows this pattern:

• Days 1-2: Colostrum production continues
• Days 2-5: Transitional milk begins
• Days 5-14: Mature milk production establishes

During this transition, you might notice several physical sensations and changes. Your breasts may feel fuller, heavier, and warmer as milk production increases. Some mothers experience temporary engorgement, which usually subsides as their body adjusts to their baby’s feeding patterns.

If you’re interested in optimizing your milk production, I’ve created a comprehensive guide on how to increase breast milk supply that can help you understand the factors affecting milk production.

Common signs that your milk is coming in include:

• Increased breast fullness and warmth
• Milk leaking between feedings
• Changes in baby’s feeding patterns
• Noticeable let-down sensations
• Changes in milk color and consistency

I’ve observed that this transition period can feel overwhelming. Remember that while the timeline I’ve described is typical, every mother’s experience is unique. Some women notice their milk coming in earlier or later, and both scenarios can be perfectly normal.

The key to supporting this transition is frequent, effective nursing or pumping. Your baby’s suckling stimulates the hormones needed for milk production, helping establish your supply. Even if you don’t feel your milk has fully come in, continuing to nurse regularly provides your baby with valuable colostrum while signaling your body to increase production.

Normal Variations in Lactation

While there’s a typical timeline for lactation development, it’s important to understand that variations are common and usually normal. Factors such as first-time motherhood, cesarean delivery, and overall health can influence the timing and experience of lactation (Source: Femia Health). Let me address some of the most common variations I encounter in my practice.

Individual Differences

Every mother’s lactation journey is unique, and I’ve seen countless variations in my years of supporting breastfeeding mothers. If you have breastfeeding questions about your personal experience, understanding these common variations can help provide reassurance:

You might notice changes in your milk’s appearance and consistency throughout your journey. If you’re wondering why is my breastmilk watery or why it looks different from day to day, these variations are typically normal and reflect your body’s adaptation to your baby’s needs.

Special Circumstances

Several situations can affect the timing and progression of lactation:

• First-time motherhood
• Cesarean birth recovery
• Premature delivery
• Previous breast surgery
• Certain medical conditions
• Retained placenta
• Significant blood loss during/after birth

In my experience, mothers often need additional support and reassurance. While these circumstances might affect the timing of milk production, most women can still achieve successful breastfeeding with proper support and guidance.

Here are some important points to remember about variations in lactation:

The absence of typical signs doesn’t necessarily indicate a problem. I’ve worked with many mothers who experienced few early signs of lactation yet went on to have an abundant milk supply. What matters most is your baby’s feeding cues and output once breastfeeding begins.

If you’re experiencing any of these variations, monitoring these indicators can help ensure things are progressing normally:

• Baby’s feeding patterns and behavior
• Diaper output (wet and soiled)
• Baby’s weight gain pattern
• Your physical comfort and symptoms

While variations are standard, there are times when you should seek professional support. Contact your healthcare provider or a lactation consultant if you experience:

• Severe breast pain or engorgement
• No signs of milk production by day five postpartum
• A significant difficulty with latching
• Concerns about baby’s weight gain

Remember, seeking support isn’t a sign of failure – it’s a smart way to ensure you and your baby get the help you need to thrive in your breastfeeding journey. Every mother’s experience is unique, and understanding these variations can help you approach your journey with confidence and realistic expectations.

Preparing for Lactation

While your body naturally prepares for lactation during pregnancy, there are several steps you can take to support this process and prepare for your breastfeeding journey. As a lactation consultant, I’ve found that mothers who educate themselves and prepare during pregnancy often feel more confident when their breastfeeding journey begins.

Let’s explore some practical ways to prepare for lactation and preparing for breastfeeding success:

Educational Preparation

• Take a prenatal breastfeeding class
• Read evidence-based breastfeeding resources
• Learn about normal newborn feeding patterns
• Understand the signs of effective feeding

Knowledge is empowering, but remember that practical experience will be your best teacher. While learning about breastfeeding before your baby arrives is helpful, be open to learning and adjusting as you go.

Physical Preparation

When it comes to breastfeeding supplies, focus on the essentials first. In my experience, you don’t need many specialized items to breastfeed successfully. Here are the basics I recommend:

Building a support system is crucial for breastfeeding success. Consider:

• Identifying local lactation consultants (or connecting with a member of my team virtually – we love helping moms worldwide!)
• Joining breastfeeding support groups (Fuss-Free First Year includes a private community where you can talk with other breastfeeding moms)
• Discussing your plans with your partner and family
• Connecting with other expecting or nursing mothers

Remember that preparation doesn’t guarantee a perfect journey, but it can help you feel more confident and know where to turn for help if needed. Every mother’s experience is unique, and flexibility in your approach will serve you well as you begin this journey.

Frequently Asked Questions About Lactation During Pregnancy

Here are answers to the most common questions I get from new moms about this topic, along with guidance on when to seek additional support.

Is it normal if I’m not leaking any colostrum during pregnancy?

Yes, absolutely! While some women notice colostrum leaking during pregnancy, many don’t experience any leaking at all. This variation is normal and doesn’t predict your ability to produce milk after birth. What matters most is understanding the breastfeeding truths rather than myths about early milk production.

Can I collect and store colostrum before birth?

Some mothers choose to hand express and store colostrum before birth, typically from 37 weeks onwards. However, this should only be done with your healthcare provider’s approval, as nipple stimulation can trigger contractions in some women.

Why are my breasts not growing much during pregnancy?

Breast size changes during pregnancy vary significantly among women. Some experience dramatic growth, while others notice minimal changes. The extent of visible changes doesn’t indicate your ability to produce milk. Internal changes in milk-producing tissue occur regardless of external size changes. However, this sometimes can indicate a problem, so reach out to a lactation consultant that specializes in low supply to help you navigate this situation.

Is it normal for only one breast to leak during pregnancy?

Yes, this is completely normal. Breasts often behave differently from each other, and uneven leaking during pregnancy is common. This asymmetry typically doesn’t affect your overall milk production ability after birth.

When should I be concerned about lactation development?

While variations are normal, consult your healthcare provider if you experience:

• Sudden, painful breast changes
• Signs of infection (redness, fever, pain)
• No breast changes at all throughout pregnancy
• Previous breast surgery affecting the nipples or milk ducts

Will leaking colostrum during pregnancy decrease my milk supply after birth?

No, leaking colostrum during pregnancy doesn’t affect your future milk supply. Your body continuously produces colostrum, and leaking doesn’t deplete your storage. Your milk supply will be established based on your baby’s feeding patterns after birth.

How can I tell if my breasts are developing normally for breastfeeding?

Normal breast development during pregnancy typically includes:

Can anything prevent my milk from coming in?

While most women will produce milk successfully, certain factors can affect milk production:

• Retained placental tissue
• Previous breast surgery affecting milk ducts
• Certain hormonal conditions
• Some medications

If you have concerns about any of these factors, discuss them with your healthcare provider or a lactation consultant during pregnancy.

When should I start preparing for breastfeeding?

The second trimester is an ideal time to begin learning about breastfeeding and making preparations. This gives you plenty of time to:

• Attend breastfeeding classes
• Find local support resources
• Gather necessary supplies
• Discuss your plans with your support system