Labor and birth are powerful, life-changing experiences, and pain is often one of the biggest concerns for expecting parents. In this episode, we reframe your perspective on labor pain by exploring why childbirth is challenging, how evolution has equipped us with adaptations, and what actually happens during each stage of labor. Learn the role of hormones, your baby’s contribution to the birth process, and the limitations of pain research. Also learn about the many factors that can influence your perception of pain, like support, environment, and positions, and the medical and non-medical interventions available to manage it. By the end of this episode, you will have a new perspective to help you feel prepared, capable, and confident as you approach your birth.

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Labor and Birth Vocabulary

Pain is the last thing you want to think about when you picture meeting your baby. The word pain carries negative associations, and for that reason, some people choose to avoid it. Some practitioners and expecting parents prefer words like discomfort instead of pain, or surges or waves rather than contractions. Whatever vocabulary you select, labor and birth can still be physically demanding and challenging. In this episode, I use the term’ pain’ because it is the most commonly used term in research and medical literature.

Reframing Pain

Labor and birth almost always involve some level of pain, although the experience is different for everyone. You may hear stories about pain-free births, but most expecting mothers do feel pain or discomfort as part of the process. In Western culture, movies and TV often portray childbirth as an extreme, dramatic event where the mother screams in agony. That image makes for drama on screen, but it does not reflect everyone’s reality. When you understand what to expect and why birth can involve pain, you can approach labor with more calm, clarity, and confidence. Even if the word pain feels uncomfortable to you now, by the end of this episode, you will have a better understanding of labor pain and feel less fear or negativity around it.

How We Feel Pain

Pain starts when nerves in your body send signals to your brain. Your brain interprets those signals and creates the feeling of pain. Because every brain is unique, pain is subjective, and people experience the same sensation in different ways. For example, one person might feel intense pain from a small cut, while another barely notices it. What you feel depends not only on the physical sensation but also on your emotions, your past experiences, your environment, and even your expectations.

Theories as to Why Childbirth is Difficult or Painful

It feels counterintuitive that something so essential to our survival would be difficult and come at a high cost. Historical texts, as far back as we can trace, describe women experiencing pain during birth. Some religions teach that childbirth pain was a punishment for Eve’s eating from the tree of knowledge of good and evil (Genesis 3:16). Beyond cultural or religious perspectives, researchers have studied scientific reasons rooted in human evolution and biology that help explain why labor and birth involve pain.

The Obstetric Dilemma

Researchers first proposed the concept of the obstetric dilemma in 1960 to explain why childbirth in humans is more challenging than in other primates. They argued that humans made a biological trade-off. When humans began walking upright, their hips became narrower, and the shape of the pelvis and birth canal changed. At the same time, babies’ brains grew larger, which meant their heads got bigger. A smaller pelvis in the mother combined with a bigger head in the baby made childbirth more challenging.

Supporters of this hypothesis also suggest that humans had to shorten the length of pregnancy so babies could be born while their heads still fit through the birth canal. This would explain why newborns rely so heavily on parents and why people often refer to the first three months of life as the fourth trimester.

Constrained Maternal Metabolism

Not everyone in the scientific community agrees with the obstetric dilemma, and instead, some researchers propose that gestational length is a function of constrained maternal metabolism. Meaning a mother’s body can only support a baby’s growth up to a specific energy limit, so labor begins when the baby’s needs exceed what the mother can provide.

The Move from Nomadic to Agricultural Societies

Some researchers point to lifestyle changes about 10,000 years ago as another reason birth became more difficult. When humans shifted from living as nomads to settling in farming communities, their diets changed. People became shorter in height, and shorter stature often comes with a narrower pelvis. At the same time, carbohydrate-rich diets led to larger babies. A smaller maternal pelvis, combined with bigger babies, added to the challenges of childbirth.

The Evolution of Childbirth

Although researchers may not agree on a single theory, everyone agrees that childbirth comes with challenges. The good news is that evolution has equipped us with adaptations that help us meet those challenges. Compared to men, women have a wider pelvis, which expands further at puberty to prepare for reproduction. During pregnancy, the hormone relaxin loosens ligaments and joints, adding flexibility to the pelvis. Evolution has also equipped babies with adaptations that support the birth process. They are born with unfused skull plates, which allow their heads to mold and shift as they move through the birth canal. Research even shows that women with larger heads often have birth canals that can better accommodate a baby with a bigger head. Together, these adaptations demonstrate how human evolution has worked to mitigate some of the challenges of childbirth.

The Mechanisms of Labor and Birth

We have covered theories about why childbirth is difficult and how humans have evolved to adapt. To understand labor pain even more clearly, it helps to look at the process itself. Labor follows a series of stages, each with specific changes in the body that move you closer to meeting your baby.

The First Stage of Labor

The first stage of labor starts when labor begins and ends when your cervix dilates (widens) to 10 centimeters and effaces (thins). Your uterine muscles tighten and shorten, which creates contractions to help your baby descend. Contractions follow a pattern with a rise, a peak, and then a break before the next one begins. You can picture them like hills on a graph. As labor progresses, contractions become longer, stronger, and closer together.

Hormones in the First Stage

Oxytocin is the hormone that drives contractions. Your body also releases beta-endorphins, natural stress hormones that act like painkillers. High levels of beta-endorphins can temporarily lower oxytocin and slow contractions. This may seem counterproductive to birth, but this allows you to experience the positive effects and relief from beta-endorphins, and keep labor at a pace where your body can handle the stress. Beta-endorphins do more than dull pain; they also create feelings of calm, pleasure, and even euphoria. Many people describe this as entering “labor land,” a state where you tune out your surroundings and focus inward on your body and your baby.

The Second Stage of Labor

The second stage of labor, often called the pushing stage, begins once your cervix is fully dilated to 10 centimeters and ends when your baby is born. You will continue to feel contractions along with pressure as your baby descends. Even though your cervix is open, your vaginal opening and perineum still need to stretch to allow your baby’s head to emerge. Many people describe the burning sensation at this point as the “ring of fire.” Tearing is common during this stage, but techniques like slow pushing, warm compresses, and gentle pressure can reduce the risk. For more on vaginal tears and healing, see this article.

Hormones in the Second Stage

During the second stage of labor, your body releases additional fight-or-flight hormones, called catecholamines. These include adrenaline (epinephrine) and noradrenaline (norepinephrine). Your adrenal glands release them in response to stress, and while they can slow labor in the first stage, they act very differently just before birth.

Right before your baby is born, catecholamine levels surge, especially noradrenaline. This works with oxytocin to trigger the fetal ejection reflex. These are powerful contractions that push your baby out quickly. You may feel a sudden rush of energy, become alert, notice a dry mouth, and breathe more rapidly. Some people describe emotions like fear, excitement, or intensity in this moment. These hormones also protect your baby. When your uterus contracts, blood and oxygen flow temporarily decrease. Catecholamines help your baby tolerate that stress. After birth, your levels drop sharply, which allows oxytocin to rise again and support bonding and recovery.

Your Baby is Also Working During Labor

Labor is not only about what your body does; your baby is working too. Unlike primates, who have a straight birth canal that allows their babies to descend directly, humans have a curved pelvis. To fit through it, babies must rotate as they descend. Typically, a baby descends head down, tucks their chin into their chest, and then turns their head and shoulders from sideways to facing your back. As the head emerges, the baby rotates again so the shoulders can fit through the birth canal. While you manage contractions, your baby is doing their part by making these movements.

Assessment of Pain in Research

Evaluating the research on interventions that affect pain is difficult because pain is subjective and self-reported. The most common tool researchers use is the visual analog scale, first introduced in 1921. This tool asks participants to mark a point on a 10-centimeter line that runs from “no pain” to “worst pain.” More recently, researchers have also created electronic versions of this scale. The challenge is that no two people experience pain in the same way, even when researchers apply identical measures to induce it. To work around this, researchers often look at averages across large groups.

For example, you might hear about a study that an intervention reduced the mean pain score by two points. That finding tells us the group, on average, reported less pain. It does not mean every individual experienced the same reduction. Even detailed analyses of labor pain cannot predict precisely what you will experience during birth.

Other Factors that can Influence Your Perception of Pain

While your body and your baby both play critical roles in labor, there are other factors you can control that shape how you experience pain. Individually, these tools or techniques may only make a small contribution, but stacking them together can make a larger impact.

How Continuous Support Can Influence Pain

Continuous support means having one person by your side throughout your entire labor. This support can be in many forms, like psychological, physical, emotional, informational, advocacy, or encouragement. A support person may be a nurse, midwife, doula, partner, relative, or friend. For most of human history, continuous support was the norm. Since births in the United States have shifted to hospitals over the past century, it is no longer guaranteed. In a hospital, you are likely to see several different nurses or other staff members rotate through your care. Often, your primary care provider is not present until the final part of labor.

A Cochrane review of 27 studies examined the effects of continuous support during labor. Four studies included in this review reported on pain, and continuous support did not seem to affect the pain experienced. However, the review found that the mean length of labor was 41 minutes shorter with continuous support. Less time in labor equates to less pain. The review also found that women with continuous support were less likely to use pain medication.

How Your Labor Room Environment Can Influence Pain

The environment where you give birth plays a powerful role in how labor progresses and how you experience pain. Stress hormones like adrenaline can interfere with oxytocin, the hormone responsible for contractions and slow labor. Creating a space that feels calm, safe, and supportive helps your body release oxytocin, allowing labor to move forward more smoothly. Even small details like lighting, sound, scents, and who is present in the room can stack together to influence your comfort and shape your overall birth experience.

A randomized clinical trial examined the use of Snoezelen rooms during birth. Snoezelen is a Dutch term for a controlled multi-sensory environment designed to promote relaxation. These rooms featured an overhead projector emitting a green light with changing images, an aquarium containing live fish, and soft background music. Rooms also included oil-burning candles with the option to add lavender essential oil. Researchers found that Snoezelen rooms were associated with significantly lower pain intensity than standard labor rooms. Participants in the Snoezelen rooms reported an average pain score of 5.26, while those in the control group reported an average of 9.56.

This is just one example of how optimizing your birth environment can create a better labor experience. Check out this episode for more research and actionable tips to improve your birth space.

How Positions Can Influence Pain

The way you position your body during labor has a significant impact on how you experience pain and how effective your contractions are. Moving around and trying different positions can also help you find what feels most comfortable in the moment and even shorten the duration of your labor.

Research backs this up. A review of women in the first stage of labor found that walking or staying upright reduced labor duration, lowered the risk of cesarean birth, and decreased the need for an epidural. Another study compared women who spent more than half of their labor upright to those who labored lying down. Women who stayed upright had more effective contractions, greater perineal muscle relaxation, shorter labors, and fewer requests for epidurals. They also had lower rates of assisted deliveries and cesarean sections.

No matter where you give birth or what interventions you include, you have options on the positions you labor in. Even in a hospital bed, you can sit upright and use support from your partner, doula, or nurse. What works best may change throughout labor, so keep experimenting with different positions. Check out this episode to learn what positions are most helpful in specific labor stages, tools to make positions easier, and how to modify positions when birth interventions affect your mobility.

Interventions for Pain Relief

Understanding the biology and your modifiable factors is helpful, but you also have medical and non-medical options available if you wish to utilize them. According to the American College of Obstetricians and Gynecologists, there is no other circumstance in which it is considered acceptable for an individual to experience untreated severe pain that is amenable to safe intervention while the individual is under a physician’s care. When it comes to managing labor pain, you have many options. Some mothers choose an unmedicated birth, while others use medical interventions.

Common medical options include epidurals, which are the most widely used and very effective, nitrous oxide, and intravenous medications. Each comes with its own benefits, limitations, and possible side effects. There are also non-pharmacological strategies, like hydrotherapy, breathing techniques, and TENS. It helps to know the range of options available so you can make informed decisions on which aligns best with your preferences and circumstances. In the coming weeks, we will cover your options for pain management in more detail.

Positive Perspectives for Birth

As you prepare for labor, it can help to keep a few encouraging reminders in mind. These are not evidence-based strategies but reflections and insights I’ve gathered through many years of research and my own personal experience with unmedicated birth.

You Are Birthing a Human

As natural as pregnancy and childbirth may be, it’s still extraordinary that your body is capable of creating human life. No lab or machine can replicate this. The journey and energy it takes to bring your baby into your arms is remarkable, and you deserve to give yourself and your body credit for that.

Birth as a Transformational Rite of Passage

Birth is not only a physical process but also an emotional and transformational experience. In the book “Ancient Map for a Modern Birth,” Pam England describes birth as both the birth of a child and the birth of a new self. You are embarking on a journey of becoming a mother, which will forever change who you are and how you exist in the world. Even if this is not your first baby, each birth marks a new stage in your life and a transformation as your family grows.

Break Between Contractions

Even when contractions feel their strongest, they don’t last forever. Labor comes with built-in breaks. Take advantage of those moments to rest and reset before the next contraction.

You Do Not Do This Alone

There may be moments when you feel alone because you are the only one experiencing the contractions. Remember that from the first signs of labor, you and your baby are a team. With each contraction, your body works to open and make space, while your baby works to descend and rotate into position.

Light at the End of the Tunnel

The pain and intensity of birth are temporary. At the end of labor, you will hold your baby and look into a face that will change your world forever. The reward of meeting the baby you created and carried is worth every contraction. Along with that comes another gift, and that is the feeling of empowerment in knowing you did this. Birth is hard work, but you are capable, strong, and more powerful than you know.

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