37 Weeks Pregnant: Baby Development, Symptoms & Labor Signs

At 37 weeks of pregnancy, you have entered the final stretch of one of life’s most transformative journeys. Your body continues to undergo remarkable changes as it prepares for labor and delivery, while your baby completes crucial developmental milestones. Understanding what to expect during this pivotal week can help you feel more confident and prepared as you approach your due date.

The Size and Development of Your Baby at Week 37

Your baby has grown considerably by week 37, reaching impressive dimensions that signal readiness for life outside the womb. At this stage, your infant typically weighs between 6 and 6.5 pounds and measures approximately 19 to 21 inches in length. This size comparison is often described as similar to a bunch of Swiss chard or a leek, depending on the source consulted.

The physical development of your baby continues to refine at this stage. Your baby’s respiratory system is now fully capable of functioning independently, and the lungs have matured significantly. Many babies have developed a full head of hair by this point, though the amount and color can vary considerably from infant to infant. The skin has also transitioned to a smoother texture as the protective vernix caseosa—the waxy coating that covered your baby during most of pregnancy—begins to diminish.

Behavioral and Neurological Development

Beyond physical growth, your baby’s behavioral repertoire expands noticeably by week 37. Your infant has begun practicing facial expressions, including frowning and smiling, which demonstrates advancing neurological development. These subtle movements reflect the maturation of your baby’s central nervous system and suggest developing awareness of their environment.

Your baby’s coordination has also improved dramatically. Movements are becoming increasingly refined and purposeful, allowing your baby to grasp objects with greater precision, including their own umbilical cord—a completely normal phenomenon that requires no intervention. Most babies have achieved the optimal head-down position by this stage, which is ideal for delivery through the birth canal.

Positioning and Fetal Presentation

The positioning of your baby becomes increasingly important as delivery approaches. By week 37, the majority of babies have naturally rotated into a head-down presentation, known as vertex presentation, which is the standard position for vaginal delivery. If your healthcare provider observes that your baby remains in a breech position (buttocks or feet first), they may discuss the possibility of an External Cephalic Version (ECV), a procedure designed to help reposition your baby externally.

Physical Changes in Your Body at Week 37

While your baby continues to develop, your body is undergoing its own set of dramatic transformations in preparation for labor and delivery. Understanding these changes can help you distinguish between normal pregnancy progression and symptoms that warrant medical attention.

Weight and Body Composition

By week 37, your total pregnancy weight gain should approximate 25 to 35 pounds, representing a healthy increase that supports fetal development and maternal physiology. Importantly, most women do not experience significant additional weight gain beyond this point, as the focus shifts from expansion to preparation for delivery. Any rapid or unusual weight gain at this stage should be reported to your healthcare provider, as it may indicate fluid retention associated with complications such as preeclampsia.

The amount of amniotic fluid surrounding your baby begins to decline around week 37, which is a normal physiological adjustment as your body prepares for labor. This reduction in fluid volume reflects the baby’s maturity and readiness for birth.

Cervical Changes and Mucus Plug

Your cervix undergoes significant transformation as labor approaches. The cervix begins to dilate and efface—a process whereby it thins out and shortens—in preparation for labor. As part of this process, you may pass your mucus plug, which has served as a protective barrier throughout your pregnancy by preventing bacteria from entering the uterus. This thick, gelatinous substance may be expelled all at once or in small amounts over several days.

The mucus plug may appear tinged with blood, a phenomenon known as “bloody show,” which is a completely harmless indication that your cervix is preparing for delivery. This distinction is important because it differs from abnormal vaginal bleeding, which requires immediate medical evaluation.

Increased Vaginal Discharge

Heavier vaginal discharge is entirely normal at week 37, reflecting increased cervical mucus production as your body prepares for labor. This discharge may appear thick and yellow in appearance. Light spotting may also occur, particularly following intercourse, since your cervix becomes increasingly sensitive and friable during late pregnancy. However, any bleeding that extends beyond light spotting warrants a call to your healthcare provider, as heavier vaginal bleeding could indicate placental complications such as placental abruption, which requires immediate medical attention.

Common Pregnancy Symptoms at Week 37

The final weeks of pregnancy often bring a combination of familiar and new symptoms as your body intensifies its preparation for labor. Recognizing these symptoms can help you manage them more effectively.

Heartburn and Digestive Discomfort

Heartburn remains a common complaint at week 37, as your expanding uterus continues to place pressure on your stomach. This pressure can leave you feeling bloated, burpy, or experiencing an uncomfortable burning sensation in your chest. Rather than consuming three large meals daily, eating smaller amounts more frequently can help alleviate this symptom. Your womb pressing on your stomach can create these uncomfortable sensations, making dietary adjustments essential for managing this complaint.

Sleep Disturbances

It is entirely normal to experience sleep disruptions during late pregnancy, with many women finding themselves awake during the middle of the night. Multiple factors contribute to these sleep challenges, including physical discomfort, frequent urination, and the emotional anticipation of approaching labor. Strategies for improving sleep quality include obtaining adequate light exercise during daytime hours, consuming ample water during the day while limiting intake near bedtime, and reducing caffeine consumption.

Abdominal and Pelvic Pressure

As your baby descends deeper into your pelvis in preparation for delivery, you may experience increased pressure and new aches and pains in your lower abdominal region. This phenomenon, often referred to as “lightening” or “dropping,” can create a sensation of heaviness and may be accompanied by an increased urge to urinate, as your baby’s head presses more directly on your bladder.

Additional Common Symptoms

Several other symptoms frequently occur at week 37:

• Hemorrhoids: Pregnancy hormones relax blood vessel walls, making enlarged hemorrhoids more likely. Consuming adequate water and dietary fiber can help prevent constipation and reduce hemorrhoid discomfort.
• Stretch marks: New stretch marks may continue appearing on your abdomen and other areas throughout the final weeks of pregnancy. Regular application of body oil and consistent hydration can help your skin maintain elasticity.
• Nausea and diarrhea: Many women experience digestive changes before labor as the body undergoes final preparations.
• Swollen feet: Continued fluid retention may cause noticeable swelling in your extremities.

Distinguishing Labor Contractions from False Labor

One of the most significant concerns for expectant parents at week 37 involves correctly identifying whether contractions signal the onset of labor or represent false labor, also called Braxton Hicks contractions. Learning to differentiate between these two types of contractions is crucial for knowing when to seek medical attention.

Characteristics of Braxton Hicks Contractions

Braxton Hicks contractions, also known as practice contractions, become increasingly frequent as pregnancy advances toward term. These contractions have several distinctive characteristics: they are irregular in timing, they tend to stop and start unpredictably, they typically cease when you sit or lie down, and they do not increase in intensity or frequency over time. Although false contractions can feel remarkably real and may be as strong as actual labor contractions, they lack the progressive nature of true labor.

False contractions may wax and wane for days or even weeks before the onset of true labor. They typically occur in response to physical activity or certain positions and may resolve with rest or positional changes. Despite their discomfort, Braxton Hicks contractions are not strong enough to cause cervical dilation or effacement.

Signs of True Labor

True labor contractions display distinctly different patterns from Braxton Hicks contractions. If your contractions are increasing in intensity, lasting longer with each occurrence, and coming closer together in a regular pattern, labor may have officially begun. Unlike false contractions, true labor contractions continue regardless of whether you sit, lie down, or change positions.

True labor contractions become progressively stronger and more regular, eventually requiring considerable physical and mental focus. If this is your first pregnancy, you may experience regular contractions for several hours before entering “active labor,” the phase during which contractions become intensely painful and command all your attention—this is typically when you should proceed to the hospital.

Other Important Labor Signs to Monitor

Beyond contractions, several other developments may signal the onset of labor and warrant prompt communication with your healthcare provider or a trip to the hospital.

Water Breaking

The rupture of your amniotic sac—commonly described as “water breaking”—can occur at any moment from week 37 onward. The sensation you experience may range from a dramatic gush of fluid to a slow, steady trickle. Some women, however, never consciously notice when their water breaks, making education about other labor signs essential. The TACO method—noting the Time, Amount, Color, and Odor of any fluid—can help you and your healthcare provider determine whether amniotic fluid has indeed leaked.

Changes in Fetal Movement

Your baby should continue moving regularly throughout week 37 and beyond. If you notice a significant decrease in fetal movement, it is essential to contact your healthcare provider immediately for evaluation. Reduced fetal movement can sometimes indicate fetal distress or other complications requiring medical assessment. Familiarizing yourself with your baby’s normal movement patterns helps you recognize when something might be different.

Vaginal Discharge and Bloody Show

As previously discussed, the appearance of bloody show—blood-tinged cervical mucus—represents a normal prelude to labor. However, distinguishing this from abnormal vaginal bleeding is critical. If you experience more than minimal spotting or heavier vaginal bleeding, seek medical evaluation promptly, as this could indicate complications such as placental abruption.

Symptoms Requiring Immediate Medical Attention

While many symptoms at week 37 are benign indicators of normal pregnancy progression, certain warning signs demand immediate medical evaluation. Alert your healthcare provider or seek emergency care if you experience:

• Sudden, severe, and unusual swelling: Rapid swelling of the face, hands, feet, or other body areas may indicate preeclampsia.
• Sudden, severe, and unusual headaches: Severe headaches, particularly when accompanied by vision changes, may signal preeclampsia.
• Severe abdominal pain: Intense pain in your abdomen may indicate various complications requiring immediate assessment.
• Sudden, severe, and unusual vaginal bleeding: Heavier vaginal bleeding could represent placental complications.
• Vision changes: Blurring, flashing lights, or other vision disturbances may indicate preeclampsia or other serious conditions.
• Decreased fetal movement: A noticeable reduction in your baby’s movements warrants immediate evaluation.
• Vomiting: Persistent vomiting may be associated with serious pregnancy complications.
• Pain just below the ribs: This symptom, especially when combined with other preeclampsia signs, requires urgent medical attention.

Preparing for Labor and Delivery

As you navigate week 37, practical preparation becomes increasingly valuable. Unless your healthcare provider has advised against it, continue engaging in light exercise such as walking around the block, as this gentle physical activity supports sleep quality, reduces body aches, and helps manage swelling—all beneficial during the final weeks of pregnancy.

Ensure your hospital bag is packed and ready, and review your labor and delivery preferences with your healthcare provider. Understanding what to expect during labor and delivery can significantly reduce anxiety and help you feel more empowered during this transformative experience.

Frequently Asked Questions

Q: Is it normal to experience contractions at week 37?

A: Yes, Braxton Hicks contractions are very common at week 37. These practice contractions are irregular and cease when you rest, unlike true labor contractions, which become progressively stronger and more regular.

Q: What should I do if I experience vaginal bleeding at week 37?

A: Light spotting is normal, particularly after intercourse. However, if you experience more than minimal bleeding or pass your mucus plug with a significant amount of blood, contact your healthcare provider immediately to rule out complications such as placental abruption.

Q: How much should my baby weigh at week 37?

A: At week 37, your baby typically weighs between 6 and 6.5 pounds and measures approximately 19 to 21 inches in length.

Q: When should I go to the hospital if I am having contractions?

A: You should proceed to the hospital when contractions become regular, increasingly intense, and closer together, or when you have other clear signs of labor such as water breaking or heavy vaginal bleeding.

Q: Is it safe to exercise at week 37?

A: Yes, unless your healthcare provider has advised against it, light exercise such as walking is beneficial and can help with sleep, body aches, and swelling during late pregnancy.

Q: What does the “bloody show” look like?

A: Bloody show is thick, yellow or clear cervical mucus tinged with blood, which appears as your cervix begins to dilate and efface in preparation for labor. It is a completely normal sign of approaching labor.