The third trimester marks the final chapter of your pregnancy journey, spanning from week 28 until the birth of your baby, typically around week 40. This exciting yet challenging period brings significant changes to both your body and mind as you prepare to welcome your little one. Understanding what to expect during these last few months can help you navigate this transformative time with greater confidence and peace of mind.
When Does the Third Trimester Begin?
The third trimester officially begins at week 28 of pregnancy and continues until you give birth. For most pregnancies, this means approximately 12 to 13 weeks. During this time, your baby will gain most of their birth weight, and their organs will mature in preparation for life outside the womb. Your body will also undergo remarkable changes to support your growing baby and prepare for labor and delivery.
Physical Changes During the Third Trimester
As your pregnancy advances into the final stretch, you will likely experience a variety of physical symptoms and changes. While every pregnancy is unique, many women report similar experiences during this period.
Weight Gain and Belly Growth
Your belly will continue to expand significantly during the third trimester as your baby grows rapidly. Most women gain approximately one pound per week during this time. You may notice your belly button protruding outward, and stretch marks might become more visible on your abdomen, breasts, and thighs. Your skin may feel tight and itchy as it stretches to accommodate your growing uterus.
Braxton Hicks Contractions
These practice contractions become more frequent and noticeable during the third trimester. Your uterus tightens for 30 seconds to two minutes, then relaxes. Unlike true labor contractions, Braxton Hicks contractions are irregular and typically don’t increase in intensity or frequency. They help prepare your body for labor but don’t cause cervical dilation. However, if you experience regular contractions that become increasingly stronger and closer together, contact your healthcare provider immediately, as this may indicate preterm labor.
Back Pain and Pelvic Discomfort
Lower back pain affects up to 50 percent of pregnant women, particularly in the third trimester. The added weight of your baby, coupled with hormonal changes that loosen your joints and ligaments, can strain your back muscles and spine. Your center of gravity shifts forward, which may cause you to adjust your posture in ways that create additional strain.
To manage back pain, maintain good posture, avoid standing for prolonged periods, sleep on your side with a pillow between your knees, wear supportive shoes, and engage in pregnancy-safe exercises such as swimming or prenatal yoga. Applying heat or cold packs to affected areas may provide relief. If pain becomes severe or persistent, consult your healthcare provider about physical therapy options.
Breathing Difficulties
As your uterus expands upward, it pushes against your diaphragm and compresses your lungs, making it harder to take deep breaths. You may feel short of breath, especially during physical activity or when lying flat. Your body compensates by breathing more efficiently, taking in more oxygen with each breath. This sensation usually improves in the final weeks of pregnancy when the baby drops lower into your pelvis, a process called lightening.
To ease breathing difficulties, practice good posture to maximize lung capacity, sleep propped up with pillows, move slowly and take breaks during activities, and try relaxation techniques such as deep breathing exercises. Contact your healthcare provider if you experience severe shortness of breath, chest pain, or rapid heartbeat, as these could indicate a more serious condition.
Swelling and Fluid Retention
Mild swelling in your feet, ankles, hands, and face is common during the third trimester. Your body retains more fluid during pregnancy, and the pressure of your growing uterus on blood vessels can slow circulation, causing fluid to accumulate in your lower extremities. Swelling typically worsens throughout the day and in hot weather.
To reduce swelling, elevate your feet when sitting or lying down, avoid standing for long periods, wear comfortable shoes, stay hydrated, reduce sodium intake, sleep on your left side to improve circulation, and engage in gentle exercise such as walking or swimming. However, sudden or severe swelling, especially in your face and hands, accompanied by headaches or vision changes, may indicate preeclampsia, a serious pregnancy complication requiring immediate medical attention.
Sleep Challenges
Getting comfortable at night becomes increasingly difficult during the third trimester. Your growing belly, frequent urination, leg cramps, heartburn, and baby movements can all disrupt your sleep. Many pregnant women experience insomnia or restless sleep during this time.
To improve sleep quality, establish a consistent bedtime routine, sleep on your left side with pillows supporting your belly and between your knees, avoid large meals and caffeine close to bedtime, keep your bedroom cool and dark, practice relaxation techniques before bed, and take short naps during the day if needed. Remember that some sleep disruption is normal and doesn’t harm you or your baby.
Frequent Urination
As your baby descends into your pelvis, pressure on your bladder increases, causing you to urinate more frequently, including multiple times throughout the night. You may also experience stress incontinence, where small amounts of urine leak when you cough, sneeze, laugh, or exercise.
To manage frequent urination, empty your bladder completely by leaning forward while urinating, practice Kegel exercises to strengthen pelvic floor muscles, limit fluids before bedtime while staying well-hydrated during the day, and wear panty liners if needed for leakage. Contact your healthcare provider if you experience burning during urination or notice changes in urine color or odor, as these may indicate a urinary tract infection.
Digestive Issues
Heartburn, indigestion, and constipation often worsen during the third trimester. Pregnancy hormones slow digestion, and your expanding uterus crowds your stomach and intestines, contributing to these uncomfortable symptoms.
For heartburn relief, eat smaller, more frequent meals, avoid trigger foods such as spicy, fatty, or acidic foods, don’t lie down immediately after eating, sleep with your upper body elevated, and wear loose-fitting clothing. For constipation, increase fiber intake through fruits, vegetables, and whole grains, drink plenty of water, exercise regularly, and establish regular bathroom habits. Always consult your healthcare provider before taking any medications or supplements for digestive issues.
Varicose Veins and Hemorrhoids
Increased blood volume and pressure from your growing uterus can cause veins in your legs and rectum to swell. Varicose veins appear as enlarged, twisted veins visible beneath the skin, while hemorrhoids are swollen veins in the rectal area that can cause itching, pain, and bleeding.
To prevent and manage these conditions, avoid sitting or standing for extended periods, elevate your legs when possible, wear compression stockings, exercise regularly, maintain a healthy weight, avoid constipation by eating fiber-rich foods and staying hydrated, and avoid straining during bowel movements. For hemorrhoid relief, try warm sitz baths, apply cold compresses, and keep the area clean and dry. Discuss treatment options with your healthcare provider if symptoms persist or worsen.
Emotional and Mental Changes
The third trimester brings a complex mix of emotions as the reality of parenthood draws near. Understanding these emotional shifts can help you navigate them more effectively.
Anticipation and Excitement
As your due date approaches, feelings of excitement and anticipation typically intensify. You may find yourself daydreaming about your baby, decorating the nursery, and eagerly preparing for your new arrival. These positive emotions can help motivate you through the physical discomforts of late pregnancy.
Anxiety and Fear
It’s completely normal to experience anxiety about labor, delivery, and parenthood during the third trimester. Common concerns include fear of pain during childbirth, worry about potential complications, anxiety about caring for a newborn, and uncertainty about how your life will change. First-time parents often experience heightened anxiety as they face the unknown.
To manage anxiety, educate yourself about labor and delivery through childbirth classes, talk openly with your healthcare provider about your concerns, connect with other expectant or new parents for support and reassurance, practice stress-reduction techniques such as meditation, deep breathing, or prenatal yoga, and consider speaking with a mental health professional if anxiety becomes overwhelming or interferes with daily functioning.
Mood Swings and Irritability
Hormonal fluctuations, physical discomfort, sleep deprivation, and stress can contribute to mood swings during the third trimester. You may feel more emotional, tearful, or irritable than usual. These feelings are normal and don’t mean something is wrong.
Nesting Instinct
Many women experience a strong urge to clean, organize, and prepare their home for the baby’s arrival during the final weeks of pregnancy. This nesting instinct is a natural way of gaining a sense of control and readiness. However, be careful not to overexert yourself during nesting activities, and don’t hesitate to ask for help with physically demanding tasks.
Fatigue and Impatience
By the third trimester, many women feel physically and emotionally exhausted from pregnancy. You may feel impatient for pregnancy to end, especially if you experience significant discomfort or pass your due date without going into labor. These feelings are valid and common. Focus on self-care, rest when possible, and remind yourself that pregnancy won’t last forever.
Prenatal Care in the Third Trimester
Regular prenatal appointments become more frequent during the third trimester, typically occurring every two weeks from weeks 28 to 36, then weekly until delivery. These appointments are crucial for monitoring your health and your baby’s development.
Routine Checkups
At each appointment, your healthcare provider will typically check your weight, blood pressure, urine for protein and glucose, measure fundal height to assess baby’s growth, listen to your baby’s heartbeat, check for swelling in your extremities, and discuss any symptoms or concerns you’re experiencing. Your provider may also perform cervical exams in the final weeks to check for signs of approaching labor.
Important Screening Tests
Several important tests are conducted during the third trimester to ensure optimal health for you and your baby.
Gestational Diabetes Screening: If you haven’t been tested earlier, you’ll be screened for gestational diabetes between weeks 24 and 28. This condition affects how your body processes sugar during pregnancy and requires careful management to prevent complications.
Anemia Testing: Blood tests check for iron deficiency anemia, a common condition in pregnancy that can cause fatigue and other symptoms. Your healthcare provider may recommend dietary changes or supplements if your iron levels are low.
Group B Streptococcus (GBS) Screening: Between weeks 35 and 37, you’ll be tested for Group B strep bacteria, which can be passed to your baby during delivery and cause serious infections. If you test positive, you’ll receive antibiotics during labor to protect your baby.
Fetal Monitoring
Your healthcare provider monitors your baby’s well-being through various methods during the third trimester. You may be asked to track fetal movements, counting kicks to ensure your baby remains active. If you notice decreased movement, contact your provider immediately. Non-stress tests may be performed if you have certain risk factors or go past your due date. These tests monitor your baby’s heart rate and movements to ensure they’re receiving adequate oxygen. Additional ultrasounds may be ordered to check baby’s position, estimate birth weight, assess amniotic fluid levels, or evaluate placental function.
Vaccinations
Certain vaccinations are recommended during the third trimester to protect both you and your baby. The Tdap vaccine, which protects against tetanus, diphtheria, and pertussis (whooping cough), is ideally administered between weeks 27 and 36 of each pregnancy. This vaccination helps pass protective antibodies to your baby before birth. COVID-19 vaccination is recommended if you haven’t already been vaccinated, as it protects you from severe illness and provides antibodies to your baby. The RSV vaccine may be offered during weeks 32 to 36 in certain months to protect your baby from respiratory syncytial virus infection. Always discuss vaccination recommendations with your healthcare provider.
Baby’s Development in the Third Trimester
Understanding your baby’s development during these final weeks can help you appreciate the incredible changes happening inside your body.
Weeks 28-32
During this period, your baby’s eyes can open and close, and they can sense light and dark. Their brain develops rapidly, forming billions of neurons and establishing connections. The lungs continue maturing but aren’t fully developed yet. Your baby begins to regulate their own body temperature, and their bones harden, although the skull remains soft and flexible for delivery. By week 32, most babies weigh around 4 pounds and measure about 16-17 inches long.
Weeks 33-36
Your baby’s brain and nervous system continue developing rapidly. The skull bones remain separated to allow for an easier passage through the birth canal. Your baby practices breathing by inhaling and exhaling amniotic fluid, strengthening their respiratory muscles. Fat continues accumulating under the skin, giving your baby a more rounded appearance and helping with temperature regulation after birth. Most babies settle into a head-down position in preparation for delivery. By week 36, babies typically weigh 5.5 to 6 pounds and measure about 18 inches long.
Weeks 37-40
Your baby is considered full-term at 37 weeks, meaning their organs are mature enough to function outside the womb. They continue gaining weight at about half a pound per week. The lungs produce surfactant, a substance that helps air sacs remain open after birth. Your baby’s movements may feel different as they have less room to move, but you should still feel regular activity. At birth, most babies weigh between 6 and 9 pounds and measure 19 to 21 inches long, though healthy babies come in a wide range of sizes.
Preparing for Labor and Delivery
The third trimester is the ideal time to finalize your preparations for your baby’s arrival and educate yourself about the birth process.
Childbirth Education
If you haven’t already, consider enrolling in childbirth education classes during the third trimester. These classes cover stages of labor, breathing and relaxation techniques, pain management options, medical interventions and their purposes, breastfeeding basics, and postpartum care. Many hospitals and birthing centers offer classes specifically for expectant parents. Online classes are also available if in-person attendance isn’t convenient.
Creating a Birth Plan
A birth plan outlines your preferences for labor and delivery. While it’s important to remain flexible since circumstances can change, having a plan helps communicate your wishes to your healthcare team. Consider your preferences regarding pain management options, movement and positioning during labor, interventions such as continuous fetal monitoring or IV fluids, support people you want present, immediate postpartum preferences such as skin-to-skin contact and delayed cord clamping, and feeding plans for your baby. Discuss your birth plan with your healthcare provider well before your due date and include a copy in your hospital bag.
Understanding Pain Management Options
Educate yourself about available pain relief options so you can make informed decisions during labor. Options may include natural pain management techniques such as breathing exercises, position changes, hydrotherapy, and massage, as well as medical interventions. Discuss the benefits and risks of each option with your healthcare provider. Remember that it’s perfectly acceptable to change your mind about pain management during labor, and there’s no right or wrong choice.
Recognizing Labor Signs
Understanding the signs of labor helps you know when to contact your healthcare provider and head to the hospital or birthing center. Early signs of approaching labor include lightening (baby drops lower into pelvis), loss of mucus plug, bloody show (pink or blood-tinged discharge), increased Braxton Hicks contractions, and nesting urge. Active labor signs include regular contractions that increase in frequency, duration, and intensity, contractions that don’t stop when you change position or move around, water breaking (rupture of membranes), and lower back pain that may come in waves. Contact your healthcare provider immediately if your water breaks, you experience regular contractions, you notice heavy bleeding, you have severe abdominal pain, you notice decreased fetal movement, or you have severe headaches with vision changes or significant swelling.
Packing Your Hospital Bag
Prepare your hospital bag around week 36 so you’re ready when labor begins. Essential items include identification and insurance information, birth plan copies, comfortable clothing for labor, toiletries and personal care items, phone charger, comfortable going-home outfit for you and baby, car seat properly installed in your vehicle, and items for your support person. Pack items for your baby including going-home outfit, blanket, diapers, and any other hospital-recommended items.
Arranging Postpartum Support
The third trimester is an excellent time to arrange support for after the baby arrives. Consider who can help with meals, household tasks, and childcare for older children. Stock your freezer with prepared meals, research lactation consultants if you plan to breastfeed, and discuss postpartum expectations and division of labor with your partner. Don’t hesitate to accept offers of help from friends and family.
Nutrition and Exercise
Maintaining healthy habits during the third trimester supports your well-being and your baby’s continued development.
Nutritional Needs
Your nutritional requirements remain high during the third trimester. Focus on eating a balanced diet rich in lean proteins for baby’s growth and tissue repair, complex carbohydrates for sustained energy, healthy fats for baby’s brain development, calcium for bone development, iron to prevent anemia, and plenty of fruits and vegetables for vitamins, minerals, and fiber. Continue taking your prenatal vitamin as directed. Stay well-hydrated by drinking 8-10 glasses of water daily. Limit caffeine intake and avoid alcohol completely.
Safe Exercise
Unless your healthcare provider advises otherwise, continuing regular physical activity during the third trimester offers numerous benefits, including improved mood and energy, better sleep quality, reduced pregnancy discomfort, preparation for the physical demands of labor, and easier postpartum recovery. Safe activities include walking, swimming and water aerobics, prenatal yoga, stationary cycling, and low-impact aerobics. Avoid activities with fall risk, contact sports, exercises requiring lying flat on your back after the first trimester, and hot yoga or exercise in excessive heat. Listen to your body, stay hydrated, avoid overheating, and stop exercising if you experience dizziness, chest pain, headache, calf pain or swelling, decreased fetal movement, vaginal bleeding, or contractions. Always consult your healthcare provider before starting or continuing an exercise program during pregnancy.
When to Contact Your Healthcare Provider
While many third trimester symptoms are normal, certain signs require immediate medical attention. Contact your healthcare provider right away if you experience vaginal bleeding, sudden severe swelling in face or hands, severe headaches with vision changes, severe abdominal pain, signs of preterm labor before 37 weeks, water breaking or leaking fluid, severe vomiting or inability to keep food down, fever above 100.4°F, decreased fetal movement, painful urination or inability to urinate, chest pain or difficulty breathing, or thoughts of harming yourself or your baby.
Trust your instincts. If something doesn’t feel right, don’t hesitate to contact your healthcare provider. They would rather check on a concern that turns out to be normal than miss something important.
Common Questions About the Third Trimester
Can I still travel during the third trimester?
Many airlines restrict travel after week 36 of pregnancy, and most healthcare providers recommend avoiding long-distance travel after week 32 due to the risk of going into labor away from home. If you must travel during the third trimester, get your healthcare provider’s approval first, bring copies of your medical records, research healthcare facilities at your destination, stay hydrated and move frequently during the journey, and wear your seatbelt properly with the lap portion below your belly.
Is it safe to have sex during the third trimester?
For most women with uncomplicated pregnancies, sex is safe throughout pregnancy, including the third trimester. However, your healthcare provider may recommend avoiding sex if you have placenta previa, risk of preterm labor, unexplained vaginal bleeding, or ruptured membranes. Physical discomfort may make sex less appealing during late pregnancy. Communicate with your partner about positions that are comfortable and any concerns you have.
What if I go past my due date?
Only about 5 percent of babies arrive on their actual due date. Going a week or two past your due date is common and usually not a cause for concern. Your healthcare provider will monitor you and your baby more closely and may recommend induction if you reach 41 to 42 weeks or if there are concerns about your health or your baby’s well-being.
Conclusion
The third trimester is a time of anticipation, preparation, and significant physical and emotional changes. While these final weeks of pregnancy can be challenging, remember that each day brings you closer to meeting your baby. Focus on self-care, maintain open communication with your healthcare provider, and don’t hesitate to ask for help when you need it. Trust your body’s ability to nurture and deliver your baby, and look forward to the incredible moment when you finally hold your little one in your arms.
By understanding what to expect during the third trimester and taking proactive steps to care for yourself, you can approach labor and delivery with greater confidence and peace of mind. Remember that every pregnancy is unique, and your experience may differ from others. What matters most is that you receive proper prenatal care, listen to your body, and prioritize your physical and emotional well-being during this remarkable time.
Sources:
- Mayo Clinic – Third Trimester Pregnancy
- American College of Obstetricians and Gynecologists – Fetal Development
- Centers for Disease Control and Prevention – During Pregnancy
- March of Dimes – Third Trimester
- National Institute of Child Health and Human Development – Pregnancy Complications
The information on this page is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions related to your health.
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