The third trimester—weeks 28 through delivery—brings pregnancy into its final phase. Your baby is growing rapidly, your body is preparing for labor, and you’re likely thinking concretely about labor, delivery, and becoming a parent. For women over 35, the third trimester includes specific monitoring and considerations that reflect age-related factors and ensure the healthiest possible outcome.
Physical Changes in the Third Trimester
The third trimester brings dramatic physical changes as your baby grows substantially and your body prepares for labor. Research indicates that weight gain accelerates, with most women gaining 1-2 pounds per week. Additionally, your belly reaches its maximum size, affecting posture, balance, and comfort significantly. For women over 35, these physical demands may feel more challenging than younger pregnancy experiences.
Braxton-Hicks contractions—practice contractions—often become noticeable in the third trimester. Research indicates these are normal and don’t signal labor. Evidence suggests learning to distinguish Braxton-Hicks from real labor contractions helps you avoid unnecessary emergency department visits. Generally, Braxton-Hicks stop with movement or position change, while true labor contractions continue and intensify.
Many women experience increased pelvic pressure, back pain, and pelvic discomfort in the third trimester as the baby drops into the pelvis. Research indicates that this lightening (baby dropping lower into the pelvis) typically occurs a few weeks before labor for first-time mothers and may occur just before labor for those with previous pregnancies. Evidence suggests that physical therapy, appropriate movement, and pain management help manage discomfort.
Sleep Challenges and Restlessness
Sleep becomes increasingly difficult in the third trimester due to belly size, physical discomfort, and frequent urination. Research indicates that many pregnant women sleep poorly in the final weeks of pregnancy. Evidence suggests that accepting this disruption as normal, using body pillows for support, and resting when possible help manage exhaustion.
Additionally, some women experience restless leg syndrome (RLS) in the third trimester. Research indicates this involves uncomfortable sensations in legs, typically in the evening, relieved by movement. Evidence suggests discussing RLS with your healthcare provider, as safe management strategies exist.
Monitoring and Testing in the Third Trimester
Fetal Monitoring and Non-Stress Tests
In the third trimester, regular prenatal visits include assessing fetal wellbeing through fetal heart rate monitoring. Research indicates that for pregnancies with complications, more frequent monitoring may be recommended. Additionally, non-stress tests (NSTs)—monitoring fetal heart rate and contractions—assess fetal wellbeing. Evidence suggests that for women over 35, particularly those with pregnancy complications, more frequent monitoring helps ensure safety.
Ultrasound in the Third Trimester
A third trimester ultrasound assesses baby’s growth, amniotic fluid amount, placental position, and baby’s position. Research indicates this ultrasound helps identify any concerns requiring management and confirms whether baby is in vertex (head-down) position. Evidence suggests that for women over 35, particularly those at risk for complications, third trimester ultrasound provides valuable information.
Group B Streptococcus (GBS) Testing
Between 35-37 weeks, testing screens for GBS, a bacterium that can be transmitted to baby during delivery. Research indicates that GBS colonization is common and doesn’t indicate infection. However, if positive, IV antibiotics during labor prevent transmission to baby. Evidence suggests that routine GBS testing is standard care and important for preventing neonatal infection.
Preparing for Labor and Delivery
Many women use the third trimester to prepare mentally and practically for labor and delivery. Research indicates that childbirth classes, reading about labor, and discussing preferences with your healthcare provider help you feel prepared. Evidence suggests that education reduces fear and anxiety about labor.
Additionally, many women create birth plans outlining their preferences regarding labor management, pain relief, and delivery approach. Research indicates that birth plans help you communicate preferences to your healthcare team. Evidence suggests that flexibility about birth plans—understanding that labor often requires adaptation—helps you accept necessary changes without feeling disappointed.
Emotional Changes and Nesting
The third trimester often brings emotional shifts. Research indicates that anxiety about labor and delivery increases, along with excitement and anticipation about meeting your baby. Some women experience nesting—a strong drive to prepare the home for baby’s arrival. Evidence suggests that these emotional changes are normal and reflect the reality that you’re approaching a major life transition.
Key Takeaways
- The third trimester involves rapid baby growth and increased physical symptoms and discomfort.
- Braxton-Hicks contractions are normal practice contractions that differ from true labor.
- Sleep disruption and physical discomfort are common; management strategies help.
- Third trimester monitoring assesses baby’s wellbeing and helps identify any complications.
- GBS testing at 35-37 weeks identifies colonization; positive results prompt antibiotics during labor.
- Childbirth education and birth planning help you prepare mentally and practically for labor.
- Emotional changes—anxiety, excitement, nesting—are normal third trimester experiences.
- Women over 35 may benefit from increased monitoring and support in the third trimester.
FAQ
What’s the difference between Braxton-Hicks and real labor?
Research indicates that Braxton-Hicks contractions are irregular, often stop with movement or position change, and don’t cause cervical change. Real labor involves regular contractions that continue and intensify, becoming progressively closer together. Additionally, real labor is typically accompanied by other signs like bloody show or water breaking. When uncertain, contacting your healthcare provider helps clarify whether labor has begun.
What does it mean if baby is breech?
Research indicates that breech position (bottom or feet first instead of head first) occurs in about 3-4% of pregnancies at term. Evidence suggests that vaginal breech delivery is possible in select circumstances with experienced providers, but many healthcare systems recommend cesarean delivery for breech presentation. If your baby is breech, discussing delivery options and any turning techniques with your healthcare provider helps you understand options specific to your situation.
Should I be concerned about going overdue?
Research indicates that pregnancy continuing beyond 39-40 weeks increases risks slightly. Evidence suggests that pregnancies at 42 weeks or beyond warrant induction to prevent complications. Most healthcare providers recommend induction around 39-40 weeks if labor hasn’t begun naturally. Discussing your healthcare provider’s approach to due date management helps you understand your specific care plan.
What if I’m having more prenatal visits because of my age?
Research indicates that more frequent monitoring for older mothers reflects age-related risks and ensures close attention to any developing complications. Evidence suggests that increased monitoring is often preventive and helps catch any issues early. While more appointments may feel burdensome, they provide reassurance and support your health and baby’s wellbeing.
When should I call my healthcare provider about symptoms?
Research indicates that certain symptoms warrant immediate medical evaluation: severe abdominal pain, heavy vaginal bleeding, loss of consciousness, severe headache, vision changes, or swelling in face or hands (signs of preeclampsia). Evidence suggests contacting your healthcare provider with any concerning symptoms, understanding that healthcare providers prefer to evaluate potentially concerning situations rather than have patients wait.
Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice. Individual health situations vary significantly. Always consult a qualified healthcare provider before making decisions related to your health, fertility, or pregnancy.
About the Author
Emily Carter is a women’s health writer focused on fertility, pregnancy after 35, and sleep changes in midlife. She writes research-informed, non-alarmist content to help women navigate reproductive and hormonal transitions with clarity and confidence.