The third trimester—weeks 29 through 40—is the final stretch of pregnancy. As your baby grows rapidly in size and readiness for birth, you’ll likely experience new physical and emotional changes. This stage is about preparation, both mentally and physically, for labor, delivery, and parenthood. Here’s what to expect as you approach the finish line.
Common Physical Changes in the Third Trimester
Your growing uterus, changing hormones, and increased blood volume contribute to a range of physical symptoms:
- Shortness of breath: As your uterus expands, it can press against your diaphragm and lungs.
- Frequent urination: Your baby’s position may add pressure on your bladder.
- Backaches and pelvic pressure: Your posture shifts as your baby drops lower into your pelvis.
- Swelling (edema): Mild swelling in your feet, ankles, and hands is common.
- Braxton Hicks contractions: Also known as “practice contractions,” these are irregular and usually not painful.
- Leaky breasts: You may start producing colostrum (early milk).
- Sleep disruptions: Finding a comfortable position may become difficult.
Emotional and Mental Changes
- Nesting instinct: Many people feel an urge to clean, organize, or prepare for baby’s arrival.
- Anxiety or mood swings: It’s common to feel overwhelmed or emotional as your due date nears.
- Fatigue: Despite bursts of energy, you may feel more tired and physically limited.
Baby’s Growth and Development
By the third trimester, your baby is fully formed and focused on gaining weight and developing critical systems:
- Lungs mature to prepare for breathing air after birth.
- Brain and nervous system continue to develop rapidly.
- Positioning: Most babies turn head-down by 36 weeks in preparation for delivery.
- Movements: Kicks and rolls may feel stronger or more restricted due to limited space.
Prenatal Appointments and Screenings
Expect more frequent visits with your provider:
- Biweekly visits starting at 28 weeks, then weekly visits after 36 weeks.
- Group B Strep screening around 36–37 weeks.
- Cervical checks may begin in the last weeks to assess dilation and effacement.
- Ultrasounds or non-stress tests, if medically necessary, to monitor baby’s health and position.
Preparing for Labor and Delivery
- Pack your hospital bag around week 36 with essentials for you and your baby.
- Install your car seat and confirm proper fit.
- Create or review your birth plan, including preferences for pain relief and delivery.
- Sign up for childbirth classes if you haven’t already.
- Know the signs of labor: Regular, painful contractions, water breaking, and back pain that doesn’t go away.
When to Call Your Provider
Contact your OB/GYN right away if you experience:
- Vaginal bleeding
- Sudden or severe swelling in your face or hands
- Blurred vision or severe headaches
- Decreased fetal movement
- Signs of preterm labor (before 37 weeks)
- Leaking fluid or a gush from your vagina
Looking Ahead
The third trimester is a time of anticipation and important physical milestones. Staying in close contact with your healthcare provider and taking care of your body can help ensure a smooth transition into labor and delivery.