The final stretch! Third trimester monitoring ensures you and baby are ready for delivery.
Growth Scan (32-36 Weeks)
Checks baby’s growth and position as delivery approaches
What the Scan Measures
Baby’s Size:
- Head circumference
- Abdominal circumference
- Femur (thigh bone) length
- Estimated fetal weight
Baby’s Position:
- Head down (cephalic) – ideal for delivery
- Breech (bottom or feet first)
- Transverse (sideways)
Amniotic Fluid:
- Too much (polyhydramnios) or too little (oligohydramnios)
- Both can indicate problems
Placenta:
- Location (ensuring not covering cervix)
- Maturity level
- Blood flow
Umbilical Cord:
- Blood flow through cord
- Position
Growth Assessment
Measuring baby’s growth:
- Compared to standard curves
- Ensures baby is growing appropriately
- Too small or too large flagged
Small for gestational age (SGA):
- Below 10th percentile
- May need closer monitoring
- Sometimes early delivery
Large for gestational age (LGA):
- Above 90th percentile
- Common with gestational diabetes
- May affect delivery plan
Baby’s Position
Head down (cephalic): Best position for vaginal delivery
Breech (3-4% at term):
- Bottom or feet first
- Options: External cephalic version (turning baby) or cesarean delivery
- Some babies turn on their own before labor
Transverse: Sideways – requires cesarean delivery
Biophysical Profile (BPP)
Comprehensive assessment of baby’s well-being
When It’s Done
- Usually after 32 weeks
- More common if:
- High-risk pregnancy
- Decreased fetal movement
- Past due date
- Pregnancy complications
What BPP Measures (5 Components)
Scored 0 or 2 for each (total score out of 10):
- Fetal breathing movements
- At least 30 seconds of breathing in 30 minutes
- Fetal body movements
- At least 3 discrete movements in 30 minutes
- Fetal tone
- At least one episode of extending and flexing
- Amniotic fluid volume
- Adequate pocket of fluid
- Non-stress test (NST)
- Reactive heart rate pattern
Understanding Scores
8-10: Normal, baby is doing well
6: Equivocal, may repeat test or deliver
4 or less: Concerning, may need immediate delivery
Non-Stress Test (NST)
Monitors baby’s heart rate and response to movement
How It Works
The procedure:
- Two monitors placed on your belly
- One tracks baby’s heart rate
- One tracks contractions
- You press button when you feel baby move
- Test lasts 20-40 minutes
What’s “reactive” (normal):
- Baby’s heart rate increases with movement
- At least 2 accelerations in 20 minutes
- Each lasting at least 15 seconds
- Heart rate increases by 15 beats per minute
When NST Is Done
Common situations:
- Decreased fetal movement
- Post-dates pregnancy (after due date)
- High blood pressure
- Gestational diabetes
- Multiple pregnancy
- High-risk conditions
May be done weekly or twice weekly depending on your situation.
If Test Is “Non-Reactive”
Doesn’t necessarily mean problem:
- Baby might be sleeping
- Test continued or repeated
- Further evaluation if still non-reactive
- Possible delivery if concerns
Group B Strep (GBS) Screening
Vaginal and rectal swab around 35-37 weeks
What Is Group B Strep?
- Common bacteria
- About 25% of women carry it
- Harmless to you
- Can be dangerous to newborn during delivery
The Test
Simple procedure:
- You or provider swabs vagina and rectum
- Sent to lab (results in few days)
- No discomfort
If You’re GBS Positive
Not a problem with proper treatment:
- IV antibiotics during labor
- Started when labor begins or water breaks
- Every 4 hours until delivery
- Protects baby from infection
Prevents serious newborn infections:
- Pneumonia
- Meningitis
- Blood infections
Baby monitored after birth for any signs of infection.
Pelvic Examination (After 38 Weeks)
Checks cervical readiness for labor
What’s Checked
Cervical dilation:
- How many centimeters cervix has opened
- 0 cm to 10 cm (fully dilated)
Effacement:
- How thin cervix is
- 0% (thick) to 100% (paper-thin)
Station:
- Baby’s position in pelvis
- -5 (high) to +5 (crowning)
Cervical position:
- Posterior (pointing back) to anterior (pointing forward)
Cervical consistency:
- Firm to soft
What It Means
“Favorable” cervix:
- Dilated, thin, soft, anterior
- Labor may start soon (but not always!)
“Unfavorable” cervix:
- Closed, thick, firm, posterior
- Not ready yet (but can change quickly)
Important: Pelvic exam can’t predict exactly when labor will start. Some women walk around dilated for weeks; others go from zero to baby in hours.
Third Trimester Symptoms
Normal Discomforts
Back pain:
- Baby’s weight pulling forward
- Use support belt, good posture
Braxton Hicks contractions:
- “Practice” contractions
- Irregular, don’t get stronger
- Change with position or hydration
Shortness of breath:
- Baby pushing on diaphragm
- Improves when baby “drops”
Frequent urination:
- Baby on bladder
- Normal but annoying
Swelling (edema):
- Feet and ankles swell
- Elevate feet, stay hydrated
- Call doctor if sudden or severe
Insomnia:
- Hard to get comfortable
- Frequent bathroom trips
- Anxiety about labor
Leaking colostrum:
- Breasts preparing for breastfeeding
- Yellowish fluid
- Completely normal
Warning Signs – Call Doctor
Severe or sudden swelling:
- Face, hands, feet
- May indicate pre-eclampsia
Severe headache:
- Especially with vision changes
- Pre-eclampsia symptom
Decreased fetal movement:
- Don’t assume baby is “resting”
- Call immediately
Vaginal bleeding:
- More than spotting
- Could indicate placenta problem
Fluid leaking:
- Might be amniotic fluid
- Water breaking before labor
Regular contractions before 37 weeks:
- May be preterm labor
- Get checked
Severe abdominal pain:
- Especially if constant
Preparing for Delivery
Final weeks focus on preparation:
Week 32-36:
- Hospital tour
- Finalize birth plan
- Pack hospital bag
- Install car seat
- Prep frozen meals
Week 37+:
- Full term! Baby can come anytime
- Final doctor visits weekly
- Learn signs of labor
- Have hospital route planned
- Phone charged and ready
Third Trimester Checklist
✓ Growth scan (32-36 weeks)
✓ GBS screening (35-37 weeks)
✓ Weekly appointments (starting week 37)
✓ Monitor fetal movement daily
✓ Learn signs of labor
✓ Pack hospital bag
✓ Install car seat (inspected if possible)
✓ Finalize birth plan
✓ Tour hospital/birth center
✓ Practice relaxation/breathing techniques
✓ Arrange childcare for older children (if applicable)
✓ Stock up on postpartum supplies
Remember
These final tests ensure you and baby are healthy and ready for delivery. Most pregnancies reach full term without complications.
You’re in the home stretch! Soon you’ll meet your baby.
Trust your body, trust your healthcare team, and get ready for the most amazing moment of your life.