The second trimester brings important screening tests to check your baby’s development and your health.
Triple Marker Test (15-20 Weeks)
Also called: Maternal serum screening or quad screen
What It Screens For
Measures three (or four) substances in your blood:
- AFP (Alpha-fetoprotein)
- hCG (Human chorionic gonadotropin)
- Estriol (a form of estrogen)
- Inhibin A (if quad screen)
Screens for:
- Down syndrome (Trisomy 21)
- Edwards syndrome (Trisomy 18)
- Neural tube defects (spina bifida)
Understanding Results
This is a screening test, not diagnostic.
Low risk: No further action needed (but not 100% guarantee)
High risk: Further testing offered (amniocentesis for diagnosis)
Factors affecting results:
- Gestational age (timing is critical)
- Multiple pregnancy
- Maternal weight
- Diabetes
Important: Abnormal results don’t mean baby definitely has condition. Many women with abnormal results have healthy babies.
Anomaly Scan (18-20 Weeks)
The most detailed ultrasound of your pregnancy
This comprehensive scan checks every part of your baby’s body.
What the Scan Examines
Head and Brain:
- Skull bones
- Brain structures
- Face and lips (cleft palate screening)
Spine:
- All vertebrae
- Checks for spina bifida
- Spinal cord
Heart:
- Four chambers
- Major blood vessels
- Heart rhythm
- Detects most major heart defects
Abdomen:
- Stomach
- Kidneys
- Bladder
- Abdominal wall (checks for openings)
- Bowel
Limbs:
- Arms and legs
- Hands and feet
- All major bones measured
Placenta:
- Location (checking for placenta previa)
- Appearance
- Umbilical cord (three vessels)
Amniotic Fluid:
- Amount (too much or too little can indicate issues)
Baby’s Growth:
- Measurements compared to expected size
- Head circumference
- Abdominal circumference
- Femur (thigh bone) length
Finding Out Baby’s Sex
Optional at this scan (if you want to know)
- Visible on ultrasound if baby cooperates
- About 95% accurate at this stage
- Tell sonographer if you DON’T want to know
If Abnormality Is Detected
Most scans show healthy babies.
If issue found:
- Fetal medicine specialist consultation
- Further detailed scans
- Sometimes amniocentesis
- Discussion of prognosis and options
- Support and counseling
- Plan for specialized care if needed
Many detected abnormalities are minor and treatable.
Placenta Position
Low-lying placenta (placenta previa):
- Placenta covers cervix
- Found in about 1 in 200 pregnancies at 20 weeks
- Usually resolves by 37 weeks as uterus grows
- Follow-up scan at 32 weeks to recheck
- If still low at term, cesarean delivery planned
Glucose Tolerance Test (24-28 Weeks)
Screens for gestational diabetes (GDM)
Why This Test Is Important
Gestational diabetes affects 10-15% of pregnancies:
- Usually no symptoms
- Can harm baby if untreated
- Increases birth complications
- Treatable with diet and sometimes medication
Risk factors:
- Family history of diabetes
- Overweight or obese
- PCOS
- Previous GDM
- Age over 35
- Certain ethnic groups
Everyone gets screened – even without risk factors.
How the Test Works
Standard protocol:
Step 1: Fasting (8-10 hours)
- No food or drinks (except water)
- Usually done morning
Step 2: Baseline blood sugar
- Fasting glucose measured
Step 3: Glucose drink
- Sweet drink containing 75g or 100g glucose
- Must finish within 5 minutes
- Many women find it very sweet
Step 4: Wait and test
- Blood drawn at 1 hour and 2 hours
- Must stay at clinic/lab
- Don’t eat or drink during waiting period
Preparing for the Test
Day before:
- Eat normally (don’t restrict carbs)
- Get good night’s sleep
Morning of test:
- Nothing to eat or drink except water
- Bring something to do (book, phone) – you’ll be waiting
- Bring a snack for after test
Tips:
- Ask for glucose drink to be cold (tastes better)
- Drink quickly
- Suck on ice chip after
- Breathe through nausea if it occurs
Understanding Results
Normal fasting glucose: Under 92 mg/dL
Normal 1-hour: Under 180 mg/dL
Normal 2-hour: Under 153 mg/dL
If one or more values are high: You have gestational diabetes.
What happens next:
- Referral to diabetes educator
- Dietary counseling
- Blood sugar monitoring at home
- Possible medication (metformin or insulin)
- More frequent monitoring
Fetal Movement Monitoring
Starts around 18-25 weeks
When You’ll Feel Movement
First-time moms: Usually 18-22 weeks
Second+ pregnancy: May feel earlier (16-18 weeks)
Early movements feel like:
- Flutters
- Bubbles
- Gentle rolling
- “Butterflies”
Later movements:
- Distinct kicks
- Jabs
- Rolling
- Hiccups
Monitoring Movement
After 28 weeks, pay attention to patterns:
- When is baby most active?
- Regular movement is reassuring
- Quality matters more than specific counts
If movement decreases or stops:
- Call your doctor immediately
- Don’t wait until next appointment
- Better safe than sorry
Second Trimester: The “Honeymoon Phase”
Why It’s Easier
Symptoms improve:
- Nausea usually gone by 14 weeks
- Energy returns
- Less fatigue
- Not too big yet to be uncomfortable
You feel great!
- “Pregnancy glow”
- Hair and nails grow
- Excitement builds
You start to look pregnant:
- Bump appears
- Can feel baby move
- Gender reveal parties
- Baby shopping begins
Enjoy This Time
- Take babymoon trip (if desired)
- Second trimester is safest for travel
- Take maternity photos
- Prepare nursery
- Attend prenatal classes
- Bond with your baby
Second Trimester Checklist
✓ Schedule anomaly scan (18-20 weeks)
✓ Consider triple marker test (15-20 weeks)
✓ Complete glucose tolerance test (24-28 weeks)
✓ Start feeling baby move (document first kick!)
✓ Begin prenatal/childbirth classes
✓ Start thinking about baby names
✓ Plan maternity leave
✓ Consider baby registry
✓ Continue prenatal vitamins
✓ Attend all antenatal appointments
Remember
These screenings provide valuable information about your baby’s health and development. Most scans show healthy, developing babies.
If any issues are found, early detection allows for the best possible care and preparation.
You’re past the hardest part of pregnancy. Enjoy your second trimester!