Weeks 13–27: A Closer Look at Your Baby’s Development
The second trimester is often called the “honeymoon phase” of pregnancy — morning sickness usually fades, energy returns, and baby starts to move. It’s also when several important tests are done to make sure everything is progressing well for you and your baby.
Here’s what to expect during this stage and why each screening matters.
1. Anatomy Scan (Around 18–22 Weeks)
Also called the “mid-pregnancy ultrasound”, this is one of the most detailed and exciting scans of your pregnancy.
What it checks:
- Baby’s organs and structures: heart, brain, kidneys, spine, limbs, stomach, and more
- Placenta location and amniotic fluid levels
- Baby’s size and growth
- Sex of the baby (if you choose to find out)
It’s a great moment to see your baby in action, and your provider will use the images to check for any physical abnormalities. Don’t worry — if something looks unclear, follow-up imaging may be recommended.
2. Quad Screen or Multiple Marker Test (Optional)
This blood test, typically done between 15–20 weeks, screens for potential chromosomal or neural tube defects such as:
- Down syndrome (trisomy 21)
- Trisomy 18
- Spina bifida and other open neural tube defects
The test measures four substances in your blood (hence “quad”):
- AFP (alpha-fetoprotein)
- hCG (human chorionic gonadotropin)
- Estriol
- Inhibin-A
Keep in mind: This is a screening, not a diagnosis. An abnormal result doesn’t mean something is wrong — it just means more testing might be offered for clarity.
3. Glucose Screening for Gestational Diabetes (24–28 Weeks)
This is a standard test to check how your body processes sugar. Gestational diabetes can develop even in healthy pregnancies and may cause complications if left untreated.
What happens:
- You’ll drink a sweet glucose solution, wait 1 hour, then have your blood sugar tested.
- If your result is high, your provider may order a longer 3-hour glucose tolerance test.
Managing blood sugar early ensures both you and your baby stay healthy.
4. Monitoring Growth, Placenta, and Cervix Health
Your provider will continue monitoring with:
- Fundal height measurements (to estimate your baby’s growth)
- Checking the position and health of the placenta (especially if it was low-lying in earlier scans)
- Cervical length assessments (via ultrasound if you’re at risk for preterm labor)
These assessments help track how your pregnancy is progressing and catch any early signs of complications.
5. Optional NIPT (Non-Invasive Prenatal Testing)
Although typically done in the first trimester, NIPT can still be performed in the second trimester if it wasn’t done earlier.
It’s a blood test that analyzes fetal DNA circulating in your blood to assess the risk for:
- Down syndrome
- Trisomy 13 and 18
- Sex chromosome conditions
- Fetal sex (very accurate)
It’s optional but useful for parents who want more information without invasive procedures.
Final Thoughts
Second trimester screenings offer reassurance and deeper insight into how your baby is growing. Some tests are routine, while others are optional — but all are designed to empower you and your healthcare team with knowledge.
Don’t hesitate to ask questions or express your preferences during this phase. Whether you’re tracking measurements, preparing for glucose testing, or eagerly awaiting your baby’s first kicks, this is a special and important part of your journey.
