Common Prenatal Scans & Their Purposes
• Dating Scan (6–10 weeks): Confirms pregnancy, estimates gestational age via Crown‑Rump Length (CRL).
• Nuchal Translucency (NT) Scan (11–14 weeks): Screens for chromosomal anomalies by measuring fluid at the back of the fetal neck.
• Anomaly Scan (18–22 weeks): Detailed anatomy check for structural anomalies in brain, spine, heart, kidneys, and limbs.
• Growth Scan (28–34 weeks): Measures fetal biometry—head circumference (HC), abdominal circumference (AC), femur length (FL)—to assess growth trajectories.
• Doppler Ultrasound (32–38 weeks): Evaluates blood flow in umbilical artery and fetal vessels to monitor placental function.
Key Laboratory Tests by Trimester
| Test | When | Purpose | Normal Range |
|---|---|---|---|
| Hemoglobin (Hb) | Booking & 28 weeks | Check for anemia | 12–16 g/dL |
| Blood Group & Rh | Booking | Detect incompatibility | N/A |
| HIV, HBsAg, VDRL | Booking | Screen infections | Negative |
| Glucose Tolerance Test (GTT) | 24–28 weeks | Screen for gestational diabetes | < 140 mg/dL (2‑hr) |
| Thyroid (TSH) | Booking or if indicated | Thyroid function | 0.4–4.0 mIU/L |
| Urine Routine & Culture | Booking & symptomatic | Detect UTI, proteinuria | No bacteria; < 150 mg protein |
How to Read and Interpret Your Reports
1. Identify the Test: Match headings (e.g., CRL, NT, Hb) to your test list.
2. Check Dates & Gestational Age: Ensure the scan date aligns with your expected week.
3. Compare Values to Normal Ranges: Use the provided reference ranges—values outside may require follow‑up.
4. Look for Comments: Sonographer or lab technician notes can highlight areas needing review.
5. Follow the Flowchart: Use the reportInterpretationFlowchart to decide next steps—reassurance, repeat tests, or specialist referral.
Scheduling Your Scans & Labs
- Use a test schedule calendar to mark appointments and avoid missed windows.
- Coordinate scans with lab visits to minimize travel and fasting requirements.
- Confirm scheduling at each prenatal visit and set reminders.
Safety Precautions for Imaging & Blood Work
- Ultrasound is safe in all trimesters—no ionizing radiation involved.
- Fasting for 8–10 hours before GTT ensures accurate results; hydrate well afterward.
- Inform lab staff of pregnancy for safe handling and minimal discomfort.
- Avoid unnecessary scans; adhere to recommended schedules only.
Glossary of Common Terms
• CRL (Crown‑Rump Length): Measurement from top of head to bottom of buttocks—key dating parameter.
• NT (Nuchal Translucency): Fluid measurement at fetal neck—screening marker for Down syndrome.
• AFP (Alpha‑Fetoprotein): Maternal serum protein—elevated levels may indicate neural tube defects.
• hCG (Human Chorionic Gonadotropin): Pregnancy hormone—rises rapidly in early weeks.
• GTT (Glucose Tolerance Test): Measures blood sugar response to glucose load.
• UTI (Urinary Tract Infection): Bacterial infection detected via urine culture.
When to Consult Your Provider
• Abnormal scan findings—growth restriction, fluid anomalies, structural concerns.
• Lab values out of range—anemia, elevated glucose, abnormal thyroid function.
• Any new symptoms—bleeding, severe pain, decreased fetal movement.
• Questions about report comments or next steps.
Record Keeping & Sharing
- Maintain a binder or digital folder for all scan images and lab reports.
- Date‑stamp and label each report with gestational week.
- Share copies with your partner and any specialist you consult.
Next Steps & Resources
- Review your upcoming appointments and confirm bookings.
- Prepare questions in advance based on this guide and your last report.
- Use trusted sources—SHELY app, WHO guidelines, and your healthcare provider—for further learning.