Mnemonics: Normal fetal growth
Fetal Biometry Parameters
What needs to be memorized: The five main ultrasound parameters used to assess fetal growth: Crown-Rump Length, Biparietal Diameter, Head Circumference, Abdominal Circumference, and Femur Length
Mnemonic: "Cricket Batting Helps Achieve Fame"
🔗 The Breakdown:
- Cricket → Crown-Rump Length (CRL)
- Batting → Biparietal Diameter (BPD)
- Helps → Head Circumference (HC)
- Achieve → Abdominal Circumference (AC)
- Fame → Femur Length (FL)
💡 Remember: Just like cricket batting helps achieve fame in India, these 5 parameters help achieve accurate fetal assessment!
Fetal Weight at Key Gestational Ages
What needs to be memorized: Critical fetal weights at important weeks: 24 weeks = 600g, 28 weeks = 1000g (1 kg), 40 weeks = 3000-3400g (3+ kg)
Mnemonic: "CHE-EK-TEEN" (6-1-3)
🔗 The Breakdown:
- CHE (6) → 600 grams at 24 weeks
- EK (1) → 1 kilogram (1000g) at 28 weeks (viability milestone)
- TEEN (3) → 3+ kilograms (3000-3400g) at 40 weeks (term)
💡 Remember: The weeks go 24-28-40, and the weights follow CHE-EK-TEEN pattern. At 28 weeks (7 months), baby crosses the magical 1 kg mark!
Periods of Fetal Development
What needs to be memorized: Three developmental periods - Germinal period (0-2 weeks), Embryonic period (3-8 weeks with organogenesis), Fetal period (9 weeks to term)
Mnemonic: "GEF - Grow, Evolve, Flourish"
🔗 The Breakdown:
- Grow → Germinal period (0-2 weeks) - Initial growth and implantation
- Evolve → Embryonic period (3-8 weeks) - Organs evolve/form (organogenesis)
- Flourish → Fetal period (9 weeks to term) - Baby flourishes and matures
💡 Remember: Like a student's journey - first you grow (learn basics), then evolve (develop skills), then flourish (achieve success)! The embryonic period (3-8 weeks) is most critical for teratogen exposure.
Maximum Fetal Growth by Trimester
What needs to be memorized: Maximum length growth occurs in 2nd trimester; Maximum weight gain occurs in 3rd trimester
Mnemonic: "Baby becomes LONG in 2nd trimester, HEAVY in 3rd trimester"
🔗 The Breakdown:
- LONG → Length growth maximum → 2nd trimester (baby grows tall)
- HEAVY → Weight gain maximum → 3rd trimester (baby gains weight)
💡 Visualize: In the second trimester, baby stretches and becomes long. In the third trimester, baby puts on weight and becomes heavy - ready for delivery!
Types of IUGR (Intrauterine Growth Restriction)
What needs to be memorized: Symmetric IUGR (all parameters equally reduced, early insult) vs Asymmetric IUGR (head sparing, abdomen most affected, late insult)
Mnemonic: "SYMMETRIC = SMALL from START, ASYMMETRIC = ABDOMEN Affected"
🔗 The Breakdown:
- SYMMETRIC IUGR:
- SMALL from START → Early insult (1st/2nd trimester)
- All parameters equally reduced (head and body both small)
- Causes: Chromosomal abnormalities, Infections (TORCH), Congenital malformations
- ASYMMETRIC IUGR:
- ABDOMEN Affected → Late insult (3rd trimester)
- Head sparing - AC (abdominal circumference) most affected
- Cause: Placental insufficiency (uteroplacental)
💡 Remember: Symmetric = Everything is equally small from the start. Asymmetric = Abdomen gets hit hardest, brain is spared (brain-sparing effect). Think of placental insufficiency as a late problem that affects nutrition (belly) but protects the brain!
Best Parameter for Pregnancy Dating by Trimester
What needs to be memorized: CRL is most accurate in 1st trimester (up to 13 weeks); Combination of parameters used later; Dating becomes less accurate as pregnancy advances
Mnemonic: "CRL is the Champion of early dating - Crown measurement Comes Really earLy"
🔗 The Breakdown:
- CRL (Crown-Rump Length) → Most accurate dating parameter in First trimester (7-13 weeks)
- Champion → CRL is the "king" of dating when baby is small
- Later trimesters → Use combination of BPD, HC, AC, FL (accuracy decreases)
💡 Remember: In first trimester, baby is small and uniform in size, so CRL gives the best dating (±5 days accuracy). As baby grows, individual variations increase, making dating less accurate. Always date pregnancy in first trimester when possible!
