Decrease in femur (FL) centile in the third trimester and suspicion of dysplasia – has anyone experienced this?
Hi ladies, I'm currently 35 weeks pregnant (35+0 to be exact), and after today's appointment, I'm going crazy. The doctor said "skeletal dysplasia (dwarfism) can't be ruled out," and I'm very worried. I wanted to ask if any of you have had a similar situation, where your leg measurements fell in the percentiles, but your baby was born healthy?
Throughout the pregnancy, the measurements increased as follows (approximate percentiles are given in parentheses):
18+3 tc: BPD 46 mm (75%), HC 157 mm (50%), AC 135 mm (50%), FL 28 mm (50%), Masa: 265 g (55%)
22+3 tc: BPD 59.76 mm (75%), HC 218 mm (60%), AC 193 mm (70%), FL 35.40 mm (35%), EFW: 550 g (65%)
26+3 tc: BPD 72.20 mm (85%), HC 254 mm (75%), AC 204 mm (15-20%), FL 45.09 mm (30-35%)
30+3 tc: BPD 84.03 mm (92%), HC 303 mm (85%), AC 273 mm (75%), FL ~56.3 mm (35%), EFW: 1736 g (75-80%)
33+3 tc: BPD 86.26 mm (55-60%), HC 310 mm (60%), AC 307 mm (65-70%), FL ~58.9 mm (15-20%), EFW: 2237 g (55-60%)
34+0 tc: BPD 90.1 mm (85%), HC ~319 mm (70-75%), AC 314.7 mm (75-80%), FL ~55.6 mm (10-15%), EFW: 2317 g (65-70%)
35+0 weeks (current): BPD 93.3 mm (90%), HC 326.3 mm (70-75%), AC 325.3 mm (80%), FL 57.1 mm (drop to 3-5th percentile!), HL 51.4 mm (5-10%), HC/AC ratio = 1.00, EFW: 2492 g (ideal 50th percentile).
As you can see, the head and belly are plump, the baby's overall weight is perfectly within the normal range, but the femur (FL) is falling into lower percentiles with each examination and has now reached the lower limit (3-5%).
The good news: the doctor said the bones are straight, without signs of fracture, and well calcified. The chest is also normal (no signs of stenosis). Blood flow (Doppler) is excellent, and the cerebro-umbilical cord index (CPR PI) is 1.80, so the placenta is functioning perfectly. However, the doctor couldn't see the baby's face and forehead profile clearly because the baby is already low and the positioning didn't allow for it.
Has anyone experienced a situation where their femur slowed down so much towards the end of pregnancy, reaching the 3rd percentile with a large head, only to find out after delivery that it was simply a natural part of the baby's appearance (e.g., after their father/grandfather)? I'd appreciate any words of support or your experiences, as I'm going crazy.