Prospective Evaluation of Internal Cranial Fronto-Occipital Diameter/Corpus Callosum Length Ratio on Normal Depistage and IUFGR Prenatal Ultrasound.

Abstract

Introduction: Aim to explore the feasibility of assessing the relationship between the internal cranial fronto-occipital diameter (IFOD) and corpus callosum (CC) length and compare this to fetuses with intrauterine growth restriction (IUGR).

Materials and methods: Observationnal study including 989 fetuses: 912 eutrophic fetuses and 75 with IUGR. Strict quality control criteria were applied to CC measurements, which were taken in median sagittal section including the vermis. IFOD was measured along the same axis between the internal bone tables. IFOD/CC ratio was calculated and analyzed by pregnancy trimester. We compared the IFOD/CC ratio between eutrophic fetuses and those with IUGR, excluding cases with cerebral malformations or genetic disorders.

Results: IFOD/CC ratio was, on average, 3.32 (±0.91) in the first trimester (< 21 GW) for 40 patients, 2.54 (±0.18) in the second trimester (21-30 GW) for 487 patients, and 2.47 (±0.08) in the third trimester (31-38 GW) for 385 patients. The ratio decreased proportionally with advancing pregnancy. The IFOD/CC ratio was 2.51 (±0.13) in eutrophic fetuses and 2.49 (±0.10) in fetuses with IUGR, with no significant difference between the two groups (Student's t-test, p value = 0.18).

Conclusion: There was no significant difference between eutrophic fetuses and those with IUGR. This method appears to be quick and could offer an advantage over standard CC charts. It may also help minimize potential biases in detecting CC hypoplasia.