The fetal cheek-to-cheek diameter and abdominal circumference: are they correlated?

Objective: The cheek-to-cheek diameter (CCD) has been shown to be an indicator of subcutaneous tissue mass in the fetus. However, the correlation between CCD and the abdominal circumference (AC) has not been investigated yet. The objective of the present study was to demonstrate whether a correlation exists between fetal CCD, AC, estimated fetal weight (EFW), and the 1 h, 50 g, glucose challenge test (GCT) levels in patients with and without gestational diabetes mellitus.
Methods: A prospective, institutional review board approved study was performed. The CCD was obtained as part of the ultrasound for obstetric interval growth scans and biophysical profiles. Exams were performed during the third trimester. The CCD was obtained on a coronal view of the fetal face, at the level of the nostrils and lips. Patients were enrolled between November 2005 and May 2006. Pearson correlation coefficient and linear regression modeling were used as appropriate.
Results: Eighty-three patients were enrolled, 29 (33%) of them were diabetic. The mean gestational age is 34.8 +/- 3 weeks and the mean maternal age is 29.9 +/- 5.1. A significant linear association was found between CCD and EFW (Pearson coefficient of correlation being 0.51, P = 0.01). The Pearson correlation coefficient of the relationship between the CCD and AC was 0.47 (P = 0.01). Using a linear regression model, controlling for gestational age at performance of the ultrasound, the association between CCD and EFW remained significant (P = 0.021). There were no significant differences between diabetic and non-diabetic patients regarding the CCD (6.2 +/- 0.9 vs. 6.3 +/- 0.9 respectively, P = 0.669) or the EFW (2,527.9 +/- 705 vs. 2,645 +/- 760 g). While AC was significantly correlated with the GCT levels (Pearson coefficient of correlation = 0.46, P = 0.024), no such correlation was demonstrated for CCD (Pearson correlation coefficient = 0.23, P = 0.160).
Conclusions: The cheek-to-cheek diameter is significantly correlated to the abdominal circumference and the estimated fetal weight. However, the abdominal circumference has a tighter correlation with the glucose challenge test.