Use of fetal colon thickness for auxiliary term dating of pregnancy.
OBJECTIVE
To verify whether fetal colon thickness can be used as a marker for estimating, independent of biometrics and fetal weight percentile, the gestational age (GA) of fetuses between 37 and 40 weeks.


METHODS
The study group was 1296 fetuses aged between 33 and 40 weeks. The correlation between GA and colon thickness was assessed by the Pearson correlation test. For term fetuses (≥ 37 weeks), comparisons among the mean colon thickness for different weight percentiles at each GA (in weeks) were made with an analysis of variance test.


RESULTS
A significant relationship was observed between GA and colon thickness (P < 0.001, r(2) = 0.6). For term fetuses, significant differences were observed among the mean colon thickness values for different weight percentiles at 38 and 39 weeks. Of the 157 term fetuses for which biometrics would have underestimated GA by 2 weeks or more, 126 (80.3%) had a colon thickness equal to, or greater than, 14 mm. This colon thickness was also observed in 52 (70.3%) of term fetuses weighing less than the 10th percentile (n = 74).


CONCLUSIONS
The present study suggested that colon thickness might be a good marker for 37 weeks of gestation, and might identify term fetuses for which biometrics has underestimated the GA.
Department of Radiology, Fluminense Federal University, Niterói, Rio de Janeiro, Brazil. anaalice@ultracentro.com.br
Ana A Vidal
AA
de Carvalho
Edson
E
Marchiori
José-Antônio
JA
Carvalho
Israel
I
Figueiredo
Luis G C
LG
Velarde
D000293:Adolescent; D000328:Adult; D003106:Colon / Q000033:anatomy & histology*; D005260:Female; D047109:Fetal Development; D020567:Fetal Weight; D005865:Gestational Age; D006801:Humans; D008297:Male; D009929:Organ Size; D011247:Pregnancy; D016216:Ultrasonography, Prenatal; D055815:Young Adult