Fetal ventricles and posterior cranial fossa development in second and third trimesters and their variations with gestational age: a quantitative MRI study / 中华围产医学杂志

ABSTRACT

Objective:To investigate the normal range of fetal ventricles and posterior cranial fossa development in the second and third trimesters and their variations with gestational age using quantitative MRI analysis.Methods:This retrospective study enrolled 675 pregnant women who underwent prenatal MRI examination with an average gestational week of 29.0±8.5 in the Third Affiliated Hospital of Guangzhou Medical University from January 2016 to January 2020. MRI data of all the subjects were collected and analyzed, including left lateral ventricle trigonometric width (LLVTW) and right lateral ventricle trigonometric width (RLVTW), third ventricle width (TVW), fourth ventricle width (FVW), the anterior-posterior diameter of the fourth ventricle (APDFV), cavum septum pellucidum width (CSPW), cisterna magna width (CMW), etc. Spearman, Pearson correlation analysis, and t-test were used for the statistical analysis. Results:(1) Totally 675 fetuses were recruited, including 392 female and 283 male fetuses. No statistical difference of gestational weeks at MRI was found between male and female fetuses. (2)The mean value of TVW and CMW of the female fetuses were significantly higher than those of male fetuses [(0.60±0.05) vs (0.63±0.04) cm, t=－5.059; (0.57±0.14) vs (0.67±0.15) cm, t=－7.445; both P<0.001]. Spearman correlation analysis showed that TVW and CMW were negatively correlated with fetal gender ( r=－0.179 and－0.312, both P<0.001). (3)Pearson correlation analysis showed that LLVTW, RLVTW, TVW, FVW, APDFV, CSPW, and CMW were all positively correlated with gestational weeks ( r=0.310, 0.267, 0.205, 0.801, 0.829, 0.216 and 0.284, all P<0.001). FVW and APDFV were significantly linearly correlated with gestational weeks (r=0.801 and 0.829, both P<0.001). (4) There was no significant change in LLVTW and RLVTW in the second trimester, but a slight increase was found in the third trimester. TVW showed a scattered distribution in the second and third trimesters and increased slightly with the gestational week at 26 to 27 +6 gestational weeks. FVW and APDFV increased linearly while. CSPW increased slowly with gestational weeks in the second and third trimesters. CMW increased slightly with gestational weeks in the second and third trimesters but showed little change in the third trimester. Conclusions:The development of fetal ventricles and posterior cranial fossa in the second and third trimesters show a growth trend of varying degrees with the increase of gestational weeks. TVW and CMW are significantly negatively correlated with the fetal gender.