Nomogram of Fetal Cisterna Magna Width in the Second Trimester of Pregnancy

BACKGROUND/AIMS We aimed to determine the normal value interval for the Turkish population by measuring the cisterna magna width of fetuses in the 18-24th weeks of gestation and to determine the correlation of cisterna magna width with gestational week, maternal age, maternal body mass index, and fetal parameters. MATERIAL and METHODS This study included 1,236 healthy fetuses in the 18-24th gestational week of cases aged from 18 to 40 years. The cisterna magna width, biparietal diameter, femur length, and abdominal circumference of the fetuses were measured. Additionally, groups were divided according to the maternal age and body mass index. RESULTS The cisterna magna width of fetuses from 18 to 24 weeks of gestation was identified to vary from 3.84 +/- 0.57 to 5.25 +/- 0.83 mm. Additionally, the mean and standard deviation of cisterna magna width and fetal parameters were determined according to the gestational week, maternal age, and maternal body mass index. Later, the correlations of cisterna magna width with pregnancy week, maternal age, maternal body mass index, and fetal parameters were examined. Cisterna magna width was correlated with pregnancy week and fetal parameters (P < .01) but was not correlated with maternal age (P > .01). Additionally, cisterna magna width and fetal parameters were determined to show negative correlation with maternal body mass index (P < .01). CONCLUSION We believe our data related to the cisterna magna width obtained at the end of the study will be beneficial for the assessment of fetal development and identification of fetal anomalies.