Monochorionic vs Dichorionic Twins: Kanet Test vs Postnatal Neurodevelopment

Abstract

The twin pregnancy is a risk pregnancy, being associated with a series of fetal and neonatal complications when compared to singleton pregnancies. Ultrasound assessment of the fetal brain is mandatory in the prenatal screening for fetal, congenital and acquired anomalies. Fetal neurosonography is useful in the prenatal diagnosis of cerebral anomalies, combining ultrasonography with fetal ultrasound. In this study, we assessed the Kanet score in two populations of pregnant women with dichorionic twin pregnancies (DC twin) (n=67) and monochorionic twin pregnancies (MC twin) (n=24). In the two groups we included pregnancies with normal fetal growth and pregnancies with discordant fetal growth (DC twin) and selective intrauterine reatriction (MC twin). For both groups, we assessed the antenatal Kanet score during three visits and compared the results with the neurodevelopment immediately after birth up to the two-year-old children. The calculation of the average values of the Kanet score for dichorionic pregnancies revealed normal, maximal average values at all three visits, for all fetuses, no matter if they had normal growth or discordant growth. At the first and third visit, we observed statistically significant differences between the average Kanet scores in DC twins with discordant growth vs. DC twins with normal growth. The analysis of average values of the Kanet score in the group of MC twin pregnancies revealed statistically significant differences between monochorionic twins with discordant growth vs. twins with normal growth at all three visits (p=0.0001), with average values between 17.30 and 19.62 being deemed normal. Amiel-Tison score was used as a standard tool for the neurological assessment both immediately after birth and for children up to two years of age.

TABLE 1.

KANET score interpretation, with permission, Kurjak et al. (8, 11)

TABLE 2.

Kanet score distribution in dichorionic twins at the first visit

TABLE 3.

Kanet score distribution in dichorionic twins at the second visit

TABLE 4.

Kanet score distribution in dichorionic twins at the third visit

TABLE 5.

Comparisons between Kanet score average values in the dichorionic twins at the three visits

TABLE 6.

Comparisons between average values of the Kanet score in MC twins at the three visits