Pregnancy outcome of fetal tethered cord diagnosed by MRI: analysis of 38 cases / 中华围产医学杂志

ABSTRACT

Objective:To evaluate the pregnancy outcomes of fetal tethered cord (TC) prenatally diagnosed by MRI.Methods:Clinical data of 38 fetuses diagnosed as having TC by MRI, including 36 singletons and two fetuses who were both one of dichorionic diamniotic twins, were retrospectively collected and analyzed in the Obstetrics and Gynecology Hospital of Fudan University from January 2015 to August 2019. According to whether conus medullaris was located above the bladder or reached the lower edge of the bladder, all cases were divided into high or low groups. Pregnancy outcomes were compared between the two groups using Fisher's exact test and Student's t-test. Results:(1) The gestational age at MRI was (25.5±4.7) weeks. Among the 38 cases, 14 (36.8%) were isolated TC, 24 (63.2%) were complicated by other anomalies. The meningocele was responsible for the most (39.5%, n=15). The results of the ultrasound were consistent with those of MRI in 24 cases (63.2%). While in the other 14 cases (36.8%), the ultrasound only showed vertebral body's abnormal morphology, after which further MRI examination revealed a tethered cord. (2) Twenty-nine women (76.3%) chose to terminate the pregnancy. One patient (2.6%) underwent fetal reduction at 23 gestational weeks (one normal twin was delivered prematurely), and one (2.6%) was lost to follow-up. Seven (18.4%) cases continued the pregnancies to delivery. The postnatal follow-up period was 8.1 months (4.0 to 54.9 months). Two infants without comorbidities showed normal growth and development. Another three cases underwent surgeries after birth, and two cases died in the neonatal period. (3) The average width of the medullary cone was (2.5±0.8) cm. There was no significant difference in the spinal cord width between the high [(2.5±0.8) cm, n=34] and low group [(2.7±1.1) cm, n=4]. Six pregnancies (17.6%) in the high group was continued to delivery, and one of the neonates died of severe hydrocephalus. One patient in the low group (1/4) was delivered, while the baby died of neonatal asphyxia. Conclusions:Fetuses with isolated TC are prone to have a good prognosis. Further study should focus on the relation between the high or low position of the conus medullaris and pregnancy outcomes.