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.

Objective:To investigate the prenatal MRI diagnosis of fetal intracranial hemorrhage (ICH) and the pregnancy outcomes.Methods:This retrospective study included 49 cases of fetal ICH diagnosed by MRI in Obstetrics and Gynecology Hospital of Fudan University from July 2011 to November 2019. Two experts with more than five years of experience in obstetric radiology determined the location, number, area, stage and grade of the hemorrhage based on the MRI findings. Maternal age, gestational age at MRI, and the site, number, stage and grade of hemorrhage as well as other intracranial and extracranial abnormalities of the fetuses were compared between women with fetal germinal matrix-intraventricular hemorrhage (GM-IVH; GM-IVH group, n=39) and those without (non-GM-IVH group, n=10). MRI and ultrasound examination results of 37 cases who had MRI within three days after the ultrasound examination were compared. Postnatal and follow-up outcomes were summarized. Statistical analysis was performed using the independent sample t-test, Mann-Whitney U test and Chi-square test. Results:There was no significant difference in the maternal age, gestational age at MRI, or the site, number or stage of hemorrhage between the GM-IVH group and non-GM-IVH group (all P>0.05). The incidence of ventriculomegaly was higher in the GM-IVH group than that in the non-GM-IVH group [87% (34/39) vs 0/10, t=24.522, P<0.001]. There were 51% (19/37) of the lesions that were missed by ultrasound found by MRI, including GM-IVH in 17 cases, right cerebellar hemisphere hemorrhage in one case and corpus callosum hemorrhage in one case. Among the 49 cases, seven were lost to follow-up, 29 terminated the pregnancy (six in non-GM-IVH group and 23 in GM-IVH group), two experienced intrauterine fetal death in late pregnancy and 11 gave live birth. Ten live births had GM-IVH, among them a relatively good prognosis was noted in fetuses with grade Ⅰ (two cases), grade Ⅱ (four cases), and grade Ⅲ (three cases) GM-IVH, while one case with grade Ⅳ GM-IVH had mental retardation at eight years old; one non-GM-IVH infant had hearing loss at birth and a cochlear was implanted with no other anomalies reported during a three-year follow-up. Conclusions:MRI can provide a more direct view of the location and grade of fetal ICH and is more accurate than prenatal ultrasound in diagnosing fetal ICH, which is a beneficial supplement to ultrasound. The prognosis of cases with grade Ⅳ GM-IVH is not good.

Objective:To explore the value of apparent diffusion coefficient (ADC) and renal volume in assessing fetal kidney development and disease.Methods:From January 2016 to October 2020, 84 fetuses with congenital anomalies of the kidney and urinary tract (CAKUT) were identified with MRI (CAKUT group), and 97 fetuses with no significant abnormalities on MRI or postnatal follow-up (control group) from the Obstetrics and Gynecology Hospital of Fudan University were enrolled and analyzed retrospectively. ADC value and renal volume were measured to compare the two groups, and the relationship was analyzed between these two parameters in the control group with gestational age, location (left or right kidney), and fetal gender. Two independent or paired sample t-tests, and linear correlation analyses, were adopted for the statistical analysis. Results:(1) There were 84 pregnant women in the CAKUT group, including a twin pregnancy, with an average age of (29±4) years old, ranging from 21 to 39 years old. The gestational age at MRI was (26±4) weeks with a range of 21-34 weeks. Of the 85 fetuses, 52 were male (61.2%), and 33 were female (38.8%). The polycystic dysplastic kidney was found in 32 cases (37.6%), hydronephrosis in 29 cases (34.1%), and an isolated kidney in 24 cases (28.2%). There were 97 singleton pregnancies in the control group, including 45 (46.4%) male and 52 (53.6%) female fetuses. The average maternal age was (30±5) years old, with a range of 19-41 years old, and the gestational week at MRI was (27±4) weeks, with a range of 21-34 weeks. (2) In the control group, the mean ADC value and renal volume were (1.255±0.112)×10 －3 mm2/s and (4 747±2 479) mm 3, which were negatively ( R 2=0.30, P<0.01) and positively correlated ( R 2=0.80, P<0.01) with the gestational age, respectively. There was no significant difference between ADC value and renal volume between different fetal gender in the control group. (3) The ADC value and the renal volume of fetuses with polycystic dysplastic kidney [(1.720±0.200) ×10 －3 mm2/s and (8 154±8 337) mm 3] were higher than those in the control group ( t=－13.11 and－3.08, P<0.001 and P=0.004). Compared with the control group, ADC of fetuses with hydronephrosis [(1.333±0.171) ×10 －3 mm2/s] was higher ( t=－3.90, P<0.001); and the renal volume [(7 201±4 460) mm 3] was larger but without statistical significance. The fetuses with an isolated kidney had an increasing trend in renal volume [(5 239±4 244) mm 3] and a decreasing trend in the ADC value [(1.239±0.125) ×10 －3 mm2/s] when compared with the normal fetuses, but neither difference was significant. Conclusions:In normal fetuses, the ADC value decreases, and the renal volume increases with the gestational age. Fetuses with CAKUT may have a larger kidney than normal.