Prenatal transabdominal ultrasonography in diagnosing abnormal nasal bone development of in vitro fertilization-embryo transfer fetus: clinical values

Abstract

Objective To evaluate the clinical value of prenatal transabdominal ultrasonography in diagnosing abnormal nasal bone development in fetuses undergoing in vitro fertilization-embryo transfer (IVF-ET). Methods From January 2015 to March 2019, a total of 4 360 cases of IVF-ET fetuses who received prenatal transabdominal ultrasonography in West China Second University Hospital, Sichuan University were selected as research subjects. Retrospective analysis method was used to collect transabdominal ultrasound images, chromosome karyotype analysis results and 6-month postnatal follow-up of fetuses with abnormal nasal bone development diagnosed by prenatal transabdominal ultrasonography. The incidences of chromosomal abnormality in fetuses with bilateral and unilateral abnormal nasal bone development, isolated and non-isolated abnormal nasal bone development were compared by chi-square test, respectively. This study was consistent with the requirements of the World Medical Association Declaration of Helsinki revised in 2013. Results ①Among the 4 360 cases of IVF-ET fetuses in this study, 104 cases (2.4%, 104/4 360) had chromosomes abnormality. There were 168 cases (3.9%, 168/4 360) of abnormal nasal bone development, including 102 cases of singleton, 66 cases (33 pairs) of twins, and 67 cases (1.5%, 67/4 360) were combined with chromosome abnormality, including 62 cases of 21-trisomy syndrome and 5 cases of 18-trisomy syndrome. ②Among the IVF-ET fetuses in this study, the sensitivity, specificity and crude accuracy of IVF-ET fetal abnormal nasal bone development in predicting fetal chromosome abnormality were 64.4%, 97.6% and 96.8%, respectively. ③Among the 61 cases of fetuses with non-isolated abnormal nasal bone development, 22 cases (36.1%) were combined with fetal nuchal translucency (NT) thickening, and 39 cases (63.9%) were combined with other structural malformations. The incidences of chromosome abnormality of IVF-ET fetuses with bilateral and unilateral abnormal nasal bone development were 41.5% (44/106) and 38.7% (24/62), respectively, and the difference was not statistically significant (χ2=0.127, P=0.722). The incidences of chromosome abnormality of IVF-ET fetuses with isolated and non-isolated abnormal nasal bone development were 38.3% (41/107) and 44.3% (27/61), respectively, and the difference was not statistically significant (χ2=0.570, P=0.450). Conclusions The specificity and crude accuracy of prenatal transabdominal ultrasonography in diagnosis of abnormal nasal bone development of IVF-ET fetuses are good. The prenatal transabdominal sonographic diagnosis of abnormal nasal bone development in IVF-ET fetuses is helpful to indicate fetal chromosome abnormality, and clinical attention should be paid to the prenatal ultrasonography of nasal bone of IVF-ET fetus. Key words: Nasal bone; Dysostoses; Chromosome aberrations; Ultrasonography, prenatal; Fertilization in vitro; Embryo transfer; Fetus