Rationale: Sacrococcygeal teratoma (SCT), derived from early embryonic pluripotent stem cells, is one of the most common neoplasms in fetuses. We report a case of a large mass in the fetal sacrococcygeal region detected by ultrasonography at a gestational age of 16+ weeks. Patient concerns: A 26-year-old woman, gravida 2, para 1, was referred to our hospital with a mixed echo protrusion (3.6 × 2.8 × 2.8 cm in the fetal sacrococcygeal region. Diagnoses: Ultrasound scan showed that the sacrococcygeal mass had grown to 7.1 × 5.8 cm. Magnetic resonance imaging revealed a large exophytic mass about 7.7 × 4.5 × 6.5 cm in the perineum of the fetus. Pathological examination revealed malignant SCT. Interventions: The patient was closely monitored and followed-up through prenatal examinations to assess the condition of the mother and child. Outcomes: The fetus was found dead in utero at 20-week gestation. The pregnant woman then induced labor. Lessons: SCT is a common germ cell tumor in fetuses. Attention should be paid to maternal and fetal conditions due to serious complications. Appropriate interventions during pregnancy and timely surgery after delivery are recommended.

Objective We describe a fetus with a 2.12-Mb terminal deleted fragment in 16q associated with alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) and lymphedema-distichiasis syndrome (LDS) and intend to provide a comprehensive prenatal management strategy for the fetuses with ACDMPV and LDS through reviewing other similar published studies. Methods The fetus presented a series of diverse structural malformations including congenital cardiovascular, genitourinary and gastro-intestinal anomalies in ultrasound at 23 + 5 weeks of gestation (GA). Amniocentesis was conducted for karyotype analysis and copy number variation sequencing (CNV-seq) after informed consent. Results The fetal karyotype was 46,XX, however the result of CNV-seq showed an approximately 2.12-Mb deletion in 16q24.1q24.2 (85220000-87340000) × 1 indicating pathogenicity. Conclusion Genomic testing should be recommend as a first line diagnostic tool for suspected ACDMPV and/or LDS or other genetic syndromes for the fetuses with structural abnormalities in clinical practice.

Purpose To investigate genetic etiology and pregnancy outcomes of fetal central nervous system (CNS) anomalies. Methods 217 fetuses with CNS anomalies were included in our cohort from January 2016 to December 2022. 124 cases received karyotyping and 73 cases simultaneously underwent copy number variant sequencing (CNV-seq). Dynamic ultrasound screening and pregnancy outcomes were followed up, including neonates’ neurodevelopmental outcomes. Results (1) 20 types of CNS anomalies were revealed by ultrasound and the most common was ventriculomegaly. (2) 14 (11.3%) of 124 cases were found chromosomal abnormalities by karyotyping, and copy number variations (CNVs) were revealed in 13 (17.8%) of 73 cases by CNV-seq. Fetuses with non-isolated CNS anomalies had a higher detection rate (DR) of abnormal karyotypes and CNVs than those with isolated CNS anomalies (25.0% vs. 4.8%; 35.0% vs. 11.3%) (P < 0.05). And the DR of abnormal karyotypes was significantly higher in multiple CNS anomalies than in single CNS anomaly (16.7% vs. 2.8%, P < 0.05), while there were no significant differences in the DR of CNVs. (3) Through dynamic ultrasound, 12 cases were further found progression or additional malformations. (4) Pregnancy outcomes of 209 cases were obtained, including 136 (65.1%) live births, 3 (1.4%) intrauterine fetal deaths, and 70 (33.5%) terminated. Two neonatal deaths at 6 months and one infant with motor and intellectual disabilities were finally found after long-term follow-up. Conclusion Genetic analysis combined with dynamic ultrasound screening and multidisciplinary consultation plays an important role in evaluating the prognosis of fetal CNS anomalies, especially for those with multiple CNS or extracranial abnormalities.