背景:我们提出了羊水过多的两种遗传原因,由于其稀有性和复杂性,因此难以诊断。鉴于其严重影响,当产科医生考虑妊娠晚期羊水过多的鉴别诊断时,我们希望强调这些罕见的遗传状况.
方法:患者1是一名34岁的亚洲女性,在妊娠28周时被诊断为羊水过多。孕早期测试,胎儿异常扫描,宫内感染筛查正常。随后的产前超声扫描显示巨大的舌头,怀疑Beckwith-Wiedemann综合征.染色体微阵列分析显示女性特征,没有病理拷贝数变异。患者在怀孕期间进行了两次羊膜减压术。该患者在妊娠34周时早产,但当选为紧急剖腹产。出生后,婴儿的胸部呈钟形,衣架排骨,低张力,腹胀,和面部畸形提示Kagami-Ogata综合征。患者2是一名30岁的亚洲女性,在妊娠30周时被诊断为羊水过多。她进行了高风险的孕早期筛查,但拒绝进行侵入性检测;非侵入性产前检测风险较低。超声检查显示大体胎儿具有1级回声肠,但没有其他异常。宫内感染筛查阴性,也没有胎儿贫血的超声表现.她在37+3周时自发性胎膜破裂,但随后根据病理性心脏造影通过剖腹产分娩。注意到婴儿有吸气喘鸣,低张力,低设定的耳朵,双侧脚趾多指。进一步的基因检测揭示了一个具有GLI3基因致病变异的女性特征,确认诊断为Greig头型多指综合征。
结论:这些病例说明了在鉴别诊断中考虑羊水过多的罕见遗传原因的重要性。特别是在20周的结构扫描中胎儿异常不明显时。我们想提高对这些罕见疾病的认识,由于高度怀疑可以进行适当的咨询,产前检查,并及时转诊给儿科医生和遗传学家。早期识别和诊断允许在多学科团队管理的三级中心规划围产期护理和分娩。
BACKGROUND: We present two genetic causes of polyhydramnios that were challenging to diagnose due to their rarity and complexity. In view of the severe implications, we wish to highlight these rare genetic conditions when obstetricians consider differential diagnoses of polyhydramnios in the third trimester.
METHODS: Patient 1 is a 34-year-old Asian woman who was diagnosed with polyhydramnios at 28 weeks\' gestation. First trimester testing, fetal anomaly scan, and intrauterine infection screen were normal. Subsequent antenatal ultrasound scans revealed macroglossia, raising the suspicion for Beckwith-Wiedemann syndrome. Chromosomal microarray analysis revealed a female profile with no pathological copy number variants. The patient underwent amnioreduction twice in the pregnancy. The patient presented in preterm labor at 34 weeks\' gestation but elected for an emergency caesarean section. Postnatally, the baby was noted to have a bell-shaped thorax, coat hanger ribs, hypotonia, abdominal distension, and facial dysmorphisms suggestive of Kagami-Ogata syndrome. Patient 2 is a 30-year-old Asian woman who was diagnosed with polyhydramnios at 30 weeks\' gestation. She had a high-risk first trimester screen but declined invasive testing; non-invasive prenatal testing was low risk. Ultrasound examination revealed a macrosomic fetus with grade 1 echogenic bowels but no other abnormalities. Intrauterine infection screen was negative, and there was no sonographic evidence of fetal anemia. She had spontaneous rupture of membranes at 37 + 3 weeks but subsequently delivered by caesarean section in view of pathological cardiotocography. The baby was noted to have inspiratory stridor, hypotonia, low-set ears, and bilateral toe polysyndactyly. Further genetic testing revealed a female profile with a pathogenic variant of the GLI3 gene, confirming a diagnosis of Greig cephalopolysyndactyly syndrome.
CONCLUSIONS: These cases illustrate the importance of considering rare genetic causes of polyhydramnios in the differential diagnosis, particularly when fetal anomalies are not apparent at the 20-week structural scan. We would like to raise awareness for these rare conditions, as a high index of suspicion enables appropriate counseling, prenatal testing, and timely referral to pediatricians and geneticists. Early identification and diagnosis allow planning of perinatal care and birth in a tertiary center managed by a multidisciplinary team.