Iniencephaly is a predominantly lethal and rare form of neural tube defect characterized by fixed hyperextension of the head, occipital bone abnormalities, and cervical dysraphism. Its estimated incidence ranges from 0.1 to 10 per 10,000 births and is frequently associated with both neurological and non-neurological developmental anomalies. Here, we present the first documented case of iniencephaly apertus in conjunction with heterotaxy syndrome (HS), alobar holoprosencephaly (HPE) and myelomeningocele. Our report describes a 19-year-old primigravida with no significant medical history, whose ultrasound at 19 weeks of gestation identified findings consistent with iniencephaly apertus associated with alobar HPE and myelomeningocele. Fetal magnetic resonance imaging (MRI) at week 20 confirmed these findings and additionally revealed a centrally positioned liver and asplenia, consistent with HS. The pregnancy was terminated at week 21, resulting in a stillborn female with a normal 46 XX karyotype. The family did not consent to an autopsy. Here, we discuss the prenatal ultrasonographic, fetal MRI, and external macroscopic findings of this unique association. This case highlights the importance of prenatal diagnosis in decisions about pregnancy viability and opens a window for future research on factors contributing to the co-occurrence of these rare conditions.

Iniencephaly is a rare malformation of the base of the cranium, with an almost always fatal prognosis. This condition is part of the category of defects related to neural tube closure. Prenatal diagnosis can now be performed through ultrasound evaluation, allowing timely counseling. We present the case of a woman for whom an ultrasound diagnosis of iniencephaly at 13 weeks of gestation enabled early termination of the pregnancy.

Introduction  Iniencephaly is an extremely rare type of neural tube defect characterized by the fusion of the cervical and cervicothoracic vertebrae. This condition results in acute retroflexion of the head, a short neck, significant lordosis of the cervical spine, and an upturned facial appearance. This condition typically results in poor fetal outcomes, with many cases ending in stillbirth or neonatal death. Case summary  Here, we present a case of iniencephaly diagnosed during intrapartum ultrasound in a 34-year-old gravida 5 woman referred from a health center to a primary hospital due to preterm premature rupture of membrane and labor. The fetus died intrapartum a few minutes before delivery. Conclusion  Iniencephaly remains a rare but critical condition that poses significant challenges for prenatal diagnosis and management. This case underscores the importance of early and accurate imaging in the detection of such severe anomalies, which can provide essential information for clinical decision-making and counseling.

Iniencephaly is a rare neural tube defect (NTD) characterized by deformities in the occiput and inion, along with rachischisis in the cervical and thoracic spine, resulting in the head appearing in retroflexion. This report details the case of a female newborn who underwent surgery for an encephalocele. She survived up to 6 months, exhibiting good overall health, although she displayed physical abnormalities, including facial deformity, a short neck, and minor spasms in all limbs. Both cardiovascular and abdominal assessments remained stable, and imaging revealed defects in the occipital bone, a large cephalocele, and spinal dysraphism. Although iniencephaly is generally incompatible with life, a few cases have been reported otherwise. Our patient, one of these notable exceptions, remains alive at 6 months old, possibly due to the lack of major vascular deformities. However, she does exhibit significant psychomotor retardation.