A Tale of Two Anencephalies: Multimodal Imaging Approach for Prenatal Diagnosis and Management

Purpose: This case series provides vital insight into diagnosis, imaging modalities, prenatal counseling, and delivery recommendations in the setting of anencephaly and/or encephalocele. Methods: This study is a case series detailing the diagnosis, imaging, counseling, and delivery approach of two individual cases. The first case included the course of a pregnant patient whose prenatal anatomy ultrasound at 24 weeks and 5 days gestation demonstrated anencephaly. This patient’s case also provided details of Neonatology and Palliative Care consultations and her primary cesarean section for delivery. The second case involved a prenatal ultrasound suspicious for anencephaly, with fetal MRI later revealing encephalocele. This patient also proceeded with primary cesarean section for delivery. We searched PubMed for all English language articles from 2000 to 2023, with search terms including “anencephaly,” “encephalocele,” “anencephaly diagnosis,” “encephalocele diagnosis,” “anencephaly management,” and “encephalocele management.” Results: Case 1: This patient presented to care at 24 weeks 5 days gestation with an anatomy ultrasound that diagnosed fetal anencephaly. In addition to late entry to prenatal care, her pregnancy was complicated transaminitis, possible fetal ventricular septal defect, and polyhydramnios. Counseling throughout the patient’s prenatal course included details of anencephaly, including that it is considered a lethal defect with no treatment or corrective surgery. Discussions with the patient also surrounded the fetus’ potential course following delivery, including likelihood of passing. The patient accepted consultations from the Neonatology and Palliative Care teams. Ultimately at a gestational age of 30 weeks and 1 day, the patient was admitted in latent labor and proceeded with a primary cesarean section. On delivery, the infant was clearly anencephalic, with the defect extending from brow ridge to base of skull. The cavarum was absent. The overall volume of the infant’s head was smaller than expected, with the rest of the body was normal for gestational size. The infant remained with mother and father and passed within two hours following delivery. Case 2: This patient presented to care at 35 weeks 3 days gestation with an initial ultrasound suspicious for anencephaly. This case was complicated by several maternal pregnancy complications, including polyhydramnios, suspected pregestational diabetes, insufficient prenatal care, and advanced maternal age. A follow-up fetal ultrasound one week later revealed posterior skull with central defect with herniation of meninges and fetal brain through defect which appeared more consistent with a large encephalocele rather than anencephaly. Fetal MRI the next day demonstrated a small cranial vault with a large occipital encephalocele containing nearly the entirety of the brain parenchyma through a defect measuring up to 3.1 cm. The encephalocele sac contained fluid as well as herniated brain component measuring up to 7.1 x 9.7 x 4.5 cm. The herniated brain component contained most of the bilateral cerebral hemispheres which appeared separated with no obvious corpus callosum. In the absence of operative repair options with Pediatric Neurosurgery, the parents opted for palliative care and a primary cesarean section at 37 weeks 0 days gestation. On delivery, the infant appeared to have a small cranial vault and a large occipital encephalocele containing nearly the entirety of the brain parenchyma. The infant later passed on day three of life. Conclusions: These two cases underscore the importance of advanced imaging modalities, such as fetal MRI, in diagnosing and differentiating complex fetal anomalies like anencephaly and encephalocele. This case series highlights the challenges in managing such cases and the need for further research to improve prenatal counseling and intervention strategies as well as counseling regarding delivery route recommendations and discussions.