Pre & Perinatal care characteristics and management of children with myelomeningocele after 25 years of folate fortification of staple foods in Costa Rica

Purpose: To describe the clinical characteristics of pre and perinatal care of children born with myelomeningocele in Costa Rica from 2004 to 2022 after the introduction of mandatory four staple food fortification policy, describing the clinical features of this cohort including the size of the meningomyelocele, neurological level, presence of symptomatic Chiari II at birth, kyphosis and the severity of hydrocephalus requiring cerebrospinal fluid (CSF) shunting. Methods: We performed a retrospective review of the clinical records of patients with myelomeningocele at the spina bifida clinic from the National Children´s Hospital of Costa Rica who were born after the introduction of the four staple food folic acid fortification. Pre and perinatal care data pertaining to the number of obstetric ultrasound studies, the trimester in which they were performed and the detection of myelomeningocele and associated hydrocephalus, gestational age and route of delivery, neurological level, myelomeningocele defect size, associated kyphosis and symptomatic Chiari II malformation at birth, time periods of myelomeningocele repair and eventual CSF shunting were examined. Results: A total of 215 patients born between 2004 and 2022 were eligible for analysis with a follow up ranging from 1 to 19 years (median follow up: 7.9 years). Among 99.1% of the mothers of patients who had prenatal consultations, 95.8% had an average of 3.8 obstetric ultrasound studies which led to a 59% prenatal detection rate of myelomeningocele. This cohort had a slight male predominance (54.8%). Among these newborns, 7.5% had the myelomeningocele lesion repaired in less than 8 hours, 12.2% from 8-12 hrs., 66.5% 12-24 hrs. and 12.7% from 24-48 hrs. and 1% later than 48 hrs. Regarding the myelomeningocele anatomic and functional characteristics, defect size was measured as less than 3 cm in 7% of cases, 3 to 5 cm in 50% of cases, 5 to 7 cm in 42% of cases and greater than 7 cm in 1% of cases. 13% of the cases had paraplegia due to a thoracic level, 9.3% had a high lumbar level, 58% had a middle lumbar level, 13% a lower lumbar level and 5.6% only sacral compromise. Postnatal closure was performed in less than 8 hrs. in 7.4% of cases, 8 to12 hrs. in 12.1% of cases, 12 to24 hrs. in 65.8% of cases, and 24 to48 hrs. in 12.5% of cases. Kyphotic deformities were observed in 3 patients who had very large defects and only 6 patients had symptomatic Chiari II malformation at birth. 79% of the cohort required CSF VP shunting with a mean time for insertion of 10 days after spinal defect closure. Conclusions: This study describes a four staple folate fortified population of live born patients with myelomeningocele lesions whose neurological level, defect size, and associated deformities such as spinal kyphosis and symptomatic Chiari II at birth, suggest that folate fortification could have diminished the severity of this congenital disease.