Preferred Reporting Items for Systematic Review and Metaanalysis (PRISMA) protocols were employed in this study. Eligibility criteria were set using the Patient, Intervention, Comparison, and Outcome (PICO) approach. Table 1 shows the PICO criteria.

The databases of PubMed, Directory of Open Access Journals, EBSCO, and Cochrane were extensively researched. The following keywords were used to carry out additional research: “fetal” or “prenatal” or “postnatal” or “myelomeningocele” or “closure” or “surgery” or “long” or “term” or “neurological” or “cognitive” or “behavioral” or “functional” or "quality of life” or “outcome.” Literature searching was conducted along with the librarian of Universitas Sumatera Utara, Medan, Indonesia. The date of publication within 2007–2022 and all studies with more than 5 years of follow-up were the inclusion criteria. All animal studies and systematic reviews were excluded. Microsoft Excel was used to collect the papers.

The PRISMA statement indicates that the titles and abstracts of the records that were acquired were checked, and the whole texts of those that were considered relevant were evaluated. Full-text research with meta-analyses, clinical trials, and randomized controlled trials (RCTs) were given priority; thus, a total of 13 research was selected. In the end, 11 research were included in this systematic review. While the other 2 publications were disregarded because of their overlap with other works, their confusing remarks, their irrelevant connections to the core problem, or their focus on diseases other than myelomeningocele. The PRISMA flow diagram for the research identification and selection process is shown in Fig. 1, and the list of publications that made up the systematic review is shown in Table 2.

The primary outcomes of this study were the long-term neurological cognitive, behavioral, and functional outcomes. The secondary outcome was the long-term QoL outcome.

At 5 years of age, the mean verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), and full intelligence quotient (FIQ), and processing speed, high-average or average scores of the preschool neurodevelopmental outcome of children following fMMC were reported in 93%, 90%, 90%, and 60%; and were revealed to be within the normal population range by Danzer et al. [8] Individuals who did not require shunt insertion had substantially higher mean VIQ, PIQ, FIQ and processing speeds.

Another research by Danzer et al. [9] examined the preschool functional status following fMMC and showed that most fMMC children had attained cognitive and movement independence but still needed a lot of help with self-care. At 5 years of age, the mean functional quotients for cognitive ability, self-care, mobility, and overall, in fMMC individuals were all considerably lower than age-appropriate population norms. Full caregiver independence was attained by 84%, 38%, 62%, and 58% of fMMC individuals in the areas of cognition, self-care, mobility, and total functional outcome. Individuals with fMMC who were not shunted exhibited greater cognitive, mobility, and overall independence than those who were, as did those with average neurodevelopmental scores. Self-care independence was more prevalent in the nonshunted group and in fMMC individuals with normal neurodevelopmental outcomes [9].

Preterm delivery and fMMC have not been linked to an increase in behavioral issues, impaired social interactions, or restricted behavior patterns in preschool-aged (>5 years) children, according to another research by Danzer et al. [10] For internalizing, externalizing, and overall behavioral issues, the prevalence of "at-risk" or "clinically substantial" scores was comparable to population norms. Between nonshunted and shunted fMMC individuals, there was no difference in the overall internalizing, externalizing, or total behavioral scores. The prevalence of anxiety and depressive, pervasive developmental, and withdrawn behavior was higher in shunted fMMC individuals. There were no indications of oppositional defiance, attention deficit disorder, or hyperactivity [10].

There was no discernible difference in overall adaptive behavior across the surgical groups, according to the study of Houtrow et al. [11] on fMMC and school-age (5.9–10.3 years) functional outcomes. The long-term advantages of fMMC included greater mobility and independence as well as fewer procedures for shunt insertion and correction, but there was no clear evidence of enhanced cognitive functioning. There was no difference in the Vineland composite score. Children in the fMMC group had higher mean percentage scores on the Functional Rehabilitation Evaluation of Sensory-Neurologic Outcomes, lower rates of hindbrain herniation, fewer shunts placed for hydrocephalus, and, among those with shunts, fewer shunt revisions than those in the postnatal group. They also walked without orthotics or assistive devices more frequently [11].

Executive functioning (EF), behavioral adaptive skill (BAS), and long-term neurofunctional results following fMMC were all studied by Danzer et al. [12] fMMC surgery was revealed to enhance long-term functional outcomes. 79% of individuals are community ambulators, 9% are household ambulators, and 14% are wheelchair-dependent at the median follow-up age of 10 years. In contrast, the requirement for tethered cord surgery was connected to a sustained decline in ambulatory status. 26% of individuals had normal bladder function. The majority of individuals who underwent fMMC had average or above-average scores on the Behavioral Regulation Index, Metacognition Index, and Global Executive Composite indices; nonetheless, substantially more of them than the population as a whole exhibited EF deficits in all 3 BRIEF indices. Following fMMC, the general adaptive composite scores tended to perform below average. Normal EF and BAS were predicted by normal early neurodevelopmental outcomes. A considerable BAS impairment was linked to the need for shunting. The majority of fMMC individuals are capable of accomplishing routine jobs at home and school. fMMC enhances long-term ambulatory status. Functional loss is linked to symptomatic spinal cord tethering, whether or not there is an intradural inclusion cyst. The fMMC individuals are more continent than predicted, but bowel and bladder control remain problematic for the fMMC individuals [12].

The physical functional advantages of fMMC for myelomeningocele documented at age 30 months continued throughout school age, according to studies by Houtrow et al. [13] on fMMC and physical functioning. According to the Modified Hoffer Classification, those in the fMMC group tended to be community ambulators and had better self-care skills and gait quality, performed the 10-m walk test 1 second faster, and were able to perform higher-level mobility skills. The likelihood that a child's motor function level would be poorer than their anatomic lesion level was lower in the fMMC group. In this study, 78 individuals with postnatal closure (mean age, 7.4 years) and 76 individuals with fMMC (mean age, 7.5 years) were included [13].

Clayton et al discovered that management of neurogenic bowel and bladder in individuals after fMMC remains a major problem. At a mean age of 9.6 years, 82.1% of individuals needed clean intermittent catheterization to control their bladders, 85.7% needed bowel management to deal with constipation, and 21.4% had lower urinary tract reconstruction surgery that included enterocystoplasty and a catheterizable bladder channel. When videourodynamics were conducted on half of the individuals, at a mean age of 7.4 years, it was discovered that 71% of the individuals had lower bladder capacity, 35% had overactive detrusors, and 25% had elevated detrusor pressure. No discernible differences in bladder management, urinary tract surgery, or urodynamics were seen when compared to individuals of the same age and sex who had postnatal closure [14].

fMMC individuals results in a higher percentage of individuals who have achieved continence than the postnatal group, according to the study of Carr [15] in pre-Management of Myelomeningocele Study (MOMS) trial individuals with follow-up for 5 years following fMMC, 18.5% of individuals have efficaciously trained their toilets, whereas 3.7% have bowel continence, 1.8% have bladder continence but need enemas, and 3.7% of individuals who successfully trained their toilets had spinal dermoid cysts that need to be surgically removed [15].

Incontinence between catheterizations, the requirement for clean intermittent catheterization, or the use of anticholinergic/ antibiotic medications did not differ across the groups, according to research by Lee et al. [16] about whether fMMC enhances lower urinary tract function. Detrusor overactivity, bladder capacity, detrusor pressure at capacity, and the presence of detrusor sphincter dyssynergia were all urodynamic parameters that did not substantially differ across the groups. The rates of ventriculoperitoneal shunting and untethering operation were identical. fMMC group had a mean follow-up of 7.2 years, while the postnatal group had a mean follow-up of 7.3 years. For fMMC and postnatal closure, the average individual age at comparable urodynamic examinations was 5.9 years and 6.0 years, respectively. In the postnatal closure cohort, the fMMC group consisted of 5 lumbar and 6 sacral level abnormalities with equal matching [16].

With a mean age of 7.4 years, Brock et al. [17] investigated the effectiveness of fMMC on urological outcomes at school age. With 24% of the fMMC group reporting voluntary voiding compared to 4% of the postnatal group, they discovered that the voiding status was significantly different across the groups. The 2 groups did not differ in terms of vesicostomy, urethral dilatation, or augmentation cystoplasty. Except for a larger postvoid residual urodynamic catheterization volume, there were no other statistically significant changes between the renal/ bladder ultrasonography results and the videourodynamic data. Overall, 62% of prenatal surgery patients and 87% of postnatal surgery patients were put on clean intermittent catheterization, respectively [17].

fMMC is associated with a better long-term QoL in comparison to postnatal closure, according to Mummareddy et al. [18] Individuals who received fMMC had considerably better psychological health than the postnatal group. Between the 2 groups, there were not statistically substantial differences in physical health, number of procedures performed on the individuals, and proportion of individuals who underwent nonneurosurgical operations. Neurosurgical procedures were performed on fewer individuals in the fMMC group than in the postnatal group. There were also no differences between the intrauterine group and the postnatal group in terms of age (median: 17 years vs. 15 years), sex, or lesion level [18].