Specific birth defects in pregnancies of women with diabetes: National Birth Defects Prevention Study, 1997-2011.

BACKGROUND: Diabetes is associated with an increased risk for many birth defects and is likely to have an increasing impact on birth defect prevalence because of the rise in diabetes in the United States in recent decades. One of the first analyses in which specific birth defects were assessed for their relationship with both pregestational and gestational diabetes used data from the initial 6 years of the National Birth Defects Prevention Study. That analysis reported strong associations for pregestational diabetes with several birth defects, but few exposures among some of the less common birth defects led to unstable estimates with wide confidence intervals. Since that analysis, the study continued to collect data for another 8 years, including information on approximately 19,000 additional cases and 6900 additional controls. OBJECTIVE: Our objective was to use data from the National Birth Defects Prevention Study, the largest population-based birth defects case-control study in the United States, to provide updated and more precise estimates of the association between diabetes and birth defects, including some defects not previously assessed. STUDY DESIGN: We analyzed data on deliveries from October 1997 through December 2011. Mothers of case and control infants were interviewed about their health conditions and exposures during pregnancy, including diagnosis of pregestational (type 1 or type 2) diabetes before the index pregnancy or gestational diabetes during the index pregnancy. Using logistic regression, we separately assessed the association between pregestational and gestational diabetes with specific categories of structural birth defects for which there were at least 3 exposed case infants. For birth defect categories for which there were at least 5 exposed case infants, we calculated odds ratios adjusted for maternal body mass index, age, education, race/ethnicity, and study site; for defect categories with 3 or 4 exposed cases, we calculated crude odds ratios. RESULTS: Pregestational diabetes was reported by 0.6% of mothers of control infants (71 of 11,447) and 2.5% of mothers of case infants (775 of 31,007). Gestational diabetes during the index pregnancy was reported by 4.7% of mothers of control infants (536 of 11,447) and 5.3% of mothers of case infants (1,653 of 31,007). Pregestational diabetes was associated with strong, statistically significant odds ratios (range, 2.5-80.2) for 46 of 50 birth defects considered. The largest odds ratio was observed for sacral agenesis (adjusted odds ratio, 80.2; 95% confidence interval, 46.1-139.3). A greater than 10-fold increased risk was also observed for holoprosencephaly (adjusted odds ratio, 13.1; 95% confidence interval, 7.0-24.5), longitudinal limb deficiency (adjusted odds ratio, 10.1; 95% confidence interval, 6.2-16.5), heterotaxy (adjusted odds ratio, 12.3; 95% confidence interval, 7.3-20.5), truncus arteriosus (adjusted odds ratio, 14.9; 95% confidence interval, 7.6-29.3), atrioventricular septal defect (adjusted odds ratio, 10.5; 95% confidence interval, 6.2-17.9), and single ventricle complex (adjusted odds ratio, 14.7; 95% confidence interval, 8.9-24.3). For gestational diabetes, statistically significant odds ratios were fewer (12 of 56) and of smaller magnitude (range, 1.3- 2.1; 0.5 for gastroschisis). CONCLUSION: Pregestational diabetes is associated with a markedly increased risk for many specific births defects. Because glycemic control before pregnancy is associated with a reduced risk for birth defects, ongoing quality care for persons with diabetes is an important opportunity for prevention.

Descriptive and risk factor analysis of nonsyndromic sacral agenesis: National Birth Defects Prevention Study, 1997-2011.

Sacral agenesis is a rare birth defect characterized by partial or complete absence of the sacrum. We sought to (a) describe case characteristics, (b) estimate birth prevalence, and (c) identify risk factors for nonsyndromic sacral agenesis using data from the National Birth Defects Prevention Study (NBDPS). The NBDPS was a population-based, case-control study involving pregnancies with estimated dates of delivery from October 1997 through December 2011. We estimated birth prevalence using all NBDPS eligible cases. Using self-reported maternal exposure information, we conducted multivariable logistic regression analysis to identify potential risk factors overall and among women without diabetes. The birth prevalence of sacral agenesis was 2.6/100,000 live births. In the multivariable analysis, multifetal pregnancy, pre-existing Type 1 diabetes, and pre-existing Type 2 diabetes were positively and significantly associated with sacral agenesis, albeit estimates were imprecise. Preexisting Type 1 diabetes was the strongest risk factor (adjusted odds ratio = 96.6, 95% confidence interval = 43.5-214.7). Among women without diabetes, periconceptional smoking was positively and significantly associated with sacral agenesis. Our findings underscore the importance of smoking cessation programs among women planning pregnancy and the importance of better understanding the role of glycemic control before and during pregnancy when designing interventions for primary prevention of sacral agenesis.

Coexistence of meningoencephalocele and hippocampal sclerosis: a new type of dual pathology.

Both temporal lobe meningoencephalocele (TE) and hippocampal sclerosis (HS) are causes of drug-resistant temporal lobe epilepsy. Spontaneous TE constitutes a rare but well-known and increasingly recognised cause of refractory epilepsy. It is well known that HS may be associated with another neocortical lesion (dual pathology). Here we report for the first time a new type of dual pathology; namely, the coexistence of temporal pole meningoencephalocele and HS.

Neural tube dysraphism: review of cutaneous markers and imaging.

Neural tube dysraphisms are congenital anomalies resulting from impaired formation of structures along the craniospinal axis during central nervous system development. When these malformations are large or lack a skin covering, they are easily recognized, whereas smaller or skin-covered malformations may not be readily apparent. Due to the intimate embryologic origin of the skin and nervous system, these occult malformations are often heralded by associated cutaneous abnormalities. In this article, the common clinical presentations and cutaneous markers of craniospinal dysraphism are reviewed, along with the recommended imaging modalities.

PATTERNS OF NEURAL TUBE DEFECTS AT TWO TEACHING HOSPITALS IN ADDIS ABABA, ETHIOPIA A THREE YEARS RETROSPECTIVE STUDY.

BACKGROUND: Neural tube defects (NTDs), one of the most common congenital malformations, are potentially preventable cause of perinatal morbidity and mortality. OBJECTIVES: To give baseline description of NTDs and their outcome at two teaching hospitals in Addis Ababa, Ethiopia. MATERIALS AND METHODS: A retrospective cross sectional descriptive study conducted from September 2009 to August 2012. RESULTS: During the study period out of 28,961 deliveries 177 cases of NTDs were identified, giving an overall NTD prevalence of 6.1/1000. Only 12% (21/177) were diagnosed before 28 weeks of gestation. The mean gestational age at diagnosis of NTDs was 33.8 weeks (±5.5). Majority, 93.2% (165/177), had antenatal care (ANC) follow-up. Most, 72% (127/177), were diagnosed by ultrasound before delivery while 28% (50/177) were identified at the time of delivery or expulsion. Majority, 85.3% (151/177), never received folic acid supplementation. Only less than 1% (2/177) of the mothers started taking folic acid supplementation pre-conceptionally. Only a third, 33.3% (59/177), of the fetuses were born alive while only 13.6% (24/177) were discharged alive. Myelomeningocele, identified in 51.4% (91/177), was the commonest NTD in this study. CONCLUSION AND RECOMMENDATIONS: The proportion of NTDs in this study is among the highest globally reported rates. The practice of periconceptional folic acid supplementation is negligible. And although most had ANC follow-up the vast majority of NTDs were diagnosed late in the third trimester. It is, therefore, highly recommended to consider implementing national preventive strategies to reduce the prevalence of NTDs in Ethiopia.

Meningoceles in idiopathic intracranial hypertension.

OBJECTIVE: MRI abnormalities have been described in patients with increased intracranial pressure (ICP), including in those with idiopathic intracranial hypertension (IIH). Spontaneous CSF-filled outpouchings of the dura (meningoceles) and secondary CSF leaks can occur from elevated ICP in patients with IIH; however, few studies have evaluated these findings. Our objective was to evaluate the frequency of spontaneous intracranial meningoceles among IIH patients and determine their association with visual outcome. MATERIALS AND METHODS: We performed a retrospective case-control study of consecutive IIH patients between 2000 and 2011 who underwent MRI that included T2-weighted imaging. Demographics, presenting symptoms, CSF opening pressure, and visual outcome were collected for the first and last evaluations. Control subjects included patients without headache or visual complaints who had normal brain MRI results. Stratified analysis was used to control for potential confounding by age, sex, race, and body mass index. RESULTS: We included 79 IIH patients and 76 control subjects. Meningoceles were found in 11% of IIH patients versus 0% of control subjects (p<0.003). Prominent Meckel caves without frank meningoceles were found in 9% of IIH patients versus 0% of control subjects (p<0.003). Among IIH patients, the presence of meningocele or prominent Meckel caves was not associated with demographics, symptoms, degree of papilledema, CSF opening pressure, visual acuity, or visual field defect severity. CONCLUSION: Meningoceles are significantly more common in IIH patients than in control subjects and can be considered an additional imaging sign for IIH. Meningoceles are not, however, associated with decreased CSF opening pressure or better visual outcome in IIH.

Surgical management of temporal meningoencephaloceles, cerebrospinal fluid leaks, and intracranial hypertension: treatment paradigm and outcomes.

OBJECT: Thinning of the tegmen tympani and mastoideum components of the temporal bone may predispose to the development of meningoencephaloceles and spontaneous CSF leaks. Surgical repair of these bony defects and associated meningoencephaloceles aids in the prevention of progression and meningitis. Intracranial hypertension may be a contributing factor to this disorder and must be fully evaluated and treated when present. The purpose of this study was to establish a treatment paradigm for tegmen defects and elucidate causative factors. METHODS: The authors conducted a retrospective review of 23 patients undergoing a combined mastoidectomy and middle cranial fossa craniotomy for the treatment of a tegmen defect. RESULTS: The average body mass index (BMI) among all patients was 33.2 ± 7.2 kg/m(2). Sixty-five percent of the patients (15 of 23) were obese (BMI > 30 kg/m(2)). Preoperative intracranial pressures (ICPs) averaged 21.8 ± 6.0 cm H(2)O, with 10 patients (43%) demonstrating an ICP > 20 cm H(2)O. Twenty-two patients (96%) had associated encephaloceles. Five patients underwent postoperative ventriculoperitoneal shunting. Twenty-two CSF leaks (96%) were successfully repaired at the first attempt (average follow-up 10.4 months). CONCLUSIONS: Among all etiologies for CSF leaks, those occurring spontaneously have the highest rate of recurrence. The surgical treatment of temporal bone defects, as well as the recognition and treatment of accompanying intracranial hypertension, provides the greatest success rate in preventing recurrence. After tegmen dehiscence repair, ventriculoperitoneal shunting should be considered for patients with any combination of the following high-risk factors for recurrence: spontaneous CSF leak not caused by another predisposing condition (that is, trauma, chronic infections, or prior surgery), high-volume leaks, CSF opening pressure > 20 cm H(2)O, BMI > 30 kg/m(2), preoperative imaging demonstrating additional cranial base cortical defects (that is, contralateral tegmen or anterior cranial base) and/or an empty sella turcica, and any history of an event that leads to inflammation of the arachnoid granulations and impairment of CSF absorption (that is, meningitis, intracranial hemorrhage, significant closed head injury, and so forth).

Comparison of dural grafts and methods of graft fixation in Chiari malformation type I decompression surgery.

Suboccipital decompression with duraplasty is a widely accepted method for treating patients with Chiari malformation type I. However, important details of the duraplasty technique are still controversial. This retrospective study analyzes clinical and radiological outcomes after surgery depending upon the type of graft and methods of graft fixation. Seventy consecutive decompressions with duraplasty were analyzed. Two types of grafts, nonautologous (Non-AutoG; 60.0%) and autologous (AutoG; 40.0%), and two methods of graft fixation, suturing (S; 67.1%) and gluing (G; 32.9%), were used in four different combinations: (Non-AutoG+S: 31.4%; Non-AutoG+G: 28.6%; AutoG+S: 35.7%; AutoG+G: 4.3%) according to surgeon preference. The mean follow-up was 63.4 months. According to gestalt and Chicago Chiari Outcome Scales, satisfactory results were obtained in 72.9% and 78.6% of cases, respectively, in the long term. The outcomes were not related to the kind of graft (p = 0.44), fixation method (p = 0.89) or duraplasty pattern (p = 0.32). Decreased syringomyelia was observed in 88.9% of cases, and no associations with the kind of graft (p = 0.84), fixation method (p = 1) or duraplasty pattern were found (p = 0.96). Pseudomeningocele occurred 5 times more often in the Non-AutoG group than in the AutoG group (52.4% vs. 10.7%; p < 0.05), whereas their formations were not related to the fixation method (p = 0.34). Three cases (12.0%) required reoperation with reduraplasty. Autologous and nonautologous dural grafts can be sutured or glued with similar clinical results; however, the use of nonautologous grafts is linked with a much higher risk of pseudomeningocele formation.

Prevalence and Outcome of Anterior and Middle Cranial Fossae Encephaloceles without Cerebrospinal Fluid Leak or Meningitis.

BACKGROUND: With advances in imaging techniques, encephaloceles, meningoceles, and meningoencephaloceles are occasionally discovered incidentally. These can be located in anterior cranial fossa (ACF), mostly protruding into sphenoid and ethmoid sinuses, or middle cranial fossa (MCF), protruding into the temporal bone. We reviewed a large series of cranial computed tomography and magnetic resonance imaging scans to identify the prevalence of asymptomatic encephaloceles, meningoceles, and meningoencephaloceles and describe their outcome. METHODS: We retrospectively reviewed a database of all magnetic resonance imaging and computed tomography scans done at Weill Cornell Medicine for any reason between 2003 and 2018. Encephaloceles, meningoceles, or meningoencephaloceles were confirmed on 72 scans. Of these, chart reviews were performed to identify incidentally discovered cases with symptoms other than cerebrospinal fluid leak, and chart reviews and phone calls were conducted to determine patient demographics, treatment, and outcome. RESULTS: There were 18 incidental cases for a prevalence of 0.0074%, of which 6 were located in ACF, and 12 were located in MCF. The mean age for ACF cases was 39 ± 15.9 years and for MCF cases was 49.5 ± 19.8 years. There were no leaks in any cases after the encephaloceles were discovered. Eleven of 12 (91.6%) MCF cases were treated conservatively, while 3 of 6 (50%; P = 0.083) ACF cases were treated surgically. CONCLUSIONS: This study showed that encephaloceles, meningoceles, and meningoencephaloceles without cerebrospinal fluid leak or meningitis in MCF were more often conservatively managed with observation only, whereas these entities in ACF were often repaired prophylactically. Incidentally discovered encephaloceles have a relatively benign natural history and do not precipitously leak.

Idiopathic ventral spinal cord herniation: a rare presentation of tethered cord.

Idiopathic ventral spinal cord herniation is a rare condition that has been increasingly reported in the last decade. The natural history and optimal management have yet to be defined. Therefore, debate exists regarding the pathogenesis and surgical management of this condition. The purpose of this review article is to further educate neurosurgeons about the surgical techniques and outcomes associated with treating this rare and often misdiagnosed condition.

The risk of growing skull fractures in craniofacial patients.

BACKGROUND/AIMS: Growing skull fractures (GSFs) are unusual sequelae of head injury in young children which have also been reported to occur after craniofacial procedures complicated by inadvertent durotomy. We reviewed the craniofacial experience in a single institution, detailing 180 cases of craniofacial surgery and suspected dural tears and their relationship to the subsequent development of GSFs. This experience was then compared to that of the pertinent published literature. METHODS: A retrospective review of the senior authors' craniofacial surgical experience from 2000 to 2007 was performed. This was compared to an English-language literature review of GSFs after craniofacial surgery. RESULTS: In our institution, 180 cases of craniofacial surgery (83 open, 97 endoscopic) were performed, with an average follow-up of 23.5 months. Twenty-five patients (15 open, 10 endoscopic surgeries) had operative dural compromise. One of these patients developed a persistent pseudomeningocele requiring reoperation. Twelve cases of GSF after craniofacial surgery were identified in a review of the English-language literature, of which 7 (58%) had coronal suture fusion. CONCLUSIONS: While durotomy may occur during craniofacial surgery, the subsequent development of a GSF appears to be an unlikely event with an aggressive intraoperative approach of identification and repair. Coronal craniosynostosis may confer an increased risk for this complication.

Tisseel® versus Hemopatch® for dural sealing in neurosurgery. A prospective study in a tertiary center.

BACKGROUND: Dural repair is a potential source of complications in neurosurgery. We make a comparison in pseudomeningocele and CSF leak incidence with the sealants Tisseel® and Hemopatch®. METHODS: We collected 147 patients from September 2017 to December 2018 in a prospective observational study. Inclusion criteria were adult patients with an intradural cranial or spinal surgery whose dura was closed with a fibrin sealant. Primary endpoints were the incidence of pseudo meningocele and CSF leak. Secondary endpoints were the surgical-site infection, epidural hematoma, and the influence of previous surgery. RESULTS: In 65 and 82 patients Tisseel® and Hemopatch® were used as sealants respectively. The incidence of CSF leak presented a significant statistical relation with the use of Tisseel® in a univariate and multivariate analysis. Infratentorial surgery presented a higher incidence of pseudomeningocele and CSF leak, but the approach used was not a significant factor in multivariate analysis. Patients who were operated previously had a higher risk present a postoperative complication. CONCLUSIONS: The incidence of pseudomeningocele and CSF leak was higher with Tisseel® compared with Hemopatch® with a statistic significant relation in case of CSF fistulae. The procedure done may be a confusion factor in our study. There was no report of adverse effects or a higher incidence of complications. However, it is recommended to plan randomized trials with larger samples to get stronger evidence.

Duraplasty with Cervical Fascia Autograft to Reduce Postoperative Complications of Posterior Fossa Tumor Surgery with Suboccipital Midline Approach.

BACKGROUND: The suboccipital midline approach is common dealing with posterior fossa tumors but has a high risk of postoperative complications, such as pseudomeningocele, cerebrospinal fluid (CSF) leak, and meningitis. Neurosurgeons used various kinds of method to lower its rate. METHODS: A retrospective, single-center review of patients diagnosed with posterior fossa tumor underwent a suboccipital midline approach. Compare the rates of pseudomeningocele, CSF leak, and meningitis between 2 groups (artificial dura mater or cervical fascia autograft). We get the cervical fascia autograft from the superficial layer of deep cervical fascia just above the trapezius. RESULTS: Our retrospective review involved 123 patients matching the inclusion criteria between January 2009 and April 2019. The complication rate of pseudomeningocele, CSF leak and meningitis were 8.9%, 4.9%, and 17.9%, respectively. The presence of pseudomeningocele or CSF leak for group "artificial" was 11 of 75 (14.67%) and for group "autograft" it was 3 of 48 (6.25%). The rate of meningitis for group "artificial" (24.0%, 18 of 75) was significantly higher (P = 0.027) than the one for group "autograft" (8.33%, 4 of 48). Multivariate regression analysis suggested that the age was negatively correlated with postoperative pseudomeningocele or CSF leak (P = 0.006), with meningitis (P < 0.001). Using cervical fascia autograft decreased the rate of meningitis (P = 0.021) while showing no statistically significant clinical impact on pseudomeningocele or CSF leak. CONCLUSIONS: Applying the cervical fascia autograft to reconstruct the dura during posterior fossa surgery is a simple and effective method to reduce the rate of meningitis as compared with artificial dura mater.

Prevalence of temporal bone tegmen defects among patients with Marfan syndrome.

BACKGROUND: Marfan syndrome (MFS) is a genetic disorder affecting connective tissue. The composition of the dura can change. Consequently, lumbo-sacral dural herniations and cerebrospinal fluid (CSF) leaks are encountered, however, they have yet to been described in the temporal bone. AIMS/OBJECTIVES: To define the prevalence of temporal bone meningocele or encephalocele among patients with MFS. MATERIALS AND METHODS: Reviewed medical records of all adult patients, diagnosed with MFS, who were treated between 1993 and 2018 at a single academic referral institute. Head targeted CT scans were analyzed. The presence of an anterior or lateral skull base defect was recorded. RESULTS: One-hundred and one patients diagnosed with MFS were identified. Twelve of which had suitable CT scans and were enrolled in the study. The median age of patients with defects was 65 years (range 41-71). Five of the twelve patients (41.6%) had tegmen defect. Of the seven defects found, the median size of the defects was 3 mm (range 2-5 mm). All defects were in the temporal bone, none in the anterior skull base. CONCLUSIONS AND SIGNIFICANCE: The prevalence of radiological evidence of a temporal bone defect among patients with MFS is high. This is a new, important, and potentially life-threatening association with the syndrome.

Prevalence of Spontaneous Asymptomatic Facial Nerve Canal Meningoceles: A Retrospective Review.

BACKGROUND AND PURPOSE: The prevalence of patent facial nerve canals and meningoceles along the facial nerve course is unknown. This study aimed to assess the frequency of such findings in asymptomatic patients. MATERIALS AND METHODS: A retrospective review was completed of patients with high-resolution MR imaging of the temporal bone whose clinical presentations were unrelated to facial nerve pathology. Facial nerve canals were assessed for the presence of fluid along each segment and meningoceles within either the labyrinthine segment (fluid-filled distention, ≥1.0-mm diameter) or geniculate ganglion fossa (fluid-filled distention, ≥2.0-mm diameter). If a meningocele was noted, images were assessed for signs of CSF leak. RESULTS: Of 204 patients, 36 (17.6%) had fluid in the labyrinthine segment of the facial nerve canal and 40 (19.6%) had fluid in the geniculate ganglion fossa. Five (2.5%) had meningoceles of the geniculate ganglion fossa; no meningoceles of the labyrinthine segment of the canal were observed. No significant difference was observed in the ages of patients with fluid in the labyrinthine segment of the canal or geniculate ganglion compared with those without fluid (P = .177 and P = .896, respectively). Of the patients with a meningocele, one had a partially empty sella and none had imaging evidence of CSF leak or intracranial hypotension. CONCLUSIONS: Fluid within the labyrinthine and geniculate segments of the facial nerve canal is relatively common. Geniculate ganglion meningoceles are also observed, though less frequently. Such findings should be considered of little clinical importance without radiologic evidence of CSF otorrhea, meningitis, or facial nerve palsy.

Awareness of spina bifida among family of affected child. A cross sectional questionnaire.

OBJECTIVES: To evaluate the awareness of spina bifida (SB), risk factors and possible preventive measures among mothers who had been following in our clinic with a spina bifida affected child. Methods: A cross-sectional questionnaire-based study with 38 mothers of SB patients who are following at SB and hydrocephalus clinic at King Fahad University Hospital, Khobar, Eastern Province, Saudi Arabia. RESULTS: Thirty-eight mother were included in this questionnaire. Most of the participants were Saudi (94.7%). Ten out of 38 women (26.3%) had used medications during pregnancy (pain medications and herbal drugs), 4 out of 38 (10.5%) had been exposed to imaging radiation, while 9 (23.7%) had experienced moderate to high grade fever (39-41°C) during pregnancy. Moreover, the majority (86.8%) of these women did not receive folic acid (FA) before pregnancy, and 42.1% of them did not have FA during their first trimester. Only one (2.6%) gave positive family history of SB while, 6 (15.8%) reported having other SB children.  Conclusion: There is a considerably low level of awareness in mothers of SB patients despite prevalence of this anomaly in the Eastern province. This necessitates an effort from health care providers to educate the community about this birth defect entity. Furthermore, genetic counseling should be encouraged especially in those who have a positive familial history for better understanding. Also, larger sample size with randomized controlled trials and larger epidemiological studies should be implemented.

Risk factors associated with the occurrence of frontoethmoidal encephalomeningocele.

OBJECTIVES: To determine factors associated with the occurrence of frontoethmoidal encephalomeningocele (FEEM), a congenital defect with unique geographical distribution. METHODS: The subjects of this study were 160 unrelated cases of FEEM. Subjects were recruited between 1999 and 2006 from 15 medical centers throughout Thailand. Data obtained from FEEM cases were analyzed and compared with data from 349 cases of oral clefts studied in the same centers and during the same time and those from the general population (GP) taken in 2003. RESULTS: About 52% of FEEM cases had brain anomalies which were not different among types of FEEM. We found familial aggregation reflected by an increased risk to siblings. All of the FEEM cases were of Thai nationality and came from low socioeconomic status. Seven FEEM cases had amniotic rupture sequences. Compared with oral clefts, advanced maternal age (OR: 1.08, 95% CI: 1.02-1.15) was found to be associated with FEEM. In addition, the interpregnancy interval between the FEEM cases and their previous siblings was significantly longer than that of the oral cleft patients and unaffected sibs (OR: 1.17, 95% CI: 1.06-1.28). CONCLUSIONS: Low socioeconomic status, advanced maternal age, and a long interpregnancy interval may lead to an unfavorable intrauterine environment which, with a certain genetic background such as Thai ethnicity, could contribute to the occurrence of FEEM.

Validation of neural tube defects in the full featured--general practice research database.

BACKGROUND: The General Practice Research Database (GPRD) has been used to identify associations between pregnancy medication exposures and birth defects, but experts have argued that databases such as this one cannot provide detailed information for the valid identification of complicated congenital anomalies. Our objective was to determine if the GPRD could be used to identify cases of neural tube defects (NTDs). METHODS: First, we created algorithms for anencephaly, encephalocele, meningocele, and spina bifida and used them to identify potential cases. We used the algorithms to identify 217 potential NTD cases in either a child's or a mother's record. We validated cases by querying general practitioners (GPs) via questionnaire. Where cases of NTD were identified in the mother's record, in addition to confirming the diagnosis, we asked the GPs if the diagnosis was for the mother or that of her fetus or offspring. RESULTS: Two hundred seventeen cases were identified, and 165 GP questionnaires were returned. We validated an NTD diagnosis for 117 cases, giving our algorithms a positive predictive value (PPV) of 0.71. The PPVs varied by NTD type: 0.81 for anencephaly, 0.83 for cephalocele, 0.64 for meningocele, and 0.47 for spina bifida. CONCLUSIONS: Our identification algorithm was useful in identifying three of the four types of NTDs studied. Additional information is necessary to accurately identify cases of spina bifida.