Maternal exposure to prescription and non-prescription pharmaceuticals or drugs of abuse and risk of craniosynostosis

The Effect of Using In Vitro Fertilization (IVF) on Increasing the Prevalence of Craniosynostosis

BACKGROUND

Craniosynostosis, a malformation caused by premature closure of one or more cranial sutures, is a rare congenital disability usually of unknown cause; however, it is often associated with assisted reproductive technology. Given the increasing prevalence of craniosynostosis and the use of the in vitro fertilization (IVF) method, the authors evaluated the association between IVF and the prevalence of craniosynostosis.

METHODS

This retrospective study reviewed records of patients with nonsyndromic craniosynostosis who underwent surgery in Mofid Hospital, a tertiary children's hospital affiliated to Shahid Beheshti University of Medical Sciences, between 2010 and 2019.

RESULTS

A total of 200 patients aged one month to 7 years old, were evaluated. Out of 200 patients, 43% were plagiocephalic, 39% trigonocephalic, 8.5% scaphocephalic, 8% brachiocephalic, and 1.5% were mixed. Nine (4.5%) patients had received clomiphene citrate. Eight (4%) mothers had become pregnant under IVF, and they all had used clomiphene citrate for ovulation stimulation. No use of artificial insemination was reported. Of the eight patients whose mother had become pregnant through IVF, three were trigonocephalic, and five were plagiocephalic.

CONCLUSIONS

Without a control group, we are not able report the statistical results confirming or denying a link between craniosynostosis and infertility treatment. However, 4% prevalence of IVF use among craniosynostosis patients is significant. Further studies with a broader statistical community are suggested in this regard.

Premature Fusion of the Sagittal Suture as an Incidental Radiographic Finding in Young Children

BACKGROUND

Craniosynostosis typically develops prenatally and creates characteristic changes in craniofacial form. Nevertheless, postnatal forms of craniosynostosis have been described. The purpose of this study was to determine the prevalence of incidentally identified, but temporally premature, cranial suture fusion in normocephalic children.

METHODS

Computed tomographic scans obtained from children aged 1 to 5 years evaluated in the authors' emergency department between 2005 and 2016 were reviewed for evidence of craniosynostosis. Patients with prior ventriculoperitoneal shunt, brain or cranial abnormality, or known syndromes were excluded. The presence of craniosynostosis and cranial index was assessed by a panel of three craniofacial surgeons and one pediatric neurosurgeon. Demographic information, fusion type, reason for the computed tomographic scan, and medical history were recorded as covariates. Cranial shape and intracranial volume were calculated using previously validated automated system.

RESULTS

Three hundred thirty-one patients met the inclusion criteria. The mean age was 2.4 ± 1.3 years. Eleven patients (3.3 percent) were found to have a complete (n = 9) or partial (n = 2) fusion of the sagittal suture. All patients had a normal cranial index (0.80; range, 0.72 to 0.87) and a grossly normal head shape. Only two fusions (18.2 percent) were documented by the radiologist. Cranial shape analysis performed in five of the 11 patients showed subtle phenotypic changes along the scaphocephaly spectrum in four patients, with a normal shape in the remaining case.

CONCLUSIONS

Sagittal fusion is present in 3.3 percent of otherwise phenotypically normal children aged 1 to 5 years. The clinical significance of this result is unclear, but routine screening of affected patients is paramount.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, IV.

Erf Affects Commitment and Differentiation of Osteoprogenitor Cells in Cranial Sutures via the Retinoic Acid Pathway

ETS2 repressor factor (ERF) haploinsufficiency causes late-onset craniosynostosis (CRS) (OMIM entry 600775; CRS4) in humans, while in mice Erf insufficiency also leads to a similar multisuture synostosis phenotype preceded by mildly reduced calvarium ossification. However, neither the cell types affected nor the effects per se have been identified so far. Here, we establish an ex vivo system for the expansion of suture-derived mesenchymal stem and progenitor cells (sdMSCs) and analyze the role of Erf levels in their differentiation. Cellular data suggest that Erf insufficiency specifically decreases osteogenic differentiation of sdMSCs, resulting in the initially delayed mineralization of the calvarium. Transcriptome analysis indicates that Erf is required for efficient osteogenic lineage commitment of sdMSCs. Elevated retinoic acid catabolism due to increased levels of the cytochrome P450 superfamily member Cyp26b1 as a result of decreased Erf levels appears to be the underlying mechanism leading to defective differentiation. Exogenous addition of retinoic acid can rescue the osteogenic differentiation defect, suggesting that Erf affects cranial bone mineralization during skull development through retinoic acid gradient regulation.

Craniosynostosis Develops in Half of Infants Treated for Hydrocephalus with a Ventriculoperitoneal Shunt

BACKGROUND

Craniosynostosis following placement of a ventriculoperitoneal shunt for hydrocephalus has been sporadically described. The purpose of this investigation was to determine the general risk of developing craniosynostosis in this patient population.

METHODS

The authors retrospectively reviewed records and radiographs of infants who underwent ventriculoperitoneal shunt placement for hydrocephalus from 2006 to 2012. Recorded variables included date of shunt placement, demographics, comorbidities, cause of hydrocephalus, shunt type, and number of shunt revisions. Axial computed tomographic images obtained before and immediately after shunt placement and 2 to 4 years after shunt placement were evaluated by a panel of clinicians for evidence of craniosynostosis. Patients with preshunt craniosynostosis, craniosynostosis syndromes, or poor-quality computed tomographic images were excluded. Data were analyzed using STATA Version 15.1 statistical software.

RESULTS

One hundred twenty-five patients (69 male and 56 female patients) were included. Average age at shunt placement was 2.3 ± 2.58 months. Sixty-one patients (48.8 percent) developed craniosynostosis at a median of 26 months after shunt placement. Of these, 28 patients fused one suture; the majority involved the sagittal suture (n = 25). Thirty-three patients fused multiple sutures; the most common were the coronal (n = 32) and the sagittal (n = 30) sutures. Multivariable logistic regression identified older age at shunt placement and more shunt revisions as independent predictors of craniosynostosis. Shunt valve type was not significant.

CONCLUSIONS

Craniosynostosis developed in nearly half of infants who underwent ventriculoperitoneal shunt placement for hydrocephalus. The sagittal suture was most commonly involved. The effect of suture fusion on subsequent cranial growth, shunt failure, or the development of intracranial pressure is unclear.

CLINICAL QUESITON/LEVEL OF EVIDENCE

Risk, III.

Zebrafish Models of Craniofacial Malformations: Interactions of Environmental Factors

The zebrafish is an appealing model organism for investigating the genetic (G) and environmental (E) factors, as well as their interactions (GxE), which contribute to craniofacial malformations. Here, we review zebrafish studies on environmental factors involved in the etiology of craniofacial malformations in humans including maternal smoking, alcohol consumption, nutrition and drug use. As an example, we focus on the (cleft) palate, for which the zebrafish ethmoid plate is a good model. This review highlights the importance of investigating ExE interactions and discusses the variable effects of exposure to environmental factors on craniofacial development depending on dosage, exposure time and developmental stage. Zebrafish also promise to be a good tool to study novel craniofacial teratogens and toxin mixtures. Lastly, we discuss the handful of studies on gene–alcohol interactions using mutant sensitivity screens and reverse genetic techniques. We expect that studies addressing complex interactions (ExE and GxE) in craniofacial malformations will increase in the coming years. These are likely to uncover currently unknown mechanisms with implications for the prevention of craniofacial malformations. The zebrafish appears to be an excellent complementary model with high translational value to study these complex interactions.

Recent Advances in Craniosynostosis

Craniosynostosis is a pathologic craniofacial disorder and is defined as the premature fusion of one or more cranial (calvarial) sutures. Cranial sutures are fibrous joints consisting of nonossified mesenchymal cells that play an important role in the development of healthy craniofacial skeletons. Early fusion of these sutures results in incomplete brain development that may lead to complications of several severe medical conditions including seizures, brain damage, mental delay, complex deformities, strabismus, and visual and breathing problems. As a congenital disease, craniosynostosis has a heterogeneous origin that can be affected by genetic and epigenetic alterations, teratogens, and environmental factors and make the syndrome highly complex. To date, approximately 200 syndromes have been linked to craniosynostosis. In addition to being part of a syndrome, craniosynostosis can be nonsyndromic, formed without any additional anomalies. More than 50 nuclear genes that relate to craniosynostosis have been identified. Besides genetic factors, epigenetic factors like microRNAs and mechanical forces also play important roles in suture fusion. As craniosynostosis is a multifactorial disorder, evaluating the craniosynostosis syndrome requires and depends on all the information obtained from clinical findings, genetic analysis, epigenetic or environmental factors, or gene modulators. In this review, we will focus on embryologic and genetic studies, as well as epigenetic and environmental studies. We will discuss published studies and correlate the findings with unknown aspects of craniofacial disorders.

Signaling Mechanisms Underlying Genetic Pathophysiology of Craniosynostosis

Craniosynostosis, is the premature fusion of one or more cranial sutures which is the second most common cranial facial anomalies. The premature cranial sutures leads to deformity of skull shape and restricts the growth of brain, which might elicit severe neurologic damage. Craniosynostosis exhibit close correlations with a varieties of syndromes. During the past two decades, as the appliance of high throughput DNA sequencing techniques, steady progresses has been made in identifying gene mutations in both syndromic and nonsyndromic cases, which allow researchers to better understanding the genetic roles in the development of cranial vault. As the enrichment of known mutations involved in the pathogenic of premature sutures fusion, multiple signaling pathways have been investigated to dissect the underlying mechanisms beneath the disease. In addition to genetic etiology, environment factors, especially mechanics, have also been proposed to have vital roles during the pathophysiological of craniosynostosis. However, the influence of mechanics factors in the cranial development remains largely unknown. In this review, we present a brief overview of the updated genetic mutations and environmental factors identified in both syndromic and nonsyndromic craniosynostosis. Furthermore, potential molecular signaling pathways and its relations have been described.

PLGA-based control release of Noggin blocks the premature fusion of cranial sutures caused by retinoic acid

Craniosynostosis (CS), the premature and pathological fusion of cranial sutures, is a relatively common developmental disorder. Elucidation of the pathways involved and thus therapeutically targeting it would be promising for the prevention of CS. In the present study, we examined the role of BMP pathway in the all-trans retinoic acid (atRA)-induced CS model and tried to target the pathway in vivo via PLGA-based control release. As expected, the posterior frontal suture was found to fuse prematurely in the atRA subcutaneous injection mouse model. Further mechanism study revealed that atRA could repress the proliferation while promote the osteogenic differentiation of suture-derived mesenchymal cells (SMCs). Moreover, BMP signal pathway was found to be activated by atRA, as seen from increased expression of BMPR-2 and pSMAD1/5/9. Recombinant mouse Noggin blocked the atRA-induced enhancement of osteogenesis of SMCs in vitro. In vivo, PLGA microsphere encapsulated with Noggin significantly prevented the atRA-induced suture fusion. Collectively, these data support the hypothesis that BMP signaling is involved in retinoic acid-induced premature fusion of cranial sutures, while PLGA microsphere-based control release of Noggin emerges as a promising strategy for prevention of atRA-induced suture fusion.

Prevalence of Rare Craniofacial Clefts

BACKGROUND

Craniofacial clefts are extremely rare congenital malformations that have adverse functional, psychosocial, and aesthetic effects on patients' life. Although the exact incidence is unclear, it is estimated between 1.4 and 4.9 per 100,000 live births. Prevalence of the rare craniofacial clefts is imprecise due to the paucity of literature as well as their etiologies.

METHODS

All the patients with rare craniofacial clefts during 10 years in a plastic surgery tertiary referral hospital were included, and Tessier craniofacial clefting classification was used for classifying the clefts.

RESULTS

Of 964 patients with craniofacial clefts, 80 (8.29%) patients were identified with rare craniofacial clefts. There were 39 (48.7%) males and 41 (51.3%) females. Family history was determined positive in 30 (37.5%) patients. Tessier number 0 (58.7%) was the most common cleft in the authors' study. Tessier numbers 8, 13, and 30 were the rarest clefts. There was no patient with Clefts numbers 5, 6, or 9. Maternal smoking during pregnancy was observed in 1 (1.3%) of the women and 3 of the women had used drugs, 1 of them used the dexamethasone tablets and 2 of them could not remember name of the used drug.

CONCLUSIONS

Tessier number 0 was the most common cleft and Tessier numbers 8, 13, and 30 were the rarest types. The precise etiology of rare craniofacial clefts remained undetermined in this study. Women should be educated about the risk factors and subsequent ways of preventing from these risk factors.

Differences in surgical outcomes for patients with craniosynostosis in the US: impact of socioeconomic variables and race

OBJECT Craniosynostosis is often treated with neurosurgical intervention. The aim of this study was to report and analyze the clinical and socioeconomic characteristics of patients with craniosynostosis and to present current national trends. METHODS Using the Kids' Inpatient Database for the years 2000, 2003, 2006, and 2009, the authors identified patients with craniosynostosis using International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes and their associated procedure codes. Clinical features, demographics, inpatient procedures, outcomes, and charges were collected and analyzed. RESULTS Of the 3415 patients identified, 65.8% were White, 21.4% were Hispanic, and 3.2% were Black. More than 96% were treated at urban teaching hospitals and 54.2% in southern or western regions. White patients were younger (mean 6.1 months) as compared with Blacks (mean 10.9 months) and Hispanics (mean 9.1 months; p < 0.0001) at the time of surgery. A higher fraction of Whites had private insurance (70.3%) compared with nonwhites (34.0%-41.6%; p < 0.001). Approximately 12.2% were nonelective admissions, more so among Blacks (16.9%). Mean hospital length of stay (LOS) was 3.5 days with no significant differences among races. Following surgical treatment, 12.1% of patients developed complications, most commonly pulmonary/respiratory (4.8%), wound infection (4.4%), and hydrocephalus (1.4%). The mean overall hospital charges were significantly lower for Whites than nonwhites ($34,527 vs $44,890-$48,543, respectively; p < 0.0001). CONCLUSIONS The findings of this national study suggest a higher prevalence of craniosynostosis in Hispanics. The higher predisposition among males was less evident in Hispanics and Blacks. There was a significant percentage of nonelective admissions, more commonly among Blacks. Additionally, Hispanics and Blacks were more likely to receive surgery at an older age, past the current recommendation of the optimum age for surgical intervention. These findings are likely associated with a lack of early detection. Although mean LOS and rate of complications did not significantly differ among different races, nonwhites had, on average, higher hospital charges of $10,000-$14,000. This discrepancy may be due to differences in type of insurance, craniosynostosis type, rates of comorbidities, and delay in treatment. Although there are several limitations to this analysis, the study reports on relevant disparities regarding a costly neurosurgical intervention, and ways to diminish these disparities should be further explored.

Impact of Periconceptional Use of Nitrosatable Drugs on the Risk of Neural Tube Defects

Nitrosatable drugs (NSDs) can, in the presence of nitrosating agents and highly acidic conditions, form N-nitroso compounds that have been found to be teratogenic in animal models. Using data from the Slone Epidemiology Center Birth Defects Study collected from 1998 to 2012, we compared maternal periconceptional NSD use between 334 neural tube defect cases and 7,619 nonmalformed controls. We categorized NSDs according to their functional group (secondary amine, tertiary amine, and amide). With logistic regression models, we estimated adjusted odds ratios and 95% confidence intervals. Neural tube defect risk was associated with maternal periconceptional use of secondary (adjusted odds ratio (aOR) = 1.7, 95% confidence interval (CI): 1.1, 2.4) and tertiary (aOR = 1.7, 95% CI: 1.2, 2.5) amines; an association was observed for amides, but the 95% confidence interval included the null (aOR = 1.4, 95% CI: 0.7, 2.5). Within the secondary amine group, elevated adjusted odds ratios were observed for 3 drugs but were null for the remaining medications. Increases in risk were observed for both strata of folic acid intake (<400 µg/day, ≥400 µg/day), with a slightly higher risk in the ≥400-µg/day stratum. Our findings support previously reported positive associations between neural tube defects and periconceptional exposure to NSDs containing a secondary or tertiary amine or amide.

Role of Old Antibiotics in the Era of Antibiotic Resistance. Highlighted Nitrofurantoin for the Treatment of Lower Urinary Tract Infections

Bacterial infections caused by antibiotic-resistant isolates have become a major health problem in recent years, since they are very difficult to treat, leading to an increase in morbidity and mortality. Nitrofurantoin is a broad-spectrum bactericidal antibiotic that, through a complex mode of action which is not completely understood, affects both Gram-negative and Gram-positive bacteria. Nitrofurantoin has been used successfully for a long time for the prophylaxis and treatment of acute lower urinary tract infections in adults, children and pregnant women, but the increased emergence of antibiotic resistance has made nitrofurantoin a suitable candidate for the treatment of infections caused by multidrug-resistant pathogens. Here, we review the mechanism of action, antimicrobial spectrum, pharmacology and safety profile of nitrofurantoin. We also investigate the therapeutic use of nitrofurantoin, including recent data which highlight its role in the management of community urinary tract infection, especially in cases of multidrug-resistant isolates, in which oral active antimicrobials are limited resources nowadays.

Familial incidence and associated symptoms in a population of individuals with nonsyndromic craniosynostosis

PURPOSE

Craniosynostosis is a common cranial malformation occurring in 1 per 2,000-2,500 births. Isolated defects (nonsyndromic) occur in ~75% of cases and are thought to have multifactorial etiology. It is believed that each suture synostosis is a distinct disease, with varying phenotypes and recurrence rates.

METHODS

We analyzed family histories of 660 mutation-negative nonsyndromic craniosynostosis patients and symptoms in 189 of these patients.

RESULTS

The incidence rate of craniosynostosis was highest for first-degree relatives of probands with metopic craniosynostosis (6.4%), followed by those with complex craniosynostosis (4.9%), sagittal craniosynostosis (3.8%), lambdoid craniosynostosis (3.9%), and coronal craniosynostosis (0.7%). Across all suture types, siblings had a greater craniosynostosis incidence rate than parents (7.5 vs. 2.3%). In phenotype comparisons, patients with complex craniosynostosis had the highest frequency of reported symptoms and those with sagittal craniosynostosis had the lowest. Ear infections, palate abnormalities, and hearing problems were more common in complex craniosynostosis patients. Visual problems were more common in coronal craniosynostosis, and metopic craniosynostosis patients noted increased frequency of chronic cough.

CONCLUSION

Our data suggest that the genetic component of nonsyndromic craniosynostosis appears to be suture specific. The incidence rate of craniosynostosis among first-degree relatives varies by suture and family member. Additionally, the phenotype of each suture synostosis shows both unique and shared features.

A genome-wide association study identifies susceptibility loci for nonsyndromic sagittal craniosynostosis near BMP2 and within BBS9

Sagittal craniosynostosis is the most common form of craniosynostosis, affecting approximately one in 5,000 newborns. We conducted, to our knowledge, the first genome-wide association study for nonsyndromic sagittal craniosynostosis (sNSC) using 130 non-Hispanic case-parent trios of European ancestry (NHW). We found robust associations in a 120-kb region downstream of BMP2 flanked by rs1884302 (P = 1.13 × 10(-14), odds ratio (OR) = 4.58) and rs6140226 (P = 3.40 × 10(-11), OR = 0.24) and within a 167-kb region of BBS9 between rs10262453 (P = 1.61 × 10(-10), OR = 0.19) and rs17724206 (P = 1.50 × 10(-8), OR = 0.22). We replicated the associations to both loci (rs1884302, P = 4.39 × 10(-31) and rs10262453, P = 3.50 × 10(-14)) in an independent NHW population of 172 unrelated probands with sNSC and 548 controls. Both BMP2 and BBS9 are genes with roles in skeletal development that warrant functional studies to further understand the etiology of sNSC.

Gene expression profiling in human craniosynostoses: a tool to investigate the molecular basis of suture ossification

INTRODUCTION

Non-syndromic craniosynostoses (NSC) occur as isolated skull malformations due to the premature ossification of one (single-suture forms) or more (complex forms) calvarial sutures and represent the most frequent form of craniosynostosis worldwide. The etiology of NSC is still largely unknown as a genetic basis can be rarely demonstrated especially in single-suture forms. In these cases, during the prenatal/perinatal development of affected patients, only one suture undergoes a premature direct ossification within an otherwise physiologically grown skull. This could suggest that definite somatic alterations, possibly due to unclear environmental agents, occur locally at the site of premature suture fusion during skull development. A promising tool to investigate the molecular mechanisms that may orchestrate this event is the comparative analysis of suture- and synostosis-derived tissues and cells.

PURPOSE

This review focuses on the different studies that attempted to clarify this issue using genome-wide microarray-based technologies for the comparative analysis of gene expression profiles. All relevant results have been comprehensively reviewed, possibly compared, and critically discussed.

CONCLUSION

Due to the heterogeneity of the dataset available in the literature, a univocal CRS-associated molecular profile could not be deciphered. Most differentially expressed genes are found in different studies to be involved in extracellular matrix remodeling.

Nitrosatable drug exposure during the first trimester of pregnancy and selected congenital malformations

BACKGROUND

Nitrosatable drugs can react with nitrite in the stomach to form N-nitroso compounds, and results from animal studies suggest that N-nitroso compounds are teratogens. With data from the National Birth Defects Prevention Study, the relation between prenatal exposure to nitrosatable drugs and limb deficiencies, oral cleft, and heart malformations in offspring was examined.

METHODS

Maternal reports of drugs taken during the first trimester of pregnancy were classified with respect to nitrosatability for mothers of 741 babies with limb deficiencies, 2774 with oral cleft malformations, 8091 with congenital heart malformations, and 6807 without major congenital malformations. Nitrite intake was estimated from maternal responses to a food frequency questionnaire.

RESULTS

Isolated transverse limb deficiencies and atrioventricular septal defects were associated with secondary amine drug exposures (adjusted odds ratios [aORs], 1.51; 95% confidence limit [CI], 1.11-2.06 and aOR, 1.97; 95% CI, 1.19-3.26, respectively). Tertiary amines were associated with hypoplastic left heart syndrome (aOR, 1.50; 95% CI, 1.10-2.04) and single ventricle (aOR, 1.61; 95% CI, 1.06-2.45). These two malformations were also significantly associated with amide drugs. For several malformations, the strongest associations with nitrosatable drug use occurred among mothers with the highest estimated dietary nitrite intake, especially for secondary amines and atrioventricular septal defects (highest tertile of nitrite, aOR, 3.30; 95% CI, 1.44-7.58).

CONCLUSION

Prenatal exposure to nitrosatable drugs may be associated with several congenital malformations, especially with higher nitrite intake. The possible interaction between nitrosatable drugs and dietary nitrite on risk of congenital malformations warrants further attention.

Isolated sagittal craniosynostosis: definition, classification, and surgical indications

Sagittal craniosynostosis (SC) remains the most common type of synostosis, accounting for about a half of all forms. It would result from a mesenchymal disorder involving the intramembranous ossification of the sagittal suture and leading to its early fusion. No specific data on the etiologic factors are currently available. The premature ossification of the sagittal suture can result in three main types of SC, according to the different segment prevalently involved: anterior, posterior, and complete SC. The diagnosis is easily obtained by clinical examination. However, a radiological work up (3D CT scan) may be necessary to rule out hidden venous or cranial anomalies possibly associated with most severe cases, or for the surgical planning. The most common indication for surgery is the improvement of the cosmetic appearance of the skull, since a cranial deformation may have a significant psychological impact on affected subjects. To relieve from raised intracranial pressure is a further indication to surgery. Although an increased intracranial pressure can be demonstrated in a minority of affected children at diagnosis, indeed, it can present later (usually after the second/third year of life) with chronic symptoms. The role of surgery in the preservation of cognitive functions in scaphocephalic patients does not seem to be relevant, since minor anomalies of the cerebral development associated with SC would occur independently from the cranial shape. On the other hand, the surgical correction may show a protective effect on some visual skills, like the ability to fix and follow, and the fixation shift.

Risk factors associated with craniosynostosis: a case control study

BACKGROUND

Craniosynostosis is a relatively common congenital abnormality. The underlying etiology and most probable risk factors of nonsyndromic craniosynostosis are unknown. We conducted a study to identify the risk factors for craniosynostosis.

MATERIALS AND METHODS

In this case-control project, 70 children with craniosynostosis (syndromic or nonsyndromic) hospitalized at the Children's Hospital Medical Center from September 2010 to 2011 were studied for the potential risk factors. At the same time, 70 age- and sex-matched children hospitalized with other congenital anomalies were reviewed. Information from case and control groups was obtained via personal interviews with parents of patients and a prepared checklist was filled out for each child.

RESULTS

The mean (±SE) age at admission time in the case-control group was 13 ± 1.95 (1.5-96) months, and almost half of them were boys (n = 37 or 53%). The most frequent sutures involved in craniosynostosis were coronal (n = 30 or 42.9%) and then metopic sutures (n = 16 or 22.9%), multiple (n = 12 or 17.1%), sagittal (n = 11 or 15.7%) and lambdoid (n = 1 or 1.4%). In the case group, maternal diabetes mellitus and thyroid disease were found in 8 (11.6%) and 6 (8.6%) patients, respectively. The most frequent medication used by mothers (n = 66 or 94%) in the case group during pregnancy were vitamins (including iron supplements, omega 3, folic acid and multivitamins).

CONCLUSION

A positive family history of craniosynostosis [odds ratio (OR) 19.01 and 95% confidence interval (CI) 2.24-160.7] and using clomiphene citrate for infertility (OR 12.71 and 95% CI 1.42-113.6) were the strongest independent risk factors for craniosynostosis. More comprehensive studies with a larger sample size are required to confirm the role of environmental factors in order to decrease the occurrence of craniosynostosis.

Retinoic acid induces two osteocalcin isoforms and inhibits markers of osteoclast activity in Atlantic cod (Gadus morhua) ex vivo cultured craniofacial tissues

Nutritional status including vitamin A could explain some of the developmental deformities observed in cultivated teleosts, including Atlantic cod (Gadus morhua). In the present study we aimed to investigate the transcriptional effect of retinoic acid (RA) on bone related genes using Atlantic cod craniofacial explants tissue cultures. Two different osteoblast specific osteocalcin/bone gla protein isoforms were discovered in cod. Transcription of both isoforms was up-regulated following RA treatment of 65 dph cod lower jaw explants. In contrast, transcripts coding for genes related to bone resorption and osteoclast activity, matrix metalloproteinase 9 and cathepsin K were down-regulated following RA treatment. This could be linked to the decreased transcriptional ratio between receptor activator of nuclear factor kappa-B ligand rankl and osteoprotegerin observed in the same tissue samples. RA treatment of juvenile explants had no effect on runt-related transcription factor 2 and osterix mRNA levels. However, osterix was significantly down-regulated in 25 dph cod head explants following RA treatment. In situ hybridizations revealed differential spatial distribution of the two isoforms and the predominant expression of cathepsin K in bone surrounding tissues. The present study indicates that RA causes a shift in the balance between osteoclast activity and osteoblast activity in favor of the latter.

Prevalence and patterns of nitrosatable drug use among U.S. women during early pregnancy

BACKROUND

Experimental evidence indicates that certain drugs, that are secondary or tertiary amines or amides, form N-nitroso compounds in the presence of nitrite in an acidic environment. Nitrosatable drugs have been associated with birth defects in a few epidemiologic studies. This study describes the prevalence and patterns of nitrosatable drug use among U.S. women during early pregnancy and examines maternal factors associated with such use.

METHODS

Data were analyzed from the National Birth Defects Prevention Study and included 6807 mothers who gave birth to babies without major congenital malformations during 1997 to 2005. Information was collected by telephone interview about medication use, demographic factors, and maternal health. Drugs taken during the first trimester were classified according to nitrosatability, amine and amide functional groups, and primary indication of use.

RESULTS

Approximately 24% of the women took one or more nitrosatable drugs during the first trimester, including 12.4%, 12.2%, and 7.6% who respectively took secondary amines, tertiary amines, or amides. Five of the ten most commonly taken drugs were available over the counter. Women who were non-Hispanic white (29.5%), with 1 year or more college education (27.3%) or 40 years or older (28.8%) had the highest prevalence of use. Supplemental vitamin C, an inhibitor of nitrosation, was not taken by 41.6% and 19.3% of nitrosatable drug users during the first and second months of pregnancy, respectively.

CONCLUSIONS

In this U.S. population, ingestion of drugs classified as nitrosatable was common during the first trimester of pregnancy, especially among non-Hispanic white, more educated, and older mothers. Birth Defects Research (Part A) 2011. © 2011 Wiley-Liss, Inc.

Retinoic acid enhances osteogenesis in cranial suture-derived mesenchymal cells: potential mechanisms of retinoid-induced craniosynostosis

BACKGROUND

In utero retinoid exposure results in numerous craniofacial malformations, including craniosynostosis. Although many malformations associated with retinoic acid syndrome are associated with neural crest defects, the specific mechanisms of retinoid-induced craniosynostosis remain unclear. The authors used the culture of mouse cranial suture-derived mesenchymal cells to probe the potential cellular mechanisms of this teratogen to better elucidate mechanisms of retinoid-induced suture fusion.

METHODS

Genes associated with retinoid signaling were assayed in fusing (posterofrontal) and patent (sagittal, coronal) sutures by quantitative real-time polymerase chain reaction. Cultures of mouse suture-derived mesenchymal cells from the posterofrontal suture were established from 4-day-old mice. Cells were cultured with all-trans retinoic acid (1 and 5 muM). Proliferation, osteogenic differentiation, and specific gene expression were assessed.

RESULTS

Mouse sutures were found to express genes necessary for retinoic acid synthesis, binding, and signal transduction, demonstrated by quantitative real-time polymerase chain reaction (Raldh1, Raldh2, Raldh3, and Rbp4). These genes were not found to be differentially expressed in fusing as compared with patent cranial sutures in vivo. Addition of retinoic acid enhanced the osteogenic differentiation of suture-derived mesenchymal cells in vitro, including up-regulation of alkaline phosphatase activity and Runx2 expression. Contemporaneously, cellular proliferation was repressed, as shown by proliferative cell nuclear antigen expression. The pro-osteogenic effect of retinoic acid was accompanied by increased gene expression of several hedgehog and bone morphogenetic protein ligands.

CONCLUSIONS

Retinoic acid represses proliferation and enhances osteogenic differentiation of suture-derived mesenchymal cells. These in vitro data suggest that retinoid exposure may lead to premature cranial suture fusion by means of enhanced osteogenesis and hedgehog and bone morphogenetic protein signaling.

Pfeiffer-like syndrome with holoprosencephaly: a newborn with maternal smoking and alcohol exposure

We report the case of a female infant with Pfeiffer-like syndrome and holoprosencephaly. She had a cloverleaf skull, ocular proptosis, broad thumbs and halluces, and variable accompanying anomalies compatible with Pfeiffer syndrome. She also displayed microcephaly, short palpebral fissures, and a smooth philtrum, which are clinical signs consistent with fetal alcohol syndrome. She suffered from multiple congenital anomalies and died at 41 days of age. Cardio-pulmonary failure, brain abnormalities, prematurity, and multiple complications contributed to her death. The patient displayed normal chromosomal numbers and type. DNA analysis did not reveal fibrobtast growth factor receptor (FGFR) genes FGFR1, FGFR2, FGFR3 or TWIST gene mutations. We review the previous reports of Pfeiffer syndrome and holoprosencephaly and describe our infant patient with Pfeiffer-like syndrome, holoprosencephaly, and heavy in utero maternal alcohol and smoking exposures.

Craniosynostotic variations in syndromic, identical twins

Despite intense research, etiologies underlying syndromic craniosynostosis remain poorly understood. While syndrome-related genetic factors have garnered much attention, external forces likely play a large role as well. In contrast to well-defined genetic abnormalities that may be precisely identified and statistically quantified, characterization of more environmental factors has proven difficult. Much of this challenge stems from difficulty in isolating genetic components. However, in the event that 2 individuals share similar genetics, a clearer picture of external factors impacting phenotypic differences may be drawn. Because monozygotic discordant twins have identical genomes, the differences between affected and unaffected members are the result of the environment. Here, we discuss identical twin females who presented with Crouzon syndrome, as well as variations in craniosynostosis. In addition to highlighting the impact of nongenetic factors on craniosynostosis phenotype, we review several environmental elements that may have played a role in this unusual case.

A population-based study of craniosynostosis in metropolitan Atlanta, 1989-2003

Craniosynostosis is a birth defect characterized by premature fusion of one or more cranial sutures. We describe the birth prevalence of craniosynostosis and related risk factors among infants born to residents of metropolitan Atlanta during 1989-2003. Data from the Metropolitan Atlanta Congenital Defects Program (MACDP) were used to identify infants with craniosynostosis. Case records with a code for craniosynostosis were reviewed to substantiate the diagnosis of craniosynostosis and to classify infants as having isolated craniosynostosis (no other unrelated major defects), multiple defects (one or more additional major, unrelated defects), or a syndrome (recognized or strongly suspected single-gene condition or chromosome abnormality). Vital records data on births of Georgia residents were used to analyze craniosynostosis prevalence by year of birth, maternal race and age, parity, plurality, and infants' sex, birth weight, and gestational age. We identified 281 infants born with craniosynostosis in metropolitan Atlanta during 1989-2003: 84% with isolated craniosynostosis, 7% with multiple defects, and 9% with syndromes. The birth prevalence was 4.3 per 10,000 births, results consistent with findings from other population-based studies using similar case definitions. Apert syndrome was diagnosed in 40% of the syndromic cases, and sagittal synostosis was diagnosed in 39% of the cases of nonsyndromic craniosynostosis. Maternal age 35 years or older, multiple birth, male sex, and birth weight >4,000 g were risk factors for craniosynostosis.

Priorities for public health research on craniosynostosis: summary and recommendations from a Centers for Disease Control and Prevention-sponsored meeting

On June 8-9, 2006, the National Center on Birth Defects and Developmental Disabilities at the Centers for Disease Control and Prevention held a meeting entitled "Prioritizing a Public Health Research Agenda for Craniosynostosis". The meeting goals were to review current knowledge in the area, discuss research gaps, and identify future priorities for public health research. Participants with a broad range of expertise (including clinical and molecular genetics, cranial morphology, epidemiology, pediatrics, psychology, public health, and surgery) contributed to the development of the research agenda. Meeting participants were asked to consider public health significance and feasibility when identifying areas of priority for future public health research. Participants identified several priorities, including the need to better delineate the prevalence and phenotype of craniosynostosis (CS); to identify factors important in the causation of CS (including potentially modifiable environmental risk factors as well as genes involved in isolated CS and gene-gene and gene-environment interactions); and to better understand short- and long-term outcomes of CS (e.g., surgical, neurocognitive and neuropsychological outcomes, psychological adjustment, and social relationships) and issues related to clinical care that could affect those outcomes. The need for improved collaboration among clinical treatment centers and standardization of data collection to address these priorities was emphasized. These priorities will be used to guide future public health research on CS.

Unravelling the molecular control of calvarial suture fusion in children with craniosynostosis

BACKGROUND

Craniosynostosis, the premature fusion of calvarial sutures, is a common craniofacial abnormality. Causative mutations in more than 10 genes have been identified, involving fibroblast growth factor, transforming growth factor beta, and Eph/ephrin signalling pathways. Mutations affect each human calvarial suture (coronal, sagittal, metopic, and lambdoid) differently, suggesting different gene expression patterns exist in each human suture. To better understand the molecular control of human suture morphogenesis we used microarray analysis to identify genes differentially expressed during suture fusion in children with craniosynostosis. Expression differences were also analysed between each unfused suture type, between sutures from syndromic and non-syndromic craniosynostosis patients, and between unfused sutures from individuals with and without craniosynostosis.

RESULTS

We identified genes with increased expression in unfused sutures compared to fusing/fused sutures that may be pivotal to the maintenance of suture patency or in controlling early osteoblast differentiation (i.e. RBP4, GPC3, C1QTNF3, IL11RA, PTN, POSTN). In addition, we have identified genes with increased expression in fusing/fused suture tissue that we suggest could have a role in premature suture fusion (i.e. WIF1, ANXA3, CYFIP2). Proteins of two of these genes, glypican 3 and retinol binding protein 4, were investigated by immunohistochemistry and localised to the suture mesenchyme and osteogenic fronts of developing human calvaria, respectively, suggesting novel roles for these proteins in the maintenance of suture patency or in controlling early osteoblast differentiation. We show that there is limited difference in whole genome expression between sutures isolated from patients with syndromic and non-syndromic craniosynostosis and confirmed this by quantitative RT-PCR. Furthermore, distinct expression profiles for each unfused suture type were noted, with the metopic suture being most disparate. Finally, although calvarial bones are generally thought to grow without a cartilage precursor, we show histologically and by identification of cartilage-specific gene expression that cartilage may be involved in the morphogenesis of lambdoid and posterior sagittal sutures.

CONCLUSION

This study has provided further insight into the complex signalling network which controls human calvarial suture morphogenesis and craniosynostosis. Identified genes are candidates for targeted therapeutic development and to screen for craniosynostosis-causing mutations.

Evaluation of the infant with an abnormal skull shape

PURPOSE OF REVIEW

Atypical skull shapes occur in as many as 20% of infants. The purpose of this review is to discuss the clinical approach to the evaluation of a child with an abnormal head shape. Readers will learn how to identify the head shapes caused by environmental deformation and craniosynostosis. We also review recent findings with regard to the genetics of single-suture craniosynostosis.

RECENT FINDINGS

Healthcare providers can use key aspects of the examination of a child with a head shape abnormality to differentiate positional deformity from craniosynostosis. Overlap between the genetic causes of isolated single-suture craniosynostosis and syndromic forms is discussed.

SUMMARY

Pediatricians can identify the causes of the majority of head shape abnormalities by combining their understanding of normal calvarial growth with a careful physical examination. Molecular genetics is playing an increasing role in the evaluation of children with single-suture fusion.

Isolated sagittal and coronal craniosynostosis associated with TWIST box mutations

Craniosynostosis, the premature fusion of one or more cranial sutures, affects 1 in 2,500 live births. Isolated single-suture fusion is most prevalent, with sagittal synostosis occurring in 1/5,000 live births. The etiology of isolated (nonsyndromic) single-suture craniosynostosis is largely unknown. In syndromic craniosynostosis, there is a highly nonrandom pattern of causative autosomal dominant mutations involving TWIST1 and fibroblast growth factor receptors (FGFRs). Prior to our study, there were no published TWIST1 mutations in the anti-osteogenic C-terminus, recently coined the TWIST Box, which binds and inhibits RUNX2 transactivation. RUNX2 is the principal master switch for osteogenesis. We performed mutational analysis on 164 infants with isolated, single-suture craniosynostosis for mutations in TWIST1, the IgIIIa exon of FGFR1, the IgIIIa and IgIIIc exons of FGFR2, and the Pro250Arg site of FGFR3. We identified two patients with novel TWIST Box mutations: one with isolated sagittal synostosis and one with isolated coronal synostosis. Kress et al. [2006] reported a TWIST Box "nondisease-causing polymorphism" in a patient with isolated sagittal synostosis. However, compelling evidence suggests that their and our sequence alterations are pathogenic: (1) a mouse with a mutation of the same residue as our sagittal synostosis patient developed sagittal synostosis, (2) mutation of the same residue precluded TWIST1 interaction with RUNX2, (3) each mutation involved nonconservative amino acid substitutions in highly conserved residues across species, and (4) control chromosomes lacked TWIST Box sequence alterations. We suggest that genetic testing of patients with isolated sagittal or coronal synostosis should include TWIST1 mutational analysis.

Breast Cancer Resistance Protein 1 Limits Fetal Distribution of Nitrofurantoin in the Pregnant Mouse

The efflux transporter, the breast cancer resistance protein (BCRP), is most abundantly expressed in the apical membrane of the placental syncytiotrophoblasts, indicating that it could play an important role in protecting the fetus by limiting xenobiotic/drug penetration across the placental barrier. In the present study, we examined whether Bcrp1, the murine homolog of human BCRP, limits fetal distribution of the model BCRP/Bcrp1 substrate, nitrofurantoin (NFT), in the pregnant mouse. NFT was administered i.v. to FVB wild-type and Bcrp1(-/-) pregnant mice. The maternal plasma samples and fetuses were collected at various times (5-60 min) after drug administration. The NFT concentrations in the maternal plasma samples and homogenates of fetal tissues were determined by a high-performance liquid chromatography/UV assay. Although the maternal plasma area under the concentration-time curve (AUC) of NFT in the Bcrp1(-/-) pregnant mice (97.4 +/- 10.0 microg . min/ml plasma) was only slightly (but significantly) higher than that in the wild-type pregnant mice (78.4 +/- 6.0 microg . min/ml plasma), the fetal AUC of NFT in the Bcrp1(-/-) pregnant mice (1493.0 +/- 235.3 ng . min/g of fetus) was approximately 5 times greater than that in the wild-type pregnant mice (298.6 +/- 77.4 ng . min/g of fetus). These results clearly suggest that Bcrp1 significantly limits fetal distribution of NFT in the pregnant mouse, but has only a minor effect on the systemic clearance of the drug.

Maternal thyroid disease as a risk factor for craniosynostosis

OBJECTIVE

To study the relationship between maternal thyroid disease and craniosynostosis using data from the National Birth Defects Prevention Study, a multisite, case-control study.

METHODS

Case infants (n=431) were identified through population-based birth defects surveillance systems at eight sites and had craniosynostosis verified by radiographic imaging. Control infants (n=4,094) consisted of a random sample of live births with no major birth defects from the same population as the case infants. Information on thyroid disease was based on self-report: mothers who reported either a thyroid disorder or use of a medication to treat a thyroid disorder during pregnancy were considered to have thyroid disease. Using an unconditional logistic regression model, we considered potential confounding factors (maternal age, race or ethnicity, smoking, body mass index, preexisting diabetes, plurality, gravidity, family history, infant sex).

RESULTS

Among case mothers, 19 (4.4%) were classified as having thyroid disease, compared with 65 (1.6%) of control mothers. Maternal thyroid disease was associated with craniosynostosis after controlling for maternal age (adjusted odds ratio 2.47, 95% confidence interval 1.46-4.18), the only factor that remained significant in the final model.

CONCLUSION

These data provide additional evidence that maternal thyroid disease (most likely Graves' disease) or its treatment is associated with craniosynostosis. Given the frequency of maternal thyroid disease, this association warrants further investigation.

LEVEL OF EVIDENCE

II.

Neurodevelopment of children with single suture craniosynostosis: a review

INTRODUCTION

Rates of neurocognitive risk range from 35-50% of school-aged children with isolated single suture craniosynostosis (SSC). It has been hypothesized that early surgical intervention to release suture fusion reduces risk for increased intracranial pressure (ICP) and the corresponding risk to neurodevelopment. However, studies assessing children with SSC have been inconsistent in finding an association between neurocognitive development, age of surgery, and ICP.

REVIEW

SSC produces notable distortion of the cranial vault and underlying brain mass. Although a linear relationship between skull distortion, ICP, and neurocognitive deficits has generally been assumed, recent studies have postulated an interactive process between the skull and developing brain that results in neuroanatomical changes that are not limited to areas directly beneath the fused suture. The specific neuropsychological deficits identified in children with SSC including problems with attention and planning, processing speed, visual spatial skills, language, reading, and spelling may be related to the anatomic differences that persist after correction of suture fusion.

CONCLUSIONS

Available literature on neurocognitive development of children with SSC is suggestive of mild but persistent neuropsychological deficits, which become more significant as cognitive demands increase at school age. Anatomical studies of children without SSC are beginning to identify particular groups of brain structures that if disrupted or malformed, may be associated with specific cognitive deficits. Controlled research investigating the relationship between persistent anatomical changes and neurocognitive functioning of school-aged children with SSC is needed.

Risk of selected birth defects with prenatal illicit drug use, Hawaii, 1986-2002

The literature on the association between prenatal illicit drug use and birth defects is inconsistent. The objective of this study was to determine the risk of a variety of birth defects with prenatal illicit drug use. Data were derived from an active, population-based adverse pregnancy outcome registry. Cases were all infants and fetuses with any of 54 selected birth defects delivered during 1986-2002. The prenatal methamphetamine, cocaine, or marijuana use rates were calculated for each birth defect and compared to the prenatal use rates among all deliveries. Among all deliveries, the prenatal use rate was 0.52% for methamphetamine, 0.18% for cocaine, and 0.26% for marijuana. Methamphetamine rates were significantly higher than expected for 14 (26%) of the birth defects. Cocaine rates were significantly higher than expected for 13 (24%) of the birth defects. Marijuana rates were significantly higher than expected for 21 (39%) of the birth defects. Increased risk for the three drugs occurred predominantly among birth defects associated with the central nervous system, cardiovascular system, oral clefts, and limbs. There was also increased risk of marijuana use among a variety of birth defects associated with the gastrointestinal system. Prenatal uses of methamphetamine, cocaine, and marijuana are all associated with increased risk of a variety of birth defects. The affected birth defects are primarily associated with particular organ systems.

Genotoxic and carcinogenic risk to humans of drug-nitrite interaction products

The large majority of N-nitroso compounds (NOC) have been found to produce genotoxic effects and to cause tumor development in laboratory animals; four NOC have been classified by the International Agency for Research on Cancer (IARC) as probably and another 15 as possibly carcinogenic to humans. A considerable fraction of drugs are theoretically nitrosatable due to the presence of amine, amide or other groups which by reacting with nitrite in the gastric environment, or even in other sites, can give rise to the formation of NOC, and in some cases other reactive species. This review provides a synthesis of information on the chemistry of NOC formation, the carcinogenic activity of NOC in animals and humans and the inhibitors of nitrosation reactions. It contains information on the drugs which have been tested for the formation of NOC by reaction with nitrite and the genotoxic-carcinogenic effects of their nitrosation products. In an extensive search we have found that 182 drugs, representing a wide variety of chemical structures and therapeutic activities, were examined in various experimental conditions for their ability to react with nitrite, and 173 (95%) of them were found to form NOC or other reactive species. Moreover, 136 drugs were examined in short-term genotoxicity tests and/or in long-term carcinogenesis assays, either in combination with nitrite or using their nitrosation product, in order to establish whether they produce genotoxic and carcinogenic effects; 112 (82.4%) of them have been found to give at least one positive response. The problem of endogenous drug nitrosation is largely unrecognized. Only a small fraction of theoretically nitrosatable drugs have been examined for the possible formation of genotoxic-carcinogenic NOC, guidelines for genotoxicity testing of pharmaceuticals do not indicate the need of performing the appropriate tests, and patients are not informed that the drug-nitrite interaction and the consequent risk can be reduced to a large extent by consuming the nitrosatable drug with ascorbic acid.

Maternal drug use, fertility problems, and infant craniostenosis

OBJECTIVE

To test the hypothesis that maternal drug use or treatment for infertility is related to the occurrence of infant craniostenosis.

DESIGN AND MATERIAL

Maternal drug use and infertility treatment were studied in 398 cases of craniostenosis, identified from various Swedish health registers. Exposure information was ascertained in early pregnancy, and comparisons after adjustment for some confounders were made with all infants born. In order to validate some findings, data from the Central-East France Registry were studied for first trimester drug exposure in 235 infants, and use of ovarian stimulation in 315 infants with craniostenosis.

RESULTS

A statistically significant association between maternal use of anticonvulsants and infant craniostenosis was found (risk ratio [Swedish data], 6.9; 95% confidence interval, 1.10 to 7.94). With the Swedish data, an association was found with three nitrosatable drugs (risk ratio, 3.4; 95% confidence interval, 1.10 to 7.94), previously associated with the occurrence of craniostenosis, but this was based on only five exposures, and no such exposure occurred in the French data set. No association with subfertility (odds ratio, 0.72; 95% confidence interval, 0.60 to 1.86) or infertility treatment (odds ratio, 1.06; 95% confidence interval, 0.60 to 1.87) was found in the Swedish data and no statistically significant increase in the use of ovulation stimulation in the French data.

CONCLUSIONS

A strong association was found between the maternal use of anticonvulsants and infant craniostenosis, and a tentative association was found with the use of nitrofurantoin and two other nitrosatable drugs. There was no association with maternal subfertility or infertility treatment.

Early surgical treatment of nonsyndromic craniosynostosis

BACKGROUND

Craniosynostosis, a premature fusion of cranial sutures, can happen as an isolated defect (nonsyndromic) or as part of a syndrome. It may lead to raised intracranial pressure and deformity of both the cranial and facial skeletons. Early surgery is usually the best treatment choice. The aim of this study was to review the experience of a multidisciplinary staff with the surgical treatment of nonsyndromic craniosynostosis.

METHODS

All the nonsyndromic craniosynostosis cases treated surgically from 1991 to 2005 at 2 neurosurgical centers were reviewed. The variables analyzed were sex, age, weight, type of deformity, estimated volemia, surgical technique, surgical time, blood loss, PO hospitalization time, and complications. All data were stored in a database and analyzed with Microsoft Access (Microsoft Corp, Seattle, WA) and SPSS V11.0 (SPSS, Inc, Chicago, IL).

RESULTS

The sample consisted of 120 patients (70 males, 50 females). Six patients were excluded because of their atypical timing of treatment (average age, 72 months). The final average age was 7.08 months (variation, 1-18), and the average weight was 7.8 kg. The types of deformities found were scaphocephaly (n = 54, 45%), plagiocephaly (n = 27, 22%), trigonocephaly (n = 19, 16%), brachycephaly (n = 16, 13%), and oxycephaly (n = 4, 3%). The mean surgical time was 186 minutes and the mean PO hospitalization time was 6.8 days. The mortality on this series was 2.6% (3 patients). In the last operated cases, a significant improvement in morbid-mortality was observed.

CONCLUSION

A multidisciplinary approach, including neurosurgeons, neurologists, and pediatricians, and appropriate training of the clinical surgical staff can minimize the risks and decrease the complications in the treatment of craniosynostosis, leading to a satisfactory outcome.

Dietary Nitrites and Nitrates, Nitrosatable Drugs, and Neural Tube Defects

BACKGROUND

Amine-containing (nitrosatable) drugs can react with nitrite to form N-nitroso compounds, some of which are teratogenic. Data are lacking on whether dietary intake of nitrates and nitrites modifies the association between maternal nitrosatable drug exposure and neural tube defects (NTDs) in offspring.

METHODS

We examined nitrosatable drug exposure and NTD-affected pregnancies in relation to dietary nitrite and total nitrite intake in a case-control study of Mexican American women. We interviewed 184 women with NTD-affected pregnancies and 225 women with normal live births, including questions on periconceptional drug exposures and dietary intake. For 110 study participants, nitrate was also measured in the usual source of drinking water.

RESULTS

Women who reported taking drugs classified as nitrosatable were 2.7 times more likely to have an NTD-affected pregnancy than women without this exposure (95% confidence interval [CI] = 1.4-5.3). The effect of nitrosatable drugs was observed only in women with higher intakes of dietary nitrite and total nitrite (dietary nitrite + 5% dietary nitrate). Women within the highest tertile (greater than 10.5 mg/day) of total nitrite were 7.5 times more likely to have an NTD-affected pregnancy if they took nitrosatable drugs (95% CI = 1.8-45.4). The association between nitrosatable drug exposure and NTDs was also stronger in women whose water nitrate levels were higher.

CONCLUSIONS

Findings suggest that effects of nitrosatable drug exposure on risk for neural tube defects in offspring could depend on the amounts of dietary nitrite and total nitrite intake.