Plasma zinc concentrations of mothers and the risk of nonsyndromic oral clefts in their children: a case-control study in the Philippines

The prevalence of orofacial clefts in Qatar : a cross-sectional nationwide study

BACKGROUND

Cleft lip and palate are congenital craniofacial anomalies that significantly impact individuals and their families, both medically and psychosocially. The Qatari population has unique characteristics that are suggestive of a high prevalence of congenital anomalies: high consanguinity rate, large family size, advanced paternal age and high prevalence of certain genetic disorders. The lack of existing data concerning the epidemiology of cleft lip and/or palate in Qatar warrants a descriptive study addressing this topic.

METHODS

A retrospective nationwide hospital-based cross-sectional study conducted to determine the prevalence of orofacial clefts in Qatar from 2016 to 2021. Data were extracted from the corporation's Cerner database and electronic health records. Information concerning the cleft's characteristics, type, affected side, patient's gender, presence of associated syndromes, nationality, and maternal age were collected.

RESULTS

Out of the 147,727 live births, 148 had an orofacial cleft. The prevalence of cleft lip and/or palate was determined to be 1 per 1000 livebirths (95% CI: 0.85, 1.18). The prevalence of cleft lip was 0.18 (95% CI: 0.12, 0.27), cleft palate 0.39 (95% CI: 0.30, 0.51), and cleft lip and palate 0.43 (95% CI: 0.33, 0.55). Qataris had a prevalence of CL 0.25, CP 0.40, and CLP 0.56, compared to 0.16, 0.39, 0.39 for non-Qataris (p-value 0.186). Unilateral clefts predominated over bilateral (74.4% and 25.6%, respectively). Among the unilateral cases, 70.2% occurred on the left side. Most cases were isolated clefts, with only 10.2% having associated syndromes.

CONCLUSIONS

The prevalence of orofacial clefts in Qatar is consistent with the globally reported prevalence. Most cases were unilateral and on the left side. Associated syndromes were infrequent and more common with cleft palate alone. Intriguing patterns were revealed between Qatari nationals and non-Qatari residents, with specific subtypes of orofacial clefts showing higher prevalence among nationals.

A Systematic Literature Review on the Association Between Toxic and Essential Trace Elements and the Risk of Orofacial Clefts in Infants

Orofacial clefts (OFCs) have been linked to various toxic and essential trace elements (TETEs) worldwide. However, review estimation is absent. Therefore, addressing the hypothesis that TETEs are associated with OFCs is the main area of this review. A systematic literature search was conducted using electronic databases through PubMed, Web of Science, Scopus, Science Direct, and Google Scholar between 2004 and August 2022. The "AND" and "OR" operators were used to make our search results inclusive and restrictive as follows: ("Toxic element*" OR "Heavy metal*") AND ("Toxic element*" OR "Lead OR Arsenic OR Mercury*")) AND ("Essential trace element*" OR "Zinc OR Selenium OR Copper*")) AND ("Orofacial cleft*" OR "Cleft lip*" OR "Cleft palate*") AND ("Infant*" OR "Newborn*" OR "Neonate*")). The presence of toxic elements was linked to the development of OFCs. The results showed that higher levels of toxic elements in various biological sample types were related to increased risks for OFCs. Increased concentrations of essential trace elements (ETEs) lowered the risk of OFCs. Maternal consumption of diets rich in ETEs, including zinc (Zn), selenium (Se), copper (Cu), cobalt (Co), and molybdenum (Mo), was linked to a more pronounced reduction in the risk of OFCs. Based on the findings, it is acceptable to infer that maternal exposure to toxic elements, whether through environmental contaminants or dietary sources, was associated with an elevated risk of OFCs. Furthermore, the study revealed that ETEs exhibited a potential protective role in reducing the incidence of OFCs. This observation highlights the importance of reducing exposure to toxic elements during pregnancy and suggests that optimizing maternal intake of ETEs could be an effective preventive strategy.

Maternal micronutrient biomarkers and risk of non-syndromic cleft lip/palate: A case-control study

OBJECTIVE

This case-control study investigated the associations between maternal plasma vitamin B12, homocysteine, and red blood cell (RBC) folate levels and the risk of cleft lip with or without cleft palate (CL/P) in offspring.

SUBJECTS AND METHODS

The study compared 94 mothers and children with non-syndromic CL/P from a teaching hospital in Thailand to 94 mother-infant controls from local well-baby clinics, frequency-matched by birth date and mother's education. Data included anthropometric measurements, blood sample analyses, and a questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) estimated the associations through multiple logistic regression, adjusting for confounders.

RESULTS

Mothers with higher plasma vitamin B12 levels had a lower risk of having a child with CL/P compared to those in the lowest quartile. This association was more pronounced among mothers without a family history of orofacial clefts and those who were not underweight. Conversely, elevated homocysteine levels, a marker of impaired B vitamin metabolism, increased the risk of CL/P. No association was found between RBC folate and CL/P.

CONCLUSION

Higher maternal vitamin B12 levels are associated with a reduced risk of CL/P, while elevated homocysteine levels may increase the risk.

Impact of Prenatal Care on Newborn Complications for Infants with Cleft Lip with or Without Cleft Palate

OBJECTIVE

To determine the association between prenatal care and cleft lip with or without cleft palate (CL ± P) and examine differences in newborn complications among infants diagnosed with CL ± P as a function of prenatal care.

DESIGN

Population-based retrospective cohort study.

SETTING

2018 United States National Vital Statistics System-Natality component (NVSS-N) was used to examine nationwide birth certificate data.

PARTICIPANTS

3,414,338 infants from the 2018 National Vital Statistics System, of which 1,699 had CL ± P.

MAIN OUTCOME MEASURE

Diagnosis of CL ± P and presence of newborn complications as a function of prenatal care.

RESULTS

Significant differences were found among various infant- and mother-specific variables when baseline comparisons were made between infants with and without CL ± P. After controlling for baseline differences, results indicated decreased odds of a diagnosis of CL ± P in cases where overall adequate prenatal care was obtained (OR = .841; 95% CI .757, .934), including prenatal care beginning in the 1st trimester (OR = .839; 95% CI .750, .939) and an adequate number of prenatal visits received (OR = .864; 95% CI .764, .976). Of infants with CL ± P, reduced odds of the infant admitted to the neonatal intensive care unit (OR = .777; 95% CI .613, .985) or transferred (OR = .601; 95% CI .407, .888) were apparent when adequate prenatal care was received.

CONCLUSION

Results suggest adequate prenatal care not only reduces the likelihood of CL ± P in infants but may also decrease the severity of negative outcomes in infants diagnosed with CL ± P. These findings emphasize necessity for adequate prenatal care.

Poverty and Risk of Cleft Lip and Palate: An Analysis of United States Birth Data

BACKGROUND

The relationship between poverty and incidence of cleft lip and cleft palate remains unclear. The authors investigated the association between socioeconomic status and cleft lip with or without cleft palate and cleft palate only in the United States after controlling for demographic and environmental risk factors.

METHODS

The U.S. 2016 and 2017 natality data were utilized. Proxies for socioeconomic status included maternal education, use of the Special Supplemental Nutrition Program for Women, Infants, and Children, and payment source for delivery. Multiple logistic regression controlled for household demographics, prenatal care, maternal health, and infant characteristics.

RESULTS

Of 6,251,308 live births included, 2984 (0.05 percent) had cleft lip with or without cleft palate and 1180 (0.02 percent) had cleft palate only. Maternal education of bachelor's degree or higher was protective against, and delayed prenatal care associated with, cleft lip with or without cleft palate (adjusted ORs = 0.73 and 1.14 to 1.23, respectively; p < 0.02). Receiving assistance under the Special Supplemental Nutrition Program for Women, Infants, and Children was associated with cleft palate only (adjusted OR = 1.25; p = 0.003). Male sex, first-trimester tobacco smoking, and maternal gestational diabetes were also associated with cleft lip with or without cleft palate (adjusted ORs = 1.60, 1.01, and 1.19, respectively; p < 0.05). Female sex, prepregnancy tobacco smoking, and maternal infections during pregnancy were associated with cleft palate only (adjusted ORs = 0.74, 1.02, and 1.60, respectively; p < 0.05).

CONCLUSIONS

Increased incidence of orofacial clefts was associated with indicators of lower socioeconomic status, with different indicators associated with different cleft phenotypes. Notably, early prenatal care was protective against the development of cleft lip with or without cleft palate.

CLIINCAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Metal transporter Slc30a1 controls pharyngeal neural crest differentiation via the zinc-Snai2-Jag1 cascade

The pharyngeal arch (PA) is a neural crest (NC)-derived organ that is transiently developed during embryogenesis and is required for the subsequent development of various tissues. However, the role of zinc during PA differentiation from NC progenitor cells is unknown. Here, we found that the metal transporters Slc30a1a and Slc30a1b mediate zinc homeostasis during PA differentiation. Slc30a1-deficient zebrafish develop zinc accumulation in NC cells, with increased expression of stemness markers and PA dorsal genes, and SMART-seq analyses revealed that the genes snai2 and jag1b may serve as downstream targets. Furthermore, functional studies showed that knocking down either snai2 or jag1b rescues PA development in Slc30a1-deficient zebrafish. Notably, we identified the double zinc-finger domain in the transcription factor Snai2 as a zinc-responsive element that regulates jag1b expression. Our findings indicate that the Slc30a1/zinc-snai2-jag1b axis is an essential regulatory network controlling PA differentiation, shedding new light on the function of zinc homeostasis in maintaining NC cell stemness and multipotency in vertebrates.

Maternal Vitamin B12 Status and Risk of Cleft Lip and Cleft Palate Birth Defects in Tamil Nadu State, India

BACKGROUND AND OBJECTIVE

The causal role of maternal nutrition in orofacial clefts is uncertain. We tested hypotheses that low maternal vitamin B₁₂ and low folate status are each associated with an increased risk of isolated cleft lip with or without cleft palate (CL±P) in a case-control study in Tamil Nadu state, India.

METHODS

Case-mothers of CL±P children (n = 47) and control-mothers of unaffected children (n = 50) were recruited an average of 1.4 years after birth of the index child and plasma vitamin B₁₂, methylmalonic acid (MMA), total homocysteine (tHcy), and folate were measured at that time. Logistic regression analyses estimated associations between nutrient biomarkers and case-control status.

RESULTS

Odds ratios (ORs) contrasting biomarker levels showed associations between case-mothers and low versus high plasma vitamin B₁₂ (OR = 2.48, 95% CI, 1.02-6.01) and high versus low plasma MMA, an indicator of poor B₁₂ status (OR = 3.65 95% CI, 1.21-11.05). Case-control status was not consistently associated with folate or tHcy levels. Low vitamin B₁₂ status, when defined by a combination of both plasma vitamin B₁₂ and MMA levels, had an even stronger association with case-mothers (OR = 6.54, 95% CI, 1.33-32.09).

CONCLUSIONS

Mothers of CL±P children in southern India were 6.5 times more likely to have poor vitamin B₁₂ status, defined by multiple biomarkers, compared to control-mothers. Further studies in populations with diverse nutritional backgrounds are required to determine whether poor maternal vitamin B₁₂ or folate levels or their interactions are causally related to CL±P.

Orofacial clefts embryology, classification, epidemiology, and genetics

Orofacial clefts (OFCs) rank as the second most common congenital birth defect in the United States after Down syndrome and are the most common head and neck congenital malformations. They are classified as cleft lip with or without cleft palate (CL/P) and cleft palate only (CPO). OFCs have significant psychological and socio-economic impact on patients and their families and require a multidisciplinary approach for management and counseling. A complex interaction between genetic and environmental factors contributes to the incidence and clinical presentation of OFCs. In this comprehensive review, the embryology, classification, epidemiology and etiology of clefts are thoroughly discussed and a "state-of-the-art" snapshot of the recent advances in the genetics of OFCs is presented.

Non-syndromic Cleft Palate: An Overview on Human Genetic and Environmental Risk Factors

The epithelial and mesenchymal cells involved in early embryonic facial development are guided by complex regulatory mechanisms. Any factor perturbing the growth, approach and fusion of the frontonasal and maxillary processes could result in orofacial clefts that represent the most common craniofacial malformations in humans. The rarest and, probably for this reason, the least studied form of cleft involves only the secondary palate, which is posterior to the incisive foramen. The etiology of cleft palate only is multifactorial and involves both genetic and environmental risk factors. The intention of this review is to give the reader an overview of the efforts made by researchers to shed light on the underlying causes of this birth defect. Most of the scientific papers suggesting potential environmental and genetic causes of non-syndromic cleft palate are summarized in this review, including genome-wide association and gene–environment interaction studies.

Selected essential trace elements in maternal serum and risk for fetal orofacial clefts

BACKGROUND

Disturbances in the homeostasis of essential trace elements (ETEs) may interfere with embryonic organogenesis. However, the effect of ETEs on the development of orofacial clefts (OFCs) remains unclear.

OBJECTIVES

This study examined associations between concentrations of iron (Fe), zinc (Zn), selenium (Se), cuprum (Cu), cobalt (Co), and molybdenum (Mo) in maternal serum and risk for OFCs in offspring.

METHODS

A total of 130 cases of OFCs and 260 nonmalformed controls were included in this study. Concentrations of Fe, Zn, Se, Cu, Co, and Mo in maternal serum were detected by inductively coupled plasma mass spectrometry. We examined associations between levels of the six ETEs in maternal serum and risk for OFCs for each element separately using multilevel mixed-effects logistic regression and for all elements collectively using Bayesian kernel machine regression (BKMR).

RESULTS

Higher concentrations of Mo and Co in maternal serum were associated with a decreased risk for OFCs in a dose-dependent manner, with odds ratios and 95% confidence intervals of 0.37 (0.20-0.66) for the second tertile of Mo, 0.28 (0.15-0.54) for the third tertile of Mo, 0.54 (0.29-1.00) for the second tertile of Co, and 0.47 (0.25-0.87) for the third tertile of Co, with the lowest tertile as the referent. When all six ETEs were considered together, increased levels of ETEs were associated with a decreased risk for OFCs. In addition, Mo showed a protective effect against risk for OFCs when the other ETEs were fixed at their 25th, 50th, or 75th percentile, whereas the protective effect of Co turned to a null effect in the BKMR model. No association was observed between levels of Fe, Zn, Se, or Cu and risk for OFCs in either statistical model.

CONCLUSION

Elevated concentrations of Mo in maternal serum were associated with a reduced risk for OFCs.

Zinc Adequacy Is Essential for the Maintenance of Optimal Oral Health

Zinc, a metal found in the Earth's crust, is indispensable for human health. In the human body, around 60% of zinc is present in muscles, 30% in bones, and the remaining 10% in skin, hair, pancreas, kidneys and plasma. An adequate zinc balance is essential for the maintenance of skeletal growth, development and function. It is also necessary for basic cellular functions including enzyme activation, cell signaling and energy metabolism. Inadequate zinc status is associated with a wide variety of systemic disorders including cardiovascular impairment, musculoskeletal dysfunctions and oromaxillary diseases. In this article, we briefly discuss the role of zinc deficiency in the genesis of various oromaxillary diseases, and explain why adequate zinc homeostasis is vital for the maintenance of oral and general health.

Spatial Clusters of Children with Cleft Lip and Palate and Their Association with Polluted Zones in the Monterrey Metropolitan Area

This study examines the spatial structure of children with cleft lip and palate (CLP) and its association with polluted areas in the Monterrey Metropolitan Area (MMA). The Nearest Neighbor Index (NNI) and the Spatial Statistical Scan (SaTScan) determined that the CLP cases are agglomerated in spatial clusters distributed in different areas of the city, some of them grouping up to 12 cases of CLP in a radius of 1.2 km. The application of the interpolation by empirical Bayesian kriging (EBK) and the inverse distance weighted (IDW) method showed that 95% of the cases have a spatial interaction with values of particulate matter (PM₁₀) of more than 50 points. The study also shows that 83% of the cases interacted with around 2000 annual tons of greenhouse gases. This study may contribute to other investigations applying techniques for the identification of environmental and genetic factors possibly associated with congenital malformations and for determining the influence of contaminating substances in the incidence of these diseases, particularly CLP.

Association between selected essential trace element concentrations in umbilical cord and risk for cleft lip with or without cleft palate: A case-control study

A deficiency or excess of zinc (Zn), selenium (Se), cobalt (Co), molybdenum (Mo), or manganese (Mn) may interfere with fetal organogenesis. However, the impact of these essential trace elements on the occurrence of cleft lip with or without cleft palate (CL ± P) remains to be elucidated. We aimed to investigate the associations between the amounts of Zn, Se, Co, Mo, and Mn in umbilical cord tissue and risk for CL ± P. This case-control study included 200 controls without congenital malformations and 88 CL ± P cases. Zn, Se, Co, Mo, and Mn concentrations in the umbilical cord were determined using inductively coupled plasma mass spectrometry. Information was collected on demographics, lifestyle behaviors, and dietary intake. The median concentrations of Zn in cases of CL ± P and cleft lip with cleft palate (CLP), of Se in cases of CL ± P and cleft lip only (CLO), and of Co in cases of CLO were lower than in the controls. In utero exposure to higher levels of Zn was associated with reduced risk for CL ± P (OR = 0.44, 95% CI, 0.20-0.93) and for CLP (OR = 0.35, 95% CI, 0.14-0.86), and a higher level of Se was associated with reduced risk for CL ± P and CLO, with ORs of 0.47 (95% CI, 0.23-0.95) and 0.22 (95% CI, 0.08-0.67), respectively. By contrast, higher levels of Mo in the umbilical cord were associated with 2.52-fold (95% CI, 1.23-5.20) and 2.59-fold (95% CI, 1.12-5.95) higher risk for CL ± P and CLP, respectively. No association was found between Co or Mn and risk for CL ± P. In conclusion, in utero exposure to higher levels of Zn and Se was associated with reduced risk for CL ± P, but higher levels of Mo were associated with increased risk for CL ± P.

Higher concentration of selenium in placental tissues is associated with reduced risk for orofacial clefts

BACKGROUND & AIMS

Growing evidence suggests that essential trace element imbalance during pregnancy may contribute to fetal malformations, but the role of essential trace elements in the occurrence of orofacial clefts (OFCs) is unknown. We aimed to examine the association between concentrations of zinc (Zn), manganese (Mn), selenium (Se), cobalt (Co), molybdenum (Mo), and nickel (Ni) in placental tissues and the risk for OFCs in offspring in a rural population in northern China with a high prevalence of OFCs.

METHODS

The case-control study subjects were 103 OFC infants and 206 non-malformed infants. The concentrations of selected trace elements in placental tissues were determined using inductively coupled plasma-mass spectrometry. Sociodemographic information was collected from the mothers through face-to-face interviews using a structured questionnaire. The risk for OFCs in association with higher concentrations of the trace elements was estimated using the odds ratio (OR) with its 95% confidence interval (95% CI).

RESULTS

The placental median concentrations of Se and Ni were significantly lower, but those of Mo were significantly higher in OFC cases than in controls (all P < 0.05). A Se concentration above the median of all subjects was associated with a 58% reduced risk for OFCs (adjusted OR 0.42, 95% CI 0.23, 0.77) after adjusting for potential confounding factors. The risk for OFCs decreased with increases in placental Se concentrations, with adjusted ORs of 0.45 (95% CI 0.22, 0.92) for the second tertile and 0.22 (95% CI 0.10, 0.49) for the top tertile of Se concentration, with the lowest tertile concentration as the referent (P_trend < 0.001). No association was observed between placental Zn, Mn, Co, Mo, or Ni concentration and risk for OFC.

CONCLUSIONS

The concentration of Se in placental tissues was dose-dependently associated with decreased risk for OFCs in offspring. This finding suggests that maternal Se intake during pregnancy may protect against OFCs in offspring.

Plasma zinc levels in Ecuadorian mothers of infants with nonsyndromic cleft lip with or without cleft palate: A case series

BACKGROUND

Previous studies have reported an association between maternal zinc deficiency and increased risk of nonsyndromic cleft lip with or without cleft palate (NSCL/P) in offspring. A high prevalence of zinc deficiency and a high prevalence of NSCL/P have been reported in Ecuador. We postulated that mothers of infants with NSCL/P may have lower serum zinc levels than women from the general population.

METHODS

A case series study was conducted from November 2013 to July 2016. Thirty-five healthy mothers of infants with NSCL/P were selected during surgical missions conducted by Operación Sonrisa Ecuador. A single blood sample along with pertinent medical history was collected during personal interviews after 3.6 months postpartum. The prevalence of plasma zinc concentration (PZn) deficiency among the participants was determined and analyzed along with the prevalence of PZn deficiency in Ecuadorian women of reproductive age from the general population.

RESULTS

The mean PZn was 11.47 µmol/dm³ . The prevalence of PZn deficiency among the participants was 31.4% (95% CI: 17.1-48.6) and differed significantly from the prevalence of zinc deficiency observed among women from the general population (G²  = 8.66; p < .05).

CONCLUSIONS

The results showed that the prevalence of PZn deficiency is lower in a cohort of healthy mothers of infants with NSCL/P than in women from the general population in Ecuador. More studies are required to confirm these findings and evaluate other factors related to NSCL/P pathophysiology in the Ecuadorian population.

Case-control study of nutritional and environmental factors and the risk of oral clefts in Thailand

BACKGROUND

One infant in 700 is born with an oral cleft. Prior studies suggest low micronutrient status is associated with an increased risk of oral clefts. Environmental factors such as passive smoke exposure or supplement use may also affect oral cleft risk. We examined nutrition and environmental related risk factors for oral clefts.

METHODS

We conducted a case-control study in Northeast Thailand in 2012 to 2013. We enrolled 95 cases and 95 controls. We recruited cases with a nonsyndromic cleft lip with or without a cleft palate (CL±P) less than 24 months old. Cases were matched to controls on age and place of conception. We collected survey data, a food frequency questionnaire, and measured zinc concentrations in toenail trimmings. We calculated descriptive statistics by case and control status. We used conditional logistic regression to estimate unadjusted and adjusted associations, 95% confidence intervals (CIs), and p-values.

RESULTS

Any liver intake (adjusted OR [aOR] for ≥1/week versus none), 10.58; 95%CI, 1.74-64.37, overall p = 0.02) and the presence of food insecurity (aOR, 9.62; 95% CI, 1.52-61.05; p = 0.02) in the periconceptional period increased CL±P risk. Passive smoke exposure increased the risk of CL±P (aOR, 6.52; 95% CI, 1.98-21.44; p < 0.01). Toenail zinc concentrations were not associated with CL±P risk.

CONCLUSION

Our findings add to a growing body of knowledge of environmental risk factors for oral clefts from low- and middle-income countries. Our findings on liver are contradictory to prior results. Large multisite studies are needed to identify environmental and genetic risk factors for oral clefts. Birth Defects Research (Part A) 106:624-632, 2016. © 2016 Wiley Periodicals, Inc.

Maternal smoking during pregnancy and birth defects in children: a systematic review with meta-analysis

This systematic review aimed to investigate the association between maternal smoking during pregnancy and birth defects in children. We performed an electronic search of observational studies in the databases ovid MEDLINE (1950 to April 2010), LILACS and SciELO. We included 188 studies with a total of 13,564,914 participants (192,655 cases). Significant positive associations were found between maternal smoking and birth defects in the following body systems: cardiovascular (OR: 1.11; 95%CI: 1.03-1.19), digestive (OR: 1.18; 95%CI: 1.07-1.30), musculoskeletal (OR: 1.27; 95%CI: 1.16-1.39) and face and neck (OR: 1.28; 95%CI: 1.19-1.37). The strength of association between maternal smoking and birth defects measured by the OR (95%CI) is significantly related to the amount of cigarettes smoked daily (χ2 = 12.1; df = 2; p = 0.002). In conclusion, maternal smoking during pregnancy is associated with congenital malformations in children and this association is dose-dependent.

Epidemiology, Etiology, and Treatment of Isolated Cleft Palate

Isolated cleft palate (CPO) is the rarest form of oral clefting. The incidence of CPO varies substantially by geography from 1.3 to 25.3 per 10,000 live births, with the highest rates in British Columbia, Canada and the lowest rates in Nigeria, Africa. Stratified by ethnicity/race, the highest rates of CPO are observed in non-Hispanic Whites and the lowest in Africans; nevertheless, rates of CPO are consistently higher in females compared to males. Approximately fifty percent of cases born with cleft palate occur as part of a known genetic syndrome or with another malformation (e.g., congenital heart defects) and the other half occur as solitary defects, referred to often as non-syndromic clefts. The etiology of CPO is multifactorial involving genetic and environmental risk factors. Several animal models have yielded insight into the molecular pathways responsible for proper closure of the palate, including the BMP, TGF-β, and SHH signaling pathways. In terms of environmental exposures, only maternal tobacco smoke has been found to be strongly associated with CPO. Some studies have suggested that maternal glucocorticoid exposure may also be important. Clearly, there is a need for larger epidemiologic studies to further investigate both genetic and environmental risk factors and gene-environment interactions. In terms of treatment, there is a need for long-term comprehensive care including surgical, dental and speech pathology. Overall, five main themes emerge as critical in advancing research: (1) monitoring of the occurrence of CPO (capacity building); (2) detailed phenotyping of the severity (biology); (3) understanding of the genetic and environmental risk factors (primary prevention); (4) access to early detection and multidisciplinary treatment (clinical services); and (5) understanding predictors of recurrence and possible interventions among families with a child with CPO (secondary prevention).

Systematic analysis of copy number variants of a large cohort of orofacial cleft patients identifies candidate genes for orofacial clefts

Orofacial clefts (OFCs) represent a large fraction of human birth defects and are one of the most common phenotypes affected by large copy number variants (CNVs). Due to the limited number of CNV patients in individual centers, CNV analyses of a large number of OFC patients are challenging. The present study analyzed 249 genomic deletions and 226 duplications from a cohort of 312 OFC patients reported in two publicly accessible databases of chromosome imbalance and phenotype in humans, DECIPHER and ECARUCA. Genomic regions deleted or duplicated in multiple patients were identified, and genes in these overlapping CNVs were prioritized based on the number of genes encompassed by the region and gene expression in embryonic mouse palate. Our analyses of these overlapping CNVs identified two genes known to be causative for human OFCs, SATB2 and MEIS2, and 12 genes (DGCR6, FGF2, FRZB, LETM1, MAPK3, SPRY1, THBS1, TSHZ1, TTC28, TULP4, WHSC1, WHSC2) that are associated with OFC or orofacial development. Additionally, we report 34 deleted and 24 duplicated genes that have not previously been associated with OFCs but are associated with the BMP, MAPK and RAC1 pathways. Statistical analyses show that the high number of overlapping CNVs is not due to random occurrence. The identified genes are not located in highly variable genomic regions in healthy populations and are significantly enriched for genes that are involved in orofacial development. In summary, we report a CNV analysis pipeline of a large cohort of OFC patients and identify novel candidate OFC genes.

Parental risk factors for oral clefts among Central Africans, Southeast Asians, and Central Americans

Background

Several lifestyle and environmental exposures have been suspected as risk factors for oral clefts, although few have been convincingly demonstrated. Studies across global diverse populations could offer additional insight given varying types and levels of exposures.

Methods

We performed an international case–control study in the Democratic Republic of the Congo (133 cases, 301 controls), Vietnam (75 cases, 158 controls), the Philippines (102 cases, 152 controls), and Honduras (120 cases, 143 controls). Mothers were recruited from hospitals and their exposures were collected from interviewer‐administered questionnaires. We used logistic regression modeling to estimate odds ratios (OR) and 95% confidence intervals (CI).

Results

Family history of clefts was strongly associated with increased risk (maternal: OR = 4.7; 95% CI, 3.0–7.2; paternal: OR = 10.5; 95% CI, 5.9–18.8; siblings: OR = 5.3; 95% CI, 1.4–19.9). Advanced maternal age (5 year OR = 1.2; 95% CI, 1.0–1.3), pregestational hypertension (OR = 2.6; 95% CI, 1.3–5.1), and gestational seizures (OR = 2.9; 95% CI, 1.1–7.4) were statistically significant risk factors. Lower maternal (secondary school OR = 1.6; 95% CI, 1.2–2.2; primary school OR = 2.4, 95% CI, 1.6–2.8) and paternal education (OR = 1.9; 95% CI, 1.4–2.5; and OR = 1.8; 95% CI, 1.1–2.9, respectively) and paternal tobacco smoking (OR = 1.5, 95% CI, 1.1–1.9) were associated with an increased risk. No other significant associations between maternal and paternal factors were found; some environmental factors including rural residency, indoor cooking with wood, chemicals and water source appeared to be associated with an increased risk in adjusted models.

Conclusion

Our study represents one of the first international studies investigating risk factors for clefts among multiethnic underserved populations. Our findings suggest a multifactorial etiology including both maternal and paternal factors. Birth Defects Research (Part A) 103:863–879, 2015. © 2015 The Authors Birth Defects Research Part A: Clinical and Molecular Teratology Published by Wiley Periodicals, Inc.

Risk factors involved in orofacial cleft predisposition - review

Clefts that occur in children are a special topic. Avoiding risk factors, and also an early diagnosis of cleft possibility can result in minimizing or avoiding them. If on the other hand when clefts occur they require a long-term, multistage specialized treatment. Etiology of clefts seems to be related to many factors. Factors such as genetic, environmental, geographic and even race factors are important. Identification of risk factors can lead to prevention and prophylactic behaviors in order to minimize its occurrence. Exposure to environmental factors at home and work that lead to cleft predisposition should not be disregarded. It seems that before planning a family it would be wise to consult with doctors of different specializations, especially in high-risk families with cleft history in order to analyze previous lifestyle. Clefts are very common in hereditary facial malformations and are causing a lot of other irregularities in the head and neck region. In this paper after a brief papers review authors present socio-geographic, environmental and also work place related factors that are influencing pregnant women condition and should be taken under serious consideration.

Descriptive and risk factor analysis for choanal atresia: The National Birth Defects Prevention Study, 1997-2007

Choanal atresia causes serious posterior nasal obstruction. This defect is the leading cause of nasal surgery in newborns, although its etiology is largely unknown. Data from the National Birth Defects Prevention Study, a population-based case-control study, were used to examine associations between maternal self-reports of exposures and occurrence of choanal atresia in their offspring. Overall, 117 case and 8350 control mothers with deliveries from 1997 through 2007 provided telephone interview reports of pre-pregnancy (one year before conception) and periconceptional (one month before through three months after conception) exposures. The exposures analyzed were pre-pregnancy dietary intake, pre-pregnancy and periconceptional caffeine consumption, and periconceptional cigarette smoking, alcohol drinking, and medication use. Independent associations between each exposure and all choanal atresia cases combined (n = 117) and isolated choanal atresia cases (those without additional unrelated major defects; n = 61) were examined. Odds ratios (ORs), both unadjusted (uORs) and adjusted (aORs) for potential confounders, and 95% confidence intervals (CIs) were estimated using unconditional logistic regression analysis. For all choanal atresia cases combined, positive associations were observed with maternal pre-pregnancy intake in the highest quartile for vitamin B-12 (aOR = 1.9; CI = 1.1,3.1), zinc (aOR = 1.7; CI = 1.0,3.1), and niacin (aOR = 1.8; CI = 1.0,3.1), and intake in the lowest quartile for methionine (aOR = 1.6; CI = 1.0,2.6) and vitamin D (aOR = 1.6; CI = 1.0,2.4) compared to intake in the two intermediate quartiles combined. Further, a positive association was observed with periconceptional use of thyroid medications (uOR = 2.6; CI = 1.0,6.3) compared to no use of such medications. Among isolated choanal atresia cases, negative associations were observed for pantothenic acid (aOR = 0.4; CI = 0.2,0.9) and fat (aOR = 0.5; 95% CI = 0.2,1.0) intake in the lowest quartile compared to that in the intermediate quartiles, and positive associations were observed for periconceptional cigarette smoking (aOR = 2.3; CI = 1.1,4.7) compared to no smoking and pre-pregnancy daily coffee intake of 3 or more cups (aOR = 2.5; CI = 1.1,5.6) compared to intake of less than 1 cup per day. The positive association for periconceptional exposure to thyroid medications also persisted for isolated choanal atresia cases (uOR = 4.0; CI = 1.1,11.2). Because of the large number of associations tested, these findings may be due to chance. Alternatively, they may contribute new hypotheses regarding the etiology of choanal atresia; thus, requiring replication in additional studies.

Cleft lip - a comprehensive review

Orofacial clefts comprise a range of congenital deformities and are the most common head and neck congenital malformation. Clefting has significant psychological and socio- economic effects on patient quality of life and require a multidisciplinary team approach for management. The complex interplay between genetic and environmental factors play a significant role in the incidence and cause of clefting. In this review, the embryology, classification, epidemiology, and etiology of cleft lip are discussed. The primary goals of surgical repair are to restore normal function, speech development, and facial esthetics. Different techniques are employed based on surgeon expertise and the unique patient presentations. Pre-surgical orthopedics are frequently employed prior to definitive repair to improve outcomes. Long term follow up and quality of life studies are discussed.

Micronutrients and oral clefts: a case-control study

Little is known about oral clefts in developing countries. We aimed to identify micronutrient-related and environmental risk factors for oral clefts in Thailand. We tested hypotheses that maternal exposure during the periconceptional period to multivitamins or liver consumption would decrease cleft lip with or without cleft palate (CL ± P) risk and that menstrual regulation supplements would increase CL ± P risk. We conducted a multisite hospital-based case-control study in Thailand. We enrolled cases with CL ± P and 2 live births as controls at birth from the same hospital. Mothers completed a questionnaire. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Eighty-six cases and 172 controls were enrolled. Mothers who took a vitamin (adjusted OR, 0.39; 95% CI: 0.16, 0.94) or ate liver (adjusted OR, 0.26; 95% CI: 0.12, 0.57) were less likely than those who did not to have an affected child. Mothers who took a menstrual regulation supplement were more likely than mothers who did not to have an affected child. Findings did not differ for infants with a family history of other anomalies or with isolated CL ± P. If replicated, our finding that liver decreases CL ± P risk could offer a low-cost primary prevention strategy.

Periconceptional nutrient intakes and risks of orofacial clefts in California

BACKGROUND

Evidence indicates that maternal nutrient intake may play a role in the development of birth defects. We investigated the association of maternal periconceptional intake of vitamin supplements and dietary nutrients with risk of developing cleft palate (CP) and cleft lip with or without cleft palate (CLP).

METHODS

Data were from a population-based, case-control study of fetuses and liveborn infants delivered in California in 1999-2003. Analyses included 170 cases with CP, 425 with CLP, and 534 nonmalformed controls. Dietary intake was estimated from a food frequency questionnaire.

RESULTS

Vitamin supplement intake was associated with a modestly decreased risk of clefts, but the confidence intervals (CIs) include 1.0. Among women who did not use vitamin supplements, dietary intake of several micronutrients was associated with risk of clefts. We found at least a twofold elevated risk of CP with low intake of riboflavin, magnesium, calcium, vitamin B12, and zinc; all CIs excluded 1.0. For CLP, we found at least a twofold elevated risk with low intake of niacin, riboflavin, vitamin B12, and calcium, and a decreased risk with high intake of folate and cryptoxanthin; all CIs excluded 1.0.

CONCLUSION

The results suggest that periconceptional nutrient intake may be associated with risk of CP and CLP.

Prevention of oro-facial clefts in developing world

Oro-facial cleft (OFC) remains a prominent health issue in developed and developing countries alike. It is the commonest craniofacial birth defect in humans. Mounting evidence suggest a polygenic, multifactorial and a list of epigenetic events. Primary prevention of OFC is based on recognition of the etiologic and risk factors. While a number of preventive strategies are in place for OFC in most developed countries of the world, the majority of developing countries are distant from achieving this goal for a number of reasons. Notable among these are a huge knowledge and practice gap in the field of genetics and dearth of accurate data. In addition, improper coordination and absenteeism from antenatal care contributed greatly to this set back. With ongoing efforts aimed at determining the genetics of nonsyndromic OFC in developing countries, researches directed at identifying environmental factors should equally be in place. Pending the outcome of these, implicated environmental and attitudinal risk factors in other populations could serve as preventive template in health education and interventions. Since risk factors vary between populations, definitive and effective preventive strategies and models would vary from place to place and from time to time. Frantic effort directed at identifying specific implicated risk factors in developing countries should include developing and keeping comprehensive national perinatal database and centralization of antenatal care protocol. Additionally, active health education at every level and a focus on developing manpower in the field of genetics should be in place. These would be designed and tailored toward identified, proven, and emerging risk factors.

Current concepts on the effect of environmental factors on cleft lip and palate

The aim of this study was to investigate the effect of environmental factors, such as tobacco, alcohol and folic acid intake, obesity, stressful events, low blood levels of zinc and fever during pregnancy, on the incidence of cleft lip and/or palate (CL±P). An electronic search was performed in the Cochrane Reviews, the ISI Web of Knowledge, PubMed and Scopus, along with a manual search to identify other relevant case-control and cohort studies. Quality assessments and an evaluation of publication bias were undertaken. Statistical heterogeneity was examined, and odds ratios (ORs) and 95% confidence intervals (CI) estimated using the random effects model. Of 372 articles initially retrieved, 28 studies were selected as eligible for meta-analysis. No evidence of publication bias was found using funnel plot analysis and the Egger linear regression method. Many studies were classified as low quality due to inadequate case-control data. On the basis of this research, maternal factors most associated with CL±P were: tobacco (OR 1.48), alcohol (OR 1.28), folic acid intake (OR 0.77), obesity (OR 1.26), stressful events (OR 1.41), low blood zinc levels (OR 1.82), and fever during pregnancy (OR 1.30). Folic acid intake by the mother reduced the risk of CL±P in offspring (OR 0.77).

Oral cleft prevention program (OCPP)

Background

Oral clefts are one of the most common birth defects with significant medical, psychosocial, and economic ramifications. Oral clefts have a complex etiology with genetic and environmental risk factors. There are suggestive results for decreased risks of cleft occurrence and recurrence with folic acid supplements taken at preconception and during pregnancy with a stronger evidence for higher than lower doses in preventing recurrence. Yet previous studies have suffered from considerable design limitations particularly non-randomization into treatment. There is also well-documented effectiveness for folic acid in preventing neural tube defect occurrence at 0.4 mg and recurrence with 4 mg. Given the substantial burden of clefting on the individual and the family and the supportive data for the effectiveness of folic acid supplementation as well as its low cost, a randomized clinical trial of the effectiveness of high versus low dose folic acid for prevention of cleft recurrence is warranted.

Methods/design

This study will assess the effect of 4 mg and 0.4 mg doses of folic acid, taken on a daily basis during preconception and up to 3 months of pregnancy by women who are at risk of having a child with nonsyndromic cleft lip with/without palate (NSCL/P), on the recurrence of NSCL/P. The total sample will include about 6,000 women (that either have NSCL/P or that have at least one child with NSCL/P) randomly assigned to the 4 mg and the 0.4 mg folic acid study groups. The study will also compare the recurrence rates of NSCL/P in the total sample of subjects, as well as the two study groups (4mg, 0.4 mg) to that of a historical control group.

The study has been approved by IRBs (ethics committees) of all involved sites. Results will be disseminated through publications and presentations at scientific meetings.

Discussion

The costs related to oral clefts are high, including long term psychological and socio-economic effects. This study provides an opportunity for huge savings in not only money but the overall quality of life. This may help establish more specific clinical guidelines for oral cleft prevention so that the intervention can be better tailored for at-risk women.

ClinicalTrials.gov Identifier

NCT00397917

Maternal smoking in pregnancy and birth defects: a systematic review based on 173 687 malformed cases and 11.7 million controls

BACKGROUND

There is uncertainty over whether maternal smoking is associated with birth defects. We conducted the first ever comprehensive systematic review to establish which specific malformations are associated with smoking.

METHODS

Observational studies published 1959–2010 were identified (Medline), and included if they reported the odds ratio (OR) for having a non-chromosomal birth defect among women who smoked during pregnancy compared with non-smokers. ORs adjusted for potential confounders were extracted (e.g. maternal age and alcohol), otherwise unadjusted estimates were used. One hundred and seventy-two articles were used in the meta-analyses: a total of 173 687 malformed cases and 11 674 332 unaffected controls.

RESULTS

Significant positive associations with maternal smoking were found for: cardiovascular/heart defects [OR 1.09, 95% confidence interval (CI) 1.02–1.17]; musculoskeletal defects (OR 1.16, 95% CI 1.05–1.27); limb reduction defects (OR 1.26, 95% CI 1.15–1.39); missing/extra digits (OR 1.18, 95% CI 0.99–1.41); clubfoot (OR 1.28, 95% CI 1.10–1.47); craniosynostosis (OR 1.33, 95% CI 1.03–1.73); facial defects (OR 1.19, 95% CI 1.06–1.35); eye defects (OR 1.25, 95% CI 1.11–1.40); orofacial clefts (OR 1.28, 95% CI 1.20–1.36); gastrointestinal defects (OR 1.27, 95% CI 1.18–1.36); gastroschisis (OR 1.50, 95% CI 1.28–1.76); anal atresia (OR 1.20, 95% CI 1.06–1.36); hernia (OR 1.40, 95% CI 1.23–1.59); and undescended testes (OR 1.13, 95% CI 1.02–1.25). There was a reduced risk for hypospadias (OR 0.90, 95% CI 0.85–0.95) and skin defects (OR 0.82, 0.75–0.89). For all defects combined the OR was 1.01 (0.96–1.07), due to including defects with a reduced risk and those with no association (including chromosomal defects).

CONCLUSIONS

Birth defects that are positively associated with maternal smoking should now be included in public health educational materials to encourage more women to quit before or during pregnancy.

Global oral health inequalities: challenges in the prevention and management of orofacial clefts and potential solutions

The birth prevalence of orofacial clefts, one of the most common congenital anomalies, is approximately one in 700 live births, but varies with geography, ethnicity, and socio-economic status. There is a variation in infant mortality and access to care both between and within countries, so some clefts remain unrepaired into adulthood. Quality of care also varies, and even among repaired clefts there is residual deformity and morbidity that significantly affects some children. The two major issues in attempts to address these inequalities are (a) etiology/possibilities for prevention and (b) management and quality of care. For prevention, collaborative research efforts are required in developing countries, in line with the WHO approach to implement the recommendations of the 2008 Millennium Development Goals (www.un.org/millenniumgoals). This includes the "common risk factor" approach, which analyzes biological and social determinants of health alongside other chronic health problems such as diabetes and obesity, as outlined in the Marmot Health inequalities review (2008) (www.ucl.ac.uk/gheg/marmotreview). Simultaneously, orofacial cleft research should involve clinical researchers to identify inequalities in access to treatment and identify the best interventions for minimizing mortality and residual deformity. The future research agenda also requires engagement with implementation science to get research findings into practice.

Oral clefts and maternal biomarkers of folate-dependent one-carbon metabolism in Utah

BACKGROUND

Maternal folate intake and related biomarkers have been inconsistently associated with a risk of oral clefts.

METHODS

Maternal concentrations of plasma folate (PF) and erythrocyte folate (EF), plasma pyridoxal-5'-phosphate (PLP; active vitamin B(6) ) and total plasma homocysteine (tHcy) were measured in a Utah study with 347 cases and 469 controls.

RESULTS

Risk of all clefts combined, including cleft lip with or without cleft palate (CL/P) and cleft palate only (CP), was 65% lower in the highest versus lowest PF quartile (odds ratio [OR], 0.35; 95% confidence interval [CI], 0.23-0.53; p-trend < 0.001). Results remained significant in the subgroups with isolated CL/P and CP (p-trend < 0.001 in each). EF results were similar. In the highest versus lowest PLP quartile, risk of CP with other malformations was lower (OR, 0.25; 95% CI, 0.07-0.95); however, no other associations were significant for PLP or tHcy. Differences in mean biomarker levels between cases and controls widened with an increasing interval between delivery and maternal blood collection. Decreased cleft risk with increasing quartiles of PF, EF, and PLP and decreasing tHcy was more apparent in mothers with a longer versus shorter interval between the index child delivery and blood collection.

CONCLUSION

Low maternal blood folate concentration was associated with an increased risk of clefts, and the differences in mean case and control PF, EF, PLP, and tHcy concentrations widened over time. Additional mechanistic studies are warranted to elucidate whether an acquired or inherited disorder of folate metabolism plays a role in the etiology of clefts.

Folic acid and orofacial clefts: a review of the evidence

Orofacial clefts are common and burdensome birth defects with a complex genetic and environmental etiology. The contribution of nutritional factors and supplements to the etiology of orofacial clefts has long been theorized and studied. Multiple studies have evaluated the role of folic acid in the occurrence and recurrence of orofacial clefts, using observational and non-randomized interventional designs. While preventive effects of folic acid on orofacial clefts are commonly reported, the evidence remains generally inconsistent. This paper reviews the findings of the main studies of the effects of folic acid on orofacial clefts, summarizes study limitations, and discusses research needs with a focus on studying the effects of high dosage folic acid on the recurrence of oral clefts using a randomized clinical trial design. The role of folic acid in the prevention of neural tube defects is also briefly summarized and discussed as a reference model for orofacial clefts.

Cleft lip and palate

Clefts of the lip and palate are generally divided into two groups, isolated cleft palate and cleft lip with or without cleft palate, representing a heterogeneous group of disorders affecting the lips and oral cavity. These defects arise in about 1.7 per 1000 liveborn babies, with ethnic and geographic variation. Effects on speech, hearing, appearance, and psychology can lead to longlasting adverse outcomes for health and social integration. Typically, children with these disorders need multidisciplinary care from birth to adulthood and have higher morbidity and mortality throughout life than do unaffected individuals. This Seminar describes embryological developmental processes, epidemiology, known environmental and genetic risk factors, and their interaction. Although access to care has increased in recent years, especially in developing countries, quality of care still varies substantially. Prevention is the ultimate objective for clefts of the lip and palate, and a prerequisite of this aim is to elucidate causes of the disorders. Technological advances and international collaborations have yielded some successes.

Plasma zinc concentrations of mothers and the risk of oral clefts in their children in Utah

BACKGROUND

The role of maternal zinc nutrition in human oral clefts (OCs) is unclear. We measured plasma zinc concentrations (PZn) of case and control mothers to evaluate the associations between PZn and risk of OCs with and without other malformations.

METHODS

Case mothers were ascertained by the Utah Birth Defects Network and control mothers were selected from Utah birth certificates by matching for child gender and delivery month and year. Maternal blood was collected >1 year after the last pregnancy. PZn was available for 410 case mothers who were divided into four subgroups: isolated cleft lip with or without cleft palate (CL/P-I, n = 231), isolated cleft palate (CP-I, n = 74), CL/P with other malformations (CLP-M, n = 42), and CP with other malformations (CP-M, n = 63). PZn was available for 447 control mothers. The mean age of children at blood sampling was 3.7 years for all cases combined and 4.3 years for controls.

RESULTS

Mean PZns of all groups were similar, and low PZn (<11.0 micromol/L) was found in 59% of cases and 62% of controls. Risk of OCs did not vary significantly across PZn quartiles for the four subgroups individually and all OC groups combined.

CONCLUSIONS

We previously reported that poor maternal zinc status was a risk factor for OCs in the Philippines, where OC prevalence is high and maternal PZn is low. In Utah, however, no such association was found, suggesting that poor maternal zinc status may become a risk factor only when zinc status is highly compromised.

Priorities for future public health research in orofacial clefts

The National Center on Birth Defects and Developmental Disabilities at the Centers for Disease Control and Prevention conducted a workshop in January 2006, entitled "Prioritizing a Research Agenda for Orofacial Clefts." The goals of the meeting were to review existing research on orofacial clefts (OFCs), identify gaps in knowledge that need additional public health research, and develop a prioritized research agenda that can help guide future public health research. Experts in the field of epidemiology, public health, genetics, psychology, speech pathology, dentistry, and health economics participated to create the research agenda. Research gaps identified by the participants for additional public health research included: the roles of maternal nutrition, obesity, and diabetes in the etiology of OFCs; psychosocial outcomes for children with OFCs; the quality of life for families and children with OFCs; and the health care costs of OFCs. To create the research agenda, the participants prioritized the research gaps by public health importance, feasibility, and outcomes of interest. This report summarizes the workshop.

Maternal plasma pyridoxal-5'-phosphate concentrations and risk of isolated oral clefts in the Philippines

BACKGROUND

We report that inadequate vitamin B-6 status of Filipino mothers, assessed by erythrocyte aspartate aminotransferase activity coefficient (EAST-AC), is associated with an increased risk for isolated cleft lip with or without cleft palate (CL/P) in their children. Its association with the status assessed by plasma pyridoxal-5'-phosphate (PLP) concentrations is unknown.

METHODS

In a case-control study in the Philippines including 46 cases (mothers of a child with CL/P) and 392 controls (mothers of an unaffected child), we evaluated the association between the risk for CL/P and maternal vitamin B-6 status assessed by PLP and EAST-AC.

RESULTS

The ORs of CL/P were estimated by classifying mothers by PLP (>30, 20-30, and <20 nmol/L). Using the highest PLP group as the reference, ORs (95% CIs) were 1.03 (0.45-2.37) and 2.66 (1.30-5.50) for the middle and lowest groups, respectively (p trend = .01). In multivariate models controlling for various covariates including folate, the risk for CL/P was approximately 12 times higher in mothers with inadequate vitamin B-6 status, assessed by both PLP and EAST-AC values, compared to those with adequate status by both values.

CONCLUSIONS

Inadequate vitamin B-6 status assessed by maternal PLP and EAST-AC values independently and both combined was associated with an increased risk for CL/P. The association was highest when both values were considered, suggesting that the measurement of both PLP and EAST-AC provides better assessment of vitamin B-6 status than either measurement alone.

Nutritional supplements in pregnancy: commercial push or evidence based?

PURPOSE OF REVIEW

This review examines whether nutritional supplements during pregnancy have a role to play in the health of the mother, outcome of pregnancy or health of the baby. It will put into context the increased use of nutritional supplements in pregnancy and whether there is an evidence base for this supplementation.

RECENT FINDINGS

Women are not consuming enough nutrients from their diet alone and food is depleted in many important minerals. There is increasing support that supplementation of specific vitamins, minerals and omega-3 fatty acids can have a positive impact on maternal health in terms of prevention of preeclampsia, miscarriage, preterm birth, low birthweight, gestational diabetes and also on the long-term health of the baby. There are some contradictory findings with antioxidants and prevention of preeclampsia, and these are discussed.

SUMMARY

With soil depletion, overfarming and transportation of foods over hundreds of miles with loss of nutrients en route, together with the increased use of convenience and fast foods, women can be over-fed, but under-nourished in our modern society. These can lead to nutrient deficiencies which can have an impact on the outcome of pregnancy. Evidence shows that supplementation can play a valuable role in the health of the pregnant mother and her baby. Emphasis must always be on eating a good diet, but given the limitations of the 21st century lifestyle and the nutritional content of food, good quality nutritional supplements should be used during pregnancy in combinations rather than isolated single nutrients.

Neural tube defects and maternal biomarkers of folate, homocysteine, and glutathione metabolism

BACKGROUND

Alterations in maternal folate and homocysteine metabolism are associated with neural tube defects (NTDs). The role played by specific micronutrients and metabolites in the causal pathway leading to NTDs is not fully understood.

METHODS

We conducted a case-control study to investigate the association between NTDs and maternal alterations in plasma micronutrients and metabolites in two metabolic pathways: methionine remethylation and glutathione transsulfuration. Biomarkers were measured in a population-based sample of women who had NTD-affected pregnancies (n = 43) and a control group of women who had a pregnancy unaffected by a birth defect (n = 160). We compared plasma concentrations of folate, vitamin B(12), vitamin B(6), methionine, S-adenosylmethionine (SAM), s-adenosylhomocysteine (SAH), adenosine, homocysteine, cysteine, and reduced and oxidized glutathione between cases and controls after adjusting for lifestyle and sociodemographic factors.

RESULTS

Women with NTD-affected pregnancies had significantly higher plasma concentrations of SAH (29.12 vs. 23.13 nmol/liter, P = .0011), adenosine (0.323 vs. 0.255 mumol/liter; P = .0269), homocysteine (9.40 vs. 7.56 micromol/liter; P < .001), and oxidized glutathione (0.379 vs. 0.262 micromol/liter; P = .0001), but lower plasma SAM concentrations (78.99 vs. 83.16 nmol/liter; P = .0172) than controls. This metabolic profile is consistent with reduced methylation capacity and increased oxidative stress in women with affected pregnancies.

CONCLUSIONS

Increased maternal oxidative stress and decreased methylation capacity may contribute to the occurrence of NTDs. Further analysis of relevant genetic and environmental factors is required to define the basis for these observed alterations.

Zinc supplementation of young men alters metallothionein, zinc transporter, and cytokine gene expression in leukocyte populations

An effective measure to assess zinc status of humans has remained elusive, in contrast to iron, where a number of indicators of metabolism/function are available. Using monocytes, T lymphocytes, and granulocytes isolated by magnetic sorting and dried blood spots (DBS) derived from 50 mul of peripheral blood, we evaluated the response of metallothionein (MT), zinc transporter, and cytokine genes to a modest (15 mg of Zn per day) dietary zinc supplement in human subjects. Transcript abundance was measured by quantitative real-time RT-PCR (QRT-PCR). Zinc supplementation increased MT mRNA abundance by up to 2-fold in RNA from leukocyte subsets, and 4-fold in RNA from DBS. Transcript levels for the zinc transporter genes ZnT1 and Zip3 were increased and decreased, respectively, by zinc supplementation. Expression of the ZnT and Zip genes among leukocyte subsets differ by up to 270-fold. Monocytes and granulocytes from supplemented subjects were activated by LPS, whereas T lymphocytes were activated by mimicking antigen presentation. With zinc consumption, TNF-alpha and IL-1beta expression was greater in activated monocytes and granulocytes, and IFN-gamma mRNA levels were higher in activated T lymphocytes. These studies show that QRT-PCR is a tool to reliably measure transcript abundance for nutritionally responsive genes in human subjects, and that a small sample of whole dried blood, when appropriately collected, can be used as the source of total RNA for QRT-PCR analysis. The results obtained also show that zinc supplementation of human subjects programs specific leukocytic subsets to show enhanced cytokine expression upon activation by stimulators of immunity.