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Seasonal Variations in the Incidence of open Neural tube Defects in Puerto Rico from 1995 through 2005
Source publication
Birth defects represent one of the main causes of infant mortality and morbidity around the world.
The purpose of this study is to identify seasonal changes in the incidence of various congenital anomalies in our population.
We identified all cases of open neural tube defects, cardiac anomalies, cleft lip and palate and gastroschisis of children bo...
Context in source publication
Context 1
... that are influenced by the presence of environmental teratogens may show seasonal patterns of occurrence depending on the exposure to these teratogens. Open Neural Tube Defects (Table 3): there were a total of 377 cases of open neural tube defects in Puerto Rico from January 1995 through December 2005 among 441,245 conceptions. the incidence was highest during the summer (1.03). ...
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Citations
... Karyotypic abnormalities such as trisomies, a high concordance rate in monozygotic twins, altered folate and homocysteine genes, occurrence within families, gender predilection, and ethno-racial differences provide evidence in favor of a genetic influence [1]. On the other hand, seasonal variations have been suggested as an indicator of potential environmental contributors to the development of myelomeningocele, among other factors such as folate deficiency, hyperthermia, diabetes, and drugs [5]. ...
... Nonetheless, it is crucial to remember that oxidative stress is not the only deciding environmental factor. Unknown teratogens that may exhibit seasonal patterns throughout the year are possible alternative causal factors [5]. ...
... Our findings are corroborated by previous studies conducted in other countries, including Puerto Rico, South Africa, Newfoundland, and the United Kingdom [5,6,8,25]. However, it contrasts with reports from studies from the United States, Jordan, Germany, Poland, Japan, and Algeria [9-11, 20, 26]. ...
Purpose
Myelomeningocele is the most severe birth defect compatible with long-term survival. It accounts for 5.7% of neurological surgeries in Nigeria. However, the exact cause of this neural tube defect remains unidentified. This study aims to determine if seasonal variation is a potential environmental contributor.
Method
This study prospectively recruited 242 children diagnosed with myelomeningocele at the University of Nigeria Teaching Hospital (UNTH), Enugu, Nigeria, between January 2010 and December 2022. Our primary outcome was the seasonal occurrence of myelomeningocele, while covariates included gender, birth order, maternal folic acid supplementation (FAS), and parental age. The estimated month of conception was derived from the mother’s last menstrual period (LMP), and the occurrence of myelomeningocele across the various seasons in which these babies were conceived was assessed using the Lorenz curve and the Gini coefficient.
Results
242 patients were studied with a male-to-female ratio of 1.26. The majority of cases were lumbosacral (93.4%), and none of the mothers commenced FAS before conception. The highest proportion of cases (39.7%) occurred during the hottest period of the dry season (January–March), while the lowest proportion (15.7%) occurred during the early wet season (April–June). The Gini index of 0.29, and the Gini coefficient derived from 100,000 Monte Carlo simulations of 0.24, indicate a significant variation in the distribution of myelomeningocele cases across different seasons of conception.
Conclusion
The seasonal occurrence of myelomeningocele with a peak in January–March suggests a potential association with environmental factors including oxidative stress induced by solar radiation.
... [1] On the other hand, seasonal variations have been suggested as an indicator of potential environmental contributors to the development of myelomeningocele, among other factors such as folate de ciency, hyperthermia, diabetes, and drugs. [5] Various epidemiological studies conducted in different countries, including the United Kingdom, Norway, Newfoundland, Germany, Algeria, and the United States, have investigated the seasonal variation of this defect, albeit with con icting ndings. [6][7][8][9][10][11] Interestingly, low-and mediumincome countries in sub-Saharan Africa bear the largest burden of NTDs like myelomeningocele, with substantial attendant medical, aesthetic, and socioeconomic implications. ...
... Unknown teratogens that may exhibit seasonal patterns throughout the year are possible alternative causal factors. [5] Our ndings are corroborated by previous studies conducted in other countries, including Puerto Rico, South Africa, Newfoundland, and the United Kingdom. [5,6,8,25] However, it contrasts with reports from studies from the United States, Jordan, Germany, Poland, Japan, and Algeria. ...
... [5] Our ndings are corroborated by previous studies conducted in other countries, including Puerto Rico, South Africa, Newfoundland, and the United Kingdom. [5,6,8,25] However, it contrasts with reports from studies from the United States, Jordan, Germany, Poland, Japan, and Algeria. [9][10][11]20, 26] Among the Scandinavian countries, northern Finland and Sweden demonstrated a seasonal variation, while Norway did not nd a seasonal pattern. ...
Purpose
Myelomeningocele is the most severe birth defect compatible with long-term survival. It accounts for 5.7% of neurological surgeries in Nigeria. However, the exact cause of this neural tube defect remains unidentified. This study aims to determine if seasonal variation is a potential environmental contributor.
Method
This study prospectively recruited 242 children diagnosed with myelomeningocele at the University of Nigeria Teaching Hospital (UNTH), Enugu, Nigeria, between January 2010 and December 2022. Our primary outcome was the seasonal occurrence of myelomeningocele, while covariates included gender, birth order, maternal folic acid supplementation (FAS), and parental age. The estimated month of conception was derived from the mother's last menstrual period (LMP), and the occurrence of myelomeningocele across the various seasons in which these babies were conceived was assessed using the Lorenz curve and the Gini coefficient.
Results
242 patients were studied with a male-to-female ratio of 1.26. The majority of cases were lumbosacral (93.4%), and none of the mothers commenced FAS before conception. The highest proportion of cases (39.7%) occurred during the hottest period of the dry season (January–March), while the lowest proportion (15.7%) occurred during the early wet season (April–June). The Gini index of 0.29, and the Gini coefficient derived from 100,000 Monte Carlo simulations of 0.24, indicate a significant variation in the distribution of myelomeningocele cases across different seasons of conception.
Conclusion
The seasonal occurrence of myelomeningocele with a peak in January–March suggests a potential association with environmental factors including oxidative stress induced by solar radiation.
... Similarly, Edwards reported seasonal variation in the incidence of anencephaly, with a higher occurrence in winter births (Edwards, 1961). The effects of seasons on CL/P were attributed to diets deficient in vitamins as in arid seasons and exposure to several environmental factors such as intensive ultraviolet exposure and infections (Krost and Schubert, 2006;Elliott et al., 2008;de la Vega and López-Cepero, 2009). In contrast, some authors reported no significant association between seasonal variations and the presence of CL/P (Saxen and Lahti, 1974;Amidei et al., 1994). ...
Objective: To report clinical case series of cleft lip with or without palate (CL/P) and to estimate the prevalence of infants with CL/P who were syndromic or non-syndromic.
Design: This is a clinical case series study of CL/P among live births in the maternity hospital.
Setting: The study was carried out in Maternity and Children Hospital, Najran between January 2013 and December 2016.
Materials and Methods: Sex and clinical presentation of CL/P were collected from the medical records of live births. Clinical presentations were identified by type of CL/P and stratified according to laterality of occurrence. The data were stored and analyzed using the Statistical Package for Social Sciences (SPSS; Chicago, IL, USA) program, version 20. Results were presented in simple descriptive statistics.
Main outcome: Prevalence of CL/P in the Najran region of Saudi Arabia was 0.65 per 1,000 live births (95% confidence interval [CI] 0.650 ± 0.662). Cleft lip and palate (CLP) was the commonest clinical presentation.
Result: Out of 24,367 live birth, 16 were classified as having CL/P. The overall frequency of CL/P was 0.65/1000 live births (95% confidence interval [CI] 0.650 ± 0.662). There were 10 males and 5 females. Infant sex cannot be established in 1 case. Two (12.5%) patients had cleft lip, 4 (25%) had isolated cleft palate and 10 (62.5%) had combined CL/P. Nine (56.25%) neonates were cases of non-syndromic CL/P (NSCL/P) while 7 (43.75%) were cases of syndromic CL/P (SCL/P).
Conclusions: Prevalence rate of 0.65 per1000 live births over 4-year period was observed at (95% confidence interval [CI] 0.650 ± 0.662). CL/P was the commonest clinical presentation.
... [29] The effects of seasons on OFCs were attributed to diets deficient in vitamins as in arid seasons and exposure to several environmental factors such as intensive ultraviolet exposure and infections. [30][31][32][33] In contrast, some authors reported no significant association between seasonal variations and the presence of OFCs. [26,34,35] These variations could also be attributed to chance correlation, which depends on a single set of data. ...
Objective: This study was designed to find out
risk indicators for the development of orofacial
clefts (OFCs) in the Southern Province of Saudi
Arabia. Materials and Methods: This was a
retrospective study carried out in a maternity
hospital from January 2013 to December 2016.
Data including child sex, type and site of cleft, birth
weight and birth month (season), parents’ age at
the time of their child’s birth, paternal and maternal
habits, parental consanguinity, and family history
of OFCs were obtained. The data were processed
and analyzed using SPSS software, Version 20.
Results: Overall prevalence of OFCs in the study
population was 0.65/1000 live births. There were
10 males, 5 females, and 1 ambiguous sexual
orientation. Of the 16 OFC patients, 9 (56.25%) were
classified as having syndromic OFCs (SOFCs) and
7 (43.75%) as having non‑SOFCs (NSOFCs). Cleft
lip and cleft lip/palate both had strong family history
of OFCs. Similarly, the phenotype of OFCs and the
presence of syndromic or NSOFCs did not show
a relationship with paternal smoking habits during
pregnancy. No relationship was reported between
parental consanguinity with the presence of these
factors. However, results showed that 13 (81.3%)
out of 16 identified cases of OFC had background
consanguinity. Conclusion: Prevalence of OFC
in the current study was within reported range,
consanguinity was observed in 81.3% of identified
cases. Further research is paramount in the role of
consanguinity in OFC in Arabian population.
Key words: Cleft lip/palate, consanguinity,
pregnancy, smoking habits
... Secondly, confounding factors included in the individual studies are an additional concern. In fact, there are some known or suspected risk factors for congenital anomalies including maternal age, smoking, and season of conception [42][43][44]. However, these potential confounders were not consistent in each study. ...
Nitrogen oxide (NO
x
) is produced during combustion at high temperature, which is a major constituent of air pollutants. Recent studies suggested inconsistent results on the association between NO
x
exposure and cardiovascular-related malformations. We aimed to assess aforementioned association in pregnant women in the first trimester and cardiovascular-related malformations of infants. A systematic literature review identified studies for observational studies about NO
x
exposure and cardiovascular-related malformation in PubMed. Random-effect models were used to estimate summary odds ratio (SOR) and 95% confidence intervals (CIs) for aforementioned association. Finally, nine studies met the inclusion criteria. Overall, the SOR of cardiovascular-related malformation per 10 ppb increment in NO
x
and NO2 concentration was 1.01 (95% CI: 0.98-1.04; I2 = 38.6%, P = 0.09) and 0.99 (95% CI: 0.95-1.04; I2 = 37.8%, P = 0.13), respectively. Stratifying by study design, geographic locations, and confounded adjustments, the majority of strata showed negative results, which were consistent with the main findings. However, we found that exposure to NO
x
and NO2 in the first trimester increased the risk of coarctation of the aorta (COA) malformation by 13% and 19%, respectively. Our study provided limited evidence regarding the association between NO
x
exposure in the first trimester and cardiovascular-related malformations in infants.
... Gastroschisis (GS) is the most common abdominal wall abnormality, but its etiology is still largely unknown. Multiple risk factors have been implicated in the development of gastroschisis, including maternal factors (young maternal age, low socioeconomic status, absence of maternal father, and poor prenatal care), dietary factors (poor nutrition, low glutathione and beta-carotene, and high nitrosamine) and chemical exposures [1][2][3][4][5][6][7][8]. Despite the link to chemical exposures, little evidence is available regarding farmlands and chemical plants and their potential relationships with gastroschisis patients [9][10][11][12]. ...
... The incidence of gastroschisis has reportedly increased over the past three decades, and this increase has been noted internationally [6,[13][14][15]. Many reasons for this rise have been suggested, including higher incidence of prematurity, improved survival of premature infants, better distinction from omphalocele since the 1970s, improved coding practices, increased teen pregnancy, increased drug use during pregnancy, and more frequent chemical exposures [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Nevertheless, nearly all studies note an increasing incidence above and distinct from demographic and coding variability. ...
Purpose:
Gastroschisis incidence has increased over the past decade nationally and in Hawaii. Pesticides have been implicated as potential causative factors for gastroschisis, and use of restricted use pesticides (RUPs) is widespread in Hawaii. This study was conducted to characterize gastroschisis cases in Hawaii and determine whether RUP application correlates with gastroschisis incidence.
Methods:
Gastroschisis patients treated in Hawaii between September, 2008 and August, 2015 were mapped by zip code along with RUP use. Spatial analysis software was used to identify patients' homes located within the pesticide application zone and agricultural land use areas.
Results:
71 gastroschisis cases were identified. 2.8% of patients were from Kauai, 64.8% from Oahu, 16.9% from Hawaii, 14.1% from Maui, and 1.4% from Molokai. RUPs have been used on all of these islands. 78.9% of patients lived in zip codes overlapping agricultural land use areas. 85.9% of patients shared zip codes with RUP-use areas.
Conclusion:
The majority of gastroschisis patients were from RUP-use areas, supporting the idea that pesticides may contribute to the development of gastroschisis, although limited data on specific releases make it difficult to apply these findings. As more RUP-use data become available to the public, these important research questions can be investigated further.
... In contrast (9,10,11) whose found that hot season recorded high percent of anomalies during summer months. The effect of Monthly variation in the incidence of congenital malformations may be secondary to the effect of yet to be identified teratogens acting on the population at large, or, more likely, to changes in activity and dietary patterns of the population (12). ...
The study was conducted on specimen (402) of new born congital malformations during years (2009,2010,2011) in al-Zahra hospital of obstatric / Al-Najaf , for determine the relation-ship among (age group of mother ,new borne gender, and year months ) with malformation percent. The present study was revealed that the age group (22-26) year which more percentage of malformation , was (%38) in year 2009. (%31.6) in year 2010 , and (%29.4) in year 2011. The total of congenital malformations of new borns for three (years 2009, 2010, 2011) were (105 ,117, 180) case at respectively. The high percent (%19)of malformations appeared during year 2009 was congenital hydrocephalus, in the period year 2010, the high percent of malformation (%27) was Microcephallus, while the cardiovascular malformation were high percent in year 2011, that reached to (%40.5). The effect of new borne gender on the malformations percent was biostatical significant for year 2011 in the males (%59.5) when compared with female (%40.5), while in year 2010 the percent in female (%57.5). The high malformation percent (%10.2, %13.8) were appeared in the March and April in year 2010 and 2011. while the high percent of malformation (%14.2) was in year 2009 during December period.
... 16,19,20 However, a Montreal study observed a significant seasonal increase in NSCL/P for boys with a peak in July 15 ; an English study reported a peak in December and January 14 ; an African study reported that patients with NSCL/P tended to be born more frequently during the March-August 13 ; a Chinese study showed more NSCL/P births in January to July 26 and a study realized in Puerto-Rico reported increase in the incidence of cleft and lip during the summer months. 27 A retrospective study conducted in Mexico with 835 patients showed an increased incidence of NSCL/P in sowing, fumigation and harvest periods, where women participated in the labor. This would suggest exposure to agricultural chemicals during pregnancy. ...
Aims:
Evaluate the seasonal influence in nonsyndromic cleft lip and/or palate (NSCL/P) in Brazilian patients.
Methods:
A case-control study, with 361 unrelated patients with NSCL/P and 481 healthy individuals, was done on a reference service for craniofacial deformities in Minas Gerais State, Brazil. Information was collected from clinical records considering gender, month of birth, as well as with the seasons.
Results:
Nonparametric tests did not show a seasonal variation in month of birth and in seasons of year of NSCL/P compared to a control group (p = 0.902 and p = 0.679, respectively). A difference in births between the groups was identified only in January, however, was not significant. Moreover, among the control group there were more births in the months of February and August, and for the cleft group, more in July and August. The males were more affected by cleft lip with or without palate (CLP) and the females by isolated cleft palate (CP) manifestation. The ratio of CL:CLP:CP indicated that CLP was predominant when compared with CL and CP, CLP was more frequent in male patients, and CP predominance was seen in females.
Conclusion:
This study did not show seasonal differences in births on NSCL/P in a Brazilian group, emphasizing that environmental factors may be related to oral clefts. These results provide a basis for further epidemiological studies of orofacial clefts in Brazil.
... Confounding factors included in the individual studies are an additional problem. Few confounders, such as smoking [39], parental occupation [40], maternal age [41] and season conception [42] have been addressed in congenital anomalies research. Season and maternal age at conception were the most frequent confounders considered in the studies included in the present work. ...
... Season and maternal age at conception were the most frequent confounders considered in the studies included in the present work. Seasonal variations of congenital anomalies incidence have been well described, with a higher risk in summer than in winter [42]. The association between maternal age and the risk of non-genetic congenital anomalies is still unclear. ...
Congenital anomalies are the main causes of preterm and neonatal mortality and morbidity. We investigated the association between congenital anomalies and mothers' exposure to air pollution during pregnancy by combining risk estimates for a variety of air pollutants (SO2, NO2, PM10, PM2.5, CO and O3) and anomaly defect outcomes. Seventeen articles were included in the systematic review and thirteen studies were taken into account in the meta-analysis. Combined estimated were calculated separately according to whether the exposure metric was continuous or categorical. Only one significant combination was; NO2 concentrations were significantly associated with coarctation of the aorta (OR = 1.20 per 10 ppb, 95% CI, (1.02, 1.41)). This finding could stem from strong heterogeneity in study designs. Improved exposure assessment methods, in particular more accurate spatial measurements or modeling, standardized definition of cases and of better control of confounders are highly recommended for future congenital anomalies research in this area.
... However, none of these factors could account for the observed seasonal variations in the incidence of oral-facial clefts worldwide. 1,[5][6][7][8][9][10][11] We reported earlier 12 that the incidence of isolated nonsyndromal oral-facial clefts was highest in winter and lowest in autumn and suspected that seasonal factors could have played a role. One of these factors is the duration of the available sunlight, which is shortest in winter/spring and longest in summer/autumn. ...
Abstract Objective: To examine the seasonality of fetal trisomy 21 and its relationship with ambient air pollutants. Methods: The averaged incidence by month-of-conception of the 113 cases (2002-2009) in our registry was correlated with month of conception and monthly ambient levels of nitrogen oxides (NOx, NO and NO2), sulfur dioxide, carbon monoxide, and ozone as reported by the Hong Kong Environmental Protection Department at the month of, and four-week after, conception. Results: The incidence was highest in February (3.45/1000 births) and lowest in October (1.28/1000 births), and showed a significant difference (p=0.003) and positive correlation (p = 0.003) from winter to autumn. It was also correlated with NO (p = 0.017) and inversely with ozone (p = 0.014) at conception. Conclusions: Seasonal variation in incidence of fetal trisomy 21 was correlated with ambient levels of nitric oxides and ozone. The role of environmental pollutants on fetal aneuploidy warrants further investigation.
