Discuss the Birth order and reproductive endpages in children with ASD.
The study’s objective was to analyze the relationship between ASD-related birth order and methods of birth (for children with ASD), as well as the phenomenon known to be called reproductive stoppage, and the number siblings in the case families (families with children with ASD). This will help to determine whether ASD incidence has any relationship to the method of birth.
Materials and Methods
The study involved 196 ASD children and 54 children who were not autistic.
The mean age of the ASD children was 56.9months (SD 27.1months; median 51), and 55.7months (SD 13.8months; median 54) for those in the control group.
Demographics were also gathered.
ASD cases could be identified by the Autism Behaviour Checklists (ABC), Aberrant Behaviour Checklists (AbBC), or the Childhood Autism Rating Scales (CARS).
For statistical analysis, Mann Whitney U Test and Chi-square Test were used depending on the data type and the purpose of the assessment.
A statistically insignificant value of 0.05 or less was considered statistically not significant.
This study group included children with ASD. The rate of being forced labor babies was significantly higher in this group than it was in the control group (p=0.001).
The statistical analysis of the rate for reproductive stoppage was done without excluding one-child families (p=0.001).
ASD can be explained by looking at the birth order and type of birth (CS, forced labor, normal) as well as the environmental factors that can cause it.
DSM-5 defines Autism Spectrum Disorder as a developmental disorder with impairments in communication and social interactions. It is also characterized by repetitive and restricted behavior and interest.
ASD is estimated to be between 0.9-2.7% in prevalence and has seen a significant increase in incidence over the past 20 years (1,2).
Studies both clinical and epidemiological have found that autism is more prevalent in boys (3).
ASD may have a genetic foundation (4). However, much remains to be learned and understood about the mechanisms and processes that underlie it.
ASD can also be attributed to prenatal exposures (like to environmental stimuli) (5).
The most common factors are advanced maternal and paternal years, parity and birth order. Also, obstetric related issues, such as bleeding, preeclampsia or prolonged labor, type and delivery, intrauterine medication exposure, fetal distress and drug use by the mother (such as psychotropic drugs), pre- and post maturity and birth weight.
Although birth order studies are still popular in psychiatric disease, no definitive results have been found, especially if there is a link between autism and birth or order (5;10:11).
Although some studies have shown that ASD can be detected in the first born, they are not conclusive.
There have been reports that show a negative correlation (11) and a positive relationship (12;13,14) between ASD development and birth order. Others report no correlation (5).
The phenomenon of “stoppage” is when parents of a child suffering from a severe illness have fewer children, or stop reproducing.
Numerous studies have found that an autistic child could influence the outcome of subsequent pregnancy decisions.
Studies have shown that autistic children can influence the decision of a family to get pregnant. Other studies, however, show contradictory results.
Hoffmann (2015) and Wood (2016) stated that the presence of an autistic child in a family is associated with reproductive failure. Gronborg et.al., however, reported contradictory results regarding the same issue (17;16;17).
To contribute to the research in this area, the study examined the birth order and siblings of children with ASD. This was done to see if they were different from children in the control group.
ASD risk factors were also studied. We assessed the roles of educational level, parental age (in the selected range), delivery type, and associated reproductive methods. Additionally, we evaluated the number of siblings as well as the birth order.
A further assessment was done to determine if having an autistic child can affect your decision making regarding subsequent pregnancies and if it results in a reproductive stoppage.
A total of 196 children were included in the study who were diagnosed with ASD by our clinic. The DSM 5 criteria were used. This was between January 2015 in Turkey and January 2016.
Two psychiatrists, specializing in child and adolescents psychiatry and psychoiatric examination, made the diagnosis.
Standardized clinical forms were used to collect information from the primary caregiver about the family and children’s symptoms.
A Autism Behavior Checklist was administered to primary caregivers for children with ASD (18,19,20;21).
An experienced child and adolescent psychiatrist administered the Childhood Autism Rating Scale scores.
Study participants were not allowed to include autistics with chronic conditions or malignancies.
The control group included 54 children who were not diagnosed with autism and presented at the pediatric outpatient clinic to receive vaccinations. The study group was made up of the same age and gender as the control group.
The primary caregiver obtained information from them about their family and symptoms using standard clinical forms.
These parameters included the paternal and maternal age, education levels of the patients, number of siblings and birth order. Also, the assisted reproductive techniques were examined. The impact of ASD and being the first-born on reproductive behavior in case families was also considered.
IBM SPSS Statistics For Windows version 17.0 was used for statistical analysis.
All continuous variables were identified as means and standard deviations, while categorical variables were evaluated by frequency and percentages.
Comparations were made using the Student-T, Mann Whitney U, and Pearson Chi-square tests as non-parametric alternatives.
A statistically significant level of statistical significance was defined as a value of ‘0.05’.
In order to conduct the study, the approval of the local ethics board was required.
Each participant and their legal representatives gave written consent.
The incidence of a child born after an ASD diagnosis was made was used to determine if there was a reproductive stoppage.
Due to time limitations, the study couldn’t determine whether families considered to have reached a reproductive end were pregnant after they had already had ASD children.
Future observation of these families will allow for an extension of the study. This will enable us to see if they have had children after the study ended.
Total 250 participants were from Turkey. They included 54 control children and 196 ASD-diagnosed children according to DSM-5 criteria.
The average age of ASD-afflicted children was 56.9months (SD 27.1months; median 51) and 55.7months (SD 13.8months, median 54).
P Value (Claculated probability) or Hypothesis testing and Chi Square Test did not show any significant difference in the ages of the ASD children and controls (p>0.05).
Table 1 shows that the paternal and maternal ages of ASD children were higher than those in control groups, but there was no statistical significance.
163 ASD-afflicted children (83.2%) were boys and 33 ASD-afflicted children (16.8% each) were girls in the ASD group.
In the healthy control, 47 children (%85.1) had ASD and 7 (%14.9) had it.
Gender differences were not statistically significant between the groups (p>0.05).
The rates of spontaneous delivery and Caesarean section (C -section) were comparable between children with ASD (p>0.05).
The rates of assisted reproduction techniques, including in vitro fertilization, were similar across the groups (p>0.05).
The ASD group experienced more difficulties during labor than the controls (21.4% against 3.7%; p=0.002) (Table 1.
According to the order of birth, 63.3% (n=124), the first-born children with ASD with Autism were, respectively, 26.0%(n=51), 7.7% (15) and 2.6% (55) the third-born. The fifth-born child was the fifth-born in the families (X2=15.729 p=0.003).
The control group did not have any children who were born as the fourth, fifth, or sixth child in their families. These children were therefore excluded from the analysis.
The data were then re-analyzed to exclude children who were born on the fourth or fifth birth order ranks. This result was statistically significant compared with the control group (x2=13.792,p=0.001).
The statistical significance was achieved after excluding the one-child family (n=214) from the analysis. Evaluation of being the first-born child (n=170), as a parameter, resulted with a rate 57.6% (91/70) vs 27.3% (12/44), respectively.
Demographics of Birth Order:
Statistics showed that the correlation between gender and birth or the probability of becoming a woman in the ASD group’s first-born child was statistically greater than the control group (Chi Square Test=14.338 p=0.002).
A higher percentage of ASD children were born by C-section than in the control group (Chi Square Test=8.035 p=0.032).
The percentages of ASD children born after prolonged labor or using vacuum-forceps applications were significantly higher than those in the control group (Chi Square Test=9.429 p=0.024, Table 4)
After exclusion of the one-child family (n=36), data showed that ASD was developed in the first born regardless of gender or delivery type.
Also, after controlling for the one child families, it was not possible to find a relationship between SC and difficult labors in first-born children with ASD (p0.05). However, there was a significant correlation (p=.0.85) in forced (vacuum prolonged), labour.
For all participants, the proportion of single children was 14.4% (36/250).
13.3% (26/196) of ASD-group families had only one child. 18.5% (10/54) of ASD-group families had one child. This was statistically significant for stoppage (X2=0.948 p=0.330).
It was discovered that 86.7% of children in ASD had at least one sibling (n=170), as opposed to 81.5% (n=44), for their counterparts (Table 6).
The analysis of the stoppage phenomenon excluded single-child families (n=36), as well as families whose child had ASD. (Table 7).
Statistics showed that ASD mothers had 100.0% (n=87), which was a significant percentage of all ASD-related births (X2=15.250 p=0.000).
100.0% (n=9) mother whose first-born was diagnosed with ASD had the ability to give birth to another child in a three-child family.
14.3% (n=4) were the mothers who gave birth to other children in families with ASD-diagnosed second children.
A family with four children has 100.0% (n=2) mother who had ASD as a child, and 22.2%(n=2) mother whose second-born child had ASD.
Recent research has shown that the birth order is the order of an individual’s siblings.
Different interpretations and results have been reported in relation to ASD and birth order.
ASD groups were compared to controls on the basis of birth order. This study revealed a significant difference in ASD children being first-born in the ASD group.
A study that did not control pregnancy complications revealed no association between ASD, maternal age, or birth order.
Some studies however showed an increased risk of ASD in children born to forced labor participants than in those with control births (12,13,14).
Our results support the earlier studies.
The child may be subject to congenital problems, birth canal stress, asphyxia, and other factors during labor. Each of these factors could cause brain damage (24;25).
The ASD group was found to have a higher labor difficulty rate than the control.
The results of this study, which showed that ASD children were more likely to be first-born than the control group and had higher rates, of difficulty labors during labor, indicate that forced labored children may be more vulnerable to perinatal stresses, which could play a role as a factor in ASD etiopathogenesis.
ASD research has produced contradictory findings regarding the possible role of paternal and maternal age in ASD.
A study of ASD cases showed that third-degree autism rates in children whose mothers were between 20 to 34 years old and their fathers below 40 were three times more than those of children born to older parents (10).
A second study looked at the relationship between the ASD families’ birth order and their maternal age.
In the ASD group, there was no correlation for birth order.
A higher proportion of autistic children were found in risky pregnancies (e.g., first, fourth or later borns) than the general population (26;27).
Analyzing the design of the studies reveals some limitations. These include insufficient diagnosis tools, poor selection of control groups, and inability to identify the type of delivery at birth.
The ASD group had a higher maternal and paternal age, but this was not statistically significant.
This confirms other studies which have found that the main risk factor for autistic children is not parental age.
It should be noted, however, that ASD may not be caused solely by parental age. This is because older parents might have autistic children who are different from theirs.
Understanding the relationship between ASD and advanced age of parents is essential.
ASD diagnosis may also be affected by race. Poor pregnancy outcomes, such as preeclampsia, preterm birth, and other complications, could also affect ASD diagnosis.
Our study showed that there was no statistically significant difference between sibling birth order and sibling number, CARS, ABC, AbBC scores, or birth order in the autistic population.
28) A small study with sixteen families showed that non-verbal IQ scores fell as there were more births (28).
A separate study that included one hundred sixty-one families found a significant increase of repetitive behaviors and speech difficulties in the first child and second children diagnosed with ASD in these families (29).
It was also found that autism affects children with a lower intelligence level than their birth order.
A similar study found that autism-related symptoms in children with autism were more severe in children born as second and third children.
These studies show similar patterns and limitations to previous ones, such as insufficient control groups and the choice of ASD children from the study who presented to the clinic.
Our results were not comparable to those published in the literature. However the cultural differences can be attributed to cultural variability.
86.7% of the children in autism had at least one sibling, while 81.5% of those in the control group had at most two.
It was discovered that 92 (46.6%) mothers with autistic children didn’t give birth to other children.
It was however observed that 53.1% of autistic mothers (104/196) continued to have children despite having autistic ones.
Literature has mixed results regarding whether autistic children have an impact on the decision to carry another baby (15;16;17).
Hoffmann and colleagues (2014) in the US and Wood (2015) in England demonstrated that mothers with autistic kids did not give birth (16).
Gronborg et. al. (2015) published another study that found autistic mothers in Denmark giving birth to 17 children (17).
Psychosocial consequences of having ASD-related children can influence the decision for the next child.
The decision to have another child was not affected by having an autistic child in the Turkish sample, as we found.
The relationship between gender, type and delivery (C-section or Vaginal) and assisted reproductive methods used for conception was also examined in our study.
The literature does not contain any study results regarding the sex of the autistic child’s first born.
Contradictory findings have been presented regarding the method of birth.
In some studies, Cesarean section was shown to increase the risk for ASD. However it was also highlighted in other studies (31-32;33 and 34).
A retrospective cohort study examined birth records, and found no significant differences between types of delivery and ASD (34).
A different study showed that assisted reproductive methods were one of the risk factors for autism. But another study didn’t show any difference (35,36).
The statistical analysis that included single-child families also revealed significantly higher rates of autistic first-born children among girls, Cesarean sections, forced delivery, and other factors.
These risk factors could not be excluded if single-child family members were excluded.
Our research results support the conclusion that these factors are not associated risk factors for ASD if single-child families have been excluded (6,37).
The study cannot be used to study the community as it does not include children with ASD that have applied to the clinic.
Other limitations include the smaller patient and control groups.
The results of community-based research may show some variability.
Despite having a smaller sample than the patient population, our study was able to compare the parameters of our study, such as the types of deliveries at birth and the number of children in the families, which were our study’s strengths.
Many studies have found a strong correlation between autism and birth order. However, these relationships are not always consistent and sometimes not linear.
It is difficult to understand the relationship between autism and birth order because autistic mothers are not inclined to have more children.
Therefore, it is difficult to evaluate birth order in autism. This is because the mothers may have had twin children with autism or all of their children had autism.
Although studies in this area have shed light on the relationship between autism and birth order and many of these findings, there are not enough data and no systematic evaluations to allow for generalization.
ASD can be explained by looking at the environment. This includes birth order and type.
ASD is complex, multifactorial, and well-known.
ASD can also be caused by environmental factors other than the birth order or genetics.
Compliance with Ethical Standards
The study was approved by the local ethics commission.
This study was approved by the local ethics committee in 2015.
Each participant and their legal representative consented to be included in the study.
Disclosure of Potential Conflicts of Interest
All authors declare that there is no conflict of interests.
Research involving Human Participants and/or Animals
All procedures used in studies that involved human participants were performed in accordance to the ethical standards set forth by the national and/or institutional research committees and with the 1964 Helsinki Declaration and any subsequent amendments.
The study has been approved by the Local Ethics Committee as 2015-30
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