Discuss the Birth Order and Reproductive Stoppage of Children with ASD.
This study was designed to examine the relationship between the birth order and delivery methods of children with Autism Spectrum Disorder (ASD) and their siblings (families of ASD children in the study), as well as the phenomenon of reproductive stopping and the number and percentage of siblings in each case family (families of ASD children in the study), and determine if ASD incidence is related to delivery method.
Materials and Methods
The study included 196 ASD participants and 54 non-autistic children.
The median age was 56.9 months (SD 27.1 month; median: 51), for ASD children and 55.7 months for control children (SD 13.8 mois; median: 54).
Demographic data was also collected.
ASD cases were identified using the Autism Behaviour Checklist, Aberrant Behaviour Checklist and Childhood Autism Rating Scale.
Based on the type and purpose of the assessment, Mann Whitney U Test (Chi-square Test) and Spearman Tests were used to perform statistical analysis.
A statistically significant value was defined as a p value less than 0.05.
The rate of forced labor births in this study group of ASD children was significantly higher than the control group (p=0.001).
The statistical analysis of the rate at which reproductive stoppage occurred for families with one child was not statistically significant (p0.001).
The type of birth and the order of birth (CS, normal, or forced labor) can all be used to help understand ASD.
DSM-5 diagnoses Autism Spectrum Disorder (ASD), which is characterized by impaired social interaction and communication, along with restricted interest or repetitive behaviors, as well as impairment in communication and social interactions.
ASD prevalence is between 0.9 and 2.7%. It has been increasing in the last 20 years (1;2).
Clinical and epidemiological studies show that autism is 5-5 times more common among boys (3).
Although ASD appears to have a genetic basis, there are many things that can be done to understand the mechanisms and processes involved.
A role in ASD’s etiopathogenesis has also been played by prenatal exposure to certain environmental stimuli (5).
These factors include advanced maternal and paternal ages, parity, birth orders, and obstetric-related issues such as bleeding, preeclampsia and prolonged labor. Pre and post maturity, birth weight and low Apgar scores have all been studied.
Birth order studies in psychiatric disorders continue to be popular, but there have not been any definitive results, particularly if there is an association between autism or birth order (5;10,11).
Some studies claim that ASD is present in the first child. However, these results are disputed.
Some reports point out a negative correlation (11), or a positive correlation (12-13;14), between ASD and birth order, while others report that there is no relationship between ASD and birth order (5).
A phenomenon where parents of a severely ill child have fewer children or stop reproducing is called Stoppage.
Many studies have shown that having an autistic child can affect the decision of case families to carry out their next pregnancy.
There are many studies that show the presence of an autistic child can affect the decision to have a baby. However, other studies report contradictory results.
Hoffmann et.al. (2015) and Wood (2016) reported that ASD can cause reproductive stoppage. However, Gronborg et.al. (2017) found contradictory results (15-16-17).
The study aimed to improve the knowledge base on this topic. It compared the birth orders and number of siblings for children with ASD to those in the non-autistic control group.
ASD’s risk factors were also examined. This included the possible roles of parental age, educational level, delivery method, and associated reproductive techniques. The assessment of siblings and birth orders was also done.
We also assessed the impact of having an autistic child on decisions regarding subsequent pregnancies and if it causes a reproductive stoppage.
The study included 196 children who were diagnosed with ASD at our clinic using the DSM 5 criteria. They were born between January 2015 and January 2016.
Two psychiatrists who specialize in child and adolescent psychotherapy and psychiatric exam made the diagnosis.
The primary caregiver was asked to provide information and a family history.
The primary caregivers of ASD children were given the Autism Behavior Checklist and Aberrant Behavior Checklist.
A second scale, the Childhood Autism Rating Scale (CARS), was administered by a child and adolescent psychiatrist (22).
The study excluded autistics who had been diagnosed with chronic illnesses or were suffering from malignancies.
The control group included 54 children with ASD who came to the pediatric outpatient clinic to receive vaccinations. Their ages and genders were matched with the study group.
The primary caregiver was asked for information and a family history.
The parameters to be studied were maternal and paternal ages, their education levels, number of siblings and patient ages, birth order, type and method of delivery at birth, assisted reproduction techniques, and the effect of being the first-born and having ASD on the reproductive behavior of case families.
IBM SPSS Statistics for Windows version 17.0 was used to perform statistical analysis.
Continuous variables were defined by means and standard deviations (SD) for all continuous variables, while categorical variables were analyzed using frequencies and percentages.
Non-parametric equivalents of Student-T or Mann Whitney U tests and Pearson chi square test were used to compare the results.
A statistically significant value was defined as a ‘p’ value below ‘0.05.
The local ethics committee approved the study.
All participants and their legal representative gave informed consent.
After a child was diagnosed with ASD, the rate of child birth was used to determine if there was a reproductive stoppage.
The study was limited in its ability to determine if the families that were analyzed as having reached a reproductive endpoint had had children beyond the time frame of the study.
Future observations of these families can be used to extend the study to determine if they are still in reproductive cessation.
The study included 250 participants from Turkey. These included 54 children who were not affected by ASD and 196 with ASD.
The median age of ASD children was 56.9 months, with a SD 27.1 months and median at 51 respectively. 55.7 months (SD 13.8months; median: 54) and 55.7 months (55.7 months (SD 13.8months; median: 54), were the mean ages of ASD children and controls.
P Value (Claculated Probability), Hypothesis Testing, and Chi Square Test revealed that there were no significant differences between the two age groups (p>0.05).
Although the maternal and paternal ages for children with ASD were higher than those of controls (Table 1), there was no statistical significance (p>0.05).
The ASD group had 163 ASD children (83.2%) who were both males, and 33 ASD children (16.8%) who were females.
The healthy control group had 47 (%85.1) males and 7 (%14.9) females.
The gender differences between the two groups were not significant (p>0.05).
Children with ASD had similar rates of spontaneous vaginal delivery (C-section), compared to the controls (p>0.05).
The rates of assisted reproductive methods (including in vitro fertilation) were comparable between the two groups (p>0.05).
The ASD group had significantly more labor difficulties (prolonged labor, vaginal delivery, forceps-assisted vaginal birth) than the controls (21.4% and 3.7% respectively; p=0.002) (Table 1).
According to their birth order, 63.3% of ASD children with autism were first-born (n=124), 26.0% were second-born (n=51), 7.7% (n=15), 2.6% (n=5) and 0.5% were fifth-born (X2=15.729; p=0.003).
These children were not included in the analysis because there were no children born to the control group as the fourth or fifth child.
After removing children from the fourth and fifth birth orders, statistical significance was found for the ASD group being the first-born child (x2=13.792, P=0.001).
After excluding one-child families (n=214), the statistical significance of evaluation of being the first child in ASD group (n=170), was determined. This compares to controls (n=44), with a rate at 57.6% (98/170), and 27.3% (12/44), respectively. (Chi Square Test=18.727; p=0.000). (Table 3).
Birth Order Demographics
The association between gender and birth order was statistically higher in ASD children than in the control group. (Chi Square Test=14.338; p=0.002).
The C-section group had a higher proportion of ASD children than the control (Chi Square Test=8.035; p=0.032).
The percentage of first-born babies in the ASD group who were delivered by vacuum-forceps or after prolonged labor was significantly higher than the control group (Chi Square Test=9.429; p=0.024; Table 4).
After excluding one-child families (n=36), the data analysis showed that ASD development in the first child was not dependent on gender or type delivery at birth.
After controlling for one-child families, we found no relationship between SC and the development of ASD in the first-born child. However, a significant relationship (p=.0.85) was observed in forced (vacuum-prolonged) labour.
All participants had a 14.4% chance of having one child (36/250).
The ASD group saw 13.3% of the families have one child (26/196), while the control group saw 18.5% of the families having one child (10/54) which is statistically insignificant.
Table 6 shows that the ASD children had 86.7% (n=170), compared to the 81.5%(n=44) rate for the control group.
Table 7 excludes single-child families (n=36), and families whose last child had ASD.
According to statistical analysis, 100.0% (n=87), of mothers whose first child was diagnosed with ASD gave birth to their second child. (X2=15.250; p=0.000).
100.0% (n=9) mothers whose first child was diagnosed as having ASD gave birth in three-child families to other children.
14.3% (n=4) mothers gave birth to their second child with ASD when they were examined.
Families with four children saw 100.0% (n=2) mothers whose first child was diagnosed with ASD and 22.2% (2n=2) mothers whose second child had ASD give birth to children in the family.
In recent years, many diseases etiologies have investigated the birth order. This is the order in which the individual’s siblings arrived.
The literature has provided a variety of results and interpretations regarding the relationship between ASD and birth order.
The ASD group was compared to controls in terms birth order. Our study showed a significant difference in ASD being the first-born child.
A review of the research in this area revealed that ASD was not associated with maternal age or birth order.
Other studies showed a higher incidence of ASD among children born through forced labor than those who were not.
These results are consistent with the findings of previous studies.
According to some reports, the baby is more likely to be exposed to congenital complications and birth canal stress during first labor. This could lead to brain damage (24-25).
Our study found that the ASD group had a higher rate of labor difficulties than the control group.
These findings, which include the higher rates for being first-born and the higher rates in ASD of difficult labors, suggest that children born through forced labor might be more susceptible to perinatal stress. This may play a role in ASD etiopathogenesis.
The potential role of paternal or maternal age in ASD is not clear.
A group of ASD cases found that the likelihood of their third child developing autism was three times higher in those whose mothers were aged between 20 and 34 and their fathers were under 40.
Another study compared the maternal age and the order of birth in 113 families with ASD children to the general population.
There was no correlation in birth order for the ASD group.
The population sample (26 and 27) showed more autistic children from risky pregnancies (including those with first, fourth, or later births).
The study designs reveal some limitations, such as insufficient diagnostic tools and inadequate selection of the control group. Also, the lack of identification of birth types at birth is not possible.
Our study showed that the paternal and maternal ages were significantly higher in the ASD group. However, this difference was not statistically significant.
This finding supports other studies that have shown that autistic children are not at risk from their parents’ age.
It is important to note that ASD can be caused by the fact that autistic children may have their parents stop having children because of their age.
It is important to understand the risk of ASD if parents are older than their children.
Race might also be associated with ASD diagnosis and reproductive pattern, as could poor pregnancy outcomes such as preeclampsia or preterm birth.
Our study found no statistically significant differences in birth order, sibling numbers, and CARS, ABC and AbBC scores for autistic children.
One study that included sixteen families and a small sample showed that the non-verbal IQ scores declined as more births were recorded (28).
A second study, which included 121 families, showed significant increases in repetitive behavior and speech difficulties in the first and third children with ASD (29).
The same study found a negative correlation between intelligence level and birth order in autism-afflicted children.
Similar studies showed that autistic children who were born first or second were more likely to have difficulties communicating verbally and non-verbally. Additionally, autism symptoms were more severe among those children (30).
Similar patterns and limitations are evident in these studies, including the inadequacy and selection of ASD-positive children among those who present to clinic.
Although our results were not comparable to those in the literature, they are believed to reflect cultural variability.
The autism group had 86.7% (n=170), while the control group had 81.5%(n=44). Both groups had at least one sibling.
It was found that 46.9% of autistic mothers did not have other children.
It was found that 53.1% (104/196) mothers who had autistic children gave birth to other babies.
The literature does not support the idea that autistic children can affect the decision to have another child (15,16,17).
Hoffmann et. al. (2014) in the US and Wood et. al. (2015) in England showed that autistic mothers did not have other children (15-16).
Gronborg and colleagues (2015) found that autistic mothers in Denmark continued to have children (17).
The psychological and social implications of having ASD children may influence the decision to have another child.
Our study found that the decision to have a Turkish child with autism did not change the outcome of the next pregnancy.
We also looked at the relationship between gender, delivery method (C-section or vaginal), assisted reproductive techniques and the methods used to conceive in the study groups.
There are no published studies on the sex of the autism-first child.
There have been contradictory results regarding the method of delivery.
Some studies highlighted that Cesarean sections increase the risk of ASD. However, other studies reported lower rates (31,32,33;34).
A retrospective cohort study analyzed birth records and concluded that there was no difference in ASD between different types of delivery (34).
Another study found that assisted reproductive techniques were one of the risk factors in autism development. However, another study did not report any significant differences (35;36).
Our study revealed that first-born autistic children had significantly higher rates in girls born to single-child families.
These factors were not associated with ASD when single-child families were removed.
These factors do not appear to be associated with ASD, as evidenced by our research (6;37).
Our study is not community-based because the sample of children with ASD who applied to the clinic are included. There are also limitations.
Another limitation is that the control group is smaller than the patient group.
Community-based studies can show variability, however.
Our study had a control group. Despite the smaller sample size than the patient group, our comparative analysis of parameters, including the type and number of births, and the one-child families to our control group is one of our strengths.
While a lot of studies have shown a strong relationship between autism and birth order, the relationship is often inconsistent and not linear.
This is because the mother of autistic children may not want to have another child.
The evaluation of birth order in autism is naturally difficult when the mothers have twins with autism or all their children have autism.
Although there have been studies in this area that show a link between autism and birth order, it is difficult to generalize the findings due to the small sample sizes and absence of systematic evaluations.
ASD can be understood by considering the order and type births as one of many environmental factors.
As it is well-known, ASD is complex and multifactorial in its etiology.
ASD can be caused by environmental interactions, other than genetics and birth order.
Respect for Ethical Standards
Study approval was received from the local ethics committee.
The local ethics committee approval was obtained for the study in 2015-30.
All participants, as well as their legal representatives, gave consent to the study.
Disclosure of potential conflicts of interest:
All authors declare they have no conflict of interest.
Researchers who involve humans and/or animals in research:
All procedures in human participant studies were conducted in compliance with the ethical standards of the institution and/or national committees, and the 1964 Helsinki declaration or similar ethical standards.
This study was approved by the local ethics committee in 2015.
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