Autism Risks Related to Pregnancy and Birth

How to Reduce the Risk of Autism

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A higher risk of having a child on the autism spectrum is associated with several pregnancy-related issues. Some of these, such as the use of certain pharmaceuticals during pregnancy, can be managed to reduce the risk. Others, however, are difficult, if not impossible, to change.

It’s important to remember that an association is not the same thing as a cause. For example, it's a fact that preterm babies are more likely to have autism than full-term babies, but it's not known exactly why. The reasons may actually relate more to genetics or to socioeconomic factors than to the behaviors of the birth parent.

This article will discuss the pregnancy-related risk factors for autism, with a look at which factors are supported by the most evidence, which have weaker associations, and what you can do to reduce the risk.

Mature pregnant couple in kitchen using laptop

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Established Pregnancy-Related Risk Factors

Multiple well-researched, large studies have found a link between certain pregnancy-related risk factors and autism, and the results have been reproduced in later studies. These risk factors, therefore, are valid, though they raise the risk of autism only slightly. If it’s possible for you to minimize these risks, your likelihood of having a child with autism will be reduced.

Antiepileptic Drugs

Some common antiepileptic drugs, particularly valproate (sold under the brand names Depakene and Depakote), have been shown to increase the risk of autism when taken by the childbearing parent during pregnancy. Valproate, in particular, may raise the risk by as much as 10%.

If you are considering pregnancy, talk with your neurologist about changing or even stopping your medication to reduce the risk of autism.

Older Parents

Quite a few large studies suggest that older parents are significantly more likely to have children with autism. There is some evidence to suggest that this phenomenon is more likely when the male genetic parent is older, though there is some evidence that the age of the childbearing parent is a factor, as well.

It may be helpful to discuss this issue with a doctor if it relates to your situation.

Preterm Birth

A number of studies have found a correlation between preterm birth and autism, as well as other developmental disorders. About 7% of children born preterm have autism, compared with 1%–2% of children in the general population.

A related risk is low birth weight. While there is no way to completely eliminate the risk of early delivery, it is possible to lower that risk. Speak with your doctor if you are at increased risk of delivering early.

Gestational Diabetes

A large study finds that if the birth parent experiences gestational diabetes (diabetes first diagnosed when pregnant) there is a greater-than-average likelihood of having a child with autism. Any form of diabetes mellitus in the birth parent can be a risk factor. Gestational diabetes can’t always be avoided, but it can be carefully managed with the support of a doctor.

Possible Pregnancy-Related Risk Factors

Some risk factors have been researched by well-established individuals under appropriate circumstances, but the findings have not been reproduced enough times to be conclusive. If you have concerns, you’re better off avoiding these possible risks, though it’s not absolutely certain that they will increase your risk of having a child on the autism spectrum.

Taking Tylenol (Acetaminophen) During Pregnancy

Use of Tylenol during pregnancy is very common as it is one of the only pain relievers considered safe during pregnancy. However, there is a growing concern that it may be linked to increased risks for the child, including for neurodevelopmental disorders such as autism and attention deficit hyperactivity disorder (ADHD).

Birth cohort studies in Spain and Denmark found an association between Tylenol use during pregnancy and autism in the child. One smaller study of the umbilical cord blood of children who were later diagnosed with autism or ADHD found that those with more acetaminophen in their pre-birth blood supply were more likely to develop the disorders.

The American College of Obstetricians and Gynecologists (ACOG) does not recommend any changes in how physicians prescribe acetaminophen at this time until more definitive research is done.

Environmental Toxins

Exposure to certain environmental toxins, such as PBDEs (polybrominated diphenyl ethers), PCDDs (polychlorinated dibenzodioxins), PCBs (polychlorinated biphenyls), and BPA (bisphenol A) may increase the risk of autism. While earlier studies found a connection, more recent studies were inconclusive. These are toxins found in certain plastic goods, newly built houses, new carpets, and even some food packaging.

Meta-Analysis Findings

Rather than doing their own unique studies, some researchers take the time to analyze multiple studies on related topics. This allows them to find commonalities among multiple studies and to discover trends and uncover surprises.

These large reviews of studies are called meta-analyses, and several such meta-analyses have looked at research into autism and pregnancy. According to these reviews, the following pregnancy-related issues are associated with autism in more than one study:

  • Autoimmune disease in the birth parent 
  • Infections during pregnancy 
  • Prenatal stress

A single, older meta-analysis uncovered a much longer list of possible pregnancy issues associated with increased risk of autism, including abnormal presentation of the fetus, umbilical cord complications, fetal distress, birth injury or trauma, multiple births, maternal hemorrhage,   
low birth weight, small for gestational age, congenital malformation, and feeding difficulties.

While this list is long, it’s important to remember that many of these issues may appear in a single pregnancy and birth, and are usually associated with premature birth. For example, prenatal stress, congenital malformation, and other issues may lead to an early birth, which is associated with low birth weight.

Premature infants often have issues with feeding. A baby who has low birth weight but is born at full-term and has no other issues may have only a tiny statistically increased risk of autism.

Reducing Risk of Autism During Pregnancy and Birth

Based on the research, there are several steps a birth parent can take to reduce the risk that their child will have autism. They include:

  • Having children after the age of 21 and before the age of 35 and choosing a male genetic parent in the same age range
  • Working with a doctor to choose safer medications for specific issues, such as epilepsy
  • Avoiding activities such as smoking or being around known toxins
  • Making regular prenatal visits to the doctor and following up on any potential physical issues, such as emerging gestational diabetes   
  • Closely following any medical advice regarding bed rest and stress avoidance

According to studies, your baby may also benefit from consistent and appropriate use of specific supplements. Taking supplements such as folate (folic acid), omega-3s, and vitamin D3, correcting vitamin deficiencies, boosting your immune system, and prolonging breastfeeding are all mentioned in research findings as possible ways to reduce the risk of autism (though, of course, they can't eliminate the risk altogether).

Summary

Determining pregnancy-related risk factors for autism is an ongoing area of research. Some risk factors have more evidence of an association than others. Taking certain antiepileptic drugs, being older parents, having a preterm birth, and developing gestational diabetes are believed to be risk factors. Possible risk factors include environmental toxins and taking Tylenol during pregnancy.

A Word From Verywell

Every pregnancy is unique, and it is impossible to avoid all potential risks to your baby. Simple measures can, however, decrease risks for many conditions.

At the same time, it’s important to remember that autism is known to have a strong connection to genetics. If you or your partner has autism or you have family members on the spectrum, your risk of having a child with autism increases no matter how carefully you manage your pregnancy.

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17 Sources
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  1. Wiggs KK, Rickert ME, Sujan AC, Quinn PD, Larsson H, Lichtenstein P, Oberg AS, D'Onofrio BM. Antiseizure medication use during pregnancy and risk of ASD and ADHD in children. Neurology. 2020 Dec 15;95(24):e3232-e3240. doi:10.1212/WNL.0000000000010993

  2. Sandin S, Schendel D, Magnusson P, Hultman C, et. al. Autism risk associated with parental age and with increasing difference in age between the parents. Mol Psychiatry. 2016 May;21(5):693-700. doi:10.1038/mp.2015.70

  3. Agrawal S, Rao SC, Bulsara MK, Patole SK. Prevalence of autism spectrum disorder in preterm infants: A meta-analysis. Pediatrics. 2018 Sep;142(3):e20180134. doi:10.1542/peds.2018-0134

  4. Rowland J, Wilson CA. The association between gestational diabetes and ASD and ADHD: a systematic review and meta-analysis. Sci Rep. 2021 Mar 4;11(1):5136. doi:10.1038/s41598-021-84573-3

  5. Xu G, Jing J, Bowers K, Liu B, Bao W. Maternal diabetes and the risk of autism spectrum disorders in the offspring: a systematic review and meta-analysis. J Autism Dev Disord. 2014 Apr;44(4):766-75. doi:10.1007/s10803-013-1928-2

  6. Bauer AZ, Swan SH, Kriebel D, Liew Z, Taylor HS, Bornehag CG, Andrade AM, Olsen J, Jensen RH, Mitchell RT, Skakkebaek NE, Jégou B, Kristensen DM. Paracetamol use during pregnancy - a call for precautionary action. Nat Rev Endocrinol. 2021 Sep 23. doi:10.1038/s41574-021-00553-7

  7. Avella-Garcia CB, Julvez J, Fortuny J, Rebordosa C, García-Esteban R, Galán IR, Tardón A, Rodríguez-Bernal CL, Iñiguez C, Andiarena A, Santa-Marina L, Sunyer J. Acetaminophen use in pregnancy and neurodevelopment: attention function and autism spectrum symptoms. Int J Epidemiol. 2016 Dec 1;45(6):1987-1996. doi:10.1093/ije/dyw115

  8. Liew Z, Ritz B, Virk J, Olsen J. Maternal use of acetaminophen during pregnancy and risk of autism spectrum disorders in childhood: A Danish national birth cohort study. Autism Res. 2016 Sep;9(9):951-8. doi:10.1002/aur.1591

  9. Ji Y, et al. Association of cord plasma biomarkers of in utero acetaminophen exposure with risk of attention deficit/hyperactivity disorder and autism spectrum disorder in childhoodJAMA Psychiatry. 2020 Feb 1;77(2):180-189. doi:10.1001/jamapsychiatry.2019.3259

  10. American College of Obstetricians and Gynecologists. ACOG response to consensus statement on paracetamol use during pregnancy. September 29, 2021.

  11. Marí-Bauset S, Donat-Vargas C, Llópis-González A, et al. Endocrine disruptors and autism spectrum disorder in pregnancy: A review and evaluation of the quality of the epidemiological evidenceChildren (Basel). 2018;5(12):157. doi:10.3390/children5120157

  12. Chen SW, Zhong XS, Jiang LN, Zheng XY, Xiong YQ, Ma SJ, Qiu M, Huo ST, Ge J, Chen Q. Maternal autoimmune diseases and the risk of autism spectrum disorders in offspring: A systematic review and meta-analysis. Behav Brain Res. 2016 Jan 1;296:61-69. doi:10.1016/j.bbr.2015.08.035

  13. Jiang HY, Xu LL, Shao L, et al. Maternal infection during pregnancy and risk of autism spectrum disorders: A systematic review and meta-analysis. Brain Behav Immun. 2016 Nov;58:165-172. doi:10.1016/j.bbi.2016.06.005

  14. Varcin KJ, Alvares GA, Uljarević M, Whitehouse AJO. Prenatal maternal stress events and phenotypic outcomes in autism spectrum disorder. Autism Res. 2017 Nov;10(11):1866-1877. doi:10.1002/aur.1830

  15. Gardener H, Spiegelman D, Buka SL. Prenatal risk factors for autism: comprehensive meta-analysis. Br J Psychiatry. 2009 Jul;195(1):7-14. doi:10.1192/bjp.bp.108.051672

  16. Levine SZ, Kodesh A, Viktorin A, Smith L, Uher R, Reichenberg A, Sandin S. Association of maternal use of folic acid and multivitamin supplements in the periods before and during pregnancy with the risk of autism spectrum disorder in offspring. JAMA Psychiatry. 2018 Feb 1;75(2):176-184. doi:10.1001/jamapsychiatry.2017.4050

  17. Schmidt RJ, Iosif AM, Guerrero Angel E, Ozonoff S. Association of maternal prenatal vitamin use with risk for autism spectrum disorder recurrence in young siblings. JAMA Psychiatry. 2019 Apr 1;76(4):391-398. doi:10.1001/jamapsychiatry.2018.3901