Long-term Memory of Sensory Experiences from the First Pregnancy, its Peri-partum and Post-partum in Women with Autism Spectrum Disorders without Intellectual Disabilities: A Retrospective Study

One of the key diagnostic criteria of Autism Spectrum Disorders (ASD) is the presence of anomalies in the perception and processing of sensory stimuli, in terms of both hyper- and hypo-responsiveness (accounting for, respectively, a lower and a higher sensory threshold for sensory perception) (Crane et al., 2009 DSM-5-TR, 2021). It is estimated that atypical sensory experiences occur in about 90% of individuals with a diagnosis of ASD, both children (Mukherjee, 2017) and adults (Tavassoli & Baron-Cohen, 2012). Moreover, it has been shown that perceptual abnormalities predict the severity of autistic traits, such as the difficulties in social interactions (Mayer, 2017).

In the last decades, the traditional focus on autism in male children has been evolving: there is now a wider acknowledgement that females also exhibit ASD, that children with autism grow into adults with autism (Howlin et al., 2004; Whiteley et al., 2021) and that, of course, women with ASD can also become mothers. However, very little is known about how women with ASD experience pregnancy and motherhood, and on how alterations in sensory perception impact the woman’s well-being (e.g., potential challenges in dealing with changes in their own body, or with the sensory and proprioceptive exchanges that partly characterize the relationship with the newborn). In fact, the research on maternal mental health in the autism field was negatively impacted by the so-called “refrigerator mother theory”, proposed in the mid-20th century, suggesting that autism in children was primarily caused by emotionally distant and cold parenting, particularly by mothers. This theory had significant negative consequences for families of children with ASD: parents, particularly mothers, were wrongly blamed, and severely subjected to shame and stigma; many mothers faced immense emotional distress and social isolation. Over time, this theory has widely been criticized and discredited, and contemporary research (including studies in genetics, neuroimaging, and psychology of development) has firmly established that autism is a complex multi-factorial neuropsychiatric condition. However, this theory has had significant consequences both on women’s wellbeing and on the research on maternal mental health. For example, the fear of being labeled as “refrigerator mothers” might have discouraged mothers from seeking help and/or support for any psychological challenges they faced during pregnancy and motherhood. From a clinical perspective, the focus on maternal mental well-being may have been neglected as, instead, the emphasis was placed on maternal behavior (as a supposed cause of developmental disorders in children). From a societal perspective, the enduring legacy of the harmful notions of the “refrigerator mother theory” may have delayed the broader recognition of maternal mental health during pregnancy and motherhood as a critical aspect of overall well-being. Today, there is a greater recognition of the importance of supporting maternal well-being during pregnancy and motherhood; however, it is crucial to acknowledge that this progress is still ongoing, and challenges related to maternal mental health are still present in many societies. Moreover, within numerous cultures where a persistent misogynistic perspective prevails, a strong anticipation for women to predominantly embody the roles of mothers and wives exists, consequently assigning higher importance to these emotional bonds. In the case of women with ASD, the inherent challenges of the condition may hinder their ability to meet these societal expectations, potentially leading to profound psychological distress and subjecting them to societal prejudices (Rynkiewicz et al., 2018). Hampton et al. (2022) assessed psychopathological symptoms (stress, depression, anxiety) and satisfaction with life in women with and without ASD across several time-points: once during the third trimester of pregnancy, once 2 to 3 months after giving birth, and once 6 months after giving birth. They found that mothers with ASD always scored significantly higher than neurotypical mothers on stress, depression, and anxiety scales although, for both groups, scores for anxiety went down over time. There were no differences between the groups on satisfaction with their life, in their confidence in parenting, and in most areas of parenting style; these results led the author to conclude, on one hand, that parents with autism need proper support during pregnancy and parenthood, and, on the other hand, that neurotypical and neuroatypical parents are equally likely to parent in positive ways, such as being sensitive to their baby’s needs. Hampton et al.’s results about mental health of mothers with ASD are in line with Pohl and colleagues’ (2020) findings, who conducted a comparative study of autistic and non-autistic experiences of motherhood; they found that: (i) mothers with ASD had a higher prevalence of psychiatric comorbidities, including pre- or post-partum depression; (ii) they reported greater difficulties in multi-tasking, in coping with domestic responsibilities and in creating social opportunities for their children; (iii) they reported a greater anxiety and a more frequent feeling of being misunderstood by professionals; (iv) they were more likely to find motherhood an isolating experience, to worry about others judging their parenting, and to feel unable to turn to others for support in parenting. Finally, Grant and colleagues (2022) conducted a systematic review about the experiences of mothers with ASD in infant feeding, and found that, although many women wanted to breastfeed, only a minority of them reported positive breastfeeding occurrences. In particular, the authors highlighted that sensory challenges, pain, and interoceptive differences were one of the main reasons that made breastfeeding impossible, together with unsupportive maternity and infant feeding services and with exhaustion, loss of control over routines and a lack of social support. Overall, this preliminary evidence underscores the significance of further exploring the challenges that neuroatypical mothers might encounter, to ultimately tailor maternity and infant feeding services to address potential specific need. In fact, the choice to embrace pregnancy and motherhood should be a deeply personal decision, and every pregnant woman deserves tailored support that respects her individual needs and circumstances. The results of this study will serve to enhance our understanding of maternity within the context of ASD in the absence of blame and stigma. These insights will be used to design and improve therapeutic approaches that empower and support mothers with ASD throughout their journey into motherhood, ensuring their well-being and the well-being of their children.

The aim of the present study was to retrospectively investigate the experience of pregnancy and motherhood in women diagnosed with ASD without intellectual disabilities. The results emerging from this investigation are aimed to enhance our comprehension of maternity within the context of ASD, in order to design tailored therapeutic approaches that support mothers with ASD throughout their journey into motherhood, ensuring their well-being.

We assessed the recollections of a group of mothers with ASD and a group of neurotypical mothers (comparison group) about the sensory perception that they experienced during the pregnancy of their first child, focusing on three specific time-points: the pre-partum, the peri-partum, and the post-partum; we also investigated their memories about their mood, with a specific focus on depressive symptoms of the post-partum period.

First, we found that women with ASD recalled an averagely higher sensory sensitivity than women in the comparison group, across the three time-points retrospectively assessed. This was demonstrated both by higher scores on the Maternity Questionnaire and by lower scores at the SPQ-SF35, which indicates that women with ASD reported a lower sensory threshold (and thus a higher sensory sensitivity) than the comparison group. This result is not surprising: it is already well-known in the literature (Tavassoli & Baron-Cohen, 2012) and represented in the DSM-5-TR criteria for ASD diagnosis (American Psychiatric Association, 2021) that adults with ASD have a hyper-responsiveness to external sensory stimuli compared to neurotypical adults. Moreover, the literature on gender differences with respect to this topic is growing: Grant and colleagues (2022) conducted an observational study on a group of ASD individuals investigating the incidence of the Central Sensitivity Syndrome (CSS - a group of related conditions that are thought to include an underlying sensitization of the central nervous system, in which heightened sensory sensitivity is a common feature): they found this diagnosis to be very common in people with ASD and, in particular, that women with ASD were more likely to report a CSS diagnosis and to experience more CSS symptoms, with respect to men with ASD. However, the research about the experience of pregnant women with ASD, with a particular focus on sensory sensitivity and issues related to body changes, is still in its infancy: it has been shown that sensory challenges contributed to discomfort, distress, or anxiety in many women with ASD, and in some cases had a significant impact on the individuals’ ability to communicate with others (Rogers et al., 2017; Samuel et al., 2022; Talcer et al., 2023). In this study, we made a step forward by finding that the trend of recalled sensory sensitivity levels across the three time-points assessed differs between neurotypical and neuroatypical women. In particular, in our comparison group, sensory sensitivity was reported as significantly higher during pregnancy with respect to peripartum and post-partum: this result is in line with previous studies showing that changes in sensory perception during pregnancy in neurotypical women are commonly experienced (an abnormal smell and/or taste perception (Nordin et al., 2004), a modification in cutaneous sensitivity (Ruggieri et al., 1979), and in hearing threshold levels (Kwatra et al., 2021) were reported). On the other hand, within the group of mothers with ASD, sensitivity is recalled as significantly decreased from pregnancy to peripartum (seemingly getting closer to the levels reported by neurotypical women) but, in the post-partum period, it is reported as high as during pregnancy (Fig. 1). Hence, further considerations on both the moment of childbirth and its long-term recollection are needed.

Although it varies for each woman, the experience of delivery is generally painful due to uterine contractions, which are mediated by the release of oxytocin, a key hormone in labor and lactation. It might be speculated that the lower sensory sensitivity that we found during the peri-partum might be associated with the release of oxytocin itself. The role of oxytocin in ASD has been widely studied in the last decade: Quattrocki and Friston (2014), in a comprehensive review, underlined that it seems to play a role in sensory attenuation (including proprioceptive and interoceptive signals), and suggested that people with ASD might suffer of a developmental neuromodulatory deficit in oxytocin. Moreover, thanks to its to receptors distributed in various brain regions (including the limbic system), oxytocin also works as a neurotransmitter, involved in the regulation of emotions (Huber, 2005), and acts as a mediator of several social behaviours involved in forming attachments, ultimately being branded as a “social hormone”. For this reason, this neurotransmitter has been also suggested as a possible therapy to improve social performances in individuals with ASD without intellectual disabilities (Hollander et al., 2007; Andari et al., 2010; Anagnostu et al., 2012; Watanabe et al., 2015; Yamasue, 2016; Demartini et al., 2021). Our results might be interpreted in this framework, and we could speculate that oxytocin plays a role in modulating (and, more specifically, decreasing) the hypersensitivity typical of people with ASD, ultimately determining a better well-being of the individual and therefore a greater predisposition to social interaction.

With respect to the role of memory in our investigation, several studies recently assessed neurotypical women’s recollections of their childbirth experiences, up to five years postpartum. Takehara et al. (2014) conducted a prospective cohort study assessing the childbirth experience of 1168 women in Japan at a few days postpartum and 5 years later; they concluded that, averagely, women still remember their childbirth experience clearly at 5 years after the childbirth. On the other hand, Norvell et al. (1987) questioned the reliability and validity of the retrospective assessment of labor pain, that we did not directly assess in our study. Although it is a grueling experience for mothers, it seems that, in recall, labor pain is underreported; in fact, Waldenström et al. (2009) demonstrated that neurotypical Swedish women show a significant decrease in the ratings of their labor pain when investigated 2 months, 1 year, and 5 years after childbirth. The authors concluded that in-labor pain and long-term memory of pain should be discussed as two separate outcomes, involving different memory systems. Again, according to Farley et al. (2019) this could be due to oxytocin, when physiologically released at the time of birth since its action on the central nucleus of the amygdala can modulate the memory of pain in a more favorable light. It could therefore be hypothesized that this mechanism also acts on the hypersensitivity of autistic women during childbirth: exactly as for pain, the release of oxytocin could decrease its intensity in memory; hence, our results would not represent an actual decrease in hypersensitivity, but only an underestimation of their intensity in women’s memory (which, indeed, occurs also in our comparison group). Overall, while it is possible that autistic mothers have a different moment-by-moment experience with childbirth and the post-partum period, it cannot be excluded the possibility that they have different ways of encoding and storing long-term memories of those experiences. Moreover, our results can be attributed to various environmental, cognitive, and psychological factors: given the increased attention towards one’s own body during pregnancy, mothers may have reported a heightened recall of sensitivity pre-partum; given the intense nature of labor, the recollection of sensitivity to external stimuli might be less vivid due to their lower low salience; finally, the changes in each own’s routine during the post-partum might have had a different impact on neurotypical and neuroatypical mother, ultimately influencing their experience and their recall of sensory perception. Hence, further studies are needed to better understand the potential mechanism behind our findings.

Finally, we found that mothers with ASD scored significantly higher than neurotypical mothers at the RAADS-R (confirming the ASD diagnosis) and lower at the SPQ-SF35 (confirming their hypersensitivity). Through correlational analysis, we found that the presence of higher autistic traits was associated with a higher symptomatology suggestive of post-partum depressed mood. These findings provide additional evidence supporting the necessity of investing in the development of targeted therapeutic approaches aimed at offering a significant and ongoing support to mothers with ASD during pregnancy and motherhood overall, with proper attention to the mothers’ wellbeing.

The main limitation of this study lays in its retrospective nature: the entire assessment relied on participants’ self-reported long-term memories, and not on a direct evaluation of sensory perceptions during pregnancy and the post-partum period.

Furthermore, mothers with ASD had, on average, a higher age than those in the comparison group. As a result, their memories of their first child extended further back in time, as indicated by the variable “Latency”. It’s worth noting that while this age difference was statistically significant, it was relatively small, amounting to only five years; most importantly, this difference in the length of recall did not have a statistically significant impact on our results. Moreover, we focused only on the first pregnancy, and it must be noted that the recall of potential subsequent pregnancies (that not all women in our sample experienced) might have influenced our results. We did not examine the experience of breastfeeding, which is known to significantly affect women’s well-being and their bonding with the newborn: hence, it should be investigated in a future study. Of note, the majority of the women in our sample in both groups were unemployed, and we did not investigate whether it was a personal choice, or if it was dictated by potential difficulties in finding a job; this might have had an impact on the mood of each participant at the time of the interview. Finally, it should be noted that the “Maternity Questionnaire” was designed specifically for the study, thus, it lacks statistical validation and normative data.

Future prospective research, recruiting pregnant women before childbirth and tracking their ratings about sensory sensitivity and mood for up to five years postpartum, is firmly needed to gain a better understanding of women’s experiences, and to determine whether our results stem from the initial experiences themselves or from how those early experiences are encoded as long-term memories.

In conclusion, mothers with ASD seem to recall the sensory experience during pregnancy, childbirth, and the post-partum period differently from neurotypical mothers, particularly in terms of hypersensitivity, although during the peri-partum the hypersensitivity is recalled as decreased. Our results might help in designing specific therapeutic approaches to provide a proper support to mothers with ASD during pregnancy and motherhood overall, and to build awareness (both in the medical staff and in the general population) about the enhanced efforts that women with ASD might experience in this delicate period of life.