Half of new parents have unwanted, intrusive thoughts of harming their infants. Research suggests most aren’t dangerous.

Imagine you are standing near the railing of a seventh-floor balcony with your infant in your arms when a sudden thought crosses your mind: you could drop your baby over the edge. How does that make you feel? What are you likely to do?

Now imagine you see your baby lying on his play mat on the floor, and you have a sudden image of stepping on them on purpose. Are you worried you are unwell? A bad parent or, worse, a dangerous one? This is the experience of many new parents.

Our research with colleagues has found that 99 per cent of new birthing parents (mothers and birthing parents of other genders) have some unwanted, intrusive thoughts of accidental harm coming to their newborn infant. Approximately 50 per cent experience some unwanted, intrusive thoughts of harming their infant on purpose.

Unwanted, intrusive thoughts are those that pop into a person’s mind unexpectedly. They are a common human experience. Almost everyone (about 95 per cent) has occasional unwanted, intrusive thoughts that they find morally repugnant because the content of the thoughts goes against their wishes, values and beliefs90008-Q).

These kinds of thoughts are more common when we’re stressed, and they typically reflect what preoccupies us, what we’re afraid of and what we most want to avoid.

Does this sound like new parents? They are stressed, preoccupied with their baby and strongly motivated to keep their infant safe.

Thinking about harm is not doing it

The thing most people worry about is whether unwanted, intrusive thoughts of infant-related harm signal a risk to the baby’s safety — the possibility that the parent might act on these thoughts.

My lab, the Perinatal Anxiety Research Lab (PARLab) at the University of British Columbia, has conducted the only two studies addressing this question. Across both studies, parents who reported unwanted, intrusive thoughts of harming their infant on purpose were no more likely to engage in physical aggression toward their infant than parents who did not report these thoughts.

It has long been accepted among obsessive-compulsive disorder (OCD) researchers and clinicians that neither unwanted, intrusive thoughts nor obsessions in OCD (thoughts that become distressing, which the person tries to get rid of) are a risk factor for violence.

More work needs to be done to confirm this fully, but OCD experts generally agree that when an unwanted, intrusive thought is inconsistent with a person’s values, wishes and beliefs, the person is not at risk of acting on it. Usually the opposite is true: they are highly motivated to avoid it.

Delusions and voices versus intrusive thoughts

What about when parents do harm their infants?

Postpartum psychosis and thoughts of harming one’s infant have recently attracted a lot of attention because of the Lindsay Clancy trial and the tragic deaths of her children. To understand, however, why these thoughts can be dangerous in postpartum psychosis — but not when they’re unwanted, intrusive ones — it helps to know a few things about the condition.

Postpartum psychosis affects approximately one to two out of every 1,000 birthing parents01536-7/fulltext). That is in stark contrast with unwanted, intrusive thoughts of infant-related intentional harm, which are reported by 500 or more per 1,000 birthing parents.

Most cases of postpartum psychosis — about 75 per cent — occur in parents with bipolar disorder. It typically falls within the bipolar spectrum, though it can also present as psychotic depression or, rarely, a schizophrenia-spectrum disorder. Birthing parents with bipolar disorder face a particularly high risk, as do those with a close family member who has experienced postpartum psychosis.

So how do thoughts of intentional harm in postpartum psychosis differ from unwanted, intrusive thoughts?

It’s important to note first that thoughts of infanticide in postpartum psychosis are actually relatively uncommon. They occur in roughly eight per cent of cases, and infanticide is rare, at one to 4.5 per cent of cases.

In postpartum psychosis, thoughts of harming an infant may be connected to delusions in which the parent believes that harming the infant is necessary or justified — for example, a belief that the infant is possessed or in danger, and that harming them is the only way to protect or save them. This is distinct from the unwanted, intrusive thoughts of postpartum obsessive-compulsive disorder, which the parent does not want to act on.

A person with postpartum psychosis may also hear voices commanding them to harm their infant, experienced as coming from outside themselves rather than as their own thought.

Unwanted, intrusive thoughts, by contrast, are typically experienced as distressing and confusing (“I love my baby so much. Why would I have a thought of hurting her?”). Additionally, they are experienced as a product of one’s own mind, not an external voice.

Why parents are afraid to tell anyone

Unfortunately, this isn’t widely known, and the consequences for new parents can be serious.

Many health-care professionals are poorly informed about unwanted, intrusive thoughts and obsessive-compulsive disorder. As a result, they may treat all infant-harming thoughts as a risk factor for abuse, and respond to parents who disclose these kinds of thoughts with steps meant to increase infant safety, like contacting child protective services.

These actions are important when they’re needed, but when they’re not — when the thoughts are unwanted, intrusive ones, not a sign of danger — they can cause parents significant distress, and even increase their risk of developing OCD.

Parents also often don’t know about unwanted, intrusive thoughts of infant-related harm. When the thoughts occur, they’re frightened by them and afraid to tell anyone, for fear of judgment or of having their infant taken away. These fears are not wholly unwarranted. And anecdotal evidence suggests this may be especially true for low-income, racialized or Indigenous parents.

In order for parents and their infants to be as physically and emotionally safe as possible, educating them and health-care professionals about postpartum unwanted, intrusive thoughts of infant-related harm, and about OCD, is critical.

Nichole Fairbrother currently holds funding from the Canadian Institutes of Health Research, Michael Smith Health Research BC, the Social Sciences and Humanities Research Council, and the Wellcome Foundation. She is affiliated with the Lancet Psychiatry Commission on Women’s Mental Health; European Cooperation in Science and Technology (COST) Action Consortium for Psychometrics in Perinatal Mental Health and Wellbeing; Perinatal Services BC; Maternal OCD, UK; and the Women's Health Research Cluster at the University of British Columbia.

Christine Ou receives funding from the Social Sciences and Humanities Research Council, Michael Smith Health Research BC, and the Canadian Institute of Health Research.