Almost all abortions in the UK are approved to prevent mental health problems in pregnant women. However, the scientific data indicates that abortion does not prevent mental disorder. It probably increases the risk.
The 1967 Abortion Act applies to the UK – currently except for Northern Ireland. But parliament voted last week to impose similar laws on Northern Ireland. Therefore, this is a good time to evaluate the scientific credibility of current law and practice in the rest of the UK.
“Ground C” is by far the most common category for approving an abortion:
“the pregnancy has not exceeded its twenty-fourth week and that the continuance of the pregnancy would involve risk, greater than if the pregnancy were terminated, of injury to the physical or mental health of the pregnant woman or any existing children of her family”
1967 Abortion Act
National abortion statistics for England and Wales in 2018 were recently published. 95%* of abortions were approved to prevent the risk of mental disorders in pregnant women. The UK government have reported similar rates over the past 10 years.
We would then expect to see good evidence that abortion reduces mental health risk. But the evidence is close to non-existent.
Limits of the evidence
It is very difficult to study the mental health risks of abortion. Most studies have important limitations, including:
- Assessment of mental health differs across studies
- Rarely are women who had abortions compared with those who had an unwanted pregnancy
- Researchers often do not take into account confounding factors
Confounding happens when a factor is associated with both deciding on abortion and experiencing a mental disorder. For example, people with a mental disorder (like depression or anxiety) are more likely to have an abortion. They are also more likely to develop a mental disorder later in life.
This leads to problems if these associations aren’t taken into account in the analysis. It may look like abortion is causing mental disorder when it isn’t.
Making sense of limited research
There have been four major systematic reviews on this topic:
- American Psychological Association (APA)
- Royal College of Psychiatrists (RCPsych) in the
- Patricia Coleman, Bowling Green State University
- VE Charles and colleagues, John Hopkins
These reviews try to identify all relevant studies in the
area and make a transparent assessment of what they found.
Systematic reviews aim to be objective and transparent. But the controversial nature of the topic makes this difficult. Patricia Coleman has found that abortion increases mental health risk in many of her studies. Brenda Major (the lead author of the APA review) also has a long history of research on this topic. But she has often found abortion doesn’t increase mental health risk.
It isn’t surprising that their reviews of abortion and
mental health confirm their research history! The APA review concludes that abortion
does not increase the risk of mental disorder.
But Coleman found an increased risk for a range of mental disorders. She conducted a meta-analysis, a statistical model to combine results from different studies. Women who had an abortion were more likely to experience depression (28%), anxiety (26%), and self-harm or suicidal behaviour (95%). **
The other two reviews (RCPsych; Charles and colleagues) came to similar conclusions as the APA. They found that abortion did not increase the risk of mental health problems.
I’ll look in more detail at the Coleman review and why it might differ from the other three reviews.
Psychological research and politics: Coleman and the British Journal of Psychiatry
Before the RCPsych completed their widely anticipated review, Patricia Coleman produced an audacious move. She published the first meta-analysis on abortion and mental health in the British Journal of Psychiatry. Which happens to be the RCPsych’s flagship journal and one of the leading psychiatry journals in the world.
This caused quite a storm. Within days, high powered academic groups, on both sides of the Atlantic, wrote stinging criticisms of Coleman and the RCPsych. Many demanded the journal retract the paper.
What were their concerns?
There were four main concerns:
- Coleman is linked with the pro-life movement – so she was reflecting her own biases
- Errors in the meta-analyses – some of her analyses violated statistical assumptions
- Her review lacked transparency – she did not show how she found the studies, or why she left out some studies
- Some included studies didn’t control for past mental disorders in their analyses (the problem of confounding we discussed earlier)
Coleman’s alleged links with the pro-life movement are not a
good reason for dismissing the results. There are few neutral voices on
The criticisms of her methods are more important. Coleman is not a specialist in meta-analyses. So it was easy for critics to point out how she had ‘broken the rules’ of systematic reviews.
I have mixed feelings – she left herself wide open for criticism. But, after peer-reviewing dozens of similar papers, I think her mistakes were not that rare. A journal with the status of the BJPsych should have spotted and corrected these before publication. This was a learning point for the journal, and they are much sharper now.
But the key question is whether these errors make the paper invalid? Although some of her analyses were flawed, many were not. For example, the results I’ve reported above did not make these statistical errors.
Quality of studies
I will focus on the key issue dividing the four systematic reviews. They all agree that most of the studies in this area are limited. Should we look at the average effect across all studies? Or should we focus on ‘high quality’ studies?
The APA, RCPsych and Charles reviews went for the latter option. The authors of these three reviews concluded high quality studies did not show that abortion led to a higher risk of mental disorders.
Yet each review categorised different studies as being ‘high quality’. This shows the subjective nature of these judgments. The APA review’s conclusions focused on a British study by Gilchrist and colleagues conducted in the 1970s.
The RCPsych focused on four studies. But most of their data came from the Gilchrist study and a New Zealand study by Fergusson and colleagues. The problem was that these two studies found opposing results.
Fergusson’s study found an increased mental health risk but Gilchrist’s did not. So it’s misleading to conclude from their data that abortion did not increase the risk of mental disorders.
Another meta-analysis emerges
An interesting protagonist in the story is David Fergusson – author of the New Zealand study, and a pro-choice atheist.
In response to the criticisms of the Coleman review, Fergusson re-analysed her data. He limited analyses to 8 studies comparing women who had an abortion with women who had given birth to an unwanted/unintended pregnancy.
Except for depression, all other risks were higher for women
who had an abortion:
- 20% higher risk of mental disorders
- 23% higher risk when controlling for prior mental disorders
- 24% higher risk of anxiety disorder
- 49% higher risk of self-harm or suicidal behaviour
He also used the same criteria for ‘high quality’ defined by
the Charles review. Increased risk of mental disorders persisted in these high
Psychological research and the law: what are the implications of the data?
Coleman’s meta-analyses probably over-estimated the risks. But, Fergusson’s analyses show abortion is still associated with a higher risk of mental disorders. Even when only including higher quality studies.
The APA, RCPsych and Charles reviews are correct that we need to focus on the highest quality studies. But they are small in number in this field and contradict one another. So we cannot rule out that abortion does not increase mental health risks.
However, in all the arguments and controversies, it’s important not to miss the main point. None of the four reviews concluded that abortion is an effective strategy for reducing mental health risk.
If we return to the 1967 Abortion Act, 95% of abortions in the UK were approved on ‘Ground C’ to prevent mental disorder:
“…the continuance of the pregnancy would
involve risk, greater than if the pregnancy were terminated, of injury to the
physical or mental health of the pregnant woman”.
Do we find any evidence that continuing a pregnancy increases the risk of mental disorder, compared with terminating the pregnancy?
On average, women who terminated their pregnancy either had a similar or greater risk of mental disorders. Therefore, we must conclude that there is no justification for 95% of abortions in England and Wales.
We must also question if it is appropriate to extend the law to Northern Ireland. Particularly when scientific research since 1967 has contradicted it.
Academy of Medical Royal Colleges (2011) Induced abortion and mental health.
Major and Colleagues (2008) APA task force on mental health and abortion.
Coleman P. Abortion and mental health: quantitative
synthesis and analysis of research published 1995–2009. British Journal of
Psychiatry 2011; 199: 180-186.
Charles VE, Polis CB, Sridhara SK, Blum RW. Abortion and
long-term mental health outcomes: a systematic review of the evidence.
Contraception 2008; 78: 436–50.
*97.7% of all abortions were granted on Ground C. Of these, 99.9% were to prevent risk to the woman’s mental health.
** Percentage risks are based on a conversion of odds ratios into risk ratios to avoid misinterpretation. Since odds are often wrongly interpreted as risks which can be misleading. Odds are almost always higher than risks leading to an overestimate of risk.