My views on a quick PubMed search - "Abortion Risks"

I'm lucky enough to have full access to PubMed through Uni so I thought I'd take a quick tour of the literature. My conclusion?

Anybody, pro-life or pro-choice, could cherry pick to prove whatever they wanted to about abortion risks. There were abundant papers supporting both sides, both sides being:

RISKY! - Abortion increases risk of "insert bad thing here". (I looked at preterm birth, future miscarriage, depression and breast cancer.)

and

NO WORRIES DUDE! - Abortion carries no significant risk of "insert bad thing here".

What was odd about all the figures, is that for most of them, the OR was so low, and the 95% Confidence Interval was so wide. In my view this explains the ability to widely interpret the results. For example, some authors claimed that an OR of 1.19 with a 95% CI of 0.8 - 1.5 indicated no significant risk (they would have been the pro-choice folk) yet, the next paper would give very much the same result and declare it a serious risk worthy of further medical investigation or action (meet the pro-lifers).

And that's not the oddest part, the oddest part is when you look at how the OR affects the actual risk.

The Odds Ratio (OR) is a measure of how much larger the ODDS are that one group is to suffer from a condition than another group. An OR of 1 means that both groups are equally likely to develop said condition. An OR of 1.2 would mean that a woman with a previous termination of pregnancy is 1.2 times MORE LIKELY to have a preterm birth as a woman who had not had a previous termination. (This number , 1.2, is an example, every paper had different figures.)

Most of the risks of abortion cited in the papers had ORs in the order of 1.1 - 1.6. In the grand scheme of things that increased risk is extremely low, but since it is heavily dependent on what the initial risk was, and since the initial risk is rarely cited (at least in the abstracts) it's hard to tell if the increased odds are significant.

However, here's an example of how much an OR of 1.3 would increase the risk of preterm birth using a figure from March of Dimes.

According to March of Dimes 6% of women give birth prematurely (this figure excludes known complications, such as short cervix). That's 6 out of every 100. So if you're having a healthy pregnancy the odds of a preterm delivery are 6 in 100. If you have had a previous termination you have 1.3 times that risk. 1.3 x 6 = 7.8 so the odds go up to 7.8 in 100, or rather, in the group of women who have had previous abortions, 7.8% will have a preterm birth.

That's a very very slight increase and in my view, worth taking in order to stop an unwanted pregnancy.

You see, in this case, the choice appears to be a very slightly elevated risk in future pregnancies versus a 100% certainty that you will bear a child you don't want.

It's a no brainer.

For the record, both my babies were full term unproblematic deliveries.  This means I won't be asked to participate in any preterm birth studies....