Here's the most recent thing from the NICHD on LDA and conception: http://www.ncbi.nlm.nih.gov/pubmed?term=lda%20conception%20nichd

[i]Clinical studies investigating the use of low-dose aspirin (LDA) as an adjuvant therapy to IVF have produced conflicting results. The conflicting results have come as a consequence of the heterogeneous mixture of clinical trials with lack of adequate power. Even after multiple meta-analyses, differing estimates of effect were calculated as to whether aspirin should be used in conjunction with IVF.[/i]

We know that women who are using IVF to conceive are likely to have implantation issues, so a clear benefit should show up here if there is a large effect. Since the data is equivocal, they're calling for a (expensive!) multi-center randomized controlled trial to see if there is a small benefit that's not obvious in the data we have.

The media is reporting (rather annoyingly and breathlessly) a bunch of conflicting meta-analyses here. When there are only small studies, and no big careful studies, there can be population bias. It can look like there's a benefit when really it was just an accident because the people enrolled in the population weren't going to get preeclampsia again anyway. Most women who get preeclampsia do not get it again [b]regardless of what they do[/b] to support later pregnancies. So it takes *very large* populations of women randomized to potential treatment or placebo to work out whether or not there's any benefit to any potential therapy. Since we don't have a lot of those studies, but we have a lot of small studies, they'll group together the data from 15 smaller studies and then slice and dice the data looking for any trends.

But I don't see the point of using a meta-analysis when we have actual big careful randomized controlled trials that show no benefit from aspirin. I think they are only finding little fluctuations in the data because they're doing a kind of math that we *know for sure* produces these sorts of effects. (The Expert thread on LDA talks about some of these known math problems.)

*However*, since there are no obvious problems with LDA, a lot of docs recommend it on the grounds that even if it's not doing anything, it can't harm, and maybe it is doing something and we just don't know. This makes me a little nervous; we know that other NSAIDs seem to increase miscarriage rates.

Caryn, I read all the information about what the experts think about LDA and the success rates, but I don't recall there being a specific time that the women started taking the prenatals in trials. It would make sense for all the women to take the LDA at the same point in the pregnancy to get accurate success rates. Do you know happen to know how accurate these aspirin trials are? I would really like to know if their has been a trial where all the women started taking LDA while trying to conceive for hopefully better implanation and all the way through their pregnancies.

Eh. Same answer as always with LDA - some docs like it, some docs don't. The big NICHD trial showed no benefit for women at high-risk for PE and the big meta-analyses usually show about a 10% reduction in risk - so if recurrence risk is 15% for the whole population, risk drops 1.5% to 13.5% with aspirin - but no one knows why. [url=http://www.preeclampsia.org/forum/viewtopic.php?f=19&t=40560]About two-thirds of our Experts don't recommend it[/url]. There's a big trial running right now to see if it works in conjunction with an injectible blood thinner.

They also often scrip it for fertility patients but that doesn't seem to work either: http://www.medpagetoday.com/OBGYN/Infertility/27973

My Dr prescribes LDA to everyone before they conceive. As far as I know I have no underlining problems.

I was told by my MFM to start with a positive pregnancy test.

women here seem to get lots of different answers about when to start the aspirin. I'm taking it now, but it hasn't necessarily helped me in ttc :(

I started taking LDA before conception. The idea is that it thins the blood so that the egg implants better in your uterus. I think there has been some studies, similar to those done with lovenox that it helps with blood flow which ultimately helps with growth (possibly helping with IUGR babies). Did you ask your doctor why he/she is recommending it? Your doctor might have another reason.

My Dr wants me to take LDA before conception he thinks it may help the with implanation. I do not understand why some women take it at the end of the 1st trimester or other times.. Does anyone know why?