Some data on your chances if you time it right

[eeyore2]

Am re-posting this in case anyone is interested as I think I put it on a bit of a random thread that not many people will be looking at. Here goes....

I've been interested in trying to work out what sort of a chance you have of getting pregnant if you really 'try', using some of the methods that people discuss on this board to maximise your chances. If you have a look on fertility friend you can do a search to see all charts where the timing is pretty much right (you can tick days when intercourse took place on O-3, O-2, O-1, O, O+1.

I did a little analysis (I was having a quiet day at work and am getting a bit obsessive about trying for a new baby!!!). Embarrassing as it is am going to share it with you.

For those who timed it right and hit all five of those days about 41% got pregnant and another 4% had 'chemical pregnancies' ie early miscarriages. The statistics were relatively similar if you only hit O-2, O-1 and O (39% pregnant, 4% miscarriage). Or similarly with O-1, O and O+1 it was 37% pregnant, 4% miscarriage).

So assuming that the population on Fertility Friend is similar to the general population you actually have a pretty good chance of being pregnant within 6 cycles if you manage to time it right each cycle. By my reckoning if 100 women try for a baby getting the timing right each cycle, with a 41% chance each cycle of ending up pregnant, by the end of 6 cycles 95 of those women will be pregnant.

In fact it is likely that the Fertility Friend population is slightly less fertile than the general population, because many women will only think about going on such a website if they have experienced difficulties getting pregnant. Also some of those women will have multiple cycles stored on fertility friend whereas the most fertile will have less cycles, because they got pregnant quickest. So the total collection of cycles stored in their database is slightly skewed to the less fertile.

Finally, I wondered how much age makes a difference to the chance of conceiving IF you time it right. I filtered by age in three year blocks (22 - 24, 24 - 26, etc etc up to 46.) As you would expect there is a reduction in your chances as you get older. Up until the age of 30 there was essentially little drop-off, with your chance being around 40 - 44%. At age 33 your chance is reduced to around 36%, and by age 29 your chance is around 33%. By the age of 43 you have around a 19% chance of getting pregnant IF you time intercourse correctly around ovulation.

Clearly all this depends on a woman actually ovulating and being able to determine the timing of ovulation. These statistics only included cycles where an ovulation date was determined.

Hope this is of interest to someone!

[TurtlesAreRetroRight]

It is interesting but only in a theoretical way.

Because it's based on a limited, self-selecting sample.

Research tells us that the chances of conception remain around 25% if your timing is right and fertility normal and age under 30. And it is normal for it to take up to a year.

Your stats seem a bit more optimistic but I think they have to be taken with a small pinch of salt because all other research I've seen (not a lot tbh, more a vaguely interested bystander) agrees that it's about 25%.

[Levana]

Thank you, is very interesting and makes me feel more hopeful.

I have been trying 3 cycles now but think I actually only got the timing right once!

Are you charting / taking temp. every day etc eeyore2 I feel like it is something I'm going to have to do if not pregnant this month as timing is obviously critical and have not totally got the grips of it yet.

[eeyore2]

No, I'm using a fertility monitor because I have very irregular cycles so want to catch the right days and can't be bothered with the temperature taking. I didn't make it this cycle though. Oh well.

By the way I forgot to mention this is based on a query of Fertility Friend's database which contains over 127,000 charts so it is rather a lot of data.

Turtles - 25% makes sense for the general population who AREN'T using every available method to get the timing right, and also including people who may not actually have ovulated that month. On the leaflet on my fertility monitor it says that the monitor is proven to increase the chance of conception by around 80% which makes sense if the normal rate is 25% and the rate with a monitor is 40%.

[Ladybee]

I always understood the 25% to be those who aren't using any assistance at all, including optimally-timed intercourse. Just general population, having sex regularly throughout cycle. But well-timed sex is an intervention specifically aimed at increasing the odds of conception, not the normal state, so I'm pleased that the fertilityfriend stats seem to support that.
I've only ever got pg when I've had sex on the day before OV. Temping doesn't help with that as it shows Ov but doesn't predict it. Fortunately, despite having PCOS, being on metformin means my cycles are reasonably regular and so long as I have sex every couple of days around days 12-16 I've got a decent chance of catching the right time. Normally get pg within 6 months, unfortunately I also usually lose them within 9 weeks as well. Hey ho.
THanks for sharing the information.

[TurtlesAreRetroRight]

My obstetrician says the 25% is the chance of conception having sex at exactly the right time in your cycle, whether you know it or not.

[choc1]

I was told that have a 54% chance of concieving and i am 40 notw (by mc & fertilty consultant at Liverpool womens).

However, we have been ttc for 17 months now, BUT only properly trying for about 4months. In that we do the deed every other day from day 4- day 22.

Prior to the last 4 months we have been randomly having sex about 3 times a week.....with nothing to show for it.
STILL naff all/

Tis depressing, tis hard and i have just about lost hope now.
Your stats are somewhat comforting and VERY interesting so thanks for taking the time.

[LoveInAColdClimate]

Thank you, eeyore2 - that must have taken you ages! Makes me feel all the faff of charting is worth it (not that it's that much faff really for the sake of having a baby!).

[ninani]

I had read once (in the Guardian or The Times) that women in their 20s have fertile mucus for 6 days, at their 30s for 3 days and their 40s only 1 day. Fertile mucus is essential for the sperm to survive. So if you are in your 40s you need to monitor very close your ovulation and wouldn't trying every other day make you miss this single fertile day? Of course everyone is different.

[eeyore2]

Quick update - I calculated the average number of cycles required to conceive for 100 healthy women starting at the same time and timing it right each cycle (and ovulating each cycle). It comes out at about 2.5 cycles. Although clearly it can be much longer even if you are completely healthy - after 6 cycles 5 healthy women will still not be pregnant. Plus obviously not everyone will manage to time it right or ovulate each cycle. But still sounds like decent odds though.