22.10.2014

## Percentage chance of pregnancy after 40

Having made the exciting decision to start your own family you are sure to be wondering how long it will take to get pregnant. Most women will be able to conceive naturally and give birth to a healthy baby if they get pregnant at 35 years old. About half of the women who don't get pregnant in the first year conceive during the following year, giving a pregnancy rate of 92 per cent within two years. Age aside, there are some steps you can take to give yourself the best possible chance of conceiving and having a healthy pregnancy. Learn more about getting pregnant in your 20s, 30s or 40s, or get tips, advice and support in our friendly community of mums and mums-to-be. Join now to receive free weekly newsletters tracking your baby’s development and yours throughout your pregnancy. The graph below shows information about miscarriage rates after IVF (using own eggs) from the 2012 CDC report.
Miscarriage rates would be higher if early miscarriages (such as "chemical pregnancies") were included.
Given the MFR, the probability of getting pregnant after a given number of months can be calculated with a negative binomial distribution. So almost half of the (healthy) 25 year olds get pregnant in the first monthtwo months, and after two years (the point when doctors start considering you to have fertility problems) more than 90% of 35 year olds should conceive.
This is the argument I used with my husband to get him to start trying immediately (i was 36 at the time and i told him it would take at LEAST a year to get pregnant).

You should take into account that woman get older during next attempts to become pregnant, so MFR will decrease. This analysis seems generally optimistic, especially because most of the age groups show a 100% of getting pregnant eventually. On your curve, with MFR=0.05, a woman has 85% chance to be pregnant after 3 years and 95% after 5 years. Using this (simple, dumb) model if a woman’s MFR is greater than zero, the chance of conception will eventually converge on 100%.
Another confusing issue is how to handle subjects who become pregnant multiple times in the data. My point is that your model is very far away from reality (the real curves would not look at all like that, it would be way flatter after one year) because you take MCR as an input, whereas your only input is the age, from which you make an initial estimation of MCR.
An MFR of 0.25 means that one quarter of 25-year olds will get pregnant in the first month. On a more practical note, my wife got pregnant within two cycles of starting to use an electronic ovulation tester. After 35 years, the proportion of women who experience infertility, miscarriage or a problem with their baby increases.
For some women having a multiple pregnancy brings them their dream family in one pregnancy. But if you are over 35, and finding that positive pregnancy test elusive, it is important to seek help sooner rather than later (NCCWCH 2013:6).

This results in lower chances for getting pregnant at all, as well as increasing the risk of miscarriage. In the case of extreme infertility problems (for example, you’ve had a hysterectomy and thus have no womb), the MFR is zero, and the chance is getting pregnant is zero over any time period. Clearly, to be interpreted in an intuitive way for a single woman, it does not work, it should be much flatter after 3 years (sorry for that…).
And then there’s the fact that fecundity rate changes, not least because baby-making intercourse becomes a real drag, so happens less over time. As women grow older the likelihood of getting pregnant falls while the likelihood of infertility rises. This could prevent fertilisation altogether or increase the likelihood of an ectopic pregnancy (CKS 2007, NCCWCH 2013:129, Utting and Bewley 2011). This suggests that by 12 months, 90% of those who will ever get pregnant naturally, already have.
However, it becomes possible to statistically assign couples to one of these groups based on time trying and a little bit of medical history, and then provide a much more realistic assessment of the chances of natural pregnancy.

### Comments to «Percentage chance of pregnancy after 40»

1. nobody writes:
(Which can be the identical as being pregnant and hence confuse us quite and Mineral.
2. semimi_sohbet writes:
Order for the dog to feel comfortable.