See: Mathematical induction. Then again… mathematicians are boneheads.

Reference 1: Decrease in Fertility After 40:
The biggest downside to putting off pregnancy until your 40s is significant: the longer you wait, the harder it is to get pregnant. This is principally because, as early as 15 years before a woman goes through menopause, the number of her eggs begins to decline and the eggs that are produced are more likely to have chromosomal problems that raise the risk for miscarriage and birth defects……..(Note: if you don’t want to get pregnant, you shouldn’t take this to mean that you can stop using contraception at 46. Instead you should wait until you are sure that you have stopped ovulating.) and Reference 2:

Very good.

Which seems to highlight that the above statements are much different than saying, ““The odds of a first time pregnancy after 40 are astronomical.”

Thanks again.

There’s a big difference in egg viability between the early 40s and the mid to late 40s. “There’s a steep drop in fertility in the 40s,” says Julia Johnson, a professor of obstetrics and gynaecology. “Your odds of getting pregnant at 41 are much better than they are at 43.”

A recent study in the medical journal Fertility and Sterility confirms her point. Researchers found that 40-year-old women treated for infertility had a 25 per cent chance of achieving pregnancy using their own eggs. By age 43 that number dropped to 10 per cent, and by 44 it had plummeted still further to 1.6 per cent. Among women who did get pregnant, the miscarriage rate was 24 per cent for 40-year-olds, 38 per cent for 43-year-olds, and 54 per cent for 44-year-olds.

Fertility expert James Goldfarb says that, in his 30 years on the job, he has never seen a woman get pregnant with her own eggs after age 46. “It’s like buying a lottery ticket,” he says. “Yes, someone wins every once in a while, but you shouldn’t bank on it.” (Note: if you don’t want to get pregnant, you shouldn’t take this to mean that you can stop using contraception at 46. Instead you should wait until you are sure that you have stopped ovulating.)

Using a donor egg boosts the odds of getting pregnant considerably, and according to Dr Goldfarb, that’s how most of the older celebrity mums are doing it, whether they admit it or not. “The fact that they don’t talk about it openly does a real disservice to other women,” he says. “We get at least one patient a month who comes in with the false hope that she can get pregnant using her own eggs.”

Pregnancy complications are another concern. In your 40s you’re more likely to develop problems like high blood pressure and diabetes during pregnancy, as well as placental problems and birth complications. Women over 40 have a higher risk of delivering a low-birth-weight or premature baby. Stillbirth rates are also higher, and studies show that children born to older mothers are themselves at increased risk of type-1 diabetes and high blood pressure.

And don’t forget about your partner; his age can affect his fertility too. Although men are physically capable of fathering children in their 60s and even their 70s, sperm quality deteriorates with age, and there’s a higher rate of genetic defects than there is with the sperm of younger men. In recent years clinical trials have found links between the father’s age and genetically related conditions such as Down’s syndrome and schizophrenia.

All these downsides can be disheartening, but don’t forget that some women do get pregnant well into their 40s (Cherie Blair had her fourth child, Leo, at 45) and many of them have complication-free pregnancies and healthy babies. Plus, while older mothers may be at higher risk for pregnancy complications, the overall risk is low.

One more caveat: while there are financial advantages to waiting to have children, there may be liabilities as well. “If you wait, you’re likely to have to continue working to an older age, for one thing,” says financial planner Marnie Azner. “You’ll still have financial responsibilities at a time when many of your friends are beginning to retire. If you haven’t been putting aside money for retirement up until now, it’s going to get even harder to do so after you have children. Other things become more expensive, too, like life and health insurance. Finally, if you have trouble getting pregnant, the cost of fertility treatments can really add up.”

http://www.zimbio.com/...

Women over age 35 may be less fertile than younger women because they tend to ovulate (release an egg from the ovaries) less frequently. Certain health conditions that are more common in this age group also may contribute. For example, women over age 35 are more likely to have endometriosis, a condition in which tissue attaches to the ovaries or fallopian tubes, sometimes interfering with conception.

A woman over age 35 should consult her health care provider if she has not conceived after six months of trying. Studies suggest that about one-third of women between 35 and 39 and about half of those over age 40 have fertility problems (2). Many fertility problems can be treated successfully.

http://www.marchofdimes.com/...

There’s a big difference in egg viability between the early 40s and the mid to late 40s. “There’s a steep drop in fertility in the 40s,” says Julia Johnson, a professor of obstetrics and gynaecology. “Your odds of getting pregnant at 41 are much better than they are at 43.”

A recent study in the medical journal Fertility and Sterility confirms her point. Researchers found that 40-year-old women treated for infertility had a 25 per cent chance of achieving pregnancy using their own eggs. By age 43 that number dropped to 10 per cent, and by 44 it had plummeted still further to 1.6 per cent. Among women who did get pregnant, the miscarriage rate was 24 per cent for 40-year-olds, 38 per cent for 43-year-olds, and 54 per cent for 44-year-olds.

Fertility expert James Goldfarb says that, in his 30 years on the job, he has never seen a woman get pregnant with her own eggs after age 46. “It’s like buying a lottery ticket,” he says. “Yes, someone wins every once in a while, but you shouldn’t bank on it.” (Note: if you don’t want to get pregnant, you shouldn’t take this to mean that you can stop using contraception at 46. Instead you should wait until you are sure that you have stopped ovulating.)

Using a donor egg boosts the odds of getting pregnant considerably, and according to Dr Goldfarb, that’s how most of the older celebrity mums are doing it, whether they admit it or not. “The fact that they don’t talk about it openly does a real disservice to other women,” he says. “We get at least one patient a month who comes in with the false hope that she can get pregnant using her own eggs.”

Pregnancy complications are another concern. In your 40s you’re more likely to develop problems like high blood pressure and diabetes during pregnancy, as well as placental problems and birth complications. Women over 40 have a higher risk of delivering a low-birth-weight or premature baby. Stillbirth rates are also higher, and studies show that children born to older mothers are themselves at increased risk of type-1 diabetes and high blood pressure.

And don’t forget about your partner; his age can affect his fertility too. Although men are physically capable of fathering children in their 60s and even their 70s, sperm quality deteriorates with age, and there’s a higher rate of genetic defects than there is with the sperm of younger men. In recent years clinical trials have found links between the father’s age and genetically related conditions such as Down’s syndrome and schizophrenia.

All these downsides can be disheartening, but don’t forget that some women do get pregnant well into their 40s (Cherie Blair had her fourth child, Leo, at 45) and many of them have complication-free pregnancies and healthy babies. Plus, while older mothers may be at higher risk for pregnancy complications, the overall risk is low.

One more caveat: while there are financial advantages to waiting to have children, there may be liabilities as well. “If you wait, you’re likely to have to continue working to an older age, for one thing,” says financial planner Marnie Azner. “You’ll still have financial responsibilities at a time when many of your friends are beginning to retire. If you haven’t been putting aside money for retirement up until now, it’s going to get even harder to do so after you have children. Other things become more expensive, too, like life and health insurance. Finally, if you have trouble getting pregnant, the cost of fertility treatments can really add up.”

http://www.zimbio.com/...