For me, 38 would be very late.
In addition to the fertility problems that might delay your ability to get pregnant (and possible secondary infertility making having a 2nd difficult) as well as the potential health problems of the infant due to old eggs
Seconding this. The fact you guys are even considering waiting to start your family until you're 38 means that you--like many or even most people, honestly--are not well informed about female fertility.
Without going into a long explanation, let me just say that the statistics of fertility clinics are organized by age of the woman (because it is the single most critical factor), and the categories are as follows: under 35; 35-37; 38-40; 41-42; and over 42. In other words every woman under 35 is in the same boat, and from age 35 on fertility declines rapidly enough that the age categories are only two years long.
And you can see why if you go here:
http://sart.org/frame/detail.aspx?id=3893Click on "SART National Summary" above the map, and you'll see the average IVF success rates nationwide.
The most striking thing is how the success rates (look at "percentage of cycles resulting in live births") drop as women age:
Under 35, 40.1% of IVF cycles result in a baby; at 35-37, it's 31.4%; at 38-40, 21.2%; at 41-42, 11.2%; and above 42, just 4.5%.
I'm 33 and we are currently trying. A number of people in my family have "thought pregnant and got pregnant"- basically as soon as they stopped BC, but that has not been our experience, so I wouldn't say because others in your family easily got pregnant the same will happen for you, especially if you wait until 38.
My IVF doctor explained to me that having women in your family who went into early menopause or otherwise had fertility problems is an indication that you may have problems, but the reverse is not true because there are too many things other than genes that can interfere with your fertility.
yes, of course fertility declines. but my point is it is a LINEAR decline, from age 16 onward. the rate decreases by 2% each year. there is not big jump or spike in the decline in fertility at age 35.
Wish that were true, but it's not. There is a big jump or spike in fertility problems from age 35 on, as you can see in the IVF success statistics. At the same page linked to above, there's a dropdown menu called "Diagnosis"; if you select "male factor" on that menu, you will see only the data on women who did IVF solely because of male fertility issues. In other words, women whose husbands had such bad sperm quality that they had to do IVF, even though the women had no fertility problems at all. In those women too, you see a massive drop with each successive age group.
As for there being a decrease from 16 onwards, there is a lot of "anecdata" indicating that egg donors 22 and under have lower success rates than egg donors aged 23-30. In other words it appears that, at least as far as modern American women are concerned (and remember we now get our first periods earlier than women used to--it went from 16-17 to 12-13 in a little over a century), the peak years are not the teens but the mid to late twenties.