Like you said, economically it makes sense, but I have to emphasise that biologically it's risky(er) to wait. Risk doesn't imply a negative outcome, as you have

Like you said, economically it makes sense, but I have to emphasise that biologically it's risky(er) to wait. Risk doesn't imply a negative outcome, as you have discovered for yourself, but each would-be parent should at least know what the pros and cons are. According to Uhl's Obstetrics and Gynaecology for example, fertility is impacted negatively for females of age > 35 and a first pregnancy over 35 or under 19 is considered a risky pregnancy. Same goes for subsequent pregnancies over 40, which have a higher risk of genetic defect, placenta insufficiency, etc. It's perhaps interesting to note that a genetic consultation is offered to women over 35, but only to men over 50. The risk of a trisomy over 35 is 1 : 370, whereas earlier it's in the thousands and can be shrunk further through non-invasive diagnosis. There are many more things which become problematic over 35 (thrombosis, diabetes, hypertensive disorders), I don't have time to list them all, but any good book on obstetrics will have the details. Weight issues (BMI > 25, < 19) and a sedentary lifestyle increase the risk for pre-eclampsia, pre-term birth, pregnancy diabetes or spontaneous abortion. This would explain why the lady you mentioned was likely closely monitored. It seems that some attributes of the mother (e.g. being overweight, diabetes) are also reflected in the later predisposition to disease of the child. This can include even things like natural vs. C-section birth.