Women are having kids older and older these days. I think that this could be great for so many reasons but unfortunately, the female reproductive system doesn't agree. As a woman ages, it becomes harder to get pregnant, harder to stay pregnant, and harder to have a healthy pregnancy. I may paint a gloomy picture, but I think that it's most important for people to make informed decisions regarding child bearing and studies show that most people just don't have their facts straight! Lots of women in the media are having kids well into their 40s, but it's often not discussed what lengths they have gone through and that they're most likely using donor eggs. At 25 years old, the chance of conceiving each month for the first few months is about 25% but by age 35 it's already down to 10%.
Female fertility has the most notable decline after 35 years old, and again after the age of 40. A female fetus has 6-7 million eggs in its ovaries, but by menopause there's only a few hundred left. In other words, the number of eggs that a woman has declines drastically as they age. This can be measured as a lower Antral Follicle Count (AFC) by ultrasound on the 3rd day of a woman's menstrual cycle. As well, Anti-mullerian Hormone (AMH) blood levels also tend to decline with age. This hormone reflects the number of eggs that are left in a woman, also knows as a woman's ovarian reserve. Another issue is that as a woman ages it gets harder for the female body to properly mature an egg and get it ready for ovulation. Follicle Stimulating Hormone (FSH) blood levels increase with age because it takes more hormone from the brain to stimulate the ovaries to actually mature eggs. Perhaps most importantly, the quality of a woman's eggs decline as she ages. This could mean that there are more chromosomal abnormalities within the egg resulting in lower rates of fertilization, implantation, higher rates of miscarriage, and higher rates of genetic abnormalities in babies. The "shell" or zona pellucida of the egg becomes harder for sperm to penetrate naturally resulting in lower rates of fertilization. This can often be overcome with ICSI (intra cytoplasmic sperm injection) if a woman is doing IVF. Lastly, the egg mitochondria (the power houses of the cells) often don't function properly in older eggs. Unfortunately, we can't assess egg quality very well or very easily.
As grim as this sounds, all hope is not lost! There are lots of reproductive endocrinologists that can help older women conceive with fertility treatments, or help with egg freezing if you're still young. If you're trying to conceive, are over 35 years old, and it's been longer than 6 months - please go get assessed. Naturopathic Doctors can also help using acupuncture, vitamin, and herbal treatments to combat the aging process. Many women do get pregnant easily into their late 30s, but the important thing to remember is to get checked out after 6 months of trying, plan accordingly, and keep expectations realistic.