I talked to a genetic counselor at Kaiser today about the risks of having a baby after 35. (I want to stress, this conversation was in no way related to my own family plans. I was just curious, and it’s a free service.) I thought I would post my notes for anyone who’s interested in the topic; if you have more questions about this (and a Kaiser membership) I would urge you to call the genetics department yourself. They are extremely friendly and helpful.
Here’s the full interview:
Q: Does pregnancy become much more dangerous for the baby after the mother is 35?
A: There’s a gradually changing probability of chromosome problems as you age, but there’s no age when the probability of chromosome problems becomes suddenly bigger. Even for a woman in her twenties, the chance of having a baby with a chromosome problem is never smaller than 1 in 500. These can happen to any person.
As fathers age there is a gradually increasing chance of new mutations to accumulate in the sperm, but the magnitude of risk remains very small.
Even if you’re 45, the maximum risk of a chromosome problem is around 5%. It goes from about 0.5% to 5%. But the majority of people still have a baby without these problems.
Q: Can you test for these problems in advance?
A: We have many different options to check for [chromosome problems] during pregnancy. People can choose a non-invasive screening test which estimates the probability of problems in a pregnancy, or an invasive diagnostic test which carries a small risk of miscarriage. We can’t correct these conditions, but with screening the couple can learn more about it and can choose to stop the pregnancy.
Q: When you say ‘chromosome problem,’ what are we talking about? Down Syndrome?
A: Down Syndrome is the most common chromosome problem, but there are others.
Q: Does the risk of miscarriage increase with age?
A: About 20% of all pregnancies end in miscarriage, and that’s more common as we get older. About 60% of time, the miscarriage is due to a chromosome problem.
Q: What can someone do to reduce the chance of birth defects?
A: You can reduce the chance of physical birth defects by taking a multivitamin with folic acid every day, starting at least two months before conception and continuing through the first trimester. They have done studies comparing people who get the exact same amount of folic acid from their diet (green leafy veggies and stuff) to people who take a vitamin, and vitamin people do better. Most of the time it is true that it’s much better to get your vitamins as normal food, but not with folic acid.
Also, it’s not good early in pregnancy to go in hot tubs or saunas. Overheating can affect fetal development.
Q: Does age affect fertility?
A: It is easier to get pregnant when younger. Fertility starts dropping, on average, after 28. Eighteen to 28 is peak fertility for females. But it’s different for everyone. I just had a couple in my office who got pregnant in their second month of trying, and she’s 45.
Q: How will pregnancy become more unpleasant for a woman as she gets older?
A: Well, living a Western lifestyle, there are things that catch up to us.
Q: Like corn syrup?
A: Right. Before you get pregnant, you should be at a healthy body weight, have some basic level of fitness and eat as healthy as possible. That would help reduce the chance of complications like high blood pressure or temporary pregnancy diabetes. That kind of thing becomes more common as you get older.
Q: Any other advice?
A: Difficulties getting pregnant are one of the big stresses on a relationship. Before you start trying for a baby, you should discuss with your partner:
– How long you will try.
– How you feel about stopping a pregnancy with a chromosome issue.