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It's here. Advanced Maternal Age.
The first time I heard the phrase, I thought of nearly elderly women having embryos implanted in their shriveling wombs. No wonder it's such a problem for women that age to have babies, I thought.
But the doctors and genetic counselors bandying the term around were not talking about women on the verge of menopause. They were talking about me.
Well, not me personally, but women my age. A month ago I turned 35. With that birthday I achieved Advanced Maternal Age.
Like so many other women in my age group, I have never been pregnant. That means that if I do conceive a child now I will be branded an "elderly primapara." ELDERLY at 35! (Primapara means a woman who is pregnant for the first time.)
Everyone says that age is just a number, but medically speaking, that's not true.
I've got a one in 400 chance of having a child with Down syndrome-caused by an extra chromosome 21. Much worse, I also have an elevated chance of conceiving a fetus with a more severe chromosome abnormality. Those embryos don't develop properly, leading to miscarriages.
A woman of 25 has a one in 1,250 chance of bearing a baby with Down syndrome and about a 9 percent chance of miscarriage. Those of us firmly in our 30s lose about 20 percent of pregnancies to miscarriage. About half of all 40-year-old women are already infertile, stand a one in 100 chance of having a baby with Down syndrome and miscarry between one-third and one-half of recognized pregnancies. (Sometimes a woman miscarries before she even knows she's pregnant.)
It's all due to old eggs.
The life cycle of eggs
I've had all the eggs I'm ever going to have since before I was born. They sit in my ovaries in a state of suspended animation. I probably had a couple of million when I was born. Now? Not so many. About 30 of those eggs die every day, according to Dr. Sherman J. Silber, a fertility expert at the Infertility Center of St. Louis at St. Luke's Hospital. That's rain or shine, whether I ovulate or menstruate or not, whether I eat right or exercise or do nothing at all.
Once a month, one of the contenders becomes the chosen one and matures into an egg with half the complete set of human chromosomes. (Sperm supply the other half when the egg is fertilized.)
Chromosomes ride on railroadlike tracks called a spindle. As women age, those tracks deteriorate, derailing the separation of the chromosomes. By the time a woman is 38, doctors can see abnormalities in the spindles of about 86 percent of the eggs, Silber said. And derailing the separation process can produce a train wreck-Down syndrome, miscarriage or stillbirth.
Pregnant women who are over 35 are usually offered amniocentesis to either diagnose or rule out chromosomal abnormalities. Of course, the chance that the procedure could cause miscarriage is somewhere between one in 200 and one in 400 - pretty much the same risk of having a fetus with chromosomal disorder.
And even if the egg and the resulting baby are normal, the pregnancy could present risks that 34-year-old women apparently don't face. High blood pressure. Diabetes. Arthritis. Problems with the placenta. It's scary.
PROBLEMS FOR MEN
Women aren't the only ones who have problems. Men also have more fertility problems as they age.
A 35-year old woman with a male partner of the same age has about an 18 percent chance of failing to conceive a baby in the first year of trying, according to a study of Italian couples published last year by researchers at the National Institutes of Health. If that same 35-year-old woman has a partner who is 40 or older, her chance of not getting pregnant rises to about 30 percent, said David B. Dunson, a reproductive epidemiologist who led the study.
The March of Dimes estimates that the risk of certain genetic defects is four to five times greater for fathers age 45 and above than for 20- to 25-year-olds.
For example, old dads seem to have a higher risk of producing children with a rare disorder known as progeria, a disease that causes children to age rapidly. Scientists involved in the Human Genome Project recently discovered that older men sometimes (albeit extremely rarely) make faulty sperm with a defect in a gene that encodes Lamin A. Lamin A is a protein that coats the inside of a cell's nucleus. When production of the protein goes wrong, the nucleus collapses, chromosomes are lost and the cell dies. The death of many cells leads to rapid aging.
But men make sperm like Dunkin' Donuts-fresh every day. That fresh-made quality means most men can stay fertile virtually forever. As Silber admits, "90-year-old men can have kids. Totally unfair."
Those incidents may be a little deceiving, Dunson said. His study revealed that the quality of sperm also goes down as a man ages. That drop also starts somewhere in the late 30s.
LITTLE WE CAN DO
I'd like to say I was going to rage, rage against the dying of the biological light, doing everything I can to protect my reproductive health. Unfortunately, it appears that there is little I or any woman over that certain age can do.
While virile young men can freeze their sperm for later use, women don't have the same options. Eggs do not survive freezing unless they are fertilized.
Some doctors are experimenting with freezing the outer layer of ovaries (that's the part with all the eggs) and implanting the ovarian tissue under the skin of the arm when a woman is ready to have a child. The tissue forms a functioning ovary that will release eggs. The eggs must be harvested and fertilized in a test tube before implanting into the woman's uterus.
The technology could save the reproductive lives of some women who have survived intensive chemotherapy that otherwise would have wiped out their fertility. So far no women have had babies with this method, but rats, mice and sheep have, said Dr. Nancy Klein, a reproductive endocrinologist at the University of Washington in Seattle. Research in England indicates that it could work for humans too.
I applaud the doctors who came up with this solution and the women courageous enough to try it. But my problem is not cancer and chemotherapy, it's simply getting older - hardly cause for taking such a drastic step. And Silber tells me it wouldn't work for a woman running low on viable eggs anyway. Apparently freezing kills eggs in ovarian tissue, too.
Women do have the option of having fertilized eggs frozen as embryos. That may work for married couples or women who are willing to pick out their child's biological father now (and take a chance that they won't want to change their minds later). This option is not one I'd choose to take now. I prefer to have any future husband I may have help me with egg fertilization the old-fashioned way.
Frozen embryos have been a boon for couples who have fertility problems. Those same embryos have also posed sticky ethical issues. Scientists, religious groups and plenty of regular people are still debating what should be done with leftover embryos and even whether these small balls of cells represent a new human life.
Some couples go the embryo route in order to screen out embryos that have genetic defects. The practice is highly controversial. Some people feel it's wrong to fix the roll of the genetic dice-the old "playing God" argument. Others worry that couples will abuse the technology and use it to select traits, such as sex, that have no medical benefit.
None of that is an issue for me. I just want a way to hold on to my reproductive youth. I've been trying to think positively. I figure the pressure is off now. I don't have to worry about my biological clock ticking away. The alarm has probably already rang.
POSITIVE THINKING
The way I look at it, any healthy baby I have now would be a bonus. That's a potential payoff that is worth gambling for, in my opinion. And really, the odds aren't all that bad-I still have at least 399 chances out of 400 of having a baby with a normal number of chromosomes. In fact, I'd say those are pretty good odds.
"Every other defect is something every mother has to face whether she's 22 or 30 or 40," Silber assures me. He and other fertility specialists are devising lots of ways to help couples-aged or challenged-get pregnant. And careful monitoring of pregnancies can keep babies and moms healthy.
The key is to make sure potential moms are healthy going into pregnancy, said Mary Schurk, director of the Women's Well/Perinatal Outreach Department at St. Mary's Hospital in Richmond Heights, Mo. She advocates taking vitamins that boost folic acid and iron long before you even start thinking about getting pregnant. Folic acid helps babies avoid brain and other nervous system disorders, such as spina bifida. Iron helps head off anemia in pregnant women. It's a good idea for every woman in her child-bearing years, Schurk said.
And, yes, women my age are still firmly in their child-bearing years. Dunson's study of the European couples showed that most eventually got pregnant. It just took longer. Most couples got pregnant within two years of trying, Dunson said. So if at first you don't conceive (and fertility tests check out) try, try again.
What's more, parents of advanced age are more likely to have stable relationships, careers and finances that allow them to relax and enjoy their children, Schurk said.
"I think the pluses outweigh the minuses in terms of parenthood for the older couple," Schurk said.
If there is one thing my 35 years have taught me, it's that you can't waste time worrying about things you can't control. I can't stop the aging process-not yet anyway. So if I can't beat it, I may as well join the ranks of "older" women who are leading happy, healthy, fabulously productive lives and worry about the rest when the time is right.
Advanced Maternal Age? Bring it on!
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(c) 2003, St. Louis Post-Dispatch. Distributed by Knight Ridder/Tribune News Service.
