Ask an Expert: Pregnancy past 40

Q:  I just turned 40 and my husband and I would like to have a baby. What are the risks and what would you advise to optimize our chances of having a healthy baby?

Answer from Angela Keating, M.D., board-certified obstetrician/gynecologist with Providence Medical Group Columbia Women’s Clinic: 

The most important factor in preparing for a healthy pregnancy at any age is to stay as healthy as possible yourself. As a woman of 40, however, it’s true that you may have more challenges ahead of you than a younger woman would.

Those challenges may include the following:
  • A higher likelihood of having pre-existing medical conditions that could worsen during pregnancy or that could complicate a pregnancy
  • A more difficult time getting pregnant
  • A higher chance of miscarriage
  • A greater risk of having a child with Down syndrome or other chromosomal abnormalities
  • A greater risk of labor and delivery complications

Even with these increased challenges, however, the odds are still in favor of a healthy pregnancy as long as you take good care of yourself and get appropriate screening exams, prenatal care and monitoring.

So we’re glad you asked; understanding what you can do to improve your health and to reduce your risks will help you give yourself the best possible chance at conceiving and having a healthy child. 

Checking up on your health
The most important thing you can do, before you try to get pregnant, is to consult with your health care provider to assess any existing health conditions that might affect a pregnancy. Undiagnosed or untreated medical problems, such as high blood pressure, diabetes and depression, can have a significant impact on the safety of a pregnancy. Medications that you take for a chronic condition also could affect a pregnancy. A pre-pregnancy exam, medication review and consultation can help you optimize your medical condition and switch to safer medications or dosages before you try to conceive.

Conceiving after 40
A woman’s chance of conceiving starts to decline gradually as she reaches her mid-30s. This decline in fertility becomes more significant beyond age 40 as the quality and quantity of eggs diminishes and problems with ovulation increase. Although your chances of conceiving are lower now than they would have been in your 20s or 30s, however, there are several things that you can do to maximize your chances of conceiving in your early 40s.

The first step is to talk with your health care provider about potential fertility issues and interventions. Think about what your interests and beliefs are regarding your desired pregnancy and what steps you would or would not be willing to take on to achieve a pregnancy. 

If you have normal menstrual cycles and you still haven’t conceived after trying for six months, then the next step is to get an evaluation and to consider intervention (if desired) to help achieve pregnancy. Your evaluation may include hormone tests, ovulation tests and a dye study – called a hysterosalpingogram – to assess your uterus and fallopian tubes. In addition, your husband should have a semen analysis.

If your tests reveal that you have problems with ovulating, you can try hormone pills (clomiphene citrate is one type) or more aggressive measures, such as daily injections of gonadotropins (fertility drugs that help induce ovulation). If your assessment reveals that your fallopian tubes are blocked (a possibility that increases if you have had endometriosis or certain infections), other treatments can be recommended.

Keep in mind that one-third of fertility problems originate with the male. If your husband’s semen analysis reveals a problem, it will be important for him to talk with a health care provider about treatment options. To optimize your chances of pregnancy, your husband also should work to stay healthy, to eat well, and to avoid alcohol, drugs and tobacco, which can affect sperm count and quality.

As you age, so do your eggs
As you age, so do the eggs that you’ve carried within you since you were a fetus yourself. And just as you have a higher chance of developing health problems as you grow older, so do your eggs. At 40, as compared to 20 or 30, it’s likely that a higher percentage of your remaining eggs will have abnormalities in the number, structure or composition of the chromosomes, or that they will divide abnormally during ovulation. This increase in the percentage of abnormal eggs consequently increases the risk of miscarriage, as well as the risk of conceiving a child with a chromosomal abnormality.

The risk of miscarriage
At least 15 percent of all clinically recognized pregnancies end with miscarriage. For women in their 40s, however, the miscarriage rate is much higher, ranging from 30 to 50 percent. Since the increase is related mainly to chromosomal defects in the eggs, it is not something that can be corrected with medical intervention.

The risk of conceiving a child with a chromosomal disorder
At 40, your risk of conceiving a child with a chromosomal disorder is 1 in 66. The risk of conceiving a child with Down syndrome – the most common of these disorders – is 1 in 106.

The chart below shows how this risk continues to increase as you grow older.

Chromosomal abnormality rates at amniocentesis and in live-born infants
Mother's age   Risk of Down Syndrome   Risk of any chromosomal disorder
36                    1/289                                  1/127
37                    1/224                                  1/130
38                    1/173                                  1/102
39                    1/136                                  1/83
40                    1/106                                  1/66
41                    1/82                                    1/53
42                    1/63                                    1/42
43                    1/49                                    1/33
44                    1/38                                    1/26
45                    1/30                                    1/21
Journal of the American Medical Association, ©1983
Modified by the American College of Obstetricians and Gynecologists, ©2005

Unfortunately, no known preventive measures can reduce these risks. However, several tests are available that can help detect chromosomal defects, once you become pregnant. Chorionic villous sampling and amniocentesis are the most accurate tests, offering better than 99 percent accuracy in detecting the most common chromosomal defects.

However, these tests come with their own risks. Chorionic villous sampling, usually done at 10 to 12 weeks of gestation, carries a risk of miscarriage of about 1 in 100 to 150. Amniocentesis, usually done at 15 to 17 weeks of gestation, carries a miscarriage risk of about 1 in 200 to 300.  A lower-risk option is to have a non-invasive first-trimester ultrasound and blood test first. This test is 80 to 90 percent sensitive. If the results are normal, then the higher-risk tests may not be necessary.

If the results are abnormal, then you could consider amniocentesis or chorionic villous sampling to confirm the findings. A second-trimester test called a quad screen is another option, offering about 75 to 80 percent sensitivity. Ultimately, it is up to you whether to proceed with or decline any of these optional screening tests.

Preparing for childbirth
With increased maternal age, the risk of several pregnancy complications increases. These problems may include the following:

  • Pregnancy-related high blood pressure
  • Preeclampsia – a serious condition that increases blood pressure, fluid retention and protein in the urine
  • Pregnancy-related diabetes
  • Abruption – a complication in which the placenta separates too soon from the wall of the uterus
  • Previa – a complication in which the placenta partly or totally covers the opening of the cervix

Due to these and other causes, women over 40 are more likely to require a cesarean delivery. Your health care provider will monitor you for any signs of these problems and, should they arise, will talk with you about how to manage them to ensure the safest mode of delivery for you and your baby.

Healthier moms have healthier pregnancies
In general, the healthier you are, the healthier your pregnancy will be, so focus on the health basics that apply to any woman who wants to have a baby:

  • Follow a healthy, balanced diet.
  • Get regular, moderate exercise.
  • Avoid using tobacco, alcohol and drugs, and minimize your intake of caffeine.
  • Ensure an adequate intake of folic acid from conception to six weeks of gestation to reduce the incidence of neural tube defects (spina bifida); supplements of 400 mcg/day are probably sufficient, but we typically recommend prenatal vitamins that contain 800 to 1,000 mcg/day.
  • Avoid any unnecessary over-the-counter supplements or medications until you discuss them with your health care provider. (Read more about what’s safe to take during pregnancy.)
  • Stay in touch with your health care provider and address any pregnancy concerns as they arise.

Reading about all these risks can be frightening, so try to keep them in perspective: By taking good care of yourself, working closely with your health care provider, and maintaining some flexibility along the way, your prospects for having a happy, healthy baby are excellent. We wish you good health and good luck.

July 2006

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