Many of today's women are delaying childbearing until later in life for a variety of reasons, including career choices, financial status, late marriage, and remarriage. In addition, successful treatment of previously infertile women over 40 is occurring. In fact, reports indicate successful pregnancies in women over age 60!
While such extreme cases raise complex social and ethical issues (not to mention medical issues), the fact of the matter is that more women over age 40 are choosing to start a new family or add to their present one. But what risks do these women incur? Let's examine the facts regarding pregnancy in this age group and strategies to reduce the risks.
Standard medical teaching indicates a higher risk for pregnancy complications in women over the age of 35. These complications can be categorized as follows:
As age increases beyond 35, so does each of these risks. Nevertheless, proper preparation before pregnancy and early prenatal care can help assure the best chances of healthy outcomes.
There is nothing magical about the risks at specific ages, such as 35 or 40. Risks of genetic abnormalities and miscarriage rise progressively throughout a person's reproductive years. As a woman ages, it is more likely that she will have acquired a medical illness. However, this is a population statistic (ie, a general trend); many individual women over 40 are very healthy and have much less risk than much younger women.
Certain medical conditions occur more frequently in pregnant women over 40, including diabetes , high blood pressure , and thyroid disorders . Fortunately, these conditions can be diagnosed and controlled prior to pregnancy, and many of the medications used to treat these disorders can be safely used during pregnancy. If you currently take medication and you are planning a pregnancy, talk to your doctor. A change in medication or an adjustment of dosage may be necessary.
If not properly treated, maternal illnesses can adversely affect the fetus. Uncontrolled high blood pressure can restrict fetal growth and, in severe cases, can result in stillbirth. Undiagnosed diabetes can carry with it a higher risk of birth defects and stillbirth; and, poor blood sugar control during pregnancy can result in abnormal fetal growth. Early prenatal care and judicious use of medication can lower these risks significantly.
It is an unfortunate fact that as a woman ages, a higher proportion of her aging eggs contain chromosomal abnormalities. Therefore women who become pregnant after the age of 40, are at risk of having a child with a genetic defect. This risk increases with age. For instance, the likelihood of having a baby with Down's syndrome is approximately 1 in 400 at the age of 35. This number increases to 1 in 100 by the age of 40 and up to 1 in 40 at the age of 45.
Pregnancy loss is often seen in the first trimester and in many cases is due to genetic abnormalities of the fetus. Pregnancy loss also increases with advancing age. Below is the risk of miscarriage based on age:
| Age range | Risk of miscarriage |
| 35-39 | 20% |
| 40-44 | 35% |
| 45 | +50% |
women over 40 are also more likely to have a stillbirth.
Complications of labor and delivery that are seen more frequently in women over age 40 include:
The rate of Cesarean section is also considerably higher in this age group.
Although the risks associated with pregnancy after 40 are numerous and sometimes unavoidable, there are several strategies that women over 40 can use to reduce these risks.
First and foremost, make an appointment to see your doctor before you get pregnant. This preconception visit will give your doctor the opportunity to diagnose and treat any disorders that might otherwise go undetected prior to the initial prenatal visit.
A thorough evaluation prior to pregnancy will allow your doctor to give you an idea of your individual risk. There may be cases in which pregnancy will be ill-advised. However, for the majority of women over age 40, early prenatal care and good health habits will result in a healthy baby and a happy mother.
The idea is to be as healthy as you can before you get pregnant. Here are some tips:
If you are concerned about the risk of genetic defects, especially if you have a family history, ask your doctor about tests that can help identify these types of problems. Blood tests are available to screen for some genetic disorders either before or during pregnancy. A triple screen or quad screen blood test may be obtained to evaluate the risk of neural tube defects and Down syndrome.
Genetic amniocentesis (or chorionic villus sampling ) is offered to women after the age of 35. Amniocentesis is usually done in the third or fourth month of pregnancy and involves removal of amniotic fluid from the womb for genetic testing. There is a small risk of miscarriage associated with this test.
Chorionic villus sampling can be done earlier in pregnancy and involves the removal of a small amount of placental tissue, which can then be tested for genetic abnormalities. There is also the risk of miscarriage with this test. Discuss the risks and benefits of these tests with your doctor early on so that you will have ample time to make an informed decision.
RESOURCES:
The American Congress of Obstetricians and Gynecologists
http://www.acog.org/
March of Dimes
http://www.modimes.org
CANADIAN RESOURCES:
The Canadian Women's Health Network
http://www.cwhn.ca/indexeng.html/
Women's Health Matters
http://www.womenshealthmatters.ca/
References:
Information about amniocentesis and chorionic villi sampling. University of Pennsylvania Health Systems website. Available at: http://www.obgyn.upenn.edu/genetics/inforforamnandcvs.html .
Nurses Portal website. Available at: http://www.virtualnurse.com .
Pregnancy after 35. March of Dimes website. Available at: http://www.marchofdimes.com/pregnancy/trying_after35.html . Updated May 2009. Accessed June 7, 2011.
Last reviewed June 2011 by Brian Randall, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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