What Is Pregnancy at Advanced Maternal Age?

Women who bear children after the age of 35, regardless of their health or previous pregnancies, are considered to be of "advanced maternal age," also known as Pregnancy AMA.

In fact, one in every five women today has her first child after the age of 35.

Most women who have babies over the age of 35 have perfectly normal and healthy pregnancies and deliver healthy, happy babies. However, there are a good number of studies that show that pregnancy at advanced maternal age may cause a number of problems for both the mother and the fetus.

What Are Some Of The Reasons Women Wait To Have Children?

As gender roles have morphed over the years, more and more women are waiting to have children. In the early 1970's, the average age for a first-time mother was 23-25 years of age. Currently, the average age for a first-time mother averages between 26-29 years of age. Why? Why are many women choosing to wait until later in life to have children?

Education: Many women today are pursuing higher and higher levels of education than they have before. For many, higher education is the path they can take to find a stable career with a higher salary as well as opening the range for career opportunities in the future. In many countries, the amount of time spent pursuing higher education past high school is almost 9 years.

Employment: Many women are forced to choose between their career and taking the time out to have a child. With the rapidly increasing education levels among women, working and motherhood have been seen as incompatible: a woman can work or she can raise her children. While it is not always seen as an either/or situation, many women still opt to wait until she is advanced enough in her career to feel it is okay to begin a family.

Financial Security: As we've been faced with trying economic times, the financial security - once a given - is no longer a certainty. For this reason, woman may opt to work to ensure her financial ability to care for a child.

Waiting To Get Married: Many women are waiting until they're older to settle down and get married. This is partially due to the amount of time spent in school as well as the inability to choose a mate who may or may not be perfect for her.

Impaired Fertility: while some women wait to have children by choice, others begin to attempt to start a family much earlier, but, due to fertility issues, she may be unable to achieve pregnancy until later in life.

Possible Risks With Pregnancy At Advanced Maternal Age:

While most women over the age of 35 give birth to perfectly healthy babies, the risk for problems with the baby and the pregnancy increase as a woman's age increases. It's important to understand and identify risks associated with pregnancy AMA and decrease the risks wherever possible.

Age and Fertility: Starting after age thirty, most women have a decrease in fertility, which means that getting pregnant may be more of a challenge. After age forty, most men begin to see some decrease in their fertility as well. Women over age thirty do not ovulate (release an egg from the ovary) as frequently as younger women. A woman over the age of 35 who has been practicing unprotected, properly timed sexual intercourse should visit her OB/GYN after six months.

Other health-related issues that can impact fertility can include the following:

  1. Endometriosis - the tissue lining the uterus begins to grow outside of the uterus, banding to the ovaries, fallopian tubes, and other internal organs. 
  2. Fibroids - a non-cancerous growth in the uterus can impede implantation of a fertilized egg or block the fallopian tube from releasing an egg.

Read more about infertility.

Age and Birth Defects: Women over age 35 run the risk of having a child with certain chromosomal-type birth defects. As women age, their ova - or eggs - do as well. Having a child with Down Syndrome, the most common chromosomal birth defect, increases with maternal age. This is why all pregnant women are offered screening tests for Down Syndrome and other chromosomal defects in the second trimester of pregnancy. Diagnostic tests, such as a CVS or an amniocentesis can properly diagnose chromosomal birth defects prenatally.

The risks - by age - of having a baby with Down Syndrome are:

  • Age of 25, the odds of a woman conceiving a baby with Down Syndrome are 1 in 1250. 
  • At the age of 30, 1 in 1,000.
  • At the age of 35, the odds are 1 in 400.
  • At the age of 40, 1 in 100.
  • At the age of 45, 1 in 30.
  • At the age of 49, 1 in 20.

Read more about Down Syndrome.

Miscarriage at AMA: In all ages of pregnant women, most miscarriages occur within the first trimester of pregnancy. The risk for miscarriage increases with age.

  • In their 20's 10% of diagnosed pregnancies end in miscarriage.
  • Between ages 35-39, 20% of diagnosed pregnancies ends in miscarriage.
  • Between ages 40-44, 35% of diagnosed pregnancies ends in miscarriage.
  • Age 45, over 50% of diagnosed pregnancies ends in miscarriage.

Read more about miscarriage.

Most miscarriages are caused, in some part, by increases in chromosomal abnormalities associated with older eggs.

How Do Preexisting Health Issues Affect A Pregnancy at Advanced Maternal Age?

Women who are over age 35 are more likely to have preexisting health conditions before becoming pregnant. Certain health conditions can affect pregnancy. These include:

  • Hypertension - poorly controlled high blood pressure can slow fetal growth.
  • Diabetes - poorly-controlled diabetes can cause pregnancy complications such as birth defects and miscarriage.

It's extremely important that all women - regardless of age - have a preconception visit with her doctor before deciding to become pregnant. This way, she can go into a pregnancy as healthy as possible, after adjusting any medications that may negatively impact pregnancy.

What Are The Pregnancy Complications Associated With Pregnancy at Advanced Maternal Age?

While most women who have children at advanced maternal age deliver perfectly healthy babies, there are complications associated with pregnancy AMA. These possible complications can include the following:

AMA and Gestational Diabetes: Women over the age of 35 are twice as likely to develop gestational diabetes during her pregnancy. Gestational diabetes not only makes pregnancy more difficult, it can cause macrosomia, or large babies, who are at greater risks for injury during delivery.

Read more about gestational diabetes.

AMA and Placental Problems: problems with the placenta, such as placenta previa, a condition in which the placenta grows over the cervix, are more common in women of AMA. Placental previa may lead to problems with a vaginal delivery, necessitating a Cesarian Section. Placenta previa was found to be nearly twice as likely to happen to pregnant women in their late thirties and three times as likely to happen to pregnant women in their early forties.

AMA Pregnancy-Induced Hypertension: Similar to gestational diabetes, pregnancy may induce high blood pressure in women who have previously had no problems with their blood pressure. Its most severe form, preeclampsia, is more common in pregnant women over the age of 35.

Read more about preeclampsia.

AMA Preterm Birth - women over the age of forty are more likely to deliver their babies before term, 37 weeks gestation. Premature babies are at greater risk for developmental delays and learning disabilities, as well as other health problems related to premature birth.

Read more about prematurity.

AMA Stillbirth: A stillbirth is a fetal demise after week twenty of pregnancy, and recent studies have shown that women over age forty are 2-3 times more likely as a woman in her twenties to experience a stillbirth.

Read more about stillbirth.

Cesarian Section: the chances of having a cesarean birth increase with age. According to the CDC, the likelihood of having a Cesarean Section is:

  • Under age 20 - 22% chance of a C-Section
  • Between ages 20-24 -27% chance of a C-Section
  • Between ages 35-29 - 41% chance of a C-Section
  • Over 40 - 47% chance of a C-Section

Multiples Pregnancy: a woman over 35 has a higher risk for having a multiples pregnancy.

Read more about multiples pregnancy.

Okay, SCARY. How Can I Reduce The Risks Of The Pregnancy AMA Complications?

While many women are opting to have babies later in life, reading the literature may make the option of pregnancy at advanced maternal age terrifying. However, there are a number of ways in which a woman can reduce her risks of complications during a pregnancy over age 35. These include:


Schedule a preconception visit with your doctor to address any existing health issues as well as ensure that there are no unknown genetic issues that can impact a pregnancy.

Before getting pregnant, be sure that you are immune to rubella and chicken pox. If you aren't immune, receive vaccinations. One month post vaccine, you may begin trying to get pregnant.

Read more about trying to conceive.

Discuss all current medications and supplements with the doctor before conception in order to ensure that all medications are pregnancy safe.

Do NOT take any herbal supplements, medications, or over-the-counter drugs without first discussing these with your doctor.

Before attempting pregnancy, begin taking at least 400 micrograms of folic acid. Continue taking folic acid supplements throughout your pregnancy, as folic acid reduces the risks for neural tube defects in the developing fetus.

Ensure that you are within the proper weight range before becoming pregnant.

While Pregnant:

Get early and regular prenatal care.

Eat a nutritionally sound and healthy diet. Ensure that your diet is high in folate - natural folic acid - which is found in beans, leafy greens, orange juice, fortified grains and fortified breakfast cereals.

Do not eat fish that's high in mercury - shark, king mackerel, or tilefish. Limit white tuna to less than six ounces a week.

Begin pregnancy at a healthy BMI and maintain a healthy weight throughout pregnancy.

Exercise regularly - nothing more than you'd done pre-pregnancy.

Quit smoking, do not smoke, and be careful to avoid secondhand smoke.

Avoid alcohol - there is no established "safe dose" of alcohol during pregnancy.

Reduce stress.

Make sure to get plenty of rest.

Don't eat undercooked meat or eggs - these can lead to serious infections, like listeria, within the fetus.

Avoid lunch meats, soft cheeses, hot dogs, deli meats, pates, meat spreads,  unless they've been previously heated to prevent listeria infections.

Do not change a cat's litter box or dig in an area of the yard where cats may go to the bathroom. Cats can carry a parasite, known as Toxoplasma gondii. This parasite can cause toxoplasmosis in a developing fetus.

Minimize (or avoid) caffeine intake.

Avoid over the counter medications unless you have discussed them with your doctor.

Related Resource Pages on Band Back Together:

Pregnancy Resources

High Risk Pregnancy Resources

Pregnancy Week by Week




Gestational Diabetes




Multiples Pregnancy

Birth Defects

Additional Pregnancy At Advanced Maternal Age Resources:

Canadian Medical Association - AMA - scholarly article about pregnancy and advanced maternal age.