Pregnancy After 40

Pregnancy After 40 Statistics: A Closer Look

Couple with Doctor looking at sonogram
Written by Leslie Sangster

So it has finally happened! After trying for what seems like an endless amount of time you’re pregnant! Now you want to see how to keep your baby healthy as he grows in your belly. You know that typically younger women have babies, but you’re pregnant now! So you go to the web and start looking for information about….you start looking for….wait….this isn’t a happy time? Oh no, this is bad! Really bad! All of the statistics say that….that….your pregnancy is horrible! It’s far too late, and now it just isn’t going to work out. Stat after stat tells about how it isn’t likely this and is too risky that….you’re just about ready to throw your device out the window!

Well don’t worry too much. Those horrible looking statistics aren’t really as bad as they seem when you first see them. You see, there are ways to take the same data and present it as positive or negative, depending on what the stats actually are. In this article, we’ll go through how the stats for having a baby after 40 are typically presented. Then we’ll look at other ways of presenting the same data with the same meaning but a different spin.

One of the things you’ll see repeatedly is that a woman in her 40s has an “increased chance” of some undesirable outcome happening during pregnancy. Many times, these stats are true. However, they are often expressed in a way that makes them look far more scary than they really are. Let’s take a look at some of these stats.

Gestational Diabetes

Gestational diabetes (GD) is a type of diabetes that occurs in women who develop diabetes during their pregnancy when they were not diabetic before being pregnant. GD happens when your body doesn’t create enough insulin while being pregnant. Because your body is creating more hormones, at times this causes your body’s cells to be less efficient in using insulin, resulting in your body needing more insulin to operate properly.

According to Diabetes Research and Clinical Practice, a woman at age 40 is 5 times more likely to develop Gestational Diabetes than a younger woman. While that looks pretty bad, let’s take a closer look at the numbers. The actual cutoff used in the study is 25. That means that every woman over the age of 25 is more likely to have Gestational Diabetes.

The “younger woman” in the statement above is an 18 year old. According to the study, the chances of Gestational Diabetes increases every year after age 18. This means that 40 isn’t some “magical number” but the chances do consistently increase with time.

Now for the actual numbers: The chances of an 18 year old getting GD is around 1.1%. The chances of a 40 year old getting GD is around 5.8%, a little more than 5 times the chances of an 18 year old. Let me put that another way: You have a 94.2% chance of not developing GD if you are 40 years old, where an 18 year old has a 98.9% chance of not developing GD. Expressed as the chance of you avoiding this entirely, you see that there is a less than 5% difference in the development rate of a mother in her 40’s vs an 18 year old! It’s all in the way the data is presented.

So once we know the actual numbers, you can see that with avoidance odds of 94.2%, there really isn’t too much of a reason to worry. You definitely want to minimize your chances of developing GD, but know that many of the stats make it seem more likely that it will happen than it actually is.

Gestational Hypertension (High Blood Pressure)

In general, blood pressure is the pressure of the blood in your body pushing against the walls of your arteries, similar to filling a balloon with air. High Blood Pressure is when there is too much force pushing against your arteries. This can cause other health issues, similar to putting too much air in a balloon which can cause the balloon to pop. It can also lead to preeclampsia, which is a blood disorder that affects all of the organs in the body.

According to medlineplus, diabetes can develop in some pregnant women, typically after 20 weeks of pregnancy. Many times there are no other complications and there is no additional risk to you or your baby. In most cases, it goes away around 3 months after giving birth but can increase the chances of developing hypertension later in life.

Women over 40 are at an increased risk for having Gestational hypertension (GH), another name for High Blood Pressure that develops while you are pregnant. So what does this actually mean?

A woman at 40 is 1.63 times more likely to have Gestational hypertension than a woman in her late twenties. So if there is a 40% chance in your twenties, then there’s a 65% chance in your 40s! That’s huge! Only, there’s NOT a 40% chance in your twenties.

Around 7% of pregnancies result in GH. According to the American Journal of Hypertension there is not a consistent risk for developing GH based on age. What they found is that the risks for GH increase with the increase of extra weight carried by the mother. So the more overweight you are, the more likely you are to develop GH. As older mothers are more likely to be overweight than younger mothers, there seems to be a pattern related to age.

But once weight is removed from the formula, there is not statistical difference in developing GH with younger or older pregnant women. So while older women develop GH more often than younger women, if you keep your weight under control there is no difference in developing GH according to the statistics.

Genetic Defects

This is a big one that prospective mothers worry about. The thought of having a child whose life will be hard from the beginning due to a genetic disorder is enough to keep many women up at nights. Now you’ve likely heard all about this, and about how you are more likely to give birth to a baby with some type of genetic anomaly if you are over 40. Well let’s take a closer look at the numbers.

A mother at 40 is 8 times more likely to have a baby born with a defect than a mother at age 20. Eight times! That looks like it’s just destined to happen, right? Well, not exactly. If you look at the numbers there is a 0.19% chance that a woman at age 20 will have a baby with a defect. For a woman at 40, there’s a 1.52% chance of having a baby with a defect. That means at age 20, there’s a 99.81% chance of having a baby with no defect, and at age 40 there’s a 98.48% chance of having a baby with no defect.

So while the math is correct as a mother at 40 is 8 times more likely to have a baby born with a defect, that’s not the whole story. Because the chance is so small to begin with, a 1% increase in the chance leads to the “8 times more likely” stat, which sounds far scarier than it actually is.

Down Syndrome

Here’s a specific genetic defect that worries a lot of women. Down syndrome is the most common disorder that children are born with. It involves a child being born with an extra chromosome which can cause mental and physical differences from a child with Down Syndrome and a child without it.

Mothers in their 40s are 13 times more likely to have a child with Down Syndrome than a mother in her early 20s. Thirteen times! Surely this means that it’s just bound to happen right? Well lets take a closer look at the numbers….

The chances of a woman in her 20s giving birth to a child with Down syndrome is 0.063%. That’s point zero six three percent!! That means it happens around once every 1500 births. The chances of a woman in her 40s is 0.816%. That means it’s almost 1 in 100 for a woman in her 40s. So yes, the chance goes up, but because it is so rare an occurrence to begin with, increasing the chances still means that a woman over 40 as a greater than 99% chance of having a child who doesn’t have down syndrome.

Cesarean Section

A Cesarean Section is the delivery of a baby by creating an incision in the mothers’ stomach and uterus and removing the baby. This is done when the doctor determines that it is a safer method of birth than delivering the baby vaginally. The rate of Cesarean sections in the world is about 19%.

Now this is where there does seem to be a significant difference in ages. For women in their early 20s, the Cesarean rate is 16.5%. For women over 45 the rate of having a Cesarean section is 49.2%. In addition women the rate of going into labor naturally decreases with age. Women in their 20s went into labor naturally 73% of the time, whereas women over 35 went into labor naturally 55% of the time, an 18% drop.

Here there is a noticeably greater chance of having a C-Section than having a vaginal delivery if you are over 40. Having a C-Section, however, is not particularly dangerous, with a death rate of about 5.8 per 100,000 procedures.

Chances of Getting Pregnant

So, here’s the reason many of you are here: What are my chances of getting pregnant? Well, the short answer you don’t have as much of a chance as you did when you were younger, but you already knew that. Once of the reasons female fertility decreases with age is because women are born with all of the eggs they’ll have in their lifetimes. You release an egg each menstrual cycle, and over time deplete the eggs you were born with.

A woman at 40 years old has about a 5% chance of becoming pregnant each month. A woman in her 20’s to early 30s has about a 20% chance of becoming pregnant each month, so women in their 40s are 4 times less likely to get pregnant each month.

This is one statistic that has not be spun by the media to look worse than it is. There is a significantly lower chance of becoming pregnant when you hit age 40, although it is made to look more daunting due to the fact that it is much more likely to happen to women in their 20 and 30s. After a year of trying women in their 20s have about a 97% chance of becoming pregnant, while a woman in her 40s after a year of trying has about a 46% chance of becoming pregnant. While the odds aren’t nearly as good as they are for younger women, there is still a roughly 50% chance per year for a woman in her 40’s to become pregnant naturally.

Of course this chance doesn’t take into account alternative methods of pregnancy like in vitro fertilization or others. So although your chances are reduced, they aren’t exactly 0 as a 46% chance per year means a fair number of women over 40 will conceive naturally.

Premature Labor & Preterm Birth

Premature labor is when you begin having contractions that start before the 37th week of your pregnancy. This can lead to your child being born before fully maturing in your womb. This is called a preterm birth, which is when your baby is born between 20 and 37 weeks. Because your baby is not fully matured, they can be born with health issues. The biggest risk for health issues is with babies that are born before 34 weeks.

About 12% of all births are preterm births according to the Obstetrics & Gynecology Green Journal. For women over 40, most of the time a baby is born prematurely is due to a recommended medical procedure to preserve the health of both the baby and the mother. According to the Public Library of Science the major causes of preterm birth are the condition placenta pravia, complications from high blood pressure and the previous history of the mother. But even apart from those factors, they found that the mother being over 40 was a risk factor in preterm birth. The good news is that only 10% of women who have preterm labor go on to have preterm deliveries within 7 days of the labor beginning. For 30% of women the labor stops without any intervention.

The age group that has the lowest chance of premature labor and delivery is ages 30-34. So for women over 40 there is a greater risk. Note that there is also a greater risk for women under 30, particularly under 20.

The actual numbers are about a 5.7% chance of preterm birth for mothers in the 30-34 age range, while mothers over 40 have a 7.8% chance of preterm birth. That means there is a 2.2% difference in percentages between the age group with the lowest incidence of preterm birth, and women over 40. So although the chances are greater in your 40’s, they really aren’t much greater.


Miscarriage is the termination of a pregnancy before the 20th week. Some of the signs of a miscarriage are as follows:

Women under 35 have about a 15% chance of miscarriage. Women over 40 have between a 20 and 35% chance of miscarriage. Other factors can contribute to the chance of a miscarriage, such as not being physically active or smoking. These factors can become more pronounced with age. Note that over 50% of all miscarriages are caused by a Chemical Pregnancy, which is a miscarriage that occurs right after the embryo implants. This typically happens before the pregnancy is 5 weeks old, which in many cases is before the mother knows she is pregnant.

Based on the statistics, there is a larger chance of a miscarriage for women over 40 than for younger women. Note, however, that the chance of a successful pregnancy is still 65% at worst for women over 40, with the range going all the way to 80%. For younger women, the chance of a successful pregnancy is 85%. So the numbers aren’t really that far apart.

So yes, there is more of a risk of miscarriage as you age. There are, however, some things you can do to reduce your chances. These include:

Note that there are increased risks both for women over 35 years AND for women under 20 years old.

Admission to Intensive Care

There are other statistics, like the fact that women over 40 are 2.8 times more likely to be admitted to intensive care than women in their 20s. Looking closer at the statistics, however, shows the fact that the incidence of women in their 20s being admitted is 0.5%. That’s half a percent. The incidence of women in their 40’s being admitted to intensive care is 1.4%, or less than one percent higher. That means women in their 40s have a 98.6 percent chance of avoiding intensive care, as compared to 99.5% chance in your 20s. It’s all in how you present the numbers.

Conceiving in an imperfect world

So is it ideal to become pregnant after 40? No, it isn’t. If this were a perfect world, you would become pregnant when you are 24.6 years old and have 3.2 children to go with your husband who you dated for 4.8 years and married. But since we don’t live in that world, sometimes it can take longer to get all of the factors completely in order.

As a result, some people can become pregnant later than the “ideal”. Looking at the statistics can help to prepare you for what’s to come, but some of the statistics are presented in ways that make having a baby after 40 look like you’re trying to drive to the moon. This is hardly the case. The vast majority of women will have happy, healthy babies based on those statistics you’ve been seeing on other sites. Just keep in mind that they’re always presented from the standpoint of what will go wrong, as opposed to showing you the stats on what can (and probably will) go right. So you definitely will have to take more precautions than you would have in your 20’s, but they’ll be worth it when you will likely have a healthy baby once you give birth. Good luck!

Disclaimer: The content in this article is merely the writer's opinion and information - not advice. If you have questions, you should always seek the advice of a doctor or another appropriate medical professional.