How Long Is Pregnancy? 5 Ways To Prepare

Published May 31st, 2022 by Bridget Reed
Fact Checked by
Camille Freking
Medically Reviewed:
Dr. Angel Rivera

Most pregnancies last about 40 weeks. This term length is associated with the best health outcomes for the baby and the mom. 

It’s possible for pregnancies to be pre-term (less than 37 weeks) or post-term (more than 42 weeks), which is linked to less ideal health outcomes for mom and baby.

While some short or long-term pregnancies are out of the mother’s control, some can be impacted by what the mother does before and during her pregnancy. 

In this guide from USA Rx, we explain how long a healthy pregnancy should last, and five ways you can prepare to make your pregnancy as healthy as possible. 

How Long Is Pregnancy? 

A healthy pregnancy should last approximately 40 weeks.

The estimated due date, or EDD, will be calculated by your healthcare provider based on the first day of your last menstrual period (LMP).

Carrying a baby for its full gestation, aka a full-term pregnancy, is associated with better outcomes for both the baby’s body and the pregnant parent’s.

However, many pregnancies are shorter or longer than the ideal 40 weeks. 

How far you carry through the third trimester before giving birth can be affected by many different factors, health conditions, and levels of uterine hormones like oxytocin and prolactin.

how long is pregnancy image

Pre-Term Pregnancies

A pregnancy that lasts 37 to 38 weeks is called pre-term. Because the last few weeks of pregnancy are when a substantial amount of brain, heart, and lung development happens, pre-term babies are much more likely to experience health problems after being born. 

Some health conditions are likely to contribute to premature births, such as an incompetent cervix (also called cervical insufficiency) where the cervical tissue becomes too weak to support the baby.

Post-Term Pregnancies

When the length of pregnancy goes past your due date and surpasses 42 weeks, it is called a post-term pregnancy.

While babies likely won’t be harmed by spending extra time in the womb,  they can still experience health problems like reduced oxygen flow due to decreased amniotic fluid.

For this reason, your healthcare provider may run additional tests like ultrasounds, fetal heart rate testing, and measurements of the amniotic fluid volume to keep an eye on your post-term baby’s health at this higher gestational age.

Pregnant women can suffer from post-term pregnancy as well. A post-term birth with a longer gestational period is associated with a higher risk of longer labor, vaginal tearing, bacterial infection, and excessive bleeding.

It is also associated with an increased need for a C-section. 

5 Ways To Prepare for Pregnancy 

It’s important to be as healthy as possible before and during your pregnancy to carry to full term. 

This can include health information gathering from trusted sources like your own healthcare professional, the American College of Obstetricians and Gynecologists (ACOG), What to Expect When You’re Expecting, and even the CDC, as well as ensuring you start with prenatal care as early as possible. 

If you are planning on getting pregnant, these are five things you can do for your and your future baby’s health.

1. Improve Your Nutrition 

If you have any vitamin deficiencies, now’s the time to get them addressed.

While every deficiency should be addressed, two nutrients are especially important: folate and iron. 

Folate is needed for your baby to develop a healthy central nervous system, while iron helps your body increase blood flow and deliver much-needed nutrients to the placenta. 

If you’re actively trying to conceive, your doctor might recommend that you start taking prenatal vitamins, which contain high amounts of folate and iron.

You should also try to optimize your diet as much as possible. Vitamins, minerals, and even overall calories consumed can play a major role in your developing baby’s health. 

Although nutrition is important in the second trimester and beyond, the first trimester is when most significant, nutrition-based development happens.

Instead of playing catch-up during this crucial period, it’s best to be prepared from day one. 

2. Quit Your Unhealthy Habits

If you smoke, consume a lot of alcohol, or do illicit drugs, it’s best to stop before even the first week of pregnancy.

Unhealthy habits can interfere with a baby’s development and impact how easy it is for you to conceive. 

For instance, studies show that female smokers have much lower fertility than non-smokers.

This can also apply to the father, whose sperm count and quality can decrease due to smoking.

Fortunately, dropping unhealthy lifestyle habits (such as quitting smoking) can improve your fertility in as little as one month. 

3. Get to a Healthy Weight

According to clinical guidelines, there is a “right” amount of weight gain during pregnancy. If you gain too little, then your baby may not develop properly.

If you gain too much, you might be at an increased risk for health conditions like gestational diabetes and preeclampsia, and your baby may experience health complications after birth. 

Check your body mass index (BMI) by using an online calculator.

If you’re underweight or overweight, talk to your doctor about what you can do to get to a healthy weight safely. 

4. Start Exercising 

Exercise has tons of health benefits during pregnancy, such as better sleep, reduced food cravings, higher energy levels, and a balanced mood.

Exercise can also decrease your risk of pregnancy complications, such as gestational diabetes, preeclampsia, and blood clots. 

The body will experience tons of changes during pregnancy, which means that starting an exercise routine during this time is not the easiest task.

It’s much better to build an exercise routine before you get pregnant. That way, you’ll feel like you’re just continuing an old habit. 

5. Understand How Conception Works 

After you’ve optimized your health (and your fertility) using the strategies above, you can start trying to get pregnant. It’s important to know how conception works to do this effectively. 

During a month-long menstrual cycle, you have about seven days when you can get pregnant.

This is typically the five days leading up to the day of ovulation, ovulation itself, then the day after.

If you miss this window, you’ll have to wait another month to try for pregnancy.

Learn as much as you can about conception, such as how to tell when you’re ovulating, the best positions for getting pregnant, and how often you should be having sex. 

In Conclusion

While pregnancy can range from 36-43 weeks, the healthiest pregnancy term is about 40 weeks.

It’s important to eat healthily, start an exercise routine, and drop any unhealthy lifestyle factors to increase your chances of carrying to full term.

Once you’ve optimized your health, you can start learning all you can about conception and beginning your pregnancy journey.

References and Sources: 

Epidemiology and Related Risk Factors of Preterm Labor as an obstetrics emergency | PMC 

The Effects of Smoking on Ovarian Function and Fertility During Assisted Reproduction Cycles | NCBI

Weight Gain During Pregnancy | CDC 

Calculate Your BMI | Standard BMI Calculator