Why Should Early Pregnancy Tests Be Taken in the Morning?

Positive Pregnancy Test
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Timing is one of the most questioned topics when it comes to pregnancy tests. Is it best to take a pregnancy test in the morning?

hCG Levels in Early Pregnancy

Many companies do recommend that you take their pregnancy test in the morning because first morning urine typically contains the highest concentration of human chorionic gonadotropin (hCG), the pregnancy hormone.

The good news is that hCG nearly doubles about every two days in early pregnancy.

That means that typically, after the fourth or fifth week of pregnancy, your hCG levels are high enough to give an accurate pregnancy test result without having to use first morning urine. This allows you to take a pregnancy test at any point in the day.

In other words, first morning urine is most important when you are choosing to test very early in pregnancy. This is typically defined as before the first day your period is due, or just after. The further away you are from when your period was due, the less important first morning urine is for the purposes of an accurate pregnancy test.

It does not matter if you urinate on the stick or in a cup when collecting the urine. This does not alter the concentration of hCG at all and will not alter the results of the test.

Ensure You Don't Forget to Take First Morning Urine

It happens—sometimes you forget to collect urine before you go to the bathroom first thing in the morning, whether because you're sleepy or in a rush.

To prevent yourself from forgetting, you can shut the toilet lid and either place the pregnancy test on the top or write a note to yourself.

What Can You Do If You Don't Have First Morning Urine?

Some women are not able to reliably test first thing in the morning—you may wind up having a schedule or situation that warrants a pregnancy test outside of the morning hours.

This might be due to a weird sleep schedule for work or school, or simply because you really want to know and don't want to wait until morning.

You can recreate first morning urine for a pregnancy test by not using the bathroom for at least four hours. You should also not drink more than you normally would. This is a pretty common mistake, thinking that you can simply drink more to get more urine. However, this may cause diluted urine and in turn affect results.

Will taking an early pregnancy test at night yield inaccurate results? Not necessarily. Again, it depends on how far along in your pregnancy you are. First morning urine is most important in early pregnancy.

You can also get a blood test. Accuracy of a blood pregnancy test is not dependent on the time of day that you test.

First Morning Urine and Digital Pregnancy Tests: How Far Along Are You?

Some digital pregnancy tests will have an indicator on the front that will give a read out of how far along the test estimates your pregnancy to be. If you are not using first morning urine, this portion of the test may be inaccurate. However, the actual result indicating whether or not you're pregnant is accurate.

The time estimate may be inaccurate because the amount of hCG in the urine may be different depending on when you take the test.

Your doctor or midwife would be the best person to talk to about the supposedly length of your gestation—the pregnancy test is merely guessing. Multiple factors could make this estimate inaccurate. An early ultrasound and discussion of your due date would be better at predicting the due date of your baby.

In all cases, you may want to follow up with a health care professional to confirm results and get the care that you need.

Sources:

Food and Drug Administration (FDA). Pregnancy. 2014. 

Nerenz RD, Butch AW, Woldemariam GA, Yarbrough ML, Grenache DG, Gronowski AM. Estimating the hCGβcf in urine during pregnancy. Clin Biochem. 2016 Feb;49(3):282-6. doi: 10.1016/j.clinbiochem.2015.10.020. Epub 2015 Nov 2.

Swiss Precision Diagnostics (SPD). FAQ on Pregnancy Tests.

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