Here's Why Your Pregnancy Test Lines May Get Lighter
Try not to worry.
Questioning whether or not you are pregnant can definitely be a time of anxious nerves and uncertainty. Especially if you are actively trying to conceive, when you take a pregnancy test at home and see that positive line, you might feel a sense of cautious happiness, which can tempt you to test again and again. And if you see the positive line fading and the pregnancy tests getting lighter, you might be totally confused.
First things first, the easiest way to figure out what is actually happening if you are confused by or nervous about a pregnancy test at home is to go and see a medical professional. “Certainly, see your doctor to draw a quantitative test to get answers,” Dr. Allison Rodgers, M.D., OB/GYN and director of education at Fertility Centers of Illinois, tells Romper. In-clinic blood tests that measure your levels of human chorionic gonadotropin (hCG) will tell you for certain whether or not you are pregnant.
That being said, your at-home pregnancy tests getting lighter doesn’t necessarily mean anything is changing, and so you definitely shouldn’t panic — it could be due to a number of other factors. To help break down what exactly it means when pregnancy test lines get lighter, Romper spoke to some experts to help clear it up.
How A Pregnancy Test Works
It's important to know how a pregnancy test works in the first place. Home pregnancy indicator tests are used by putting a few drops of urine on the cassette test, which will then show two lines: a control line (to make sure the test is working) and a test line.
Home pregnancy tests detect hCG hormone, which is produced after your fertilized egg implants itself into your uterus. The hormone is released into your blood and urine during early pregnancy, and the positive lines on the pregnancy test show up only when hCG is present.
An important thing to note, though, is that urine pregnancy tests are qualitative tests. They tell you if you are pregnant, a simple yes or no. Blood tests, on the other hand, can tell you the quantitative levels of hCG in your blood, which is why if you do have questions, going to the doctor’s office will be your best bet.
Why The Lines Might Be Lighter
So, what does it mean if the lines are darker or lighter? “Remember these are qualitative tests, so only yes or no,” Rodgers says. “You cannot use the lightness or darkness of the line to tell you anything.” Given that, there are some potential reasons as to why your pregnancy tests are getting lighter with time.
Typically, the darker the line, the more hormone is reacting to the test. So, if the line is very faint, it may indicate a very low level of hCG in your urine. Those levels of hormones can fluctuate depending on how much fluid you’ve had to drink, how often you urinate, or what time of day you test.
“If you are super hydrated or dehydrated, this can influence the concentration of the hormone in your urine,” Rodgers says. “Also, time of day may influence it. [The] first urine of the morning has been concentrating the hormone all night and may be higher.” So, if you drink a lot of water or test toward the end of the day, the line may be lighter.
But does a lighter line indicate a change in your pregnancy? Rodgers says possibly. “If the line is getting lighter, it may indicate the pregnancy levels are dropping and you should get blood levels to confirm,” she says. “A blood test can tell you for sure if the number is going up or down.” But it could also simply be that you drank a ton of water that day. Remember, if you get a positive line on a home pregnancy test — even a faint one — it’s indicating the presence of hCG in your system, which still means you are likely pregnant.
If you are worried about your pregnancy and have questions, it's best not to worry yourself by taking repeated at-home tests. If you do see a positive line and think you are pregnant, it's best to call your doctor and make an appointment. Doctors can provide you with blood tests and ultrasounds, which will give you more accurate results and analysis. In the meantime, enjoy the positive lines and positive vibes that are coming your way.
Dr. Allison Rodgers, OB/GYN and director of education at Fertility Centers of Illinois
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