Hook effect -wtf!!!

[MissYogi]

I have just discovered something crazy! I am 7 weeks and yesterday I had a bit of brown spotting that had me really nervous so I took a test. It was around 5 in the evening and I had been drinking lots of water so my urine was very clear. Thankfully the test line was nice and dark, darker than the control so I felt a bit reassured. This morning I decided to test again with fmu and got right freaked out when I saw that the line was lighter than the control. So I checked in with Dr Google and found something very interesting. Apparently at a certain point some women experience light lines when their hcg gets very high. I read all about it and I guess it's because there are different types of hcg and one type doesn't make tests show color. So if you have a lot of that type, then it binds to the receptors in the test and blocks them from the hcg that would show color. The way to correct it is to dilute the urine after you get to a certain level of hcg.

I took another test a few hours later after drinking tons of water and lo and behold it's nice and dark again! I can't believe it! This should be written in big bold letters on all tests!

 

[SonnyH]

I know so many people on here are huge worriers but honestly, at 7 weeks, please stop worrying about testing! Shop pregnancy tests are simply designed to give two lines or one line a day or so after a missed period. They are not designed to give super accurate readings weeks later as a blood test would do. Tests can be faulty, have an inconsistent level of dye or as you've found out, react differently as pregnancy progresses!

If you are worried about bleed, it's far better to contact your doctor or midwife than rely on a pregnancy test. A positive test does not mean something isn't wrong that needs checking. Missed miscarriage can occur where your HCG would stay elevated. In all likelihood everything is probably absoloutly fine and you have nothing to worry about but please do use your health professionals for concerns rather than mass made shop bought tests!

Hope the rest of your pregnancy goes well

 

[MissYogi]

I know so many people on here are huge worriers but honestly, at 7 weeks, please stop worrying about testing! Shop pregnancy tests are simply designed to give two lines or one line a day or so after a missed period. They are not designed to give super accurate readings weeks later as a blood test would do. Tests can be faulty, have an inconsistent level of dye or as you've found out, react differently as pregnancy progresses!

If you are worried about bleed, it's far better to contact your doctor or midwife than rely on a pregnancy test. A positive test does not mean something isn't wrong that needs checking. Missed miscarriage can occur where your HCG would stay elevated. In all likelihood everything is probably absoloutly fine and you have nothing to worry about but please do use your health professionals for concerns rather than mass made shop bought tests!

Hope the rest of your pregnancy goes well

Thanks for your thoughts. I am certainly not putting all of my confidence on a test, I actually did call my midwife and have taken all the appropriate steps. Many women just like to test for reassurance as well which is what I was doing. I only found the hook effect interesting and wanted to share it with others who many experience the same thing.

 

[second.time]

I actually did this with my first pregnancy. I had a light test at maybe 5/6 weeks and it freaked me out. So I diluted with a ton of water until there was barely any urine and dipped and the line was nice and strong again. Kind of weird!

 

[LuBru]

Thanks for sharing this MissYogi, I agree we shouldn't be POAS but sometimes it is just reassuring somehow (I just did the exact same thing after I started spotting) and I would not have known about the hook effect. It's pretty weird! Thanks

 

[Sommerfugl]

I discovered this when I was about 8 weeks and started to panic that my tests were getting light again. It's very odd, actually diluting urine can make the tests stronger. That was the moment I finally accepted it was time to stop obsessively testing multiple times per day

 

[ricschick]

wow this is so interesting to know!!

 

[MissYogi]

It's crazy isn't it! I'm tempted to actually go and get some cheapies to test out just to see the difference now that I'm 8 weeks along. I was just amazed that this wasn't common knowledge.

 

[Holliems]

I know this post is old, but I diluted urine tonight and dipped a test, just to see what would happen. Im only 5 weeks today. Anyway, my FRER lines are the same boldness as the control line. Its been stuck like that for like 4 days.

I used half FMU and half water. The line came out exactly the same as the FMU only test! Maybe a hair darker. Weird!

I think Im too early for the hook effect, but I thought it was interesting to see that happen.