'The hook effect ' pregnancy tests. Lighter tests at 8 weeks

[Gemmaemilyx]

Hi all.

Just wanted to post on here to give some reassurance to people who test regularly and see their test line gradually becoming lighter as weeks go on. I found this was called 'the hook effect' where the test is overwhelmed by the amount of HCG the farther along you are and your test line becomes fainter than the control.

To test this out my top line is first morning wee at 8 weeks and it is considerably lighter than it has been in the past. The bottom test is diluted with some water and as you can see it is a lot darker! Same urine sample! Hopefully can save some people some worry

Best wishes to everyone on their journeys x

I have just experienced this!!!

My heart stopped for a second.

So can you take the hook effect as a good thing?

I’d say it’s a normal thing! As people in this post say it’s never happened to them, but it’s happened to a few people too!

I now have a lovely 18 month old daughter :-)

Good luck with the rest of your pregnancy, try and put the tests down as hard as it is to do! I certainly had my fair share of anxiety induced tests haha!!

sending love xxx

That's really kind.

Thank you for the reply.

I am currently 6 weeks today, I've had all symptoms but the sickness has gone today so started to panic, but people are saying to relax.

It's hard I agree :(

Thank you xxx

I had the exact same. My symptoms would disappear for days and I’d be full blown panicking. They then came back with vengeance haha!! Good luck I’m sure all will be fine and let us know how you get on (especially in 8-9 months time!!) xxx

Hi all-
My Husband and I started trying again when my daughter was 6 months old as it was very difficult to conceive and we wanted two kids close together. I needed to first have my gallbladder checked due to stomach issues and rescheduled a test that used radiation, which I was scheduled to have and had to postpone due to learning of my first pregnancy with my daughter. So- GP re-schedules tests and asks if I could be pregnant. I responded highly unlikely as we had been “trying” for maybe a week. He ordered a blood test just in case. Blood test taken around 4pm, came back negative. Gallbladder test set for 5am the following morning. I had a weird feeling that night I was pregnant so I saved the first morning urine in a cup and had hubs take me to “store” under some false guise—- I felt too silly to say I was getting a home pregnancy/ urine test on way to the hospital that was performing the gallbladder test given the incredible unlikelihood of pregnancy not just from blood test but of hardly being off birth control. At hospital, I asked hubs to start check in and discreetly dipped the stick before leaving car. It was positive. Now I was in a real situation—- how could I explain something so inexplicable? I was also worried insurance wouldn’t cover the test or that I would have a large cancellation fee if I didn’t provide a valid reason for yet again having a last minute cancellation. The hospital outright refused, though suspicious, to continue with the gallbladder test, stating that it wasn’t worth the risk. The following week, my GP asked for an explanation, stating that it was simply not possible for a urine test to be positive so soon after a negative blood test. At that point, I had already seen my OB who confirmed the pregnancy, laughingly, with an ultrasound. My son was a full term healthy baby boy. Backdating his due date, I would have been 9 weeks pregnant at the time I was scheduled to have the gallbladder test/neg blood test/pos hpt. Having just had yet another person tell me this was impossible and bored over the lunch break —- now nearly ten years later, I searched the internet for some explanation. I’ve just always called him my miracle baby and chalked it up to rare lab error. Given that it seems what I experienced was incredibly rare—- here to share that if you had a negative blood test followed within the same 12 hours by a positive urine test, there is no need to fear that something is wrong with the fetus (if OB confirms the pregnancy)— rather it’s possible something was wrong with one of the test results. Less likely, but possible. Again, caveat, don’t assume anything until an OB confirms but also don’t blow off a positive hpt. For those who say it isn’t possible…..because you obviously haven’t experienced it—— imagine how entertaining it was to walk into my GP’s office with my newborn (after being told what I said was simply impossible, knowing he now couldn’t refute the math) to let him know it was probably now safe to reschedule that gallbladder test. The hook effect does seem to explain what I experienced regarding the false negative blood test….as it was immediately followed by the expensive, & digital, at home test. I can also say that it’s the fourth time I’ve been dismissed only to later learn my medical suspicion was valid. I have the impression that patients who “just know things”… not with anxiety but the matter of fact ones, are shrugged off by doctors who are accustomed to patients either less in tune with their bodies or too into wanting to self diagnose. Go off your history… why do you feel the way you do? Are you often a hypochondriac? Are you anxious for another reason? If so, trust doctors and loved ones. Be cautious in activities if it helps ease your concern. If you have a valid reason other than what’s just in your head, like I did with the positive test, then follow up with the doctor before making any assumption.

Hook effect is so rare 0.2% to 2.0% of pregnancies. Plus it has to be a false negative with serial dilution to prove it was indeed the hook effect. Now fragment hook is more common than the hook effect. H-hcg hcg Bhcg bcfhcg are the types . These subnits would over load a test once the levels are higher. Why sometimes urine test don't work in later first tri to rarely 3 rd tri pregnancy. The issue was found in 2009 since then thefda has new protocols for new manufactured test. Ie one of the poct test cenmed upgraded the antibody formula. The new clear blue early digital pregnancy test had to be approved. Part of its approval is going through the hook effect testing I'll see if I can post the link if y'all interested.

Usually the levels get lower in second tri hook effect is really rare. Only 0.2% to 2.0 %of pregnancies . Newer pregnancy test are supposed to pass the hook effect phase of testing. Trust me I did a lot of research since I had a scare and tested around 7 weeks. Stark negative then I red about the hook effect serial dilution and looked into the newest pregnancy test realsed. Even dove as far as reading the FDA studies on first response gold digital and newer test clear blue early digital. Brought em asap. Highly unlikely I'm pregnant have blood work Monday.

So long story but advice
15th December positive tests started bleeding a little. tested negative for days although still had early preg symptoms.. week later positive again..
had on off positive and negative tests since 22nd December using various different brands
still feel pregnant also
had blood took on the 6th which was 2hcg
so unlikely pregnant they said
yet still positive tests for the last 3 days since
my boobs are swollen to point there sore, feel sick and dizzy, swollen belly.. etc
all the symptoms to why I tested in first place

now I’ve read somthing about hook effect? Any one had anything similar?
I have been known to carry twins which I also read that was common for hook effect also..
doctors are not listening to me they think I’m mad.. but why would I feel pregnant plus all the positive tests
added photos of some of my tests

i have literally tested every single day