That’s not chardonnay

Is anyone else watching VEEP? There was so much press around the show, but I don’t know anyone else who watches it. Two weeks ago we find out Selina Meyers – the VEEP – is pregnant. She pees in a cup and makes her assistant test about 20 urine pregnancy tests to find the answer. The answer is yes.  In my head, the next scene is her freaking out and demanding to know that the test is wrong. I should be a TV writer. It was a good scene.

What is the chance that that yes is really a no, and the test is a mistake?
I can tell her the answer: very very low.

What is the false positive rate on home pregnancy tests?
There isn’t an exact number in the literature … but basically it almost never happens.

First, know that a home pregnancy test is a test for the hormone BhCG (human chorionic gonadotropin). This is the “pregnancy hormone”. You need to follow instructions on the test. If it tells you to check the test in 2 minutes, check the test in 2 minutes. Sometimes waiting a few extra minutes can make the yes/no line appear faintly positive when it’s really just the saturation of the urine, not the pregnancy hormone. Besides straying from the instructions, if you don’t have BhCG in your body, and subsequently in your urine, the test should be negative.

There are only rare circumstances when you will have BhCG in your body and not be pregnant:

1. If you had a recent pregnancy, the hormone can stay in your system for up to 2 months. You can get pregnant again within weeks of giving birth though. If you take a pregnancy test a month after you gave birth and want to know if you are pregnant again, there is a chance the old pregnancy will be the “yes”. In cases like these, see your doctor for more definitive testing.

2. You may be pregnant, but with an abnormal pregnancy. This needs to be a totally separate post. Your doctor will likely be the one to diagnose you with an abnormal pregnancy.

3. Infertility treatments often use BhCG. If you are injecting BhCG into your system, it will be in your system. That’s obvious.

4. Rare types of ovarian cysts may produce the hCG hormone. The symptoms might be the same as early pregnancy: bloating, abdominal discomfort, nausea or vomiting. You will make an appointment to see a doctor when your home test comes back positive anyway, and these cysts are very rare.

5. Rare types of cancer can cause a positive pregnancy test too.

There may be one or two much rarer reasons I am forgetting. But for all these reasons, if you have a positive pregnancy test, make an appointment to see your doctor. It’s most likely true!

And, not to ruin the surprise, but the VEEP has a miscarriage. That story line closed. If only they asked me to contribute … I could have made a whole series around her pregnancy 🙂

One line two line. Pink line … pink line

I remember being a teenager and buying a home pregnancy test for a friend with a scare, too embarrassed (and afraid of being recognized by someone) to buy it herself. I’m not sure why I wasn’t equally afraid – we lived in the same town; I either had less innate shame, or the easy courage that comes of having nothing to hide. In any case, her dread was contagious and we both ended up, anxious and sick with tension, waiting at her house (because no one else was at home) for those magic lines to appear: one line: not pregnant, good. Two lines: pregnant, and VERY bad.
Those few minutes seem to drag on for eternity.
One line … one line …. still only one line.
Only one line! We were both relieved.

Fast forward 10 years, now wanting and trying to get pregnant, and it stuns me to think that the test most of us would have loaded with that same teenage anxiety and fear, now represents an entirely different set of emotions, most ironically, the same amount of hope for the precisely different outcome!

When my friends try to get pregnant, many of them begin taking pregnancy test after pregnancy test and layering huge amounts of tension and worry into the process. We’re talking twice a day. We’re talking every post-coffee pee break. We’re talking all the time. They want to see ‘positive’ so much.

My friends aren’t crazy, of course. In certain circumstances, especially with certain tests (and if they would only wait a few days after each test), that line might show up. So that leads us all to the questions: which home pregnancy test is the best? Which test shows that you are pregnant the earliest?

Happily, a group of scientists wanted to answer this same question*. They compared the most popular over the counter tests: ClearBlue, EPT (Error Proof Test) , and First Response.

I’ll skip the scientific part of testing and methods, and get to the good stuff: women who were trying to get pregnant (and ended up pregnant at the time their urine was tested) had their urine tested on the first day of their missed menstrual cycle, and then again 3 days later (so they were 4 days “late”). The study figured out when the women should have their next menses by averaging their last 5 menstrual cycles.

The winner for earliest detection was First Response, hands down…or seat down.

Let’s look at it brand by brand:
(all the following claims are quoted directly from their respective websites)


ClearBlue Easy claims you can “get results from home over 99% accurate from the day your period is due.”

RESULTS: The study would say, on the day of your missed menses, you can get 51% or 67% accuracy from the digital and manual tests, respectively. Accuracy increases daily after that, but the only time it gets to 100% accuracy is 5 days after your missed period (the day of your missed menses is Day 1). Obviously use the manual test.


EPT (Error proof test): “Over 99% accurate from the day of your expected period.”

RESULTS:  Accuracy is 68% for the digital version, and 53% for the manual test, on the day of your expected period. Similar to ClearBlue in that the 99% or better claim is only true 5 days after missed menses. Their digital version tested better.



First Response: “can now detect the pregnancy hormone, hCG, 6 days before your missed period.”

RESULTS: Accuracy was 96% for women on the day of the missed period. It was 99-100% accurate on Day 3 of the missed menstrual cycle. Of all 3 brands, it was the only one that showed a positive 6 days before the missed menses … but only in 25% of time. Overall, the rates of the other tests on day of missed menses were equal to this brand’s rate 3 days before your missed period. Manual and digital tests were basically the same.


My bottom line:
When you think you miss your period, wait a few more days, then take a home pregnancy test. It increases the accuracy to wait. All tests studied were 100% accurate 5 days after the expected first day of the period. If you can’t wait that long, use First Response for a more accurate test.

An old proverb to end:
One line, two line
yes or no
Your urine will tell you
what you want to know

By old I mean I just made it up. Feel free to spread the wisdom!

* Here’s the study I used for this information … if you’re interested in that sort of thing.
Cole, LA. The utility of six over-the-counter (home) pregnancy tests. Clin Chem Lab Med 2011; 49(8): 1317-1322