Ask your phone if you are pregnant

You pull a face when you read the instructions. “Immerse the strip into the urine.” And you pee. Into a cup. And immerse the strip, as you’ve been instructed to do, “into the urine”. You count down: Three, Two, One. Then you lay the test flat onto a surface, making a mental note to clean it afterwards. And now you wait, for 5 minutes, trying not to peek, until the vital information is ready: pregnant or not pregnant.

Pregnancy tests have required women to pee on objects since 1350 BC; the objects have changed from wheat and barley to paper strips, but the experience has remained unsettling — Especially when you consider the mental state a woman is in when taking a pregnancy test. She may have tried to conceive for a long time, or may be anxious that she has conceived without wanting to. In any case, many women are weary when testing pregnancy, sitting anxiously in their bathroom waiting for results. Pregnancy tests can be expensive too. The average price of a test kit is about $10, and you can use each test only once, which means you have to buy a new one every time you want to run a test. This quickly adds up. Social media is full of trying-to-be-parents complaining about the amount they spend on pregnancy tests. What if there was an alternative to one-off pregnancy tests? Modern computer technology could revolutionise pregnancy tests.

A brief history of the at home pregnancy test

Women have used pregnancy tests at home for over 40 years. The first at home pregnancy test was created in 1967 by Margaret Crane and became available in US stores in 1977. Before women could test pregnancy at home, they consulted a laboratory that would then test their pregnancy with the ‘Bufo’ test. The Bufo test is both fascinating and disturbing: women would deliver a urine sample, which was then filled into a syringe and injected into a female toad. If the woman was pregnant the injected female toad would produce eggs within a day. Something in the urine of pregnant women makes toads produce eggs. Today we know that this ‘something’ is hormones, and pregnancy has a large effect on hormones in the female body.

Testing pregnancy with a strip of paper

The kind of pregnancy tests you are used to seeing today are paper strips, embedded in plastic, which measure hormones in the urine of women. The hCG hormone is detected by many urine pregnancy tests as it indicates pregnancy early on: hCG increases during the first two months of pregnancy and then plummets.

Hormones affect womens’ bodies

Many of the changes a woman’s body undergoes during pregnancy involve growth. Of course her belly, but also her breasts, feet, hands, and even vocal cords swell and feel different than they did before getting pregnant.

Hormones affect women’s voices

Hormones affect voices and can transform them; This is why we all live through a vocal change during puberty. It is also why men and women sound differently, with men having deeper voices than women. Effects of hormones on female voice have been studied for decades and researchers agree that female voices are affected by hormonal changes in their bodies. Female voice is sensitive to hormonal changes, so sensitive that researchers have found female voice to signal ovulation, the time of the month a woman is most fertile. A women’s voice becomes brighter shortly before ovulating. Listeners can perceive this and they find female voices most attractive when women are most fertile. This may allow couples — without being aware of it — to have sex at the right time to conceive.

Voice also changes during pregnancy. During pregnancy voice becomes more hoarse, deeper and scientists find that pregnant women have difficulties holding a tone for a long time. Professional female singers report that their voice can change so dramatically in pregnancy that they have to stop performing. After giving birth women’s voice changes back to normal.

Quantifying voice

Some people can hear how voices are changing in pregnancy, but many of us, including the author of this post, are neither that gifted nor well trained. Therefore it is useful to come up with ways to objectively quantify changes in voice. For quantifying voice you need essentially two things: technology to record voices and technology to analyse them. Microphones were reserved for specialists not too long ago; only researchers and media professionals would have had easy access to microphones. This has changed dramatically with modern, low-cost smart phones: about 69% of Americans own a smartphone and can easily record their voice with the built-in microphone and voice recording apps.

Today many of us can easily record their voice, but how do you quantify voice? Voice is complex and has many features like brightness, intonation and hoarseness, and it is not obvious how to quantify these. People are good in noting whether someone’s voice sounds hoarse, but how do you tell a computer that’s a hoarse voice? With modern technology this problem can be solved: instead of telling a computer that’s a hoarse voice, computers can learn by themselves what a hoarse voice is. Learning computers are sometimes described as having ‘Artificial Intelligence’. The technology making this possible is inspired by how the brain works and called deep learning. Computers can essentially learn to differentiate abstract features of voices, like hoarseness. Recently researchers have used deep learning to analyse voices of patients with astounding results: with this voice analysis technology researchers can accurately diagnose conditions like Parkinson’s, heart disease and depression.

Voice pregnancy test

Why not use voice analysis technology to detect pregnancy? In the future we could see a revolution in pregnancy testing. Women could ask their phone: “Hey, do you think I am pregnant?” and get an easy, quick, and accurate response.

Authors: Birgit Brüggemeier, Linda Börner