Think You Know How To Get Pregnant?
The fact that there are almost 8 billion people alive in the world today suggests we’re pretty good at producing babies but with around 3 million pregnancies every year in the US apparently unplanned, maybe we don’t know as much about this stuff as we think?
Here are 7 of my favorite, pregnancy-related bits of surprising science. If your friend had asked you for advice, how many would you’ve got right?
1. If we were like cats, more women would get pregnant even more of the time!
Female cats are induced ovulators - they release eggs only if they’ve had party time! Linking egg release to the definite presence of sperm makes cats excellent at getting pregnant but the male cat’s spikey penis that scrapes up and down the vagina to trigger that valuable ovulation?
Definitely not so appealing.
More seriously, research suggests women might be induced to ovulate by the acute stress experienced during a sexual assault, making pregnancy sadly, much more likely to happen as a consequence of an assault than from consensual sex.
2. Women don’t ovulate when they think they do and it doesn’t matter!
School taught us women have a 28d cycle with ovulation on d.14, right?
Apparently not.
A giant study of over a million women’s menstrual cycles found only 16% of the cycles were 28 days long and only 10% of the women regularly ovulated on d.14.
There are typically no more than 6 days a month when a woman can get pregnant and five of them are ….. before ovulation. When it comes to that month’s chance of getting pregnant, ovulation marks only the very last chance because without a hot date with a sperm, eggs live less than 24 hours after their release from the ovary.
3. Ditch the calendar and spin mucus!
A rather persuasive group of scientists convinced women to “spin and score” their vaginal mucus every day for a collective total of 8000 menstrual cycles.
Impressive on all counts!
Comparing the mucus report sheets with the timing of date night, it was clear that the women who had unprotected sex when their mucus was especially stretchy and slippery (usually about 48 hours before ovulation) were more likely to get pregnant than those who waited for ovulation day.
(Interested in learning how to “spin and score” vaginal mucus, for pregnancy or contraceptive use? Head over to our geek notes!)
4. Sperm production is an impressive process.
For a man to be classed as fertile, he needs to fill every teaspoon he ejaculates with at least 75 million healthy sperm.
And even with daily sex most fertile men can maintain that eye-watering number.
Why these huge numbers though?
After sex, sperm start a challenging trek from the vagina, through the uterus to a fallopian tube where the magic happens.
Magic being sperm and egg fusion, or fertilization to be technical.
The crowds of sperm toeing the start line along with the fact that many sperm live at least 5 days, increases the odds that some sperm will make it to the newly released egg, even if the sperm “drop off” was 4 days earlier!
And that 5 day lifespan by the way? That’s only if those sperm are somewhere inside a woman’s reproductive plumbing.
On a toilet seat or in the balmy bubbles of a hot tub?
In less time than it takes to boil an egg, those sperm will be fried - don’t believe anyone who says they got pregnant that way!
5. Deciding on that special sperm donor? Choose the bookworm not the gym rat.
Those hyper-masculine-looking men using anabolic steroids?
Somewhat counterintuitively, their sperm counts are heading in the wrong direction, maybe even to zero!
Producing and releasing healthy sperm and eggs involves a long list of hormones.
“The Pill” for instance, works by flooding the body with too much estrogen/progesterone which switches off the production of the other key hormones vital for mature egg production and release.
Overflow a body with muscle-making gym juice – the anabolic steroids that contain testosterone like-chemicals, and as with the Pill, the body’s production of other key hormones stops – in this case the ones needed for sperm production.
(Not to mention the shrinking testicles and breast development that commonly happen in men using these testosterone-based drugs – a post for a future date?)
6. Still not sure who to choose?
If having a baby is the priority, forget love at first sight - lust at first smell could be the key.
Picture this scene.
Instead of swiping right to choose a date, a number of volunteers opened up their gift from the scientists, a package of 10 unwashed t-shirts, worn by potential dates, and inhaled deeply. They sniffed, reported back and were set up on a date night with the owner of their favorite armpit smell.
By looking at who chose who, scientists saw, repeatedly, that people found the smell of people with different immune system biology to them, the most appealing – and that combination of different immune systems probably makes for a healthy baby.
Of course, all this won’t necessarily help people partner up with someone who might make a half-decent life partner, but then, neither will Tinder!
7. If conception and pregnancy don’t mean the same thing, what’s the difference?
A whole lot of biology and potential loss.
Conception has occurred once an intrepid sperm has survived the epic journey to fuse with an egg but all there is to show for that effort is a single, fertilized egg (now called a “zygote”). Over the next 8 months or so, an unimaginably large number of coordinated processes have to happen for that tiny zygote to make the trillions of cells in a healthy term infant.
In fact, getting from zygote to bouncing baby is like one of those world record YouTube domino attempts - if just one piece fails to fall, the whole attempt is likely to grind to a halt!
And these processes fail really frequently - only about 25% of zygotes continue on to become a live, term baby. Most of the doomed 75% of zygotes will be gone by the 6th week of pregnancy, most of them without a woman ever missing a period or knowing she‘d conceived.
Most unsuccessful zygotes fail because of genetic errors - a random problem in the production of that egg or sperm created an error in the DNA of that zygote. We’re not talking an inherited problem like cystic fibrosis here, just a one-off error but sadly the resulting zygote won’t survive.
One thing we do know about this massive, early loss is that, almost without exception, everything that can go wrong in the first 6 weeks, is unavoidable – knowing she’s pregnant, won’t help a woman avoid these losses but will tell her she’s suffered a loss.
Is that something to think about?
Our grandmothers didn’t have pregnancy tests that gave results just days after conception, instead they usually waited until a second missed period before visiting the doctor. Of course, they must have had hopes during those first few weeks but maybe, by not allowing themselves to truly contemplate being pregnant until they were beyond the phase of massive, unavoidable loss, were they somehow better off?
As always, this blog is for fun and interest. It’s not to give medical advice, but maybe to help you have those conversations if you need to.
And if you do? The very best of luck.
