The process of a single cell forming and then growing into a baby is amazing, and the process of a pregnant body growing to accommodate that baby is too.
We are in the process of creating weekly posts, each accompanied by a new watercolor painting, walking through a normal pregnancy. As well as containing a wealth of information on the events that are occurring, these also contain information on what you might be feeling and some of the ways you might help ease common discomforts. Please discuss possible treatments and exercises with your healthcare provider before beginning them, as every body is different. All, of course, are wonderful!
Before the Beginning: Cycle day 1
When you were still inside a uterus yourself, millions of immature eggs idled in stasis in your ovaries, each waiting for the time when they might receive a chemical signal that it was time to awaken and grow. That day is finally approaching for a dozen or so eggs, including the one that will help form your baby, around two weeks from now.
Your uterus is beginning preparing to welcome your baby, flushing out the old endometrial lining so that a new lining can grow and proliferate, but that might come with uncomfortable cramping and bloating. To ease these symptoms, make sure you drink plenty of water; herbal teas such as fennel or ginger might also help.
Still two weeks away from being pregnant, this is actually counted at the first day of your pregnancy! You have a long, but wonderous journey ahead of you...
The Corpus Luteum: an ethereal marvel
A complex dance of hormones occurs to allow you to ovulate, beginning before the start of this cycle, and climaxing with rapid rises and precipitous falls of follicle stimulating hormone, luteinizing hormone, and estrogen.
During this time, a number of ovarian follicles begin to develop, but by around a week into your cycle, just one dominant follicle is normally selected, and the others fade away. Once this follicle reaches maturity, it sends a signal to the body that it's ready for ovulation, which is met by the release of a hormone that not only allows the cells surrounding the proto-egg to release it, but also for the egg to leave its stasis and complete its long-awaited division. After all these years, the chromosomes that will make up half of your baby's DNA have finally been selected!
These many hormonal changes have effects on your body that you can notice if you're looking for them, and so they can help you plan for conception (or plan to avoid it!), including changes to cervical fluid, the cervix itself, and your body temperature. You can even look for the surge of the hormone that triggers ovulation, using a simple at-home test. Some folk feel 'mittelschmerz', German for 'middle pain', which is associated with ovulation. Learning to read and understand your body is a wonderful skill to master, and menstrual cycles are an important part of that.
And so, to the title of this story, and the illustration that accompanies it. Once the egg that will help form your baby has been released and begins its journey along your fallopian tube, it leaves behind yet another amazing structure: the corpus luteum. Among other things, this golden body produces progesterone throughout its short lifetime, preparing the endometrial lining of the uterus for implantation of an embryo. It's just one example of the complexity of ovulation and pregnancy: so many little things can go wrong, causing the entire process to fail, and yet, so often, everything goes perfectly. Even with modern science, we don't fully understand the intricacies of the ebb and flow of the many hormones involved; they dance to rhythms we cannot hear, following choreographers we cannot see, and the result is an egg, ready to be fertilized, and a uterus ready to receive and grow an embryo.
It's truly breathtaking!
Tiny, Tailed Torpedoes: delivering a precious load
Today, we're introducing the second half of the equation needed to create a new life: spermatozoa. These unique and amazing cells are far younger than the oocytes they aim to join with, and, unlike the single egg that is produced by ovulation, sperm usually mature in the tens or hundreds of millions for each attempt at fertilization.
Hanging outside the body to allow the slightly lower temperature needed for producing sperm, the testes contain hundreds of meters of tightly convoluted tubules. Within these, proto-sperm cells are produced, some of which detach from the membrane lining the tubules, but they look nothing like their final form at this stage: they are round, and still contain all 46 chromosomes of the parent cells. The genetic material in these cells replicates and the cells each divide, and then divide again, resulting in round 'spermatids', each now containing just 23 chromosomes - half of those needed to create a baby. The vast majority of these cells will never have that opportunity, of course, and much of that is decided by the next, complicated stage in the process.
Many folk picture sperm as looking like tadpoles. Though they have far longer, slimmer tails, they do share another similarity, namely metamorphosis. As a tadpole changes its form when it becomes a frog, or a caterpillar changes its form to a butterfly, so a round spermatid changes its form into the sperm we recognize from many a cartoon illustration. The tail now contains protein fibers, the neck forms the powerhouse of the sperm, packed with mitochondria, and the head contains a structure that helps in the final part of a sperm's mission, along with its precious cargo of DNA.
As it travels through the cervix, into the uterus and onwards to a fallopian tube, a sperm must undergo even more changes in a process called capacitation. These changes are caused by the environment in which the sperm has found itself, and must occur for fertilization to be possible. The cell membrane becomes 'sticky', allowing it to bind to the egg (if the sperm is lucky enough to find one!), and, as it comes into close proximity with the egg, the tail becomes hyperactivated, beating more forcefully. The DNA forming the cell nucleus is densely-packed so that the head is as small as possible, now allowing the tail to move this microscopic cell at around 10 inches per hour under its own steam.
Unfertilized, an egg will only survive for around 24 hours after ovulation. The sperm can survive for a few days, and need around 10 hours for capacitation, so there's a window of around 5 days in which intercourse can result in pregnancy, with the majority of that window actually occurring before ovulation.
And this is where we will leave the story for today, as the remaining couple of hundred surviving sperm close in on the newly-ovulated egg. A pregnant pause, if you will, as we wait, a few hours from the creation of a new glimmer of life...
To increase the health of sperm, you should avoid smoking, alcohol and drugs (including some prescription medications), reduce the amount of unhealthy trans fats in your diet, refrain from using hot tubs, saunas, and wearing tight underwear (or anything else that will warm the testes), should exercise for at least 50 minutes at least 3 times a week, and ensure your diet contains or you supplement with omega-3 fatty acids, folate, zinc, fenugreek, ginseng, and Vitamin D (or get out in the sun safely). Research suggests that you should reduce consumption of red meat and processed meat and eat more fruits and vegetables (speak to Jen about starting a vegan diet!). Cantaloupe melon has been highlighted as one 'sperm superfood', so feel free to indulge in this sweet treat just now!