There's a positive on your pee stick. Or the doctor calls you at home. Suddenly, you know there's a teeny tiny being growing deep in the recesses of your uterus. You want to tell your husband, your partner, your family, your friends. But what if it doesn't stick? What then? What are the chances of this pregnancy not growing healthily into the baby you've wanted (or, are adjusting to)?

When I got the positive on my first pregnancy, I eagerly sought out a local OB. At something like 5 weeks and maybe 2 days. They did a vaginal ultrasound, which revealed nearly nothing. A sac. A white spec. And nothing more. And the doctor? He said, Well, it's either dead, going to miscarry, or it's too early to tell anything. Early miscarriage is common. Come back next week. Great enthusiastic start to our first baby's life. Note: that spec is nearly 11 years old today.

With our second, you'd think I'd learn. I did wait till the 6th week. Got a good early ultrasound, but was told, there's a 25% risk of miscarriage until after the 8th week. Gee, thanks again. Anything else you want to tell us to add to our happiness?

At least, with number 3, I was prepared. I ignored the statements, and thought positively. That child, too, is wonderfully healthy. But this, sadly enough, is not always the case.

At one site, I found that one in six pregnancies ends in miscarriage. 75% of these in the first trimester, or first 12 weeks. This risk also increases with age. If the mother is over 35 and pregnant as a result of an IVF procedures, or something similar, the risk increases. Another source states the risk of a pregnancy ending in miscarriage is as low as 6.4% in women under the age of 35, but rises to 23.1% in women over the age of 40. And yet another suggests 12% for women in their 20s. If you're over 40, and smoke? Stop now. The rate of miscarriage is already near 50%, and the smoking will take it even higher.

What tends to cause the loss of pregnancy? Sometimes, we'll never know. It is whatever you want to call it. Natural selection. Survival of the fitest. Some plan including God, or not, at which we can only guess. Dumb luck. Bad Karma. But there are some concrete reasons, sometimes. Like chromosomal abnormalities. This is by far the most common reason. The body's self-protection mechanism eliminates 95% of fertilized eggs that cannot survive due to a problematic genetic predisposition. These are likely to be children who would not be able to survive once born. And most often, these abnormalities are by chance, and have nothing at all to do with the parents' specific genetic make-up. When that occurs, there is often testing that can help narrow in on the difficulty. Genetic testing is a rapidly growing industry.

Some women have hormonal imbalances that do not allow for proper growth. Some women do not make enough progesterone, the hormone that prepares the lining of the uterus to nourish a fertilized egg. If the uterine lining cannot sustain an egg, miscarriage will occur. This is something that can often be identified, and corrected with progesterone supplements.

Uterine and cervical abnormalities are also a cause for difficulty in some cases. Fibroids which are non-cancerous growths made of uterine muscle tissue, can cause trouble. As can a weak cervix, that may widen too early in pregnancy without any warning signs of labor and result in the fetus being lost early.

A weak cervix does not occur often, but if it is an issue, it will typically be evident after the 15th week and will be a threat to every pregnancy. Is there help? After the first trimester, but before the cervix has dilated (widened) to a certain point, your doctor can reinforce the cervix with sutures, which will be removed when the baby reaches term. Again, your doctor can help you decide if this procedure is for you.

15% of repeated miscarriages are a result of these kinds of pregnancy losses. The upside is that these may often be diagnosed. Your doctor can help you with this and, very possibly correct with surgery, which then results in a 70-90% successful pregnancy rate.

Unfortunately, there can also be issues with maternal illness, and sometimes, the immune system. While more rare, even here, there are sometimes answers and available help. As far as reproductive medicine has come, there can be hope in most situations. Some women have experienced this hope, and all it has to offer, and some still seek it. For all we do know, there is much we do not. In the end, the incredible mystery of creation of life simply does not rest in human hands.

But to end on a brighter note, again, look once more at the statistics given earlier. From the very beginning, the odds are in our favor. 99, 999, 999 sperm did not make it. One did. From the very outset, the odds are being beat.