I've been an obstetrician for 13 years. When I graduated from Columbia College of Physicians & Surgeons, I was eager to learn the most high-tech, up-to-date, modern medicine - evidenced-based medicine - that this country had to offer.

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But in the field of Ob-Gyn, perhaps more than any other specialty, clinical practice has turned out to be as much art as science. I was trained by some of the best clinicians in New York City and worked side by side with some of the best midwives in the area as well, and the best of the best apply the most current evidence-based literature and their intuition in the ancient art of having a baby. These are the docs or midwives who know their facts cold, but can also simply look at a patient, examine a pregnant woman, and predict with incredible accuracy the course of her pregnancy, labor and delivery.

After delivering over 1000 babies, I've seen my share of pregnant women. I've also had two children of my own. And science, medicine, wives' tales, and gut instinct tell me we're about to see a future queen be born.

From Kate's pregnancy fashion to the odds on the name, click here for full coverage of the royal baby.

So how do it know? And how far out on a limb am I?

Hint 1: The Face

The mother's face is often the part of the body that reveals the most about the gender of an unborn baby. As the wives' tale states: Women carrying girls tend to have their faces become fuller, broader than women carrying boys.

There is ZERO physiologic basis or explanation for this - it's just a trend that I (and many others) have observed. It is not 100 percent accurate, it's simply a tendency. Kate's face appeared full almost immediately, well before she even had a "bump." Score one for girl.

Hint 2: The Belly

Wives'-tales (and many obstetricians and midwives as well) say that if a woman carries the baby straight out front, like a basketball under her shirt, and looks almost non-pregnant from behind, that she is carrying a boy. Pregnant mamas carrying girls tend to spread out from all angles (legs, rear end, back, face). Even the incredibly slender Kate seemed to fill out diffusely, legs and face included. Score two for girl.

Check out Kate Middleton's pregnancy fashion.

Hint 3: The Type of Pregnancy

In my experience, girls make for "tougher" pregnancies than boys do. Hyperemesis - the excessive nausea and vomiting that landed Kate in the hospital in her first trimester - is associated more often with girl babies, and I can attest to this experience with my daughter when I was pregnant too! That's three for girl.

Read more about hyperemesis gravidarum.

It's important to remember that there is no plausible biological or medical explanation for these observations or trends, only theories. But with every instinct and intuition and experience I have, I'm betting girl.

Of course, my odds are pretty good: 50:50!