When I had my molar pregnancy, I turned to the Internet for information. There wasn't much to find. Most of the sites were complicated medical sites that used jargon and technical language that I, as a medical editor by trade, generally understood but that I imagine few laypeople could really comprehend. The best explanation of what a molar pregnancy is from Peg Plumbo, a Certified Nurse Midwife:

"A molar pregnancy most often occurs at the extremes of reproductive life--usually in women over the age of 40. In the general population, the risk is 1 in 1000 to 1 in 1500. Most molar pregnancies occur after an ectopic pregnancy, after a pregnancy loss or even after a full term pregnancy.

There are several classifications of gestational trophoblastic disease, of which hydatidiform mole (complete molar pregnancy) is one type. The other type is known as a partial mole.

When fertilization occurs and there is no genetic information within the egg cell (so called "empty egg"), the resulting condition is known as a complete molar pregnancy. Rapid cell production occurs only within the cells which form the placenta and there is high production of the placental hormone human chorionic gonadoptropin (hCG). Such high levels of hCG account for the positive pregnancy test and the extreme nausea.

When two sperm fertilize an egg, a partial mole forms. Instead of forming twins, something goes wrong, leading to a pregnancy with an abnormal fetus and an abnormal placenta. The baby has too many chromosomes...and almost always dies in the uterus. Ultrasound can verify if a molar pregnancy exists and whether or not it is a complete or partial. Rarely, a normal fetus may also coexist with a molar pregnancy. Management of such pregnancies are at high risk for pregnancy loss and for the development of pregnancy induced hypertension. Consultation or care by an obstetrician or perinatologist would be recommended."

I didn't know much about D&Cs either, so I did some searching on that as well. Here's a short definition from Yahoo! Health:

Molar pregnancies are considered very rare, and the chance of developing cancer from a molar pregnancy--known as choriocarcinoma--is even more rare, occurring in only about 10% of cases. However, it is common for chemotherapy, particularly Methotrexate, to be used in treating a molar pregnancy to reduce the molar tissue and thus avoid a malignancy. It is also not uncommon for women with molar pregnancies to have a second or even a third D&C to remove persistent tissue.

The good news: it is possible to have a healthy, successful pregnancy after a mole. It is extremely rare to have a second mole; I have heard that this happens in less than 2% of cases. I myself have gone on to have a beautiful, healthy baby boy. I hope the same for you.

For more information about molar pregnancy, be sure to visit the Links page of this site.

REFERENCES
American Heritage Dictionary, 4th Edition, Human Chorionic Gonadotropin (Bartleby.com)
Britannica.com, Hydatidiform Mole
D. Ashley Hill, MD: "Molar Pregnancy" on OBGyn.net
Labcorp.com, Human Chorionic Gonadotropin, Beta Qualitative
Labcorp.com, Human Chorionic Gonadotropin, Beta Quantitative
Peg Plumbo, CNM: "Questions and Answers: What is a Molar Pregnancy?" on Parentsplace.com
University of Pittsburgh Cancer Institute Cancer Dictionary
Yahoo! Health: D and C