Common forms of pregnancy loss include:

• Ectopic pregnancy. During a normal pregnancy, the fertilized egg (zygote) implants itself in the uterus. An ectopic pregnancy is a pregnancy in which the fertilized egg implants itself outside the uterus, usually in a fallopian tube. Blood tests, ultrasound and laparoscopy may be used to diagnose the condition. Most ectopic pregnancies require surgical removal. In some early cases, medication is prescribed to dissolve the zygote or embryo. In most cases, an embryo left in place and allowed to grow will cause the organ it is implanted in to rupture. This can result in severe bleeding. Although most women who experience an ectopic pregnancy have healthy pregnancies in the future, there is a small chance of recurrence.
  
  
• Miscarriage. The loss of a baby in the womb before the 20^th week of pregnancy. Miscarriages most often occur in the first 12 weeks of pregnancy. According to the March of Dimes Birth Defects Foundation, as many as 50 percent of all pregnancies end in miscarriage. Many times the loss occurs before the woman knows she is pregnant. Infections, hormonal problems and other health problems can cause a miscarriage. In addition, a new study indicates that women who are underweight before they become pregnant may be more likely to suffer a miscarriage. However, most first-trimester miscarriages occur as the result of chromosomal abnormalities in the baby. After a miscarriage, most women are able to have healthy pregnancies in the future. There are no known ways to prevent a miscarriage.
  
  
• Molar pregnancy. A pregnancy in which the early placenta grows abnormally into a mass of cysts (hydatidiform mole) and the embryo does not form, or is malformed and cannot survive. According to the March of Dimes, molar pregnancy occurs in approximately 1 in every 1,000 pregnancies. The condition results from an abnormal fertilized egg with two sets of chromosomes from the father and either one or no sets of chromosomes from the mother. Normally, the embryo would receive one set of chromosomes from each parent. The condition is diagnosed with ultrasound. Many times there will also be an abnormally high level of placental hormones (HCG). Treatment requires removal of the molar tissue from the uterus. The woman is then monitored to ensure that there is no remaining tissue. Remaining tissue can develop into choriocarcinoma, a rare form of cancer. Most women who experience a molar pregnancy are able to have healthy pregnancies in the future.
  
  
• Stillbirth. The loss of a baby in the womb after the 20^th week of pregnancy. Most stillbirths occur before labor begins. However, sometimes a fetus may not survive labor and delivery. The first indication may be a lack of movement or kicking by the fetus. The condition is usually diagnosed before delivery with an ultrasound. When stillbirth is discovered, labor is typically induced.