Pregnancy loss means the unwanted ending of a pregnancy at any gestational age. It may include, but is not limited to, miscarriage, ectopic pregnancy, molar pregnancy, stillbirth, or termination for medical reasons.
- Miscarriage, or early pregnancy loss, is a pregnancy loss that happens before 20 weeks. It is estimated that up to 20% of known pregnancies end in miscarriage. About 80% of miscarriages happen before the 12th week of pregnancy.
- Ectopic pregnancies occur in about 12 in 1000 pregnancies and happen when an embryo develops outside of the womb in the fallopian tube, ovary, cervix, or abdomen. Ectopic pregnancies almost always result in a pregnancy loss because the embryo does not have enough room to develop. Ectopic pregnancies can cause serious complications including death of the mother.
- Molar pregnancies occur in about 1 in 1000 pregnancies and are caused when extra chromosomes come from the sperm of the father. A complete molar pregnancy happens when the mother’s chromosomes are not present in the egg and the chromosomes of the father are copied. A partial molar pregnancy occurs when the mother’s chromosomes are present in the egg but the father’s chromosomes are copied, resulting in 69 chromosomes instead of 46. Molar pregnancies always result in pregnancy loss and may cause serious health problems.
- Stillbirths occur in about 1 in 175 pregnancies per year and refers to loss after 20 weeks of pregnancy. (It is important to note that 20 weeks is the US definition of stillbirth. The WHO defines stillbirth as the death of a baby after 28 weeks gestation.)
- Termination for medical reasons (TFMR), is when a desired pregnancy is terminated due to a chromosomal, genetic or structural fetal abnormality, or where continuing the pregnancy would risk the health or life of the mother.