Pregnancy Loss Topic Guide

Conjoined twins (Siamese twins) are identical twins joined and develop when an early embryo only partially separates to form two individuals. Although two fetuses will develop from this embryo, they will remain physically connected — most often at the chest, abdomen or pelvis. Conjoined twins are a rare phenomenon, that represent about 1% of births of identical twins. Most conjoined twins are female. About 40% to 60% of conjoined twins are stillborn.

A miscarriage (spontaneous abortion) is a pregnancy that spontaneously ends before the fetus can survive. There are classifications of miscarriage that include threatened, inevitable, incomplete, and complete miscarriage. There are a variety of causes of a miscarriage. Causes of miscarriage include defective genes of the fetus, chronic illness, including diabetes, severe high blood pressure, kidney disease, lupus, and underactive or overactive thyroid gland, acute infections, including Germany measles, CMV, and mycoplasma (walking pneumonia), diseases and abnormalities of the internal female organs, and other factors, including certain drugs like alcohol, tobacco, and cocaine. Symptoms and signs of a miscarriage are vaginal bleeding, abdominal pain, and cramping. If a woman thinks she may be having a miscarriage, she should seek medical care with her doctor or go to an emergency department.

Placenta previa (also called low lying placenta) is a complication of pregnancy in which the placenta rests low in the uterus (womb) and covers all or part of the opening to the cervix. Causes include scarring, prior caesarian delivery, prior D&C procedure, and smoking, among other causes. The main symptom is bleeding. Treatment may include caesarian delivery.