Obgyn Key

Chromosomal Anomalies 17.1 Trisomy 13 (Patau Syndrome) Description and Clinical Features Trisomy 13 is a chromosomal anomaly in which the fetus has an extra chromosome 13 (i.e., it has three,…

Diagnosis and Characterization of Multiple Gestations 23.1 Fetal Number Description and Clinical Features Twins can arise from a single fertilized ovum (zygote) that splits into two separate embryos within the…

Complications of Multiple Gestations 24.1 Twin–Twin Transfusion Syndrome and Twin Anemia–Polycythemia Sequence Description and Clinical Features Twin–twin transfusion syndrome (TTTS) is a complication of monochorionic twinning, resulting from unbalanced shunting…

Adnexa 28.1 Ovaries Description and Clinical Features The ovaries are paired ovoid pelvic organs located on each side of the uterus. They are mobile intraperitoneal structures that lie anterior to…

Diagnostic Obstetrical Procedures 25.1 Amniocentesis Description and Clinical Features Amniocentesis is a procedure in which amniotic fluid is aspirated through a percutaneously inserted needle. This procedure is used for a…

Uterus 27.1 Myometrium Description and Clinical Features The myometrium is the muscular portion of the uterus. It is bounded internally by the endometrium and externally by the serosa, a membrane…

Placenta 19.1 Placenta Previa Description and Clinical Features Placenta previa refers to a placenta extending to or covering the internal cervical os. When there is a placenta previa at the…

Uterus and Cervix 20.1 Cervical Incompetence and Shortening Description and Clinical Features Cervical incompetence (also termed cervical insufficiency) is defined by the American College of Obstetricians and Gynecologists as the…

Umbilical Cord 22.1 Single Umbilical Artery Description and Clinical Features The normal umbilical cord has three vessels: two umbilical arteries and one umbilical vein. When there is a single umbilical…

Extremities 16.1 Skeletal Dysplasias Description and Clinical Features Skeletal dysplasias, also called osteochondral dysplasias, result from abnormal formation and remodeling of bone, which lead to diffuse skeletal deformity and shortening…