hCG: human chorionic gonadotropin.
* In the early first trimester when cardiac activity is not normally seen by ultrasound, diagnosis of a nonviable embryo is based on factors such as the mean gestational sac diameter and crown-rump length. Refer to UpToDate topics on ultrasound diagnosis of pregnancy loss. Repeat ultrasound in 7 to 10 days may be required to make a diagnosis of viable versus nonviable pregnancy.
¶ Evaluation for ectopic pregnancy involves a combination of serial hCG levels and ultrasound examinations. Refer to the UpToDate topic on diagnosis of ectopic pregnancy for detailed information.
Δ If there is no intrauterine pregnancy on ultrasound but the uterus is not empty, then gestational trophoblastic disease should be considered if ultrasound shows a central intrauterine heterogeneous mass. Refer to UpToDate topics on gestational trophoblastic disease for detailed information.
◊ Implantation bleeding is a diagnosis of exclusion. It is characterized by a small amount of spotting or bleeding approximately 10 to 14 days after fertilization (around the time of the missed menstrual period).
§ Cervical insufficiency is characterized by cervical dilation and/or effacement in the second trimester in the absence of contractions or with weak irregular contractions that appear inadequate to explain the cervical dilation and effacement. Fetal membranes may be visible at or beyond the os.Do you want to add Medilib to your home screen?