本文发表在 rolia.net 枫下论坛Threatened abortion is a clinically descriptive term that applies to women who are at less than 20 weeks' gestation, have vaginal spotting or bleeding, a closed cervical os, and, possibly, mild uterine cramping.
Pathophysiology: Threatened abortions may progress to inevitable, spontaneous, incomplete, or complete abortions.
Threatened abortion
Vaginal spotting or frank bleeding is very common and is experienced in approximately 25% of clinically apparent pregnancies at less than 20 weeks' gestational age. The bleeding and pain that accompany threatened abortion are not usually intense. Threatened abortion rarely manifests with severe vaginal bleeding. Often, the bleeding is temporary and self-limited and probably due to trophoblastic implantation within the decidualized endometrium.
Approximately half the women with threatened abortions abort, and the remainder continue to have viable pregnancies. Approximately 15% of clinically recognized pregnancies spontaneously abort, and 75% of the losses occur in the first 8 weeks of gestation. The loss rate is estimated to be 2-3 times higher with very early and, often, clinically unrecognized pregnancies.
Threatened abortion is defined by the absence of passing/passed tissue and the presence of a closed cervical os. These findings differentiate threatened abortion from later stages of abortion.
Inevitable abortion
Vaginal bleeding is accompanied by dilatation of the cervical canal, no passage of fetal tissue, and, occasionally, gross rupture of the membranes. Bleeding is usually more severe than with threatened abortion and is often associated with abdominal pain.
Incomplete abortion
Vaginal bleeding is usually heavy and accompanied by abdominal pain. The cervical os is open, with passage of only part of the products of conception. Incomplete abortion is more likely to occur at 6-14 weeks of pregnancy. Ultrasonography (if used) reveals that some products of conception are still present in the uterus; these typically appear as echogenic material.
Complete abortion
Patients usually present with a history of bleeding, abdominal pain, and passing of tissue. By the time miscarriage is complete, bleeding and pain have usually subsided and the cervix is closed. Diagnosis may be confirmed by observation of the aborted fetus with the complete placenta. Ultrasound reveals a vacant uterus with close apposition of relatively thin and regular endometrial interfaces.更多精彩文章及讨论，请光临枫下论坛 rolia.net