Differential Diagnosis for Vaginal Bleeding in a 16-Week Pregnant Woman
- Single most likely diagnosis
- Missed abortion: The presence of an intrauterine pregnancy with no fetal cardiac activity, as shown on ultrasonography, is most consistent with a missed abortion. This condition occurs when the fetus has died but remains in the uterus. The patient's symptoms of vaginal bleeding and the finding of an open cervical os support this diagnosis.
- Other Likely diagnoses
- Spontaneous abortion: Although the ultrasonography shows an intrauterine pregnancy, the presence of vaginal bleeding and an open cervical os could also suggest a spontaneous abortion, which may not have been completed.
- Subchorionic hematoma: This condition, where blood accumulates between the placenta and the uterus, can cause vaginal bleeding and is a possible explanation for the patient's symptoms.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Placenta previa: Although less likely given the gestational age and the fact that a viable uterine pregnancy was confirmed 2 weeks ago, placenta previa can cause significant bleeding and is a critical diagnosis not to miss.
- Placental abruption: This condition, where the placenta separates from the uterus, can cause vaginal bleeding and is a medical emergency.
- Rare diagnoses
- Velamentous cord insertion: This is a rare condition where the umbilical cord inserts into the amniotic membrane rather than the placenta, which can increase the risk of bleeding and fetal compromise.
- Chromosomal abnormalities: While chromosomal abnormalities can increase the risk of miscarriage, they are not directly related to the patient's symptoms of vaginal bleeding.
- Hyperfibrinolysis: This is a rare condition characterized by excessive breakdown of blood clots, which could potentially contribute to vaginal bleeding but is less likely given the patient's presentation.
- Placental thrombosis: This condition, where a blood clot forms in the placenta, is rare and not directly related to the patient's symptoms of vaginal bleeding.
- Preeclampsia: Although preeclampsia can cause complications in pregnancy, it is not typically associated with vaginal bleeding in the second trimester and is less likely given the patient's presentation.