abnormal placentation such that the placenta overlies the cervical os.
| Risk factors | • Prior placenta previa • Prior cesarean delivery (Most common risk factor) • Multiple gestation due to increased placental surface area • Advanced Maternal age ( ≥35 year old) • Multiparity • Smoking | | --- | --- | | Clinical features | • Painless vaginal bleeding >20 weeks gestation • ranging in severity from spotting to massive hemorrhage • with or without contractions. | | Diagnosis | • Transabdominal followed by transvaginal sonogram | | Management | • No intercourse • No digital cervical examination • Inpatient admission for bleeding episodes |
uterine scar + change in vascularity likely alter early pregnancy implantation.
JUH adds uterine anomaly, Assisted conception and deficient endometrium for example curettage
diagnosed during routine prenatal ultrasound at 18-20 weeks gestation with placental tissue covering the cervix.
Most patients are asymptomatic but have a significant risk of severe painless antepartum hemorrhage due to partial placental detachment with cervical manipulation or dilation.
Pelvic rest and abstinence from intercourse (due to potential cervical contact) are recommended, and clinicians should refrain from digital cervical examination. because minimal cervical manipulation can cause cervical changes (eg, shortening, dilation) that can result in partial placental detachment and massive maternal hemorrhage.
In contrast, speculum examination can be used in patients with known or suspected placenta previa to verify and quantify vaginal bleeding as it does not enter the cervical canal.
potential for massive antepartum hemorrhage because cervical manipulation (even minimal manipulation from intercourse) causes partial placental detachment and painless vaginal bleeding (eg, nontender uterus, painless irregular contractions) from the intervillous space. This bleeding is primarily of maternal origin; therefore, many patients have reassuring fetal monitoring initially (eg, accelerations, no decelerations).
The majority (~90%) of cases resolve spontaneously due to lower uterine segment lengthening and/or placental growth toward the fundus; therefore, initial management is with routine obstetric care. Repeat ultrasound is performed in the third trimester (ie, ≥28 weeks gestation), and patients with previa resolution can continue routine care without pelvic rest restrictions. Asymptomatic patients (ie, no vaginal bleeding) with persistent previa undergo scheduled cesarean delivery at 36-37 weeks gestation (ie, prior to the onset of labor).
Therefore, all asymptomatic women who have placenta previa detected early on routine screening TVUS (often performed between 18 and 20 weeks' gestation) should undergo follow-up TVUS at 32 weeks' gestation. If placenta previa or low-lying placenta is present, follow-up TVUS at 36 weeks' gestation is recommended. A confirmed placenta previa at this gestational age warrants a lower segment cesarean delivery, ideally performed between 36 and 37 weeks' gestation.
<aside> 💡 Complete bedrest is associated with an increased risk of venous thromboembolism and loss of bone density. In addition, it has not been proven to be beneficial in obstetric management and therefore is not recommended.
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Associated with accreta
(Choice E) Placental abruption, the separation of the placenta from the uterus prior to fetal delivery, causes vaginal bleeding and uterine contractions. Abruptio placentae is more common in smokers (as in this patient), but patients typically have constant abdominal pain (ie, tender uterus) and fetal decelerations.
Bleeding occurs as the placenta is sheared off the cervix, creating a partial detachment due to uterine irritability (eg, irregular, nonpainful contractions) which causes physiologic cervical changes (eg, effacement, dilation). Early in the disease process, bleeding is primarily maternal in origin; therefore, a reactive (ie, normal) fetal heart rate tracing is usually seen. However, continued maternal blood loss can eventually lead to fetal compromise, with deterioration of the fetal heart rate tracing. Management is dependent on maternal hemodynamic stability and fetal status.
May be labeled in Grades form 1-4
<aside> 💡 even in patients with minimal bleeding, stable vital signs, and reassuring fetal heart rate tracings, cesarean delivery is indicated after 36-37 weeks gestation
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(Choice A) Although limited physical exercise and pelvic rest are recommended for patients with placenta previa for bleeding prophylaxis, bed rest is not necessary, as it does not significantly decrease the risk of antepartum hemorrhage.