Placenta praevia

• Placenta praevia is an obstetric complication in which the placenta implants partially or wholly over the cervix.
• This condition can lead to significant maternal and foetal risks, primarily due to bleeding.

• Occurs in approximately 0.5% of all pregnancies.
• The incidence is higher in women with previous caesarean sections, multiple gestations, and those who smoke or use cocaine.

Placenta praevia is classified based on the degree of cervical coverage:

• Grade I (Low-Lying): The placenta is low-lying but does not cover the cervix.
• Grade II (Marginal): The placenta reaches the cervix but does not cover it.
• Grade III (Partial): The placenta partially covers the cervical os.
• Grade IV (Complete): The placenta completely covers the cervical os.

• Previous placenta praevia.
• Multiple gestations.
• Advanced maternal age.
• Smoking and substance abuse.
• Previous uterine surgery, including caesarean section.
• High parity.

• Painless, bright red vaginal bleeding in the second or third trimester is the hallmark symptom.
• Bleeding may be associated with uterine contractions in some cases.
• The foetus may present in a non-cephalic position due to abnormal placental location.

• Ultrasound: The primary diagnostic tool, preferably transvaginal ultrasound, which offers a detailed view of the placental location relative to the cervix.
• Physical examination should be cautious to avoid triggering bleeding.

Antepartum Care:

• Expectant management for asymptomatic cases or mild bleeding, with close monitoring and hospitalisation if necessary.
• Activity restriction, including pelvic rest (no intercourse, no vaginal exams unless absolutely necessary).
• Planning for delivery at a tertiary care centre with facilities for maternal and neonatal care.

Delivery Planning:

• Caesarean delivery is indicated for all cases of complete placenta praevia and most cases of partial praevia.
• The timing of delivery depends on the gestational age, foetal maturity, and severity of bleeding: aiming for delivery at 36-37 weeks if possible, or earlier if maternal/foetal status warrants.

Intrapartum Care:

• Immediate management of bleeding may include tocolytics to delay labour (if preterm), corticosteroids for foetal lung maturity (if preterm), and blood transfusions if significant blood loss occurs.
• Multidisciplinary approach involving obstetricians, anaesthesiologists, and neonatologists.

• Maternal: Significant risk of haemorrhage, which can lead to shock and require transfusion. Increased risk of hysterectomy.
• Foetal: Prematurity, low birth weight, and foetal distress due to bleeding.

• With appropriate management, the outcome for most cases of placenta praevia is positive.
• The key to managing placenta praevia is early detection, careful monitoring, and planning for delivery in a controlled setting.

• Placenta praevia is a critical condition in obstetrics characterised by the placenta covering the cervix, leading to potential severe bleeding in the second half of pregnancy.
• The focus on antepartum care, delivery planning, and addressing complications is crucial for ensuring the safety of both mother and baby.
• Medical students should understand its classification, risk factors, clinical presentation, and management principles.