Obgyn: Placenta Praevia: Free MSRA Podcast

🎧 FREE MSRA PODCAST – Placenta Praevia: High-Yield Deep DiveThis episode focuses on placenta praevia, a key topic in obstetric emergencies and a high-yield favourite for the MSRA. We unpack the condition from definition to complications, using revision notes tailored to UK guidelines and NICE recommendations.🧠 Key Learning Points📌 Definition• Placenta praevia is when the placenta implants in the lower uterine segment, partially or completely covering the internal cervical os• Low-lying placenta = within 20mm of the os, diagnosed after 16 weeks gestation via transvaginal ultrasound (TVS)📌 Why It Matters• Major cause of antepartum haemorrhage• Associated with preterm birth, maternal haemorrhage, and fetal compromise• Key risk factor for obstetric emergency C-section📌 Causes & Risk Factors🔺 Precise cause unknown🔺 Key risk factors:Previous C-section (risk rises with number)Advanced maternal ageMultiple gestationsAssisted conception (e.g. IVF)Smoking, cocaine usePrevious placenta praeviaUterine abnormalities, endometritis, or curettage📌 Pathophysiology• As the lower uterine segment stretches, it disrupts the placental attachment, leading to bleeding• Described as “peeling a sticker off a balloon” – the vascular connection tears📌 Differentials for Bleeding in Late Pregnancy🩸 Placental abruption – usually painful🩸 Cervical lesions – ectropion, polyps🩸 Vaginal trauma or infection📌 Epidemiology• Affects 1 in 200 pregnancies• Seen in 5% of mid-pregnancy scans• Less likely to “migrate” if posterior or with prior uterine surgery📌 Clinical Presentation• Painless, bright red vaginal bleeding in 2nd/3rd trimester• Soft, non-tender uterus• Malpresentation (e.g. breech)• Sentinel bleed may precede larger hemorrhage• Fetal heart rate often normal unless bleeding is severe🚫 DO NOT perform vaginal exams before confirming placental location on ultrasound📌 Investigations🩺 TVS (transvaginal ultrasound) – most accurate for os coverage🩺 Grading system:Placenta in lower segment, not reaching osReaches edge of osPartially covers osCompletely covers os = major praevia🧪 Bloods: FBC (anaemia), cross-match, coagulation screen🩻 CTG monitoring for fetal wellbeing📏 Cervical length if risk of preterm labor📋 Routine follow-up scans at 32 & 36 weeks for low-lying cases📌 Management🚨 Emergency C-section for major bleeding📦 Admit and stabilise (ABC approach)💉 Corticosteroids at 34–35+6 weeks (or earlier if risk of preterm birth)💊 Tocolytics (short-term) if contractions with mild bleeding💡 Planned elective C-section around 36–37+0 weeks if no bleeding🏥 Must deliver in unit with on-site transfusion and critical care📌 Delivery Approach• Grade 3/4 praevia = elective C-section mandatory• Grade 1/2 or resolved low-lying placenta = possible vaginal trial• Emergency delivery if labour starts spontaneously📌 Complications🔺 Antepartum and postpartum haemorrhage🔺 Maternal anaemia, shock, VTE risk (due to bedrest/admission)🔺 Placenta accreta (deep implantation), especially with prior C-sections🔺 Emergency hysterectomy👶 Baby risks:• Preterm birth• Low birth weight• Intrauterine asphyxia📌 Prognosis• Generally good with early diagnosis and appropriate planning📎 More MSRA Resources on Placenta Praevia📝 Revision Notes: https://www.passthemsra.com/topic/placenta-praevia-revision-notes/🧠 Flashcards: https://www.passthemsra.com/topic/placenta-praevia-flashcards/💬 Accordion Q&A: https://www.passthemsra.com/topic/placenta-praevia-accordion-qa-notes/🚀 Rapid Quiz: https://www.passthemsra.com/topic/placenta-praevia-rapid-quiz/🎓 Full Course: https://www.passthemsra.com/courses/obstetrics-and-gynaecology-for-the-msra/#MSRA #PlacentaPraevia #ObstetricEmergency #MSRARevision #ObstetricsAndGynaecology #AntepartumBleeding #PainlessBleeding #CSectionPlanning #MSRAFlashcards #MSRAQuiz #MSRAAccordions #PassTheMSRA #FreeMSRA