MRI helps confirm placenta accreta, a serious condition where the placenta grows too deeply into the uterus. Learn who is at risk and how MRI guides safe delivery.
Placenta accreta spectrum is a condition where the placenta grows into or through the muscle of the uterus, usually at the site of a previous caesarean scar. It can cause severe bleeding at delivery. Ultrasound is the first test, and MRI without contrast is used in selected cases to confirm the depth and extent, so that delivery can be planned safely in a well-equipped hospital.
What Is Placenta Accreta?
Normally the placenta attaches to the inner lining and separates after the baby is born. In accreta, it is stuck in the muscle (accreta), grows into it (increta) or through it (percreta), sometimes reaching the bladder. The placenta cannot separate normally, causing heavy bleeding that may need hysterectomy and blood transfusion. See anomaly scan where placenta position is checked.
Risk factorWhy it mattersPrevious caesarean sectionsScar allows the placenta to grow deepPlacenta praevia (low-lying placenta)Placenta covers the cervix openingPrevious uterine surgery or curettageScar tissueAdvanced maternal age and IVF pregnancyIncreased riskSeveral previous deliveriesCumulative scar riskRole of Ultrasound
Ultrasound, with colour Doppler, is the first and most important test. The sonologist looks for loss of the normal clear zone, irregular blood spaces in the placenta and thinning of the myometrium or bladder wall. In experienced hands, it is highly accurate. MRI is added when ultrasound is unclear, the placenta is at the back of the uterus or the depth needs mapping. See pelvic ultrasound.
MRI in Pregnancy
MRI uses no radiation and is considered safe in the second and third trimester. For placenta accreta, it is done without gadolinium contrast. It shows dark bands in the placenta, bulging of the uterus, tenting of the bladder and invasion of nearby organs. Read MRI during pregnancy.
Preparation
No fasting is needed for a non-contrast MRI, but check with the centre. Lying on your back for long can cause dizziness in late pregnancy, so staff may tilt you to the left. Remove metal and use earplugs. The scan takes 30 to 45 minutes. See MRI preparation.
Planning a Safe Delivery
- Deliver at a hospital with a blood bank, intensive care and a multidisciplinary team.
- Elective caesarean at about 34 to 36 weeks, as advised.
- Blood and cell salvage arrangements are made.
- Surgeons, anaesthetists, urologists and neonatologists plan together.
A Practical Example
Shalini, 33, has had two caesarean sections, and a scan at 28 weeks shows a low-lying placenta over the scar. An MRI confirms deep invasion without bladder involvement. Her team plans delivery at 35 weeks in a tertiary hospital with blood ready. The baby is delivered safely, and bleeding is controlled with a planned operation.
After the Scan and Next Steps
Take the MRI to your obstetrician and the high-risk pregnancy team. Report any vaginal bleeding, even painless, immediately. Avoid sex and heavy activity if advised, and keep a bag ready for hospital. After delivery, follow-up care addresses blood loss, recovery and family planning.
Questions to Ask Your Doctor
- How deep is the placenta invasion?
- Where and when should I deliver?
- What if I bleed before the planned date?
- Will I need a hysterectomy?
Common Mistakes to Avoid
- Ignoring painless vaginal bleeding.
- Delivering at a facility without a blood bank.
- Missing follow-up scans.
Booking, Timing and Report
Book a slot of about 45 to 60 minutes, and arrive 15 minutes early for the safety form. Carry your doctor's prescription, implant cards and old scans. Reports are usually ready within 24 to 48 hours, and you can request images on a CD or digital link for your specialist.
Key Facts at a Glance
- Risk is highest with previous caesareans and a low placenta
- Ultrasound is the first test; MRI confirms in selected cases
- Delivery should be planned in a well-equipped centre
- Report any vaginal bleeding immediately
Frequently Asked Questions
What is placenta accreta?
The placenta growing too deeply into the uterus.
Who is at risk?
Women with previous caesarean sections and a low placenta.
Is ultrasound enough?
Often, but MRI helps in unclear cases.
Is MRI safe in pregnancy?
Yes, without contrast.
Do I need contrast?
No.
Can it be treated?
Planned delivery in a specialist centre.
Will I need a hysterectomy?
Often, in severe cases.
How long does the scan take?
About 30 to 45 minutes.
When is the report ready?
Usually 24 to 48 hours.
Book Your Test at Ganesh Diagnostic
Ganesh Diagnostic & Imaging Centre in Rohini, Delhi offers this test with trained radiology staff and clear reports. You can book an appointment online, check our branches across Delhi NCR, contact us for current rates, or explore all our services. Reports can be downloaded online through our patient portal, so you do not need to make a second trip just to collect them.
This article is for general information only. It does not replace advice from your doctor. Always follow your doctor's instructions for your test.
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