← All decks
The first 25 slides, exactly as they appear. The full deck has 104 content slides.
Radiology
Cervical Length and Spontaneous Preterm Birth
Built from Obstetric Imaging
What’s inside
13 sections · 104 slides
Overview
- What you will learn here
Preterm birth: the size of the problem
Who is affected, and why prediction matters
- What counts as a preterm birth
- 1 in 10
- The rate fell, then climbed back
- The strongest warning sign we have
The cervix and what short means
Anatomy, the measurement, and the cut-offs
- The cervix has two opposite jobs
- Where the cervix sits in the female pelvis
- Closed cervical canal in an early pregnant uterus
- What is actually being measured
- Short means different things at different times
- The same 25 mm, four different meanings
- Why that percentile shift matters
- Other definitions used in the trials
- A short cervix is commoner in twins
How well cervical length predicts preterm birth
Three things change the answer
- Three things change how good the prediction is
- The shorter it gets, the steeper the risk
- What the pooled evidence shows
- Finding it early is worse news
- Twins start from a higher baseline
- The same test performs differently in different women
- A practical way to grade the risk
- Risk of Spontaneous Preterm Birth (SPB) Before 35 Weeks of Gestation
Why the cervix shortens
Cause, consequence, or both?
- The question nobody has settled
- Several roads lead to the same short cervix
- Infection turns up remarkably often
- The shorter the cervix, the more likely the bugs
- Inflammation switches on late and hard
- Contractions are a surprisingly weak explanation
- A stretched uterus is a different story
- The old idea of a weak cervix
- Why that label is now questioned
- The missing measurement
- Where the pathophysiology leaves us
Finding a short cervix
Who gets screened, when, and how often
- It almost never announces itself
- The cervix belongs in the anatomy scan
- Who the guidelines say to screen
- How often to repeat the scan
- Only trained hands should do it
How to measure the cervix
Transvaginal first, transabdominal as a screen
- Why the transvaginal route wins
- The transvaginal sequence, step by step
- Getting the probe pressure right
- Drawing the line
- Measuring the cervix through the vagina
- What to notice in those two images
- The transabdominal alternative
- Five landmarks to hunt for
- Measuring the cervix through the abdomen
Funnelling, sludge and other findings
What the picture shows besides a number
- The cervix opens in a predictable order
- The shape sequence as the cervix gives way
- Funnel shapes at the internal os
- What to notice in the funnel images
- Does funnelling add anything?
- Why treatment still keys off length
- Sludge in the amniotic fluid
- What about MRI?
Treating a short cervix: vaginal progesterone
Two old ideas, retested with modern trials
- Two treatments, both older than the problem
- Screening 24,000 women to find the short ones
- What that trial found
- A second trial, a different preparation
- The gel trial results
- Pooling everything: the EPPPIC review
- What EPPPIC concluded
- What is actually available now
Treating a short cervix: cerclage
The stitch, and who actually benefits
- Stitch placed around the cervix
- What the picture shows
- Three questions decide the stitch
- Where the decision path splits
- No prior preterm birth: the headline answer
- But one subgroup did benefit
- When the cervix keeps shortening on treatment
- Prior preterm birth: the early evidence
- The NICHD MFMU cerclage trial
- What that trial showed
- The pooled answer for prior preterm birth
- When the cervix is already open
- What exam-indicated cerclage buys
- Before you offer the stitch
The pessary
A promising start that later trials did not confirm
- Where the pessary stands today
- The trial that raised hopes
- A large trial that did not agree
- The trial that stopped early
- Why that trial was stopped
Twins
Higher baseline risk, weaker evidence
- Twins start closer to the edge
- Cerclage in twins with a short, closed cervix
- Cerclage in twins with a dilated cervix
- Two very different answers in twins
- Progesterone in twins: the evidence splits
- The meta-analysis that found a benefit
- The pessary in twins
- The trial still running
- So should twins be screened at all?
Putting it together
What the referring physician needs to know
- What the referring physician needs to know
- Where the guidance stops short
- Key points to carry away
- Key points, continued
- The whole topic in one line each
- References
- References (2 of 6)
- References (3 of 6)
- References (4 of 6)
- References (5 of 6)
- References (6 of 6)
- Suggested reading
- Obstetric Imaging: Fetal Diagnosis and Care, 2nd Edition