Early Pregnancy Failure - Part 2
Methods of Establishing Menstrual Age
Methods of Establishing Menstrual Age
what is pregnancy of uncertain viability (PUV)?
- Any definite intrauterine pregnancy with no heartbeat is considered a pregnancy of uncertain viability
CAN YOU DIAGNOSE PREGNANCY FAILURE BY LMP DATing ALONE?
- NO
- You can suggest this if there is a PUV > 6 weeks, but by new criteria, this is not definitive
What is minimum menstrual age?
- MMA (is not cage fighting)... It is a more conservative measure of menstrual age than LMP dating
- It essentially gives you the youngest possible age that the embryo can be
- This way you do not inadvertently overestimate the age of the fetus and suggest demise.
How is minimum menstrual age calculated?
Most women wait 4 weeks from their last period (avg cycle) to take a pregnancy test
- Ask when was the first pregnancy test
- Add 4 weeks to that date
- = Minimum menstrual age
How does minimum menstrual age help you?
- It sort of does and sort of doesn't
- A heartbeat must be visible by 7 confirmed weeks of gestation (usually seen by 6 weeks)
- Because MMA gives you the most conservative estimate of gestational age you won't inadvertently diagnose a demise.
- Studies have shown that a pregnancy of 7 weeks MMA without a visible heartbeat has a 100% PPV for diagnosing pregnancy failure.
- However, the consensus panel guidelines do not recognize MMA as definitive to diagnose early pregnancy failure
- A heartbeat must be visible by 7 confirmed weeks of gestation (usually seen by 6 weeks)
How much should the crown rump (CRL) and Mean sac (MSD) increase per day?
- It should be about 1 mm per day.
- This isn't exact, but can give you an easy to remember rule of thumb for estimation purposes.