Definition - What does Viable Pregnancy mean?
A viable pregnancy is a pregnancy that is progressing normally with all laboratory, ultrasound, and physical findings indicating the positive likelihood of giving birth to a live baby.
There are many indicators practitioners look for to assess the healthy growth of a fetus, especially in early pregnancy including the presence of an embryo with the gestational sac, length of the embryo, and the presence of a heartbeat.
In contrast, a non-viable pregnancy indicates there is no chance of live birth.
FertilitySmarts explains Viable Pregnancy
There are precise guidelines used to assess the viability of a pregnancy to ensure the pregnancy is progressing normally with healthy fetal development and has the potential to result in a live birth. Diagnostic factors in determining a nonviable pregnancy include:
- A crown-rump length of 7 mm or greater with no heartbeat
- A mean sac diameter of 25 mm or greater and no embryo
- No heartbeat at 2 or more weeks after a scan that showed a gestational sac without a yolk sac
- No heartbeat 11 or more days after a scan that showed a gestational sac with a yolk sac
These guidelines become especially important in assessing the health of a pregnancy in women who have suffered recurrent miscarriages or have a history of ectopic pregnancy.
If miscarriage or other abnormalities are not of concern, in the case of a normally progressing pregnancy the term "viable pregnancy" may be used to describe a fetus that has developed in the uterus to the point that should it be born, the baby would stand a reasonable chance of survival outside the uterus. In most cases, this fetal age of viability is 24 weeks and 0 days of pregnancy.
- First Do No Harm: Guidelines Define a Nonviable Pregnancy. (2013).
- Periviable Birth. (2016).
- Survival and Neurodevelopmental Outcomes among Periviable Infants. (2017).