An Observation profile describing pregnancy-related Observations, as defined by BabyConnect.
Observations such as gravidity and parity do not (only) pertain to the Patient but also to a particular pregnancy.
Pregnancy-related Observations use the focus extension to point to the Condition they are about. Without this, all gravidities would only be Observations about a Patient.
Pregnancy-related Observations refer to the EpisodeOfCare with Observation.context.reference