[Babase] Twins in BaBase

Catherine Markham babase@www.eco.princeton.edu
Mon, 01 Aug 2005 16:24:54 -0400


Hi all,

This note is just a summary of how twins are handled in BaBase.  I'm not 
posting a question, but of course comments are good if anyone has 
feedback or something to add.

To date, we have records on 2 cases of twins: Plum gave birth to Pili 
and Pole on 29 November 1982, and Cete had stillborn twins on 2 December 
1982.

The protocol in place for handling data entry for twins is to assign 
each twin the same pid.  This way they are both linked to a single row 
in Pregs and, in turn, to the mother's cycle data.  For example, both 
Pili and Pole have a pid of PLU6.

Because twins are so rare, finding a duplicate pid in a query result may 
look like a mistake/dupe record at first glance.  PLU's twins are easier 
to distinguish since both are named and their sexes are different (Pili 
is female, Pole was male).  CET's twins are trickier - both were males 
and, since they were stillbirths, neither one has a name or sname. 
Their records in Biograph are identical.

PLU's twins have been in Biograph since I've been here, but I have just 
added CET's twins to the system today (previously there was just a 
record for a single stillbirth).  I added a row for the second stillborn 
infant with all the same data for status, birth, sex, statdate, dcause, 
and pid.

In addition to this posting and a note in the BaBase Corrections file, 
Jeanne suggested describing how to handle entry for twins in the 
Protocols for Data Management Guide.  I'll draft a description for 
Jeanne and Susan to review.

Catherine