Defining 'pregnancy' for mothers in ECHILD

[AMJ-coder]

Question / Problem statement

I am keen to understand how a new variable of 'pregnancy' has been derived from the APC data that includes live births How have other researchers approached this? Month of birth of the baby minus gestational age in weeks? Or some other method/approach?

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[zcabh35]

Howdy

one of my PhD student's has derived it this way. To generate an estimate, they have used the middle of the month (15th) and minused the gestational age in weeks.

[klharron]

Hi Amanda. When you say a "pregnancy" variable, what exactly do you mean? Are you trying to define periods of time in which a mother is pregnant? Or a binary variable to indicate that a pregnancy occurred? If you are able to provide a bit more detail, that would be great. In the meantime, you might find the supplementary material from the Mother Baby link profile paper helpful: https://academic.oup.com/ije/article/53/3/dyae065/7664509

Table S1 describes how to identify which records relate to a delivery. From there, you can estimate the delivery date (e.g., based on the admission dates for admissions that include a procedure code for delivery), and you can use gestational age at birth to work back to generate pregnancy dates. Where gestational age is missing, you could base this on an average (39 weeks is the median in the mother baby link data) to get approximate dates.

Hope this helps but do get back to me if anything isn't clear.
Katie