Data sources
The Swedish Pregnancy Register (www.graviditetsregistret.se) is a
national quality register, established in 2013. It receives data from
multiple sources. A majority of variables are directly transferred from
the electronic medical records (EMR). The register contains detailed
information of the pregnancies, prospectively entered prospectively into
the EMR by midwives and physicians in a standardized manner, starting
with the first antenatal visit, and thereafter subsequently at every
subsequent visit, including ultrasound examinations, delivery and
postnatal care visits. Additionally, the register includes diagnoses and
procedure codes for both mothers and infants, coded using the
International classifications of disease (ICD) system (with version 10
in use since 1997). Information on clinical characteristics (symptoms
and clinical findings such as maternal and fetal heart rate pattern),
and laboratory measurements (CRP, leukocyte count and cultures) were
extracted manually from medical records by the main author (PB).