2.1 Study Design and Participants
A prospective, observational cohort study was performed between January
2017 and March 2018 at a public tertiary health center (Hospital Sótero
del Río, in Santiago, Chile). Women with a singleton pregnancy less than
14 weeks of gestation and with confirmed fetal viability were invited to
participate in the study. Patients under the age of 18 or with an
intention of delivery at other medical centers were excluded from the
present research. Patients with incomplete follow-up until delivery or
with an unsatisfactory periodontological evaluation or GCF-PLAP
measurements were also excluded from participation. The study was
approved by the Scientific and Ethical Review Boards of the Hospital
Sótero del Río and the Universidad de Los Andes, and all patients read
and signed a written informed consent form prior to sampling and
evaluation.
A full periodontal evaluation was scheduled between 11 and 13 6/7 weeks
of pregnancy. One dentist, specially trained for this study, evaluated
all participants and recorded a detailed maternal and obstetric history.
Maternal systolic, diastolic, and mean arterial blood pressure, weight,
and height were measured with standardized instruments. A full
periodontal diagnostic evaluation was performed, and GCF samples were
collected to assess concentrations of PLAP, using a standardized
sampling procedure. A plasma sample was obtained from 80 randomly
selected women to compare to paired plasma and GCF-PLAP concentrations.
Patients, researchers, and health-care providers remained blinded to the
results of GCF and plasma PLAP determinations.
After this initial periodontal evaluation, patients received standard
obstetrical care, and cases with subsequent obstetrical complications
were managed according to local hospital protocols. Patients were
followed until delivery and immediate postpartum, with special emphasis
on patients who developed gestational hypertension and PE. Data
regarding pregnancy outcomes were recorded shortly after delivery in a
pre-specified database.