Methodology
This prospective cohort study was conducted at the Jawaharlal Institute
of Postgraduate Medical Education & Research (JIPMER), Pondicherry,
India. JIPMER is a super-specialty tertiary care hospital catering to
all populations in the Pondicherry state and the adjacent districts of
Tamil Nadu.
The study protocol approval was obtained from the JIPMER Scientific
AdvisoryCommittee and the InstituteEthics Committee (Human studies).
This study was conducted according to theDeclaration ofHelsinki
guidelines. All individuals provided written informed consent.
Participants were recruited from May 2012 to June 2016. A total of 1,931
pregnant women were screened for participation in the outpatient
department of Obstetrics and Gynaecology, ofwhich 1,512 were enrolled
and consented to participate. Among the consented population, 369 were
women with risk for developing PE.Flowchart of the number of patients
recruited and analysed is reported in Figure 1.The inclusion criteria of
the risk group include any or all of the following characteristics like
family h/o PE, PE in a previous pregnancy, body mass index (BMI)
>35 Kg/m2, diastolic blood
pressure>80 mmHg at the first visit, extremes of
reproductive age (18 to 20 years and more than 35 years), Pre-existing
medical conditions such as renal disease and chronic hypertension, and
multiple gestations (more than two).
We performed a nested case-control study to determine the risk factors
for developing PE among high-risk pregnant women. We also included
patient characteristics at the time of their first visit during the
first trimester. Patient characteristics that were included are
demographic characteristics (age, socioeconomic status), medical history
(family history of high blood pressure, PE, history of abortion,
multiple gestations), and clinical risk factors (maternal blood group,
sex of the new-born). There were no missing data on covariates. Study
participants were followed till delivery and noted for the development
of PE.
Statistical Analysis: To determine the age-specific incidence of PE in
the high-risk group we report the number of PE cases to the total number
of persons at risk in each age group for the period of study. In the
comparison of cases and controls, we first compared patient
characteristics before the event using the x2statistic
for categorical variables and the Student t- test for continuous
variables. We then sought to identify risk factors associated with PE
using conditional logistical regression. All the tests for statistical
significance were 2-tailed tests and a p-value of <0.05 was
considered statistically significant. All statistical analyses were
performed using SPSS version 18.