Methods
Participants
This hospital-based nested
case-control study was based on a longitudinal GHOACS conducted at the
Obstetrics and Gynaecology Department of Komfo Anokye Teaching Hospital
(KATH). Both nulliparous and multiparous normotensive pregnant women
(NTN-PW) aged from 18 to 45 years with a singleton pregnancy at 10-20
weeks gestation, that provided written informed consent, were recruited
at baseline.
Sociodemographic data were obtained through a completed questionnaire,
and clinical and obstetric data were obtained from the antenatal folder
and participant’s record in the database of the KATH. The overall health
of participants at visit 1 was assessed using the Suboptimal Health
Questionnaire-25 (SHSQ-25) and pregnant women were classified as SHS and
OHS based on the procedure described in previous
studies.16, 17
At the start of the study, defined as wave 1 (W1) (10-20 weeks
gestation, median, 17 weeks), 593 clinically diagnosed normotensive
pregnant women (NTN-PW) were included. Of the 593, 504 returned to
participate in the first follow-up, wave 2 (W2) (21-31 weeks gestation,
median 27 weeks), whereas 498 completed the study, wave 3 (W3) (32-42
weeks gestation) and were included in the final assessment. At the time
of delivery (32-42 weeks gestation), 197 had developed PE and were
classified as cases whereas 301 returned as NTN-PW and were classified
as controls. Of the 498 participants, 248 of them had ‘SHS’ at
baseline of which 153 later developed PE (56 EO-PE and 97 LO-PE) and 95
returned as NTN-PW. Also, 250 had ‘optimal health status’(OHS) at
baseline of which 44 developed PE (14 EO-PE and 30 LO-PE) and 206
returned as NTN-PW. A total of 95 women were lost to follow-up due to
unwillingness to continue (n=32), relocation (n=48), spontaneous
abortion (n=4) and self-induced abortion (n=11) (Figure 1).
Figure 1. Study
participants.