Introduction:
Multiple reports demonstrate that women of Indian ethnicity in
high-income countries experience more adverse perinatal outcomes than
women of other ethnic groups.1-7 In a recent study we
confirmed that South Asian women in New Zealand (NZ), the majority of
whom are of Indian ethnicity, have an approximate 50% independently
increased risk of perinatal death compared with women of NZ European
ethnicity, with most excess perinatal deaths occurring at extremely
preterm gestations <24 weeks.8 It is
furthermore well-established that women of Indian ethnicity are more
likely to develop gestational diabetes (GDM),9-12 even
at a lower BMI.13-16 Other metabolic disorders are
also more common among Indian peoples, such as type II
diabetes,17,18 cardiovascular
disease,19 the metabolic syndrome
(MetS),20 polycystic ovarian
syndrome,21 thyroid disease,22,23and anaemic disorders.24
There is a growing body of evidence suggesting that women with features
of the metabolic syndrome have an increased risk of pregnancy
complications, possibly caused by a pro-inflammatory
phenotype.25 The metabolic syndrome is defined by a
combination of risk factors which can lead to chronic health conditions
such as diabetes or cardiovascular disease, including abdominal obesity,
hypertension, high fasting blood glucose and an abnormal lipid
profile.26 Typically a favourable lipid profile is
characterised by lower triglycerides and low-density lipoprotein (LDL)
cholesterol, with increased high-density lipoprotein (HDL) cholesterol.
A study by Grieger et al. found that the risk of GDM was 3.5 to 4 times
higher among women with the metabolic syndrome, utilising data from the
same prospective cohort as in the current study.27 In
addition to clinical risk factors, we previously identified that South
Asian women with perinatal death <28 weeks gestation were
significantly more likely to have features of chorioamnionitis in
placental histology compared with NZ European women (aOR 1.87, 95%CI
1.19-2.94).28 Acute chorioamnionitis is a maternal
inflammatory response of the chorionic plate of the placenta and
chorioamniotic membranes,29 and the pro-inflammatory
metabolic syndrome may contribute to this by providing a poorin-utero environment.30,31 Smaller studies have
shown an association between diabetes or GDM and
chorioamnionitis.32-34
Considering the consistent findings of pro-inflammatory and metabolic
disorders amongst women of Indian (or South Asian) ethnicity, we
hypothesise that a less favourable metabolic health profile may
contribute to the increased risk of adverse pregnancy outcome among
these mothers. The aim of this study was to compare early pregnancy
(15±1 weeks) lipid profiles and biomarkers associated with metabolic
dysfunction between healthy pregnant women of Indian and European
ethnicity.