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.