Background
Evidence suggests women of certain ethnicity may be more vulnerable to non-communicable diseases (NCDs) which may affect their health, pregnancy outcomes and health of their offspring. In contrast, a “healthy migrant phenomenon” has also been reported indicating better outcomes among foreign-born groups. We studied selected conditions in pregnant women according to ethnicity and migrant status in Western Australia.
Methods
A whole-population retrospective cohort study using linked-data (2005-2013) and multivariable logistic regression analysis was undertaken to estimate adjusted odds ratios of selected conditions (diabetes, hypertension, asthma) and pregnancy complications (gestational diabetes (GDM), preeclampsia) comparing non-Caucasian (Asian, Indian, African, Maori, Other) with Caucasian ethnicity, stratified by Australian-born or foreign-born (migrant) status.
Results
From 260,997 births in WA (2005-2013), 34% were to migrants. Migrant Asians were protected for all conditions other than GDM (Adj.OR: 2.51*,95%CI:1.41-2.17 ), Indians for all conditions other than diabetes (Adj.OR:1.90*,95%CI:1.41-2.56) and GDM (Adj.OR: 3.66*,95%CI:3.36-3.98 ) and the “Other” group for hypertension and asthma. Maoris had increased risk of asthma (Adj.OR:1.40*,95%CI:1.25-1.58) and preeclampsia (Adj.OR:1.40*,95%CI:1.10-1.78 ) compared to Caucasians. Substantial reduction of risk of Asthma (Adj.OR:0.22*,95%CI:0.17-0.27 ), and increased risk of preeclampsia (Adj.OR:1.54*,95%CI:1.26-1.87) was observed in Africans compared with Caucasians. No protective effect of ethnicity was observed among Australian-born ethnic groups except for Asthma in Asians(Adj.OR:0.83,P:0.04,95%CI:0.70-0.99). (*p<0.001)
Conclusions
In Australia, there is convincing evidence of a healthy migrant phenomenon for asthma, hypertension and preeclampsia, that is lost in next generation, as well as ethnic-specific risk of some NCDs. This knowledge offers unique opportunity for NCDs prevention especially in future generations.