The influence of acculturation on the risk of preterm birth and low birthweight in migrant women residing in Western Australia.

BACKGROUND: The risk of preterm birth (PTB) and low birthweight (LBW) may change over time the longer that immigrants reside in their adopted countries. We aimed to study the influence of acculturation on the risk of these outcomes in Australia. METHODS: A retrospective cohort study using linked health data for all non-Indigenous births from 2005-2013 in Western Australia was undertaken. Acculturation was assessed through age on arrival, length of residence, interpreter use and having an Australian-born partner. Adjusted odds ratios (aOR) for term-LBW and PTB (all, spontaneous, medically-indicated) were calculated using multivariable logistic regression in migrants from six ethnicities (white, Asian, Indian, African, Maori, and 'other') for different levels of acculturation, compared to the Australian-born population as the reference. RESULTS: The least acculturated migrant women, those from non-white non-Maori ethnic backgrounds who immigrated at age ≥18 years, had an overseas-born partner, lived in Australia for < 5 years and used a paid interpreter, had 58% (aOR 1.58, 95% CI 1.15-2.18) higher the risk of term-LBW and 40% (aOR 0.60, 95% CI 0.45-0.80) lower risk of spontaneous PTB compared to the Australian-born women. The most acculturated migrant women, those from non-white non-Maori ethnic backgrounds who immigrated at age <18 years, had an Australian-born partner, lived in Australia for > 10 years and did not use an interpreter, had similar risk of term-LBW but 43% (aOR 1.43, 95% CI 1.14-1.78) higher risk of spontaneous PTB than the Australian-born women. CONCLUSION: Acculturation is an important factor to consider when providing antenatal care to prevent PTB and LBW in migrants. Acculturation may reduce the risk of term-LBW but, conversely, may increase the risk of spontaneous PTB in migrant women residing in Western Australia. However, the effect may vary by ethnicity and warrants further investigation to fully understand the processes involved.

The influence of acculturation on the risk of stillbirth in migrant women residing in Western Australia.

OBJECTIVE: To investigate the influence of acculturation, demonstrated by age on arrival, length of residence, interpreter use and having an Australian-born partner, on disparities observed in the risk of stillbirth between migrant and Australian-born populations in Western Australia (WA). METHODS: A retrospective cohort study using linked administrative health data for all non-Indigenous births in WA from 2005-2013 was performed. Logistic regression analysis was used to estimate odds ratios (OR) and 95% confidence intervals (CI). Adjusted odds ratios (aOR) for stillbirth in migrants from six ethnicities of white, Asian, Indian, African, Maori, and 'other', with different levels of acculturation, were compared with Australian-born women using multivariable logistic regression analysis and marital status, maternal age group, socioeconomic status, parity, plurality, previous stillbirth, any medical conditions, any pregnancy complications, sex of baby, and smoking during pregnancy as the covariates. RESULTS: From all births studied, 172,571 (66%) were to Australian-born women and 88,395 (34%) to migrant women. Women from African, Indian and Asian backgrounds who gave birth in the first two years after arrival in Australia experienced the highest risk of stillbirth (aOR 3.32; 95% CI 1.70-6.47, aOR 2.71; 95% CI 1.58-4.65, aOR 1.93; 95% CI 1.21-3.05 respectively) compared with Australian-born women. This association attenuated with an increase in the length of residence in Asian and Indian women, but the risk of stillbirth remained elevated in African women after five years of residence (aOR 1.96 [1.10-3.49]). Interpreter use and an Australian-born partner were associated with 56% and 20% lower odds of stillbirth in migrants (p<0.05), respectively. CONCLUSIONS: Acculturation is a multidimensional process and may lower the risk of stillbirth through better communication and service utilisation and elevate such risk through increase in prevalence of smoking in pregnancy; the final outcome depends on how these factors are in play in a population. It is noteworthy that in women of African background risk of stillbirth remained elevated for longer periods after immigrating to Australia extending beyond five years. For migrants from Asian and Indian backgrounds, access to services, in the first two years of residence, may be more relevant. Enhanced understanding of barriers to accessing health services and factors influencing and influenced by acculturation may help developing interventions to reduce the burden of stillbirth in identified at-risk groups.

Healthcare factors associated with the risk of antepartum and intrapartum stillbirth in migrants in Western Australia (2005-2013): A retrospective cohort study.

BACKGROUND: Migrant women, especially from Indian and African ethnicity, have a higher risk of stillbirth than native-born populations in high-income countries. Differential access or timing of ANC and the uptake of other services may play a role. We investigated the pattern of healthcare utilisation among migrant women and its relationship with the risk of stillbirth (SB)-antepartum stillbirth (AnteSB) and intrapartum stillbirth (IntraSB)-in Western Australia (WA). METHODS AND FINDINGS: A retrospective cohort study using de-identified linked data from perinatal, birth, death, hospital, and birth defects registrations through the WA Data Linkage System was undertaken. All (N = 260,997) non-Indigenous births (2005-2013) were included. Logistic regression analysis was used to estimate odds ratios and 95% CI for AnteSB and IntraSB comparing migrant women from white, Asian, Indian, African, Maori, and 'other' ethnicities with Australian-born women controlling for risk factors and potential healthcare-related covariates. Of all the births, 66.1% were to Australian-born and 33.9% to migrant women. The mean age (years) was 29.5 among the Australian-born and 30.5 among the migrant mothers. For parity, 42.3% of Australian-born women, 58.2% of Indian women, and 29.3% of African women were nulliparous. Only 5.3% of Maori and 9.2% of African migrants had private health insurance in contrast to 43.1% of Australian-born women. Among Australian-born women, 14% had smoked in pregnancy whereas only 0.7% and 1.9% of migrants from Indian and African backgrounds, respectively, had smoked in pregnancy. The odds of AnteSB was elevated in African (odds ratio [OR] 2.22, 95% CI 1.48-2.13, P < 0.001), Indian (OR 1.64, 95% CI 1.13-2.44, P = 0.013), and other women (OR 1.46, 95% CI 1.07-1.97, P = 0.016) whereas IntraSB was higher in African (OR 5.24, 95% CI 3.22-8.54, P < 0.001) and 'other' women (OR 2.18, 95% CI 1.35-3.54, P = 0.002) compared with Australian-born women. When migrants were stratified by timing of first antenatal visit, the odds of AnteSB was exclusively increased in those who commenced ANC later than 14 weeks gestation in women from Indian (OR 2.16, 95% CI 1.18-3.95, P = 0.013), Maori (OR 3.03, 95% CI 1.43-6.45, P = 0.004), and 'other' (OR 2.19, 95% CI 1.34-3.58, P = 0.002) ethnicities. With midwife-only intrapartum care, the odds of IntraSB for viable births in African and 'other' migrants (combined) were more than 3 times that of Australian-born women (OR 3.43, 95% CI 1.28-9.19, P = 0.014); however, with multidisciplinary intrapartum care, the odds were similar to that of Australian-born group (OR 1.34, 95% CI 0.30-5.98, P = 0.695). Compared with Australian-born women, migrant women who utilised interpreter services had a lower risk of SB (OR 0.51, 95% CI 0.27-0.96, P = 0.035); those who did not utilise interpreters had a higher risk of SB (OR 1.20, 95% CI 1.07-1.35, P < 0.001). Covariates partially available in the data set comprised the main limitation of the study. CONCLUSION: Late commencement of ANC, underutilisation of interpreter services, and midwife-only intrapartum care are associated with increased risk of SB in migrant women. Education to improve early engagement with ANC, better uptake of interpreter services, and the provision of multidisciplinary-team intrapartum care to women specifically from African and 'other' backgrounds may reduce the risk of SB in migrants.

Stillbirth in Western Australia, 2005-2013: the influence of maternal migration and ethnic origin.

OBJECTIVE: To investigate prevalence rates and the risk of ante- and intrapartum stillbirth in Western Australia with respect to maternal country of birth and ethnic origin. DESIGN, SETTING AND PARTICIPANTS: Whole population retrospective cohort analysis of de-identified, linked routinely collected birth, perinatal and mortality data for all births to non-Indigenous women in WA during 2005-2013. MAIN OUTCOME MEASURES: Crude and adjusted odds ratios (aORs) with 95% confidence intervals were estimated by logistic regression and adjusted for confounding factors, for all stillbirths, antepartum stillbirths and intrapartum stillbirths, stratified by migrant status and ethnic background (white, Asian, Indian, African, Maori, other). RESULTS: Women born overseas were more likely to have a stillbirth than Australian-born women (aOR, 1.26; 95% CI, 1.09-1.37). There was no significant difference for any type of stillbirth between Australian-born women of white and non-white backgrounds, but non-white migrant women were more likely than white migrants to have a stillbirth (OR, 1.42; 95% CI, 1.19-1.70). Compared with Australian-born women, migrants of Indian (aOR, 1.71; 95% CI, 1.17-2.47), African (aOR, 2.12; 95% CI, 1.46-3.08), and "other" ethnic origins (aOR, 1.43; 95% CI, 1.06-1.93) were more likely to have antepartum stillbirths; women of African (aOR, 5.08; 95% CI, 3.14-8.22) and "other" (aOR, 1.86; 95% CI, 1.15-3.00) background were more likely to have an intrapartum stillbirth. CONCLUSIONS: Immigrants of African or Indian background appear to be at greater risk of ante- and intrapartum stillbirth in WA. Specific strategies are needed reduce the prevalence of stillbirth in these communities.