Measuring the invisible: perinatal health outcomes of unregistered women giving birth in Belgium, a population-based study

Abstract

Background The unregistered population remains under-researched because of its “invisible” status in statistics. Studies on perinatal health outcomes of unregistered women remains particularly limited. Our objectives were 1) to describe the sociodemographic profiles of women who are not legally residing in Belgium and 2) to analyze the associations of registration status with pregnancy outcomes according to socioeconomic status and nationality. Methods We analysed data from birth and death certificates taken from the Belgian civil registration system, linked with the National Population Registry (NPR). The data relates to all singleton babies born between 2010 and 2016 (n = 871,283), independent of their mother’s NPR registration status. We used logistic regression to estimate the odds ratios for the associations between perinatal outcomes (perinatal mortality, prematurity and low birth weight) and maternal NPR registration status according to socioeconomic status and maternal nationality. Results Over the study period, 1.9% of births were to mothers without NPR-registration. Unregistered women from newer EU member states and non-European countries were particularly disadvantaged from a socioeconomic point of view. Apart from women with a South American nationality, all other groups of unregistered women had higher rates of prematurity, low birth weight, and perinatal mortality, compared to registered mothers (p < 0.0001). Unregistered women from Belgium and EU15 nationalities had particularly higher rates of prematurity, low birth weight, and perinatal mortality, compared to registered mothers, even after adjustment for socioeconomic status (p < 0.0001). The excess of perinatal mortality for non-European unregistered mothers could partly be explained by their precarious socioeconomic situation. Conclusions This is the first study to include data on mothers who were not legally residing in Belgium. Unregistered women giving birth in Belgium are likely a heterogeneous socioeconomic group. Overall, unregistered women have increased risks of adverse perinatal outcomes, but it is likely that the causal mechanisms differ starkly between Belgian, European and non-European women. Further research is needed to understand the mechanisms behind these accrued rates. It is important to keep measuring the health outcomes of the populations which are “invisible” in national statistics, in order to identify the groups in most need of integration and access to services.

The effect of limited access to antenatal care on pregnancy experiences and outcomes among undocumented migrant women in Europe: a systematic review

“…Due to their restriction from social assistance and legal employment, numerous studies have discovered that UMs’ lives are typically ruled by poverty and instability ( 25 ). These investigations also revealed that UMs did not have easy access to affordable accommodation and that there were few job opportunities available, most of which were on the black market, where wages were low and working conditions were poor.…”

“…However, this study indicated that only undocumented migrants born in sub-Saharan Africa were at a significantly increased risk when considering both their location of birth and their legal status. Schoenborn, Spiegelaere, and Racape ( 25 ), found that the odds ratios for perinatal mortality in Belgium were statistically significantly higher for UMs compared to women with a nationality from Belgium who were captured on the National Population Register (NPR). The nationality groups of UMs with the strongest ORs were women from EU15 countries (OR (95% CI) 7.3 (6.0–8.95), p < 0.0001), followed by Belgium women without an NPR number (OR (95% CI) 4.3(3.3–5.4), p < 0.0001).…”

“…The rates were higher for preterm birth (RR 1.47, 95% CI 1.21–1.79 and RD 19.3, 95% CI 7.6–13.0 per 1,000 births), and low birth weight (RR 1.36, 95% CI 1.11–1.66 and RD 15.9, 95% CI 3.9–28.0 per 1,000 births) among UMs in Sweden compared to their Swedish counterparts ( 24 ). One Belgian study reported that infants born to UMs with a nationality from outside of the European region were significantly more at risk of perinatal mortality, compared to infants born to registered immigrants (pooled OR (CI 95%): 1.5 (1.1–2.1), p = 0.02) ( 25 ). The same study also observed a significant excess of prematurity among unregistered mothers in all nationality groups except for Turkish and South American mothers.…”

“…In spite of the fact that ANC is essential for the detection, monitoring, and treatment of several pregnancy-related health problems, UMs still find it difficult to access their legal rights, making it difficult for them to access and receive care. According to Schoenborn, Spiegelaere, and Racape ( 25 ), UMs make use of family planning and contraception less frequently and are therefore more likely to become pregnant unintentionally, which has been associated to worse maternal and infant health outcomes.…”

Country of birth as a potential determinant of inadequate antenatal care use among women giving birth in Brussels. A cross-sectional study

“…In Brussels, three-quarters of births are to mothers with an immigrant background [21], and around 1.9% are to women who are not in the Belgian register (mostly undocumented) [22]. Different settings are available for the clinical follow-up of pregnancy, including hospitals, private practices, and community perinatal centres [23].…”