This is the first study addressing the use of maternal health care services and obstetric outcomes by undocumented women in Finland. This study demonstrates three highly important issues: 1) undocumented women attended maternal health care services in a late stage of pregnancy, 2) the number of prenatal visits was inadequate, and 3) the prevalence of infectious diseases was significantly higher amongst undocumented women.
Access to prenatal care
In this study, most undocumented women had their first prenatal visit as late as in the second or third pregnancy trimester which is later than the Finnish Institute for Health and Welfare recommends . However, according to the electronic medical records, there was no information available on how long the undocumented women had resided in Finland before accessing their first prenatal visit. Undocumented women had their first prenatal visit even later compared with women in other European countries [4, 5, 9, 16,17,18]. In addition, undocumented women entered prenatal care on average ten weeks later compared with all pregnant women in Finland . The onset of prenatal care of undocumented women in Helsinki was also delayed compared with the results of de Jonge et al. , Wolff et al. , and Paquier et al.  as their studies showed undocumented women entering prenatal care one to five weeks later in comparison to other women in the same country.
In addition to delayed prenatal care, the results of this study showed undocumented women receiving inadequate prenatal care. This is consistent with previous research [6, 7, 9, 13,14,15]. Moreover, the average number of prenatal visits of undocumented women was inadequate compared with the Finnish Institute for Health and Welfare’s recommendation of eight to ten visits , in addition to the World Health Organization’s recommendation of minimum of eight visits . Undocumented women in Helsinki had eight prenatal visits less than the average of all pregnant women in Finland in 2018 . This study showed that almost one-fifth of the undocumented women had visited a health care professional at least once before arrival to Finland. Nevertheless, we suggest that the undocumented women received inadequate prenatal care as there was no reliable information or documentation available of these visits.
An additional finding of concern is that four women in this study did not receive any prenatal care. Similar results have been found in Canada, where 7% , and in the Netherlands, where nearly one-fifth of the undocumented women received no prenatal care . In addition, this study showed that three women were denied access or continuation of care by a health care professional. Previous research from Norway and Sweden, and a report from the Swedish Agency for Public Management have found similar tendencies [8, 36, 37].
As undocumented women have had access to public maternal health care in Helsinki already since 2013 , it is necessary to consider why women access these services in such a late stage of pregnancy. In this study, inadequate prenatal care can partially be explained by the late onset of prenatal care, women ending prenatal care, and women not showing up for booked appointments. Previous research also suggests that lack of information on the right to health services, fear [4, 7, 36], unfamiliar health care system, and poor financial situation [4, 11] may lead to under-utilization of health care services. It is also worth highlighting that language barriers may complicate the access to and quality of care , in addition to the delivery of maternity care . In this research, solely professional interpretation was used only in one-fourth of the prenatal visits, which is less frequently compared with a recent study conducted in Sweden, where professional interpretation was used in 82% of the prenatal visits of asylum seeker and undocumented pregnant women . Lastly, it needs to be considered that the lack of knowledge amongst health care professionals on the official guidelines on the legal rights of undocumented migrants may hinder the access to prenatal care [7, 8, 37].
The results of this study, amongst previous research [4, 9, 14, 17], underlines the importance of early access to maternal health care services for undocumented women. There is evidence to suggest that by expanding access to prenatal care, the utilization [15, 38] and the quality of care increased, and undocumented women were more likely to receive adequate prenatal care . Furthermore, late access to health services may implicate higher financial costs as timely treatment in the primary health care setting has shown to be more cost-effective compared with urgent medical care [39, 40].
As the legal right to maternity health care is not sufficient to guarantee access to prenatal care , there is a need to develop diverse and innovative ways to reach undocumented women to increase access to care. Further, the importance of policy-makers and health care managers’ responsibility in ensuring that health care professionals receive sufficient training and knowledge on the rights and practices of care of undocumented pregnant women should be emphasized [8, 37].
Screening of infections
There is only scarce research on the prevalence of infectious diseases amongst undocumented pregnant women. In this study, the prevalence of HIV and HBV was significantly higher amongst undocumented women compared with all pregnant women. The results are in line with previous research that has found the prevalence of infectious diseases higher amongst undocumented women compared with other migrant or native women in the same country [5, 17, 19, 20].
Interestingly, this study found that the prevalence of HIV amongst undocumented pregnant women in Helsinki was higher than what was found by Wolff et al.  (0.6%, n = 161) and Wendland et al.  (1.5%; n = 132). In contrast, the prevalence of HBV was less amongst undocumented women in this study than what Wendland et al.  had found (6.5%; N = 92). The prevalence of infections detected amongst the undocumented women in this study were high also compared with data from asylum seekers in Finland (HIV 0.3%; n = 45, HBV 1.6%; n = 275)  and asylum seekers in Italy (HIV 1.6%; n = 5, syphilis 0.7%; n = 2) . Though, it is possible that these discrepant observations are due to different backgrounds in different populations or the small sample size in all the studies.
The Finnish Institute for Health and Welfare recommends screening for HIV, HBV, and syphilis in the early stage of pregnancy . In addition, the official guidelines for prenatal and obstetric care issued by the Helsinki and Uusimaa hospital district recommends screening of HCV amongst undocumented women . It is noteworthy that more than half of the women were not tested for HCV. The reason for low coverage of HCV testing may be explained by the fact that the guideline is not a national regulation, merely a local recommendation, and the fact that the health care professionals may not have been aware of the specific guideline. Restricting access to preventive and timely health care is not only unequal but may lead to adverse consequences for public health due to limited or late screening and treatment of communicable infections and mother-to-child transmissions .
Strengths and limitations
This study was a register-based study conducted as a census study and the study population comprised exclusively of undocumented women. The study was conducted in Helsinki, the capital of Finland, where most undocumented migrants are assumed to reside. The heterogeneous study population represents well the population of undocumented pregnant women met in the maternity health care services and at Global Clinic in Helsinki. The reliability of this study is increased by the fact that Finnish health registers have been found to have good coverage, high validity, and data quality . The accuracy of the data used is enhanced by the fact that many of the variables already existed as such in the electronic medical records of both primary (Pegasos) and specialized health care (Obstetrix).
The limitation of the study is its relatively small study population. However, it must be considered that the number of all undocumented migrants in all of Finland is estimated to be only 3000–4000 [10, 27]. The possibility that some undocumented women may have been left outside of the study cannot be excluded. This could be due to a failure to register them under the proper statistical code (primary health care) or due to the legal status of migrants not being registered at all (specialized health care).