O-158 Social disparities in achieving a live birth after initiating ART treatment: a national register-based study among women in Denmark
Authors: Uggerhøj R , Skaaning A , Kyhl F , Schmidt L , Vassard D 
Published: July 2024

Abstract

Study question
How are educational level, labor market attachment and income associated with achieving a live birth after initiating ART treatment among women in Denmark?

Summary answer
Higher educational level, labor market attachment and higher income were strongly associated with achieving a live birth after initiating ART treatment among women in Denmark.

What is known already
Infertility is increasing in populations worldwide with an estimated lifetime prevalence of 17.5%. Approaches to this issue differs between societies and healthcare systems. In the public Danish healthcare system, three fresh ART treatments are currently offered free of charge. Additional ART treatments are self-financed in the private healthcare sector. Socioeconomic disparities in health are widely recognized. Previous studies have indicated that higher socioeconomic position (SEP) is associated with a greater probability of achieving a live birth after initiating ART treatment. However, there is limited knowledge about SEP and its relation to outcomes of ART treatment.

Study design, size, duration
This is a national, register-based study based on the DANAC II Cohort. Women undergoing ART treatment during 1994–2017 registered in the Danish IVF register were individually linked with data from sociodemographic registries and the Medical Birth Registry using the Danish Personal Identification number. The study population consisted of 68,738 women treated with ART. The outcome was a live birth. The women were followed until outcome, death, migration, or end of study (31/12/2017).

Participants/materials, setting, methods
Women included in the analyses were aged 18–45 years. Overall associations between achieving a live birth after initiating ART treatment and educational level, labor market attachment and income were examined and further stratified by nulliparity at baseline and age group. Hazard ratios (HRs) with confidence intervals (CIs) were estimated by Cox proportional hazards regression, and with adjustment for potential confounders age and ethnicity. Death was incorporated as a competing risk in all analyses.

Main results and the role of chance
Adjusted results showed that educational level, labour market attachment and income significantly determined the probability of achieving a live birth after initiating ART treatment.
HRs of achieving a first live birth after initiating ART treatment increased stepwise with higher education and income level, respectively. Compared with primary school education the highest HR was found among women with a research education (HR = 3.02 [95% CI 2.71; 3.35]). Unemployed women had the lowest HR of achieving a live birth after initiating ART treatment (HR = 0.67 [95% CI 0.64; 0.69]) compared to employed women. Women in the highest income group had two times higher HR of achieving a live birth after initiating ART compared to women in the lowest income group.
Analyses of different age groups showed that higher SEP was associated with a live birth after ART treatment in all ages. The same consistency was found for both childless women and women who had a child or children prior to ART treatment.
Subanalyses showed that women with higher SEP were more likely to continue ART treatment after unsuccessful attempts, which could explain the observed social inequality in achieving a live birth after ART treatment.

Limitations, reasons for caution
The Danish IVF register did not register non-ART treatments (intrauterine inseminations) before 2007, thus these treatments are not included. Whether severity of infertility/prognosis differs among SEP groups is unclear. Also, geographical distance to fertility clinics could have provided additional perspectives.

Wider implications of the findings
Free access to fertility treatment in public healthcare should ideally provide equal access. Patients encounter barriers during treatment and, as shown, treatment success differs based on socio-economic background. Difficulties encountered during treatment that challenge certain patients more than others based on their socio-economic background needs to be addressed.

Trial registration number
Not applicable