Abstract
Introduction: Infertility is an important global public health issue. For individuals it can result in grief, depression and deteriorating relationships, and, for societies, generate a costly burden and possibly impact on population growth. Findings from high-income countries, although variable, have suggested approximately a fifth of women had experienced infertility (defined as ever trying unsuccessfully to conceive for at least 12 months), with around half of these seeking medical help, and up to a third receiving treatment. Despite the common occurrence of infertility, surveys generally have reported poor knowledge. While New Zealand demographic data highlight delayed childbearing and high proportions of childless women over 40 years, potentially indicating substantial infertility, there has been only limited information about infertility here. This thesis aims to extend current knowledge by estimating the prevalence of infertility, assessing service use and outcomes for infertile women in southern New Zealand, and evaluating fertility knowledge and behaviours.
Methods: To meet this overall aim three studies were conducted: A population-based survey of women living in southern New Zealand aged 25–50 years to determine the proportion having: a) experienced infertility; b) sought help; and c) resolved their infertility, and to assess their fertility knowledge; an analysis of Otago Fertility Service patient data to determine the prevalence and predictors service outcomes; and national hospital discharge data on infertility, and also pelvic inflammatory disease and ectopic pregnancies (both causes of tubal factor infertility), were explored to determine their feasibility for monitoring infertility and the potential generalisability of the southern data nationally.
Results: The survey had 1,125 participants, representing a response rate of 60.1%. Overall, 21.7% (95% CI 19.1–24.4%) had tried unsuccessfully to conceive for at least 12 months, increasing to 25.3% (95% CI 22.6–28.1%) when the definition included women who sought medical help to conceive. The majority (70.6%) of infertile women sought medical help, and 37.9% reported receiving treatment. Amongst fertility clinic patients, receiving treatment was associated with low parity, younger age, not smoking and having a healthy body mass index. Three-quarters of survey participants and half of the clinic patients resolved their infertility with a live birth. Resolution was associated with a younger age at onset of infertility, being in a heterosexual relationship, being less deprived, having less severe diagnoses and receiving treatment. Knowledge amongst survey participants was particularly poor regarding identifying women’s fertile period, although a third reported engaging in ovulation monitoring. Interpretation of national data on hospitalisations for infertility, pelvic inflammatory disease and ectopic pregnancies was substantially hindered by the unknown, but likely substantial, proportion of cases not managed as publicly funded inpatients. Overall this analysis showed that it is not currently feasible to monitor infertility in New Zealand using hospitalisation data.
Discussion: Most findings were consistent with the literature identified from other high-income countries, although survey results suggest infertility could be more common than previously estimated. These data provide insights into infertility in New Zealand and highlight the need for national data on infertility care and outcomes, primary prevention strategies, and improved fertility education.