Stanford, J. B., Sanders, J. N., Simonsen, S. E., Hammoud, A., Gibson, M., & Smith, K. R. (2016). Methods for a Retrospective Population-based and Clinic-based Subfertility Cohort Study: the Fertility Experiences Study. Paediatric and Perinatal Epidemiology, 30(4), 397-407. https://doi.org/10.1111/ppe.12291
Stanford JB, Sanders JN, Simonsen SE, Hammoud A, Gibson M, Smith KR. Methods for a Retrospective Population-based and Clinic-based Subfertility Cohort Study: the Fertility Experiences Study. Paediatr Perinat Epidemiol. 2016;30(4):397-407. doi:10.1111/ppe.12291
Stanford, Joseph B., et al. "Methods for a Retrospective Population-based and Clinic-based Subfertility Cohort Study: the Fertility Experiences Study." Paediatric and Perinatal Epidemiology, vol. 30, no. 4, 2016, pp. 397-407.
Utah clinic-recruited women had more IVF than population-sampled women
A retrospective Utah cohort of 960 women with trouble getting pregnant found clinic patients got more intensive treatment than women sampled from the population. IVF was the most intensive treatment for 46 out of 100 clinic women and 14 out of 100 others. In both samples, women with a live birth were more likely to respond to retrospective recruitment.
Key Findings
The study enrolled 459 women through clinics and 501 through population sampling, from 26,678 letters. Among eligible women, 87% of clinic and 88% of population women enrolled.
Most intensive treatment, clinic versus population: IVF 46.0% and 13.8%, intrauterine insemination 30.9% and 19.4%, ovulation drugs 13.7% and 25.6%, none 9.4% and 41.3% (p<0.001).
Clinic women were older: 15.9% were 30 to 35 at the index date, against 5.1% of population women (p<0.001). Clinic women also had higher annual household income (p<0.001).
Responders were more likely to link to a live birth: 58% versus 51% at one of two clinics, and 76% versus 69% among population women indexed in 2004.
Eligibility criteria were fully confirmed for 94% of eligible clinic women and 61% of population women. Of 168 unconfirmed population women, 139 (83%) had not tried to conceive for 12 months.
Interpretation
This retrospective cohort study followed 960 women age 35 and younger with a history of trouble conceiving, recruited either through fertility clinics or through population sampling. Clinic-recruited women received far more intensive treatment than women identified through the general population, and were older and had higher household income. The authors note their findings may not extend beyond the counties and clinics studied. Larger studies across more regions could test how widely these recruitment patterns hold.
RRM Context
The authors note that most outcome data for fertility treatment come from specialty clinics. They also state that clinic patients do not represent all couples with trouble getting pregnant. Restorative reproductive medicine looks for the cause in both partners before treating. IVF bypasses the problem without finding why conception fails. This study enrolled only women.
Our editorial summary of this paper, not the article's abstract.
Abstract
Background
Most cohort-based research for subfertility has been conducted in clinic-based cohorts, which may differ from population-based cohorts.
Methods
We retrospectively recruited parallel cohorts of subfertile women: one by sampling two specialty fertility clinics in Utah, and one by population-based sampling based on marriage and birth records. The index date (of first clinic visit or subfertility status) was between 2000 and 2009, and we linked the women recruited to subsequent birth certificate records through December 2010.
Results
We enrolled 459 women through clinic-based sampling and 501 women through population-based sampling. Clinic-based women were older, had higher annual household income and more likely to have had a most intensive treatment of intrauterine insemination (31%) or in vitro fertilisation (46%) than women from population recruitment (19% and 14% respectively). Conversely, they were less likely to have received no medical treatment (9%) compared to women from population recruitment (41%). For both types of sampling, prior to eligibility screening, non-responders were less likely to link to a live birth than responders: 51% vs. 58% for clinic-based, and 69% vs. 76% for the population-based with an index date in 2004.
Conclusions
Population-based sampling for subfertility cohort research identifies women who were more likely to have had less intensive treatment or no treatment. However, in both clinic-based and population-based sampling, women who have had a live birth are more likely to respond to retrospective recruitment.
