The Canadian Assisted Reproductive Technologies Register (CARTR) Plus database: a validation study

Perinatal and pediatric outcomes associated with the use of fertility treatment: a population-based retrospective cohort study in Ontario, Canada

BACKGROUND

Around 2% of births in Ontario, Canada involve the use of assisted reproductive technology (ART), and it is rising due to the implementation of a publicly funded ART program in 2016. To better understand the impact of fertility treatments, we assessed perinatal and pediatric health outcomes associated with ART, hormonal treatments, and artificial insemination compared with spontaneously conceived births.

METHODS

This population-based retrospective cohort study was conducted using provincial birth registry data linked with fertility registry and health administrative databases in Ontario, Canada. Live births and stillbirths from January 2013 to July 2016 were included and followed to age one. The risks of adverse pregnancy, birth and infant health outcomes were assessed by conception method (spontaneous conception, ART - in vitro fertilization and non-ART - ovulation induction, intra-uterine or vaginal insemination) using risk ratios and incidence rate ratios with 95% confidence intervals (CI). Propensity score weighting using a generalized boosted model was applied to adjust for confounding.

RESULT(S)

Of 177,901 births with a median gestation age of 39 weeks (IQR 38.0-40.0), 3,457 (1.9%) were conceived via ART, and 3,511 (2.0%) via non-ART treatments. There were increased risks (adjusted risk ratio [95% CI]) of cesarean delivery (ART: 1.44 [1.42-1.47]; non-ART: 1.09 [1.07-1.11]), preterm birth (ART: 2.06 [1.98-2.14]; non-ART: 1.85 [1.79-1.91]), very preterm birth (ART: 2.99 [2.75-3.25]; non-ART: 1.89 [1.67-2.13]), 5-min Apgar < 7 (ART: 1.28 [1.16-1.42]; non-ART: 1.62 [1.45-1.81]), and composite neonatal adverse outcome indicator (ART: 1.61 [1.55-1.68]; non-ART: 1.29 [1.25-1.34]). Infants born after fertility treatments had increased risk of admission to neonatal intensive care unit (ART: 1.98 [1.84-2.13]; non-ART: 1.59 [1.51-1.67]) and prolonged birth admission (≥ 3 days) (ART: 1.60 [1.54-1.65]; non-ART: 1.42 [1.39-1.45]). The rate of emergency and in-hospital health services use within the first year was significantly increased for both exposure groups and remained elevated when limiting analyses to term singletons.

CONCLUSION(S)

Fertility treatments were associated with increased risks of adverse outcomes; however, the overall magnitude of risks was lower for infants conceived via non-ART treatments.

Fresh Compared With Frozen Embryo Transfer and Risk of Severe Maternal Morbidity: A Study of In Vitro Fertilization Pregnancies in Ontario, Canada

OBJECTIVES

To quantify the risk of severe maternal morbidity (SMM) in fresh versus frozen-thawed embryo transfers (ETs) among pregnancies conceived by in vitro fertilization and to assess SMM risk according to the number of fresh ETs prior to the index pregnancy.

METHODS

Retrospective cohort study using the provincial birth registry in Ontario, Canada. We included 13 929 individuals aged 18-55 years who conceived via in vitro fertilization between January 1, 2013, and March 5, 2018, and delivered a live or stillborn infant ≥20 weeks gestation. We compared the primary outcome, a composite of SMM or death, between fresh and frozen ETs.

RESULTS

A total of 174 individuals who conceived via fresh ETs had SMM (30.7 per 1000), compared with 280 among individuals who received frozen ETs (33.9 per 1000); adjusted risk ratio (aRR) 0.85 (95% CI 0.70-1.04). Compared with frozen ET, fresh ET was associated with a lower risk of severe hemorrhage (aRR 0.63; 95% CI 0.48-0.82) but no difference in risk of preeclampsia. Among individuals with 1 (n = 211) or ≥2 (n = 88) prior fresh cycles, the risk of SMM was not increased compared with having no prior cycles; aRR 0.96 (95% CI 0.78-1.18) and 0.91 (95% CI 0.67-1.25), respectively.

CONCLUSION

Fresh ET was associated with a lower risk of severe hemorrhage compared with frozen ET. These findings may be partly explained by the increased popularity of a freeze-all strategy, reserving fresh ETs for patients with fewer comorbidities.

Transvaginal Sonography Post-Office Hysteroscopy as a Screening Tool for Tubal Patency: A Reliable and Feasible Technique in an Outpatient Setting

OBJECTIVE

To determine feasibility and accuracy of post-hysteroscopic transvaginal ultrasonography (TVUS) measurement of pelvic fluid accumulation as a screening method for tubal patency (TP).

METHODS

We conducted a retrospective cohort study of 85 patients who underwent uterine cavity assessment by office hysteroscopy at our university-affiliated fertility centre from November 2019 to October 2020. During the study period, two-dimensional (2D) TVUS was performed pre- and post-hysteroscopy to evaluate TP. Patient records were reviewed for demographics, diagnosis, and prior/subsequent TP testing. Predictive values for TP were calculated.

RESULTS

Pelvic fluid accumulation post-hysteroscopy was found in 65.9% of patients (56). Accumulation of fluid was seen with the use of as little as 10-50 mL of saline. Using more fluid did not increase the likelihood of demonstrating TP (P = 0.17). A trend towards more false-negative results for TP was observed when less fluid was used (7.7% with 10-50 mL vs. 3.8% with 60-190 mL and 1.3% with 200-760 mL; P = 0.10). The positive predictive value (PPV) of TVUS post-hysteroscopy in comparison to known patency/occlusion was 100%; negative predictive value (NPV) was 33%; sensitivity was 82.8%; and specificity was 100%. Similar values were seen in a second analysis that included patients with highly suspected patent or occluded tubes (n = 60); presumed predictive values were: PPV 100%, NPV 42%, sensitivity 78.8%, and specificity 100%. The use of more fluid did not increase pain (P = 0.75). This finding remains after accounting for confounders (e.g., pre-medication, endometrial biopsy).

CONCLUSION

TVUS pre- and post-hysteroscopy is feasible in an outpatient setting, and can serve as a reliable screening tool for TP. When hysteroscopy is performed and TP is not known, TVUS can be added for screening, potentially omitting the need for more invasive examinations. With limited non-urgent ambulatory services, it is of upmost importance to maximize information from a single procedure.

Parenthood desire, childbearing plans and oocyte utilization among women who previously underwent planned oocyte cryopreservation

RESEARCH QUESTION

To examine the motivations, life circumstances and parenthood aspirations of a cohort of women who underwent planned oocyte cryopreservation (POC) at a Canadian academic IVF centre.

DESIGN

A single-site, cross-sectional, anonymous quantitative study using a study-specific questionnaire administrated via SurveyMonkey®. Of the 224 women who completed at least one POC cycle between 2012 and 2018, 198 were reached by email and invited to participate.

RESULTS

Of the 98 (49.5%) questionnaires returned, 86 were fully completed and were analysed. Mean age at first POC cycle was 35.7 ± 2.4 (range 27-43) and at survey was 37.7 ± 2.5 years. At POC, 77% were single and 97.7% childless. At survey, 96% had not attempted to use their cryopreserved oocytes, yet 26 (30%) had tried natural conception or fertility treatments. Of these, three conceived naturally and two by assisted reproduction. Eighty-five per cent expressed a strong motherhood desire and 67.1% indicated that usage of their cryopreserved oocytes was mostly contingent on relationship status. Many expressed a desire for shared genetic parenthood within a committed relationship. Forty-seven per cent did not want to carry a pregnancy beyond the age of 46.

CONCLUSION

The findings of this study confirm the central role of age and relationship status in influencing women's POC decisions and oocyte utilization plans. The late age at POC could be explained by women using it toward the end of their peak reproductive years to leverage their remaining chances of genetic motherhood. Surveying women at later points following POC would help to gain a more comprehensive picture of their oocyte utilization and disposition plans.

CARTR Plus: the creation of an ART registry in Canada

STUDY QUESTION

What is the status of fertility treatment and birth outcomes documented over the first 6 years of the Canadian Assisted Reproductive Technologies Register (CARTR) Plus registry?

SUMMARY ANSWER

The CARTR Plus registry is a robust database containing comprehensive Canadian fertility treatment data to assist with providing evidence-based rationale for clinical practice change.

WHAT IS KNOWN ALREADY

The rate of infertility is increasing globally and having data on fertility treatment cycles and outcomes at a population level is important for accurately documenting and effecting changes in clinical practice.

STUDY DESIGN, SIZE, DURATION

This is a descriptive manuscript of 183 739 fertility treatment cycles from 36 Canadian clinics over 6 years from the CARTR Plus registry.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Canadian ART treatment cycles from 2013 through 2018 were included. This manuscript described trends in type of fertility treatment cycles, pregnancy rates, multiple pregnancy rates, primary transfer rates and birth outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

Over the 6 years of the CARTR Plus registry, the number of treatment cycles performed ranged from less than 200 to greater than 1000 per clinic. Patient age and the underlying cause of infertility were two of the most variable characteristics across clinics. Similar clinical pregnancy rates were found among IVF and frozen embryo transfer (FET) cycles with own oocytes (38.9 and 39.7% per embryo transfer cycle, respectively). Fertility treatment cycles that used donor oocytes had a higher clinical pregnancy rate among IVF cycles compared with FET cycles (54.9 and 39.8% per embryo transfer cycle, respectively). The multiple pregnancy rate was 7.4% per ongoing clinical pregnancy in 2018, which reflected a decreasing trend across the study period. Between 2013 and 2017, there were 31 811 pregnancies that had live births from all ART treatment cycles, which corresponded to a live birth rate of 21.4% per cycle start and 89.1% of these pregnancies were singleton live births. The low multiple pregnancy rate and high singleton birth rate are associated with the increase in single embryo transfers.

LIMITATIONS, REASONS FOR CAUTION

There is potential for misclassification of data, which is present in all administrative health databases.

WIDER IMPLICATIONS OF THE FINDINGS

The CARTR Plus registry is a robust resource for ART data in Canada. It provides easily accessible aggregated data for Canadian fertility clinics, and it contains data that are internationally comparable.

STUDY FUNDING/COMPETING INTEREST(S)

There was no funding provided for this study. The authors have no competing interests to declare.