Correlation of IVF outcomes and number of oocytes retrieved: a UK retrospective longitudinal observational study of 172 341 non-donor cycles

Gulam Bahadur; Roy Homburg; Kanna Jayaprakasan; Claudia Joanne Raperport; Judith A F Huirne; Santanu Acharya; Paul Racich; Ali Ahmed; Anil Gudi; Abha Govind; Eric Jauniaux

doi:10.1136/bmjopen-2022-064711

Correlation of IVF outcomes and number of oocytes retrieved: a UK retrospective longitudinal observational study of 172 341 non-donor cycles

Bahadur G, Homburg R, Jayaprakasan K, Raperport CJ, Huirne JAF, Acharya S, Racich P, Ahmed A, Gudi A, Govind A, Jauniaux E

Published January 2, 2023 BMJ Open

DOI 10.1136/bmjopen-2022-064711 PMID 36592998 PMC PMC9809223

RRM Academy Synopsis

UK IVF live birth rates peak at 16 to 25 eggs and fall at 26 to 49

In a UK registry study of 172 341 IVF retrieval cycles, live birth rates rose only slightly from 6-15 to 16-25 oocytes retrieved, then fell significantly at 26 to 49. About 32 out of 100 cycles with 6-15 oocytes ended in a live birth, against about 35 with 16-25 and about 19 with 26-49.

Key Findings

Of 172 341 attempted fresh oocyte retrieval cycles, 10 148 (5.9%) retrieved no oocytes, and 91 797 (53.3%) retrieved 6-15 oocytes.
Live birth rates per cycle were 17.2% with 1-5 oocytes, 32.4% with 6-15, 35.3% with 16-25 and 18.7% with 26-49 oocytes.
Compared with 6-15 oocytes, the relative risk of live birth was 0.53 (0.52 to 0.54) for 1-5, 1.09 (1.07 to 1.11) for 16-25 and 0.58 (0.54 to 0.62) for 26-49.
Multiple gestation pregnancy rates were 9.2% with 1-5 oocytes, 11.4% with 16-25 and 11.3% with 26-49. The relative risk for 1-5 was 0.83 (0.77 to 0.90).
Only 2.84% of oocytes collected and 4.96% of embryos created resulted in a live birth.

Interpretation

The study is a retrospective cohort drawn from tabulated national regulator data on non-donor, non-oncology IVF and ICSI cycles. All UK clinics must report to the regulator, and the data cover 2015 to 2018. The authors note that age, diagnosis, stimulation method and embryo transfer details were unavailable, so the groups were compared without adjustment. The results are associations between oocyte number and outcome in one country. The authors conclude that moving from 6-15 to 16-25 oocytes gave minimal benefit in live birth rate, and that groups above 15 oocytes had higher multiple gestation rates than the 1-5 group.

RRM Context

Retrieval counts measure how many oocytes a stimulation produced. They say nothing about why conception failed in the first place. Restorative reproductive medicine starts from the cause of infertility in each couple, with both partners evaluated. Under 5% of embryos ending in a live birth shows how much material IVF generates for each baby.

Our editorial summary of this paper, not the article's abstract.

Abstract

Objective

How do numbers of oocytes retrieved per In vitro fertilisation (IVF) cycle impact on the live birth rate (LBR) and multiple gestation pregnancy (MGP) rates?

Design

Retrospective observational longitudinal study.

Setting

UK IVF clinics.

Population

Non-donor IVF patients.

Main Outcome Measures

LBR per IVF cycle and MGP levels against number of oocytes retrieved into subgroups: 0, 1-5, 6-15, 16-25, 26-49 oocytes and 50+ oocytes. Relative risk (RR) and 95% CIs were calculated for each group against the intermediate responder with '6-15 oocytes collected'.

Results

From 172 341 attempted fresh oocyte retrieval cycles, the oocyte retrieved was: 0 in 10 148 (5.9%) cycles from 9439 patients; 1-5 oocytes in 42 574 cycles (24.7%); 6-15 oocytes in 91 797 cycles (53.3%); 16-25 oocytes in 23 794 cycles (13.8%); 26-49 oocytes in 3970 cycles (2.3%); ≥50 oocytes in 58 cycles (0.033%). The LBRs for the 1-5, 6-15, 16-25 and 26-49 subgroups of oocytes retrieved were 17.2%, 32.4%, 35.3% and 18.7%, respectively. The RR (95% CI) of live birth in comparison to the intermediate group (6-15) for 1-5, 16-25 and 26-49 groups was 0.53 (0.52 to 0.54), 1.09 (1.07 to 1.11) and 0.58 (0.54 to 0.62), respectively. The corresponding MGP rates and RR were 9.2%, 11.0%, 11.4% and 11.3%, respectively and 0.83 (0.77 to 0.90), 1.04 (0.97 to 1.11) and 1.03 (0.84 to 1.26), respectively.

Conclusion

There was only limited benefit in LBR beyond the 6-15 oocyte group going to the 16-25 oocytes group, after which there was significant decline in LBR. The MGP risk was lower in 1-5 group.

Gulam Bahadur, Roy Homburg, Kanna Jayaprakasan, Claudia Joanne Raperport, Judith A F Huirne, Santanu Acharya, Paul Racich, Ali Ahmed, Anil Gudi, Abha Govind, Eric Jauniaux

G Bahadur, R Homburg, K Jayaprakasan, C Raperport, J Huirne, S Acharya, P Racich, A Ahmed, A Gudi, A Govind, E Jauniaux

PMID 36592998 36592998 DOI 10.1136/bmjopen-2022-064711 10.1136/bmjopen-2022-064711 Bahadur et al. 2023, Bahadur 2023

Correlation of IVF outcomes and number of oocytes retrieved: a UK retrospective longitudinal observational study of 172 341 non-donor cycles

UK IVF live birth rates peak at 16 to 25 eggs and fall at 26 to 49

Key Findings

Interpretation

RRM Context

Abstract

By this author

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