Abstract
Research question: What is the association between assisted reproductive technologies and human sex ratio as a proportion of male offspring at birth. Design: A total of 59,628 singleton deliveries resulting from IVF, intracytoplasmic sperm injection (ICSI) and intrauterine insemination (IUI) or ovulation induction from 101 IVF clinics in Germany, that had been documented in a national German IVF registry, were analysed. Sex ratio after assisted reproductive technology was also compared with the sex ratio reported in the birth records of the German Federal Statistical Office. Results: The sex ratio was 50.0% (95% CI 49.5% to 50.5%) for ICSI, 52.2% (95% CI 51.5% to 52.9%) for IVF, 52.2% (95% CI 50.9% to 53.5%) for IUI or ovulation induction and 51.3% in the national birth records, respectively. Significant differences existed across the three treatment groups (P = 6.86 × 10−7) as well as in pairwise comparisons between ICSI versus IVF (P = 6.88 × 10−7) and ICSI versus IUI or ovulation induction (P = 0.003). No difference existed between the groups IUI or ovulation induction versus IVF. Same results were also present after stratification by maternal age: IVF versus ICSI (P = 6.433 × 10−7), ICSI versus IUI or ovulation induction (P = 0.003), and IVF versus IUI or ovulation induction (non-significant). Compared with the national birth records, ICSI is associated with a lower sex ratio compared with the reference group (P < 0.001), whereas IVF is associated with a higher sex ratio (P = 0.015). Conclusions: The use of ICSI is associated with an equal proportion of sexes at birth, which is not the case for IVF, IUI or ovulation induction, or natural conception. This phenomenon is not influenced by maternal age.
| Original language | English |
|---|---|
| Journal | Reproductive BioMedicine Online |
| Volume | 37 |
| Issue number | 6 |
| Pages (from-to) | 703-708 |
| Number of pages | 6 |
| ISSN | 1472-6483 |
| DOIs | |
| Publication status | Published - 12.2018 |
Funding
This study was a retrospective exploratory analysis of data from a national German IVF registry (RecDate®), which was discontinued after 2009 ( Bühler et al., 2011 ). Therefore, the data retrieved span 1997–2009. Institutional review board approval was obtained on 13 April 2018 (Ethical review board of the University of Luebeck, file 18–113). The RecDate IVF registry was sponsored by a grant from Merck Serono, and data were collected in parallel with the national German IVF registry (Deutsches-IVF-Register®). Both registries were based on the same software system for collecting IVF cycle data. Data reporting is mandatory for the national German IVF registry; however, participation in the RecDate data collection was voluntary and a larger array of data was collected than what is mandatory for the national registry, including the voluntary submission of data on ovulation induction and IUI within a working group on ovulation induction and IUI ( Schill, 2003 ). Auditing of the centres by the RecDate registry was not carried out. It was estimated that coverage by the RecDate registry of IVF treatment cycles carried out in Germany was about 65–70% with 73–79 treatment centres (out of 109–120) exporting data at regular intervals from 1997 to 2009 ( Griesinger et al., 2008 ). In this study, data from 101 out of 103 infertility treatment centres listed in the RecDate registry were available for analysis.
