How many eggs?

doi:10.1136/bmj.329.7461.302

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Marc J N C Keirse, professor,
Frans M Helmerhorst (f.m.helmerhorst@lumc.nl), associate professor

Department of Obstetrics, Gynaecology and Reproductive Medicine, Flinders University and Flinders Medical Centre, Adelaide, SA 5042, Australia
Department of Obstetrics, Gynaecology and Reproductive Medicine, Leiden University Medical Center, NL-2300RC Leiden, Netherlands

Ideally, one egg and one offspring

For some, the most crucial part of the question of “How many eggs?” is how many eggs one should put in the same nest. For others, it is how many can one get out of the same nest? Translate nest into incubator, and the study of Pinborg et al in this issue seems to address both.1

This is the second in a series by Pinborg et al (p 311) on the outcome of 3393 liveborn twins after in vitro fertilisation (IVF) with or without intracytoplasmatic sperm injection (ICSI) compared with 10 239 liveborn control twins in Denmark between 1995 and 2000.1 2 The first was based on 3438 twins born after IVF and ICSI and 10 362 naturally conceived twins, but dealt with the neonatal outcome of the 3393 and 10 239 liveborns among them.2 The current study deals with the …