Neurological sequelae in in-vitro fertilisation babies

Abstract

Sir—Bo Stromberg and colleagues (Feb 9, p 461), in their populationbased study of long-term neurodevelopmental consequences of birth after in-vitro fertilisation (IVF), suggest that IVF is a risk factor for neurological abnormality even among singletons. However, they conclude that the real way to reduce the risk of neurological abnormality is to lower the multiple pregnancy rate. If IVF is an independent risk factor for neurological abnormality, further important questions arise: is infertility the underlying causal factor or the process of multifollicular ovarian stimulation, or do these disorders occur because of the artificial culture media used in the earliest stages of embryonic development? However, we think several additional factors may have been overlooked in the analyses and interpretation. Stromberg and colleagues’ data Sir—Robin Biellik and colleagues report a reduction in measles mortality and morbidity in southern Africa. In Japan, routine measles immunisation with one dose of measles vaccine has been used since 1978. However, measles epidemics have still occurred, and unvaccinated young adult cases of measles have risen in number. Furthermore, measles cases have been exported to the USA. The relation between measles coverage and number of children with measles was studied in Niigata Prefecture, Honshu Island, Japan. The total population of Niigata Prefecture is around 2·5 million. Vaccine had been administered to children aged 12–70 months until 1994, and 12–90 months thereafter. At the same time, recommended immunisation age was changed from 18–36 to 12–24 months. Routine vaccination coverage has been more than 90% by age 48 months since 1989, but cases of measles continued to occur in high numbers until 1995, after which the number of cases fell because of coverage of more than 60% by age 24 months after the change in immunisation age. High coverage has now controlled measles in Niigata Prefecture. Thus, we emphasise that routine administration of single-dose measles vaccine to children as soon as possible after their first birthday is essential for measles control, as reported in Canada. However, implementation of a two-dose schedule as a next step would be also required for measles elimination in Japan. *Hiroshi Suzuki, Takatsugu Sakai, Reiko Saito, Nao Seki