精蟲濃度低於4000萬仍可能下降懷孕率

正常精蟲濃度不應低於2000萬/ml
但精蟲濃度低於4000萬/ml仍可能會下降懷孕率

http://humupd.oxfordjournals.org/content/14/6/593.full

Trends in the use of intracytoplasmatic sperm injection marked variability between countries

 

Next Section

Abstract

BACKGROUND ICSI is used increasingly often compared with standard IVF. The aim of the present study was to analyse the changes in the use of ICSI, and discuss possible causes and consequences.

METHODS Data from National and Regional registers were analysed for trends in the use of ICSI and indications for assisted reproductive technology (ART).

RESULTS The use of ICSI increased from 39.6% of ART cycles in 1997 to 58.9% in 2004 (USA 57.5%, Australia/New Zealand 58.6%, Europe 59.3%). The Nordic countries, the Netherlands and the UK used ICSI to a low extent (40.0–44.3%), whereas Austria, Belgium and Germany (68.5–72.9%) and the southern European countries like Greece, Italy and Spain used ICSI frequently (66.0–81.2%). The marked increase in the proportion of ICSI cycles seems primarily due to an increased use in couples classified as having mixed causes of infertility, unexplained infertility and advanced age together with a relative decline in tubal factor infertility. An absolute increase in the prevalence of couples with impairment in semen quality remains a possibility.

CONCLUSIONS ICSI is used increasingly, but huge differences exist between countries within Europe. It is not possible to determine specific factors that explain the differences. As ICSI does not give higher pregnancy rates than IVF in couples without male factors, and as it adds additional costs, infertile couples and society may benefit from a less frequent use of ICSI in some countries.