For many years we have heard nothing but good things about test tube babies, how they are strong and grow faster, etc. Maybe the "authorities" are telling us what we want to hear, with women choosing to have children later in life.
Older women having babies had their age taken into account when measuring birth defects. If they smoked this was also given a mathematical allowance. This could be distorting the true picture.
There has been a change in the way the "art" of test tube babies is done. Today, an individual sperm is injected into an egg. In the normal fertilization process only the fastest, healthiest sperm is successful.
Evaluation of babies shows that birth defects occur in "injected" babies at a rate of 10 per cent. This compares to 6 per cent for naturally conceived babies. Couples who choose the older form of freezing embryos had normal rates of healthy babies. The attempt to get more embryos by injecting sperm, ICSI, seems to have backfired.