A fifth of the unplanned pregnancies happened among women using the Pill and a tenth among women using the IUD (intra-uterine device) both theoretically highly effective medical methods of contraception, said principal investigators Dr Nathalie Bajos and Dr Nadine Job-Spira of the INSERM team at Hpital de Bictre in Le Kremlin Bictre.
In a research paper published (Wednesday 30 April) in Europe's leading reproductive medicine journal Human Reproduction , Dr Bajos said the findings showed that the reality was that contraception was still a major problem even in a country such as France, which has the highest use of medical contraception in Europe.
One in eight of the unwanted pregnancies were among women choosing condoms and a fifth among those using natural methods, such as male withdrawal or avoiding intercourse on fertile days in the menstrual cycle. Thirty-five per cent of the unwanted pregnancies were among women using no contraception. Half of the unplanned pregnancies ended in abortion.
The study involved 1,034 women who had undergone an abortion or whose last pregnancy was unintended and 1,829 randomly selected controls taken from a representative sample of 14,704 households randomly selected from the telephone directory.
Dr Bajos said misuse was the main reason given to explain the unplanned pregnancies with 60% of the Pill users saying they had forgotten one or more pill. But over 18% said it was due to illness or taking other medication, while a fifth had no explanation or didn't know. Over 57% of the women whose IUD had failed said they did not know what had gone wrong or had no explanation, while over 30% said the IUD was in the wrong position or fell out and more than a tenth blamed illness or medication.
Contact: Margaret Willson
European Society for Human Reproduction and Embryology