Analysis of a multicentre trial of a new low-dose oral contraceptive in Great Britain.

An oral contraceptive containing D-norgestrel 150 mug. and ethinol oestradiol 30 mug. (Neovletta) was tested in 682 British women during more than 6,000 cycles. The pregnancy rate was 0.2 per 100 woman-years with the exclusion of pregnancies that followed admitted errors of tablet-taking, and 0.8 per 100 woman-years when they were included. 92.2 per cent of cycles were within 28 +/- 3 days. withdrawal-bleeding was missed in 3.3 per cent of cycles. Spotting occurred in 9.3 per cent of cycles and breakthrough bleeding in 5.8 per cent. Total bleeding averaged 4.71 days per cycle. Concurrent symptoms likely to be attributable to the pill were few and only 10.3 per cent of subjects withdrew because of them. It can be concluded that this formulation is extremely well tolerated and highly effective.