Box 1:	One or more missed pills during the first pill week could result in the extension of the hormone free interval to >7 days and hence to follicle maturation and ovulation.
Box 2:	If fewer than 3 consecutive pills are missed in weeks 2 or 3, the hormone-free interval is shortened and this can lead to breakthrough bleeding. Contraceptive efficacy is however unaffected, as long as regular COC intake was maintained for at least 7 days prior to missed pills.
Box 3:	If 3 or more consecutive pills are missed in week 3, contraception is very likely to be compromised as the hormone-free interval is continuous with the third pill week and is prolonged by the number of days for which pills have been missed. For this reason it is recommended to omit the pill-free interval, in other words to commence the next pill packet immediately following the previous one. To simplify the recommended measures, the same recommendation is made for pills missed in week two, even though in some cases the scheduled pill free interval would have no effect on contraception.