Incidence of infertility at 12 months was not significantly higher among women with a short luteal phase, although an isolated cycle with a short luteal phase may negatively affect short-term fertility, a recent study found. The analysis included 1,635 cycles from 284 women aged 30 to 44 years looking to conceive and without known infertility. Researchers found:

• A short luteal phase (<11 days including day of ovulation) occurred in 18% of observed cycles; mean luteal phase length was 14 days.
• Significantly more women with a short luteal phase were smokers.
• After adjustment for age, women with a short luteal phase had 0.82 times the odds of pregnancy in the subsequent cycle immediately following the short luteal phase compared with women without a short luteal phase.
• After the first 6 months of pregnancy attempt, women with a short luteal length in the first observed cycle had significantly lower fertility; but at 12 months there was no significant difference in cumulative probability of pregnancy.