|Nulliparity is a condition that has been associated with the development of some oncological gynecological diseases. Cancer mortality rates in Catholic nuns (breast, ovarian and uterine) is higher than in general population, and nulliparous women appear more susceptible to these three cancers, as compared to parous women, thus suggesting that pregnancy represents a âprotectedâ time . It is suggested that in nulliparous women, the increased number of cycles between menarche and menopause expose to an increased risk of hormone-dependent cancers.
The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.