This issue of Current Medical Research (CMR) includes studies that provide evidence that use of natural family planning (NFP) can be helpful for subfertile couples wishing to achieve a pregnancy, the effectiveness of a method of NFP during breastfeeding, and the effects of using NFP on marital relationships. This review also includes evidence on predicting the sex of a baby by timing intercourse, evidence that brain injuries can be reflected in changes in the menstrual cycle, and that women prefer methods of family planning that have no side effects. The issue ends with an in-depth review of new technologies that aid in the use of NFP. Topics covered include subfertile couples, breastfeeding, marriage, predicting the sex of a baby, brain injuries, and new technologies.