To study the outcomes of women with infertility or miscarriage treated with natural procreative technology (NaProTechnology or NPT), a systematic medical approach to promoting conception in vivo; and to compare the outcomes with those previously published from a general practice in Ireland. Results A total of 108 couples received NPT and were included in the analysis, of which 19 (18%) reported having 2 or more previously unexplained miscarriages. The average female age was 35.4 years. Couples had been attempting to conceive for a mean of 3.2 years. Twenty- two participants (20%) had previously given birth; 24 (22%) had previous intrauterine insemination; and 9 (8%) had previous assisted reproductive technology. The cumulative adjusted proportion of first live births for those completing up to 24 months of NPT treatment was 66 per 100 couples, and the crude proportion was 38%. The cumulative adjusted proportion of first conceptions was 73 per 100 couples, and the crude proportion was 47%. Of the 51 couples who conceived, 12 couples (24%) conceived with CrMS instruction alone, 35 (69%) conceived with CrMS and NPT medical treatment, and 4 (8%) conceived after additional surgical treatment. All births were singleton births; 54% were born at 37 weeks' gestation or later; and 78% had birth weights of 2500 g or greater.