The existence of a population of putative stem cells with germline developmental potential (oogonial stem cells: OSCs) in the adult mammalian ovary has been marked by controversy over isolation methodology and potential for in-vitro transformation, particularly where cell sorting has been based on expression of DEAD box polypeptide 4 (DDX4). This study describes a refined tissue dissociation/fluorescence-activated cell sorting (FACS) protocol for the ovaries of adult women which results in increased cell viability and yield of putative OSCs. A FACS technique incorporating dual-detection of DDX4 with aldehyde dehydrogenase 1 (ALDH1) demonstrates the existence of two sub-populations of small DDX4-positive cells (approx. 7 µm diameter) with ALDH1 activity, distinguished by expression of differentially spliced DDX4 transcripts and of DAZL, a major regulator of germ cell differentiation. These may indicate stages of differentiation from a progenitor population and provide a likely explanation for the expression disparities reported previously. These findings provide a robust basis for the further characterisation of these cells, and exploration of their potential physiological roles and therapeutic application.

Objective To determine the incidence of subsequent termination of pregnancy (TOP) within a 2-year period in relation to the method of contraception provided to women following the index TOP.Design Case note review.Setting NHS hospital TOP service, Edinburgh, UK.Population Nine hundred and eighty-six women requesting a TOP in 2008.Methods Case notes were reviewed to determine the contraception provided at index TOP and whether women had subsequent TOP at the same hospital within 2 years.Main outcome measures Incidence of subsequent TOP within 2 years amongst women receiving different contraceptive methods.Results One hundred and twenty-one women (12.3%) of the 986 who attended the clinic requesting a TOP returned requesting another TOP in the subsequent 2 years. Both intrauterine contraception and the progestogen-only implant were associated with the lowest incidence of subsequent TOP. Using the combined oral contraceptive pill as the reference method, the odds ratios (ORs) and 95% confidence intervals (CIs) of a further TOP within 2 years with intrauterine contraception and the implant were OR = 0.05 (95% CI, 0.01-0.41; P < 0.001) and OR = 0.06 (95% CI, 0.01-0.23; P < 0.001), respectively. Women choosing the implant were significantly younger than those choosing the intrauterine method (P < 0.001).Conclusion Women undergoing a TOP who wish to avoid another unintended pregnancy should consider immediate initiation of either intrauterine contraception or the progestogen-only implant. Service providers should be trained and supported to provide these methods to women at the time of TOP.