Advances in contraception : the official journal of the Society for the Advancement of Contraception最新文献

This research was designed to identify determinants of unintended pregnancy among women attending family practice or family planning clinics. Survey data were collected from 95 women who were categorized according to whether or not they had experienced an unintended pregnancy. Women reporting unintended pregnancy were younger, reported earlier sexual debut and a greater number of sexual partners than those not having experienced an unintended pregnancy. Those who had avoided unintended pregnancy displayed higher levels of preventive sexual self-efficacy, had more confidence in their ability to use contraceptive methods, perceived more negative consequences associated with having children in the near future, and believed pregnancy among unmarried women to be less acceptable than did women who had had unintended pregnancies.

Male condoms made from synthetic materials offer an alternative to latex condoms that may be more acceptable to users, thereby potentially resulting in more protected acts of intercourse. A prospective, noncomparative clinical study was conducted to evaluate the safety of using certain polyurethane materials to make condoms. Fifty-one healthy, contracepting, mutually monogamous couples were recruited between June 30 and November 24, 1993 to use a prototype roll-on polyurethane condom developed by Family Health International. Couples were to use the condoms for 10 consecutive acts of vaginal intercourse over a 4-week period. Baseline and postexposure genital examinations, including colposcopy for female participants, were performed. Fifty couples completed the study requirements and 517 acts of intercourse occurred using the condoms. Two adverse events were reported: irritation of introitus in a female participant and a small irritated erythematous lesion on a male participant's penis. Neither event was considered to be serious and both were resolved without treatment. Breakage and slippage rates were similar to those reported for latex condoms. These results suggest that polyurethane condoms represent a safe, functional and acceptable alternative to latex condoms.

Simple, well-documented, effective and inexpensive management approaches are needed for the short-term control of bleeding in progestin-only contraceptive (POC) users. Long-term continuation may improve if acceptable approaches are found to ameliorate these short-term bleeding problems. Family planning providers and researchers were surveyed on the treatment regimens they used for POC-associated bleeding disturbances. Results from this limited survey indicate that no clear indication exists regarding the duration and, severity of bleeding and spotting requiring pharmacologic intervention. Counseling was seen as a critical factor when considering treatment for these problems. This report presents the results of this survey on the different treatment regimens being used by providers throughout the world to treat POC-associated bleeding disturbances.

Statistical methods recently developed to aid in identifying environmental exposures with reproductive toxicity can also be applied to trials of interventions undertaken specifically to impair fertility, i.e. methods of contraception. Although only applicable in a trial that includes a reliable benchmark for identifying the day of ovulation, the proposed measures of contraceptive efficacy derived from such a trial offer certain interpretive advantages over the more traditional approaches of evaluating contraceptives. Extensions of the same models also allow one to evaluate efficacy under any assumed pattern of imperfect use. One can also evaluate methods based on biomarkers for the fertile phase of the cycle, such as hydration of the cervical mucus, that may prove to be enormously helpful to couples who wish to use periodic abstinence as their method. In prospective studies of fertility, couples who occasionally use a barrier method should not be excluded from the study, but can be retained, without biasing the estimates for fertility parameters.

In 1994, the Department of Health (DOH) of the Philippines issued a circular which reaffirmed natural family planning (NFP) as one of the basic services to be offered in all government family planning service sites and urged family planning workers to develop competence in teaching NFP methods. Although the circular represented a major policy breakthrough for the main-streaming of NFP it found the department without the capability or experience to directly provide NFP services. The two approaches the department is taking to respond to this new policy initiative are described in this paper. The selection of these approaches was influenced by the devolution of central government authority to local government units. The approaches include developing department capability in NFP training, service provision and service installation and creating a supportive program and policy environment. DOH partnership with an NFP non-government organization (NGO) has been critical in developing NFP capability within the government sector, particularly in NFP training and service installation.

This paper provides a case study of a model for expanding natural family planning (NFP) from a small local program to the national level through the creation of a national association and the development of a public-private partnership. The experience of the New Zealand Association of Natural Family Planning (NZANFP) is analyzed in terms of both the benefits and barriers of using this model. Recommendations are given to guide others in developing a similar model.

Objective: Various birth defects and untoward perinatal outcomes have been claimed to be associated with pregnancies conceived by gametes aged in vivo before fertilization. Thus, these outcomes were systematically assessed in pregnancies occurring in natural family planning (NFP) users. Our international multicenter cohort study of NFP pregnancies (n = 877) is by far the largest systematic study designed to assess pregnancy outcome and is of sufficient power to allow us to address the concern of low birth weight (< 2500 g) and preterm delivery (< 37 weeks gestation).

Study design: In addition to gathering baseline medical data, evaluation was performed at 16 weeks, 32 weeks and at term. Data were collected in a systematic cohort fashion, verified by the five collaborating international recruiting centers, and analyzed by investigators in the US. Most recruiting center principal investigators are obstetrician-gynecologists and, if not, have integral relationships with such specialists. Standard criteria could thus be applied within and among centers. In our cohort, birth weight was recorded accurately at delivery. Almost all of the deliveries occurred in hospitals; thus, data should be quite reliable. Neonatal examination for anomalies was usually conducted immediately after delivery, when birth weight was recorded.

Results: Analysis of risk factors for low birth weight and preterm delivery showed that this population had a low risk profile. Low birth weight infants (< 2500 g) and preterm deliveries were increased among women with a history of either prior low birth weight or preeclampsia in the index pregnancy. However, mean birth weight was unaffected by the timing of conception vis à vis ovulation or pregnancy history. Mean birth weight for the 877 singleton NFP pregnancies was 3349.6 g. The risk of preterm delivery was increased among older women who drank alcohol, but there were no significant effects of timing of conception vis à vis ovulation on preterm delivery. Results held when analysis was stratified according to whether NFP was being used for contraception or to achieve pregnancy.

Conclusions: Our data do not appear to show striking differences between 877 NFP pregnancies and the general obstetric population. The timing of conception vis à vis ovulation does not exert significant effects on the birth weight or preterm delivery of resulting pregnancies, a reassuring finding for NFP users.

Several mathematical models have been developed over the past thirty years to investigate how the probability of conception changes on the different days of the cycle with respect to ovulation. A problem general to all models is to estimate the day of ovulation. Since the most fertile days are those close to ovulation, less precise estimates of this event will lead to less accurate estimates of the probability of conception on a given day of the cycle. Given that a reference point for ovulation is available, the first model considered conception as dependent only on the timing of intercourse. Conception was found to be most likely to occur on only six days in each cycle. However, the model is biologically unrealistic because it assumes that all ova can be fertilized and lead to a viable pregnancy. There are other factors that affect the probability of conception, including whether the ovum is viable or not. Recent models have extended the idea of cycle viability to allow for differences between cycles within couples and for the introduction of couple specific covariates. In a second group of models the probability of conception depends mainly on the time of intercourse and the survival times of sperm and ovum. A graphical summary of the results available in the literature is presented. Conception probabilities have been found to be significantly different from zero from five days before ovulation to the day of ovulation itself. On average, less than half of the cycles are viable in women, although recent studies suggest that different cycle viability between women should be taken into account. Survival times for sperm and the ovum have been estimated to be 1.4 days and 0.7 days, respectively. Sperm would have a 5% probability of surviving more than 4.4 days and a 1% probability of surviving more than 6.8 days.

To make well-informed decisions about reproductive health, individuals need information about their body, gender and sexuality as well as the communication skills to convey their choices to their family, partners and health care providers. Gender and sexuality are at the core of each individual's identity; understanding and acceptance of these aspects of ourselves is basic to our ability to have healthy relations with self, family and sexual partners. Throughout an individual's life cycle information is needed about gender and sexuality changes according to needs of their age group. A holistic approach to reproductive health is needed, based in the community where people live, in the schools where young people study and in the community health care centers where they receive services.