[Period of fertility and infertility].
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Female↗
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Results for “Fertile Period”
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Fertility and legal abortion in England and Wales: performance indicators for family planning services.
The relation between fertility rates and legal abortion rates was investigated in a sample of health authorities in England and Wales to see how these varied. Total period fertility rates and total period legal abortion rates were derived from the average number of live births or legal abortions that would be experienced per woman if women experienced the age specific rates of the year in question throughout their childbearing years. The sample of 30 health authorities was selected by taking the districts with the highest and lowest fertility rates in each English region and in Wales in 1986. Total period fertility rates varied from 1.37 in Riverside to 2.42 in Tower Hamlets, while abortion rates varied from 0.25 in East Yorkshire to 0.99 in Riverside. When the two rates were added to provide a potential fertility rate it became clear that some districts with similar potential fertility rates had very different underlying component rates. Such comparisons can be used for service monitoring, indicating the need for better abortion and family planning services in districts with high fertility rates and for better family planning services in those with high abortion rates.
Abortion, Legal↗
Temporal dimensions of the fertility transition: an age-period-cohort analysis of frontier fertility.
"This paper evaluates age, period, and cohort effects on marital fertility during onset of the Utah fertility transition (1880-1900). Computerized genealogies are used to derive age-period-cohort fertility rates for 49,842 once-married couples. Age, period and cohort effects on marital fertility are then estimated using Johnson's (1985) relational model. Declining marital fertility in Utah is shown to be explained by both lower fertility levels across periods and increasing age-specific limitation across cohorts. Direct cohort effects on fertility are insignificant. These results are consistent with prior research, and the view that fertility levels were adaptive (in part through birth spacing across ages) to immediate contexts of childbearing while age-specific fertility truncation increased across cohorts (in part through the more general diffusion of contraceptive innovations)."
Age Factors↗
Period effects on fertility for parity cohorts, Egypt: 1965-1980.
"This paper presents a detailed investigation of period fertility trends in Egypt. It focusses on parity groups and changes in quantum and tempo of fertility of these groups. The analysis is further refined by controlling for age within each parity considered. The source of data...is the Egyptian Fertility Survey (EFS 80)....a retrospective fertility survey collected from a sample of 8,788 ever married Egyptian women in 1980."
Africa↗
Birth statistics 1993.
The key birth statistics for 1993, in Table E of the Annual Review on page 7 of this volume, show that: The total number of live births fell for the third consecutive year and was 673 thousand in 1993, 2 per cent fewer than in 1992, and the lowest annual total since 1986. The number of women in reproductive ages changed only marginally, so that the crude birth rate (CBR), the general fertility rate (GFR) and total period fertility rate (TPFR) each decreased. The TPFR was 1.76 in 1993, 2 per cent lower than in 1992. The mean age of women at childbirth continued to rise, and reached 28.1 years. The proportion of births outside marriage increased by a further 1 per cent between 1992 and 1993, to reach 32.2 per cent. There were 105.6 male births for every 100 female births--a higher ratio than in 1992.
Adult↗
Enhanced follicle regulatory protein levels accompany reinitiation of ovulatory function after parturition.
OBJECTIVES: We examined the changes in follicle regulatory protein, estrone-3-glucuronide, pregnanediol-3-glucuronide, and luteinizing hormone levels in first-morning urine samples from postpartum, fully breast-feeding women to characterize the reemergence of these urinary hormones after pregnancy ovarian quiescence and early postpartum period and to determine whether follicle regulatory protein could be used prospectively to predict the return of fertility. STUDY DESIGN: Twenty-five hundred urine samples collected from six postpartum women were evaluated. Daily urine samples collected from normally cycling women were used to establish normal urinary hormone and hormone metabolite cyclicity. Luteinizing hormone, estrone-3-glucuronide, and pregnanediol-3-glucuronide levels were measured by radioimmunoassay. Follicle regulatory protein level was assayed with a double-antibody enzyme-linked immunosorbent assay. RESULTS: Although follicle regulatory protein levels were found to be very low or undetectable in early postpartum urine, they began to rise with episodes of estrone-3-glucuronide and pregnanediol-3-glucuronide secretion. A chi 2 analysis suggests that increasing urinary follicle regulatory protein levels are most closely associated with the luteal phase of the first menstrual cycles in postpartum women. CONCLUSIONS: These results suggest that follicle regulatory protein is of little value in predicting either the onset of renewed ovarian activity or the fertile period.
Adult↗
[Evolution of fecundity in the Valencian community during the 1975-1990 period].
BACKGROUND: To study the evolution of specific cases of fertility by age groups in the Autonomous Region of Valencia, between 1975 and 1990, and compare this development with the evolution on a national level. METHODS: The specific fertility rates were calculated for seven 5-year age groups within the female fertility period (15-49 years). The number of births per age of mother (Natural Movement of the Spanish Population) has been used and the denominator is the female population calculated be geometrical interpolation from the figures provided by different censuses and electoral roles for each one of the age groups. The study period is 1975 to 1990. RESULTS: The evolution of the fertility rate in the Autonomous Region of Valencia is declining in all age groups except the 30-34 year age group, where fertility showed a slight increase at the end of the eighties, the same as in the rest of the country. Worthy of mentioned is the 15-19 year old group, with figures below the national level, and the 25-29 year old group, where the figures are greater than for the rest of the country as a whole. On a province (county) level, the development is similar to what has been described above. Alicante has the highest figure out of the three provinces (counties) for women in the 15-19 and 35-39 year age ranges. CONCLUSION: The evolution of the fertility rate in the Autonomous Community of Valencia is similar to the development in the rest of the country, a slight increase being detected in women in the 30 to 40 year group, which is similar to what has happened in other European countries.
Adolescent↗
Copulation and mate-guarding patterns in polygynous European starlings
We recorded the timing and frequency of copulation and mate-guarding behaviour during the fertile period in relation to day of first ovulation and time of day in the facultatively polygynous European starling, Sturnus vulgarisAll within-pair copulations were female-solicited. Females solicited them at a high rate during both the pre-ovulatory and ovulatory period, but there were differences in solicitation rates between monogamous, primary and secondary females. Extra-pair copulation attempts were all male-initiated and females rarely engaged in them. Attempts by males were most frequent during the ovulatory period, when the probability of extra-pair fertilization was highest. Males intensively guarded their mate during both the pre-ovulatory and ovulatory period. In contrast to most other passerines, female starlings lay their eggs not at dawn but usually between 0900 and 1100 hours, implying that they may be most fertile in the late morning. During the ovulatory period, extra-pair copulation attempts were more frequent in the late morning than in the early morning, suggesting that males try to take advantage of this putative 'insemination window'. Accordingly, there was some indication that mate guarding during the ovulatory period was more intense in the late than early morning. Females solicited within-pair copulations at a higher rate in the early morning than in the late morning, but copulation rate did not differ between early and late morning. The proportion of monogamous and polygynous males attempting extra-pair copulations did not differ significantly, but mate-guarding intensity differed significantly between female categories. Primary females were guarded less intensively than monogamous females suggesting that males trade mate guarding against mate attraction/courting additional females.
Journal Article↗
The period of human ovulation and a consideration of the fertile and infertile periods.
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Female↗
Natural family planning indicators of ovulation.
Indirect evidence of the occurrence of ovulation, which is generally accepted, is an increase in plasma or serum progesterone. Pelvic ultrasonography can estimate the probable time of ovulation within 12 h. There is a close association between the rise in progesterone, luteinizing hormone (LH) and oestrogen peaks and ovulation. A WHO study reported that ovulation occurred at a median time of 8 h after the rise in plasma progesterone, 15 h after the LH peak and 24 h after the oestrogen peak. The basal body temperature (BBT) method is the most effective in determining the premenstrual infertile period, but it is unreliable for an accurate determination of ovulation and the postmenstrual infertile period. Nor is BBT an effective method of predicting ovulation during postpartum lactational amenorrhoea. Therefore, BBT is usually used as a secondary indicator of ovulation and is combined with more reliable indicators. Observed changes in cervical mucus patterns can be used to define the probable fertile period, although this method produces a wide range of days. The peak mucus symptom is closely correlated with ovulation. Mucus symptoms can be used as a guide for the timing of blood or urine samples for estimation of LH, oestrogen and progesterone or their metabolites. Symptothermal methods incorporate other symptoms such as cervical changes, intermenstrual pain, breast tenderness and backaches, but these are secondary signs of ovulation and are recommended to be used in conjunction with mucus and BBT.
Body Temperature↗
[The critical period in natural fertility].
In order to learn the natural expectancy period of first pregnancy as well as the influences of some biosocial variables, a clinical-retrospective study was performed within 1120 gravida I women. All of them attended the major institutes of health care in Mexico City (IMSS, ISSSTE, SS and DDF). Data were obtained by means of predetermined questions from subjects after the first postpartum hours. None of them had previously used any contraceptive method. Results showed age at the first pregnancy: 21.6 +/- 3.8 (years); gestational interval 22.1 +/- 19.9 (months) and a 67% achievement rate the following twelve months of sexual activity. Eutocia was seen in 54% of these population and significant linear correlation was attained between age of the patient and the gestational interval. It seems that this is the first information regarding the fertility critical period within our society.
Adolescent↗
Adolescent contraception: nonhormonal methods.
A comparison of the advantages, disadvantages, and costs of each method is presented in Table 1. Barrier methods of contraception offer adolescents protection against both pregnancy and STDs, but innovative approaches are needed to enhance availability and acceptability. Condom use in conjunction with a vaginal spermicide would provide optimal protection. The "female condom" may prove to be an effective alternative. Diaphragms and cervical caps can be prescribed for well-educated, highly motivated adolescents comfortable with insertion and removal. The vaginal contraceptive sponge provides many of the advantages of the diaphragm and cap without the need for an examination and fitting and also may be used as a backup method with the condom. Vaginal spermicides used alone are significantly less effective than in combination with a mechanical barrier. The IUD is not considered appropriate for most adolescents due to its association with an increased risk of pelvic infection. Periodic abstinence requires accurate identification of the fertile period, extensive education, and partner cooperation. Sterilization is rarely considered an option in adolescents. Alternate forms of sexual expression are available to adolescents who choose to abstain from intercourse.
Adolescent↗
A new method for estimating the trend in the fertility rate.
"This article describes the method devised by Gerard Calot...for estimating monthly TPFRs [total period fertility rates] when only provisional monthly figures for numbers of births are available. The application of the Calot method, together with the US Bureau of the Census X-11 seasonal adjustment package, for computing the trend in the England and Wales fertility rate is also described."
Birth Rate↗
Natural family planning.
It is now well accepted that a woman can conceive from an act of intercourse for a maximum of only about 7 days of her menstrual cycle. The reliability of natural family planning depends on identifying this window of fertility without ambiguity. Several symptomatic markers, cervical mucus and basal body temperature, have been used extensively and with considerable success in most women but failures occur. Ovarian and pituitary hormone production show characteristic patterns during the cycle. Urinary estrogen and pregnanediol measurements yield reliable information concerning the beginning, peak, and end of the fertile period, provided that the assays are accurate and performed on timed specimens of urine. We have developed such enzyme immunoassays for urinary estrogen and pregnanediol glucuronides that can be performed at home. In the early versions of the assays, enzyme reaction rates were measured by eye, but more recently, a simple photoelectronic rate meter has been used. The final problem to be solved is not technologic but whether women are sufficiently motivated to expend the same time and effort each day for 10 days a month, with less cost, on fertility awareness as they spend on making a cup of tea.
Adult↗
Natural family planning.
Natural family planning includes the calendar (rhythm), basal body temperature, ovulation (mucus), and sympto-thermal methods. Reliability of such methods often is underestimated, but effectiveness of various methods has been reported. Correct understanding and use of proper techniques, primarily abstinence during fertile periods, is imperative for effectiveness. New methods being studied may heighten awareness of fertile times and shorten required periods of abstinence or use of back-up methods.
Adolescent↗
Factors affecting walking activity at estrus during postpartum period and subsequent fertility in dairy cows.
The postpartum period is critical for efficient reproduction, and certain features of the normal estrus cycle during this period have been associated with subsequent reproductive performance. The objectives of the present investigation were to evaluate the effects of environmental, production, and reproductive factors on walking activity at estrus as determined using pedometers during the first 50 days in milk (DIM) (study 1). In a second study, we tried to establish whether pedometer measurements recorded during this period could be used to predict subsequent fertility by considering the number of cows becoming pregnant before 90 DIM. We analyzed data derived from 995 parturitions in a single herd. Detection of estrus was performed using a pedometer system. Variables were screened for associations with walking activity by analysis of variance (ANOVA) through generalized linear model procedures (PROC GLM). Increased milk production and parity, and a mean relative humidity (RH) higher than 95% were associated with lower pedometer measurements. A higher number of animals simultaneously in estrus rendered higher pedometer readings. No significant effects of the year, season, DIM, number of previous estruses, and climatic data other than high mean RH were observed. Relationships between pedometer measurements and other variables recorded during the first 50 days postpartum, and subsequent fertility were assessed by applying logistic regression models. We detected no significant effects of year, milk production, season, and mean activity increase at estrus on high fertility. The likelihood of pregnancy before 90 DIM decreased for each additional lactation and for cows in anestrus between days 0 and 50 postpartum. However, pedometer readings during the first 50 days postpartum were unable to accurately predict subsequent fertility.
Analysis of Variance↗
Validity of the Bioself 110 fertility indicator.
The Bioself 110 (Bioself Canada, Inc., Montréal, Québec, Canada) is an electronic computerized thermometer designed to identify the fertile and infertile phases of the menstrual cycle. The purpose of this study was to evaluate the validity of the device by comparing it with a reference method, the Ovustick (Monoclonal Antibodies, Inc., Mountain View, CA) luteinizing hormone (LH) surge detection kit. The Bioself 110 identified the 6-day fertile period in 86.4% of 220 cycles studied and 5 fertile days in 93.2%. The Bioself 110 correctly identified the postovulatory infertile phase in 93.3% of 178 cycles. On average, the device identified 10.9 fertile days and 10.6 postovulatory "safe" days per cycle. It was concluded the device would be a useful aid to couples trying to conceive or prevent pregnancy.
Adult↗
Experimental mate switching in pied flycatchers: male copulatory access and fertilization success
By making female birds pair successively with different males, and analysing the paternity of the eggs laid, it is possible to examine how a male's success in obtaining fertilizations is determined by the timing of his copulatory access to the female. Such an experiment is reported here with pied flycatchers, Ficedula hypoleucaMate switching was induced at different stages within the female's fertile period by removing the resident male. The paternity of the clutch was analysed by microsatellite DNA typing. Removed males had full paternity in the clutch if they were removed as late as after the second egg was laid (day 1), and they lost all paternity if they were removed more than 1 day before the first egg was fertilized (less than day -2). Male switching during the period day -2 to day 1 always resulted in mixed paternity in the clutch. Males that were paired to the female for only a few (1-3) days during this period achieved on average more than one fertilization per access day, with a peak on day -1. Thus, assuming that the timing of observed pair bonds reflects the timing of each male's copulatory access to the female, the first eggs in the laying sequence were fertilized by inseminations occurring shortly before the time of fertilization, whereas the last eggs were fertilized by inseminations taking place several days prior to their fertilization. Our documentation of the most important period for copulatory access has some important implications for understanding sexual behaviour in this species.
Journal Article↗