Day-specific probabilities of clinical pregnancy based on two studies with imperfect measures of ovulation.
Two studies have related the timing of sexual intercourse (relative to ovulation) to day-specific fecundability. The first was a study of Catholic couples practising natural family planning in London in the 1950s and 1960s and the second was of North Carolina couples attempting to become pregnant in the early 1980s. The former identified ovulation based on the ovulatory shift in the basal body temperature, while the latter used urinary assays of hormones. We use a statistical model to correct for error in identifying ovulation and to re-estimate the length of the fertile window and day-specific fecundabilities. We estimate the same 6-day fertile interval in both studies after controlling for error. After adjusting for error both data sets showed the highest estimate of the probability of pregnancy on the day prior to ovulation and both fell close to zero after ovulation. Given that the fertile interval is before ovulation, methods that anticipate ovulation by several days (such as the assessment of cervical mucus) would be particularly useful for couples who want to time their intercourse either to avoid or facilitate conception. (+info)
Plasma LH and progesterone levels before and after ovulation and observation of ovarian follicles by ultrasonographic diagnosis system in dogs.
Recently, canine frozen semen has been attracting attention for breeding purposes, and methods of judging ovulation and optimum timing for insemination have become important. As methods of predicting the canine ovulation, vaginal smear, plasma sex hormone levels and ultrasonographic diagnosis system (US) have been investigated in combination, but a standard technique has not yet been established. Therefore, we investigated a method of predicting canine ovulation in dogs by US, and by measuring plasma LH and progesterone (P) levels three times a day. Ovulation could be observed by detecting irregularly shaped ovarian follicles by US in six of 11 dogs (54.5%). In these dogs, the time between the LH peak and ovulation was 24-48 hr, 38.0 hr on average. The P level on the ovulation day was 1.88-2.81 ng/ml, 2.34 ng/ml on average. A value of 1.88 ng/ml was detected in one dog, but the other five dogs showed P levels of 2 ng/ml or higher. The P level on the day before ovulation was 0.8-1.56 ng/ml, 1.12 ng/ml on average. Assuming that ovulation occurred two days after the LH peak in the 11 experimental dogs, the P level was 2.12-4.06 ng/ml, 2.78 ng/ml on average. The period of a high LH level, not less than 10 ng/ml, continued for 12 hr around the LH peak. Based on these findings, to predict ovulation using US and LH level, it would be necessary for the tests to be performed several times a day. In contrast, it was shown that the day on which a plasma P level of 2 ng/ml or higher was detected by the test performed once a day corresponded to the ovulation day. (+info)
Prediction of ovulation by urinary hormone measurements with the home use ClearPlan Fertility Monitor: comparison with transvaginal ultrasound scans and serum hormone measurements.
The timing of sexual intercourse in relation to ovulation strongly influences the chance of conception. Daily serum LH measurements or transvaginal ultrasonography are not practical to determine ovulation in consecutive cycles for an individual. A prospective study was initiated to test the home use performance of the ClearPlan Fertility Monitor (CPFM) in ovulation prediction compared with transvaginal ultrasonography and serum hormone measurements. A total of 53 women aged 18-39 years with a normal uterus and at least one ovary, cycle length between 21-42 days and not using medication which interferes with ovarian function contributed 150 cycles for analysis. One cycle was anovulatory and no LH surge, indicating peak fertility, was detected by the monitor. Of the remaining 149 cycles, 135 (90.6%) had a monitor LH surge and ultrasonographically confirmed ovulation. Ovulation was detected in 91.1% of cycles during the 2 days of CPFM peak fertility. Ovulation was observed in 51.1% of cycles 1 day and in 43.2% of cycles 2 days after the surge in serum LH. Ovulation never occurred before CPFM peak fertility or the serum LH surge day. CPFM can help women who desire pregnancy to time intercourse. It may also have potential as a diagnostic aid and for monitoring the treatment of infertility. (+info)
Transfer of canine embryos at various developmental stages recovered by hysterectomy or surgical uterine flushing.
In dogs, embryo transfer (ET) techniques such as induciton of excessive ovulation and synchronization of estrus have not progressed well. Therefore, using embryos at various developmental stages, ET was investigated in dogs from a beagle colony in which the ovulation days were close, as estimated by the progesterone level. Embryos were, recovered 8-11 days after ovulation (4-9 days after mating) by excising the oviducts and uteri (excision method) in 16 animals and by surgical flushing of the uteri at laparotomy (surgical method) in 3 animals. In 24 dogs with -4 to +2 days of difference in the timing of ovulation between donor and recipient dogs, 1-10 embryos at the 8-cell to blastocyst stages were transferred per animal. The mean embryo recovery rate by the excision method (97.1%) was significantly higher than that by the surgical method (42.5%) (p<0.01). Twelve (57.1%) of 21 animals with -1 to +2 days difference in ovulation day became pregnant after the transfer of 8-cell to blastocyst stage embryos. Although 3 dogs with -4 to -2 days of difference of ovulation day underwent ET of morula or compacted morula, none of these dogs became pregnant. The mean ratio of the number of newborns to the number of transferred embryos was only 51.9%. The mean duration of the period between ovulation and delivery in the pregnant recipients was 65.8 days, which tended to be longer than that in natural mating. These results demonstrate that pregnancy can be induced by ET at the 8-cell to blastocyst stage in dogs with -1 to +2 days difference in ovulation day. (+info)
Prediction of the potentially fertile period by urinary hormone measurements using a new home-use monitor: comparison with laboratory hormone analyses.
BACKGROUND: The study compared a new urinary hormone monitoring system, Clearview Primera Fertility Monitor (CPFM), with laboratory hormone analyses in the prediction of the potentially fertile period. METHODS: Thirty healthy female volunteers provided blood and early morning urine samples for one cycle. Serum oestradiol, progesterone and luteinizing hormone (LH), and urinary LH and oestrone-3-glucuronide (E3G) were measured. The fertility status of volunteers; Low, High or Peak, was collected from monitors and compared with the hormone measurements. RESULTS: There was agreement between the first day of peak fertility and the urinary LH peak day in 65.6% of cycles and detection 1 or 2 days before the urinary LH peak day in 24.1 and 6.9% of cycles respectively. In 58.6% of cycles the system detected up to 5 days of increased fertility prior to the urinary LH peak day. Warning days of the urinary LH peak were similarly determined using defined thresholds of E3G and oestradiol providing up to 5 days warning in 82.8 and 96.6% of cycles respectively. CONCLUSIONS: The system can provide couples attempting to conceive with information about the potentially fertile days in the cycle in order that they may time intercourse. It also has potential for use in evaluation and treatment of infertile couples. (+info)
The relationship between cervical secretions and the daily probabilities of pregnancy: effectiveness of the TwoDay Algorithm.
BACKGROUND: The TwoDay Algorithm is a simple method for identifying the fertile window. It classifies a day as fertile if cervical secretions are present on that day or were present on the day before. This approach may be an effective alternative to the ovulation and symptothermal methods for populations and programmes that find current natural family planning methods difficult to implement. METHODS: We used data on secretions from a large multinational European fecundability study to assess the relationship between the days predicted to be potentially fertile by the TwoDay Algorithm and the day-specific probabilities of pregnancy based on intercourse patterns in 434 conception cycles from the study. RESULTS: The days around ovulation that had the highest fecundability were the days most likely to be classified as fertile by the TwoDay Algorithm. In addition, intercourse on a particular day in the fertile interval was twice as likely to result in a pregnancy if cervical secretions were present on that day or the day before. CONCLUSIONS: The TwoDay Algorithm is effective, both in identifying the fertile days of the cycle and in predicting days within the fertile interval that have a high pregnancy rate. Our data provide the first direct evidence that cervical secretions are associated with higher fecundability within the fertile window. (+info)
Assessing menstrual cycles with urinary hormone assays.
The Study of Women's Health Across the Nation (SWAN) is a multiethnic cohort study of middle-aged women enrolled at seven US sites. A subset of 848 women completed a substudy in which their urinary gonadotropins and sex steroid metabolites were assessed during one complete menstrual cycle or up to 50 consecutive days. Urine was analyzed for LH, FSH, estrone conjugates (E1c), and pregnanediol glucuronide (Pdg). To prepare for serial analysis of this large, longitudinal database in a population of reproductively aging women, we examined the performance of algorithms designed to identify features of the normal menstrual cycle in midreproductive life. Algorithms were based on existing methods and were compared with a "gold standard" of ratings of trained observers on a subset of 396 cycles from the first collection of Daily Hormone Substudy samples. In evaluating luteal status, overall agreement between and within raters was high. Only 17 of the 396 cycles evaluated were considered indeterminate. Of the 328 cycles rated as containing evidence of luteal activity (ELA), 320 were considered ELA by use of a Pdg threshold detection algorithm. Of 51 cycles that were rated as no evidence of luteal activity, only 2 were identified by this algorithm as ELA. Evaluation of the day of the luteal transition with methods that detected a change in the ratio of E1c to Pdg provided 85-92% agreement for day of the luteal transition within 3 days of the raters. Adding further conditions to the algorithm increased agreement only slightly, by 1-8%. We conclude that reliable, robust, and relatively simple objective methods of evaluation of the probability and timing of ovulation can be used with urinary hormonal assays in early perimenopausal women. (+info)
Estimated maximum failure rates of cycle monitors using daily conception probabilities in the menstrual cycle.
BACKGROUND: A number of menstrual cycle monitors have been developed to detect the fertile window of the menstrual cycle, mainly for contraceptive purposes. Reliable data on most of these systems are still missing but are urgently needed because many women use them and the tested systems differ enormously in price and effectiveness. We suggest a new efficacy estimating method to evaluate cycle monitors prior to full prospective clinical trials. METHODS: Sixty-two women prospectively tested seven cycle monitors and the symptothermal method (STM) of natural family planning (NFP) but not more than two different systems at the same time. The clinical fertile window was determined by detecting the day of ovulation using daily urinary LH measurements and daily ultrasonic folliculometry. This was compared to the fertile phase predicted by the systems. Maximum failure rates were estimated for each cycle monitor and the STM, using the daily conception probability rates taken from the European Fecundability Study. Intercourse was assumed to occur on each of all falsely predicted days of infertility. RESULTS: Sixty-two women with a mean age of 31 years (range: 21-42 years) contributed a total of 122 cycles to this study. Monitors based on the microscopic evaluation of saliva or mucus had many more false infertile days than the other methods based on temperature or hormonal measurements (225 versus 42 days). The maximum unintended pregnancy rates per cycle for temperature computers were estimated to be 0.0134-0.0336, for the hormonal computer 0.1155 and for mini-microscopes 0.2313-0.2369. For the STM of NFP, there were no false infertile days. CONCLUSIONS: The STM of NFP proved to be the most effective contraceptive method to detect the fertile window among all the methods tested. The estimated efficacy of the other cycle monitors range from the temperature computers (upper level) to the hormonal computer (medium level) and the mini-microscopes with very low estimated contraceptive efficacy. (+info)