1988
Continuous Mucus Correlation of Point of Change with Preovulatory Rise in Estradiol-17β
Author affiliations
- Pope Paul VI Institute for the Study of Human Reproduction, Omaha, Nebraska. ROR
1988
Cvetkovich LL , Gentrup B , Thomas W Hilgers
Cervical mucus observation may be difficult for women who experience continuous mucus throughout their menstrual cycles. This study aims to prove the value of cervical mucus methods for these women. Rather than examining a woman's onset of cervical mucus, this study evaluates the "Point of Change" in the mucus and its correlation to the woman's hormone levels.
Cvetkovich, L. L., Hilgers, T. W., & Gentrup, B. B. (1988). Continuous Mucus Correlation of Point of Change with Preovulatory Rise in Estradiol-17β.
Cvetkovich LL, Hilgers TW, Gentrup BB. Continuous Mucus Correlation of Point of Change with Preovulatory Rise in Estradiol-17β. 1988.
Cvetkovich, L. L., et al. Continuous Mucus Correlation of Point of Change with Preovulatory Rise in Estradiol-17β. 1988.
Najmabadi S et al., 2021 · Hum Reprod ·
What is the normal range of cervical mucus patterns and number of days with high or moderate day-specific probability of pregnancy (if intercourse occurs on a specific day) based on cervical mucus secretion, in women without known subfertility, and how are these patterns related to parity and age? The mean days of peak type (estrogenic) mucus per cycle was 6.4, the mean number of potentially fertile days was 12.1; parous versus nulliparous, and younger nulliparous (<30 years) versus older nulliparous women had more days of peak type mucus, and more potentially fertile days in each cycle. The rise in estrogen prior to ovulation supports the secretion of increasing quantity and estrogenic quality of cervical mucus, and the subsequent rise in progesterone after ovulation causes an abrupt decrease in mucus secretion. Cervical mucus secretion on each day correlates highly with the probability of pregnancy if intercourse occurs on that day, and overall cervical mucus quality for the cycle correlates with cycle fecundability. No prior studies have described parity and age jointly in relation to cervical mucus patterns. STUDY DESIGN, SIZE, This study is a secondary data analysis, combining data from three cohorts of women: 'Creighton Model MultiCenter Fecundability Study' (CMFS: retrospective cohort, 1990-1996), 'Time to Pregnancy in Normal Fertility' (TTP: randomized trial, 2003-2006), and 'Creighton Model Effectiveness, Intentions, and Behaviors Assessment' (CEIBA: prospective cohort, 2009-2013). We evaluated cervical mucus patterns and estimated fertile window in 2488 ovulatory cycles of 528 women, followed for up to 1 year. PARTICIPANTS/MATERIALS, SETTING, Participants were US or Canadian women age 18-40 years, not pregnant, and without any known subfertility. Women were trained to use a standardized protocol (the Creighton Model) for daily vulvar observation, description, and recording of cervical mucus. The mucus peak day (the last day of estrogenic quality mucus) was used as the estimated day of ovulation. We conducted dichotomous stratified analyses for cervical mucus patterns by age, parity, race, recent oral contraceptive use (within 60 days), partial breast feeding, alcohol, and smoking. Focusing on the clinical characteristics most correlated to cervical mucus patterns, linear mixed models were used to assess continuous cervical mucus parameters and generalized linear models using Poisson regression with robust variance were used to assess dichotomous outcomes, stratifying by women's parity and age, while adjusting for recent oral contraceptive use and breast feeding. MAIN The majority of women were <30 years of age (75.4%) (median 27; IQR 24-29), non-Hispanic white (88.1%), with high socioeconomic indicators, and nulliparous (70.8%). The mean (SD) days of estrogenic (peak type) mucus per cycle (a conservative indicator of the fertile window) was 6.4 (4.2) days (median 6; IQR 4-8). The mean (SD) number of any potentially fertile days (a broader clinical indicator of the fertile window) was 12.1 (5.4) days (median 11; IQR 9-14). Taking into account recent oral contraceptive use and breastfeeding, nulliparous women age ≥30 years compared to nulliparous women age <30 years had fewer mean days of peak type mucus per cycle (5.3 versus 6.4 days, P = 0.02), and fewer potentially fertile days (11.8 versus 13.9 days, P < 0.01). Compared to nulliparous women age <30 years, the likelihood of cycles with peak type mucus ≤2 days, potentially fertile days ≤9, and cervical mucus cycle score (for estrogenic quality of mucus) ≤5.0 were significantly higher among nulliparous women age ≥30 years, 1.90 (95% confidence interval (CI) 1.18, 3.06); 1.46 (95% CI 1.12, 1.91); and 1.45 (95% CI 1.03, 2.05), respectively. Between parous women, there was little difference in mucus parameters by age. Thresholds set a priori for within-woman variability of cervical mucus parameters by cycle were examined as follows: most minus fewest days of peak type mucus >3 days (exceeded by 72% of women), most minus fewest days of non-peak type mucus >4 days (exceeded by 54% of women), greatest minus least cervical mucus cycle score >4.0 (exceeded by 73% of women), and most minus fewest potentially fertile days >8 days (found in 50% of women). Race did not have any association with cervical mucus parameters. Recent oral contraceptive use was associated with reduced cervical mucus cycle score and partial breast feeding was associated with a higher number of days of mucus (both peak type and non-peak type), consistent with prior research. Among the women for whom data were available (CEIBA and TTP), alcohol and tobacco use had minimal impact on cervical mucus parameters. LIMITATIONS, We did not have data on some factors that may impact ovulation, hormone levels, and mucus secretion, such as physical activity and body mass index. We cannot exclude the possibility that some women had unknown subfertility or undiagnosed gynecologic disorders. Only 27 women were age 35 or older. Our study participants were geographically dispersed but relatively homogeneous with regard to race, ethnicity, income, and educational level, which may limit the generalizability of the findings. Patterns of cervical mucus secretion observed by women are an indicator of fecundity and the fertile window that are consistent with the known associations of age and parity with fecundity. The number of potentially fertile days (12 days) is likely greater than commonly assumed, while the number of days of highly estrogenic mucus (and higher probability of pregnancy) correlates with prior identifications of the fertile window (6 days). There may be substantial variability in fecundability between cycles for the same woman. Future work can use cervical mucus secretion as an indicator of fecundity and should investigate the distribution of similar cycle parameters in women with various reproductive or gynecologic pathologies. STUDY FUNDING/COMPETING INTEREST(S): Funding for the three cohorts analyzed was provided by the Robert Wood Johnson Foundation (CMFS), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (TTP), and the Office of Family Planning, Office of Population Affairs, Health and Human Services (CEIBA). The authors declare that they have no conflict of interest. N/A.
Nassaralla CL et al., 2011 · J Womens Health (Larchmt) ·
Menstrual cycle function may continue to be altered after discontinuation of oral contraceptives (OC). Few studies have been published on the effects of recent OC use on menstrual cycle parameters; none have examined characteristics of the menstrual flow or the quality of cervical mucus. The purpose of this retrospective matched cohort study is to assess biomarkers of the menstrual cycle after discontinuation of OCs. Among a sample of women who daily recorded observations of menstrual cycle biomarkers, 70 women who had recently discontinued OCs were randomly matched by age and parity with 70 women who had not used OCs for at least 1 year. Outcomes investigated included overall cycle length, length of the luteal phase, estimated day of ovulation, duration of menstrual flow, menstrual intensity, and mucus score. Differences between recent OC users and controls were assessed using random effects modeling. Recent OC users had statistically significantly lower scores for mucus quality for cycles 1 and 2. Additionally, OC users had a later estimated day of ovulation that was statistically significant in cycle 2 and a decreased intensity of menstrual flow that was significant in the first four cycles (difference = -0.48 days). In random effects modeling, all these parameters were significantly different for the first six cycles combined. Menstrual cycle biomarkers are altered for at least two cycles after discontinuation of OCs, and this may help explain the temporary decrease in fecundity associated with recent OC use.
Hilgers TW, 2004 · The Medical and Surgical Practice of NaProTECHNOLOGY ·
The CREIGHTON MODEL FertilityCare System (CrMS) rests on a decades-long body of research demonstrating that cervical mucus functions as a physiologically regulated biological valve, opening predictably at the periovulatory estrogen rise and closing in the post-Peak phase. Chapter 15 of Hilgers (2004) synthesizes hormonal, ultrasound, cytologic, and biophysical evidence to establish that a woman's external observation of her Peak Day reliably identifies the fertile window, and documents the system's effectiveness data for both achieving and avoiding pregnancy across a five-study meta-analysis of nearly 1,900 couples.
Odeblad E, 1992 · Jordemodern ·
Natural family planning (NFP) is based on the knowledge *largely nonexistent) of a women as to whether she is in her fertile period or not. In contrast to the calendar method, the Billings method consists of observing bodily functions, whereby women learn about the fertile and infertile period during the menstrual cycle. This method is very safe as long as the woman has been instructed thoroughly. The Pearl index (the number of pregnancies/100 woman years) can be 1. In a Swedish province, 7/1000 population used this method and had an abortion rate of .5/1000, a fact contradicting the allegation of mass abortion as a result of the method. Only well-trained NFP instructors can teach women, and at the University of Umea such training has been available for some years. The biological basis of the Billings method rests on the fact that every release of an egg is preceded by a ripening process of a follicle in the ovary. This follicle secretes increasing amounts of estrogen which stimulates the cervix to produce secretions for the sperm. Right before ovulation, the follicle reduces estrogen production and noradrenaline takes over, stimulating the peak-day secretion (P-secretion) for further selection of sperm. Ovulation usually occurs on the peak day, which is the day of maximum fertility and the last day of mucous symptoms. For 3 days after peak day until menstruation, the risk of becoming pregnant diminishes successively until it is as low as after sterilization. The instructor is trained to recognize and overcome certain factors that make it more difficult to identify the mucous symptoms, such as the previous use of oral contraceptives, certain illnesses, drugs, and life styles. NFP can also be used for attaining pregnancy by identifying the peak day; women with premenstrual syndrome can calculate when their symptoms start, and sportswomen can predict the time of their menstruation. NFP is fascinating when it is compared to other methods because of its human dimension, and there is still a great deal to be learned about it.