Time of ovulation and prolonged pregnancy

Saito, Motoi; Yazawa, Keijiro; Hashiguchi, Akinori; Kumasaka, T; Nishi, Nozomu; Kato, Kohei

doi:10.1016/0002-9378(72)90525-x

Cited by 59 publications

(31 citation statements)

References 14 publications

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“…Similar research by Saito et al 24 found that 70% of the variation in menstrual age of apparently postmature pregnancies is attributable to a prolonged preovulatory interval. In a prospective study of 110 women with good BBT records and spontaneous onset of labor, 15.5% of the pregnancies exceeded 42 weeks from LMP, and without BBT records would have been classified as postmature.…”

Section: Ovulatory Datingsupporting

confidence: 71%

See 1 more Smart Citation

Postdate pregnancy Part I. A literature review

Nichols¹

1985

Journal of Nurse-Midwifery

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Section: Ovulatory Datingsupporting

confidence: 71%

“…When menstrual data fail to predict an EDD within 2 weeks of actual delivery, there is a significant chance (approximately 70%) of delayed ovulation 18,24 . This proportion of inaccurately dated pregnancies was based on populations with written BBT, coital, and menstrual records.…”

Section: Discussionmentioning

confidence: 99%

Postdate pregnancy Part I. A literature review

Nichols¹

1985

Journal of Nurse-Midwifery

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“…Given the absence of a biomarker of ovulation for the study, we used the Ogino–Knaus method for estimating the likely date of ovulation by counting back 14 days from the end of the cycle (Knaus, 1929; Ogino, 1930). This approach is in keeping with greater cycle variability in the secretory rather than proliferative phase of the menstrual cycle (Saito et al ., 1972). The fertile window was purposefully broadly defined as an 8-day window commencing 5 days before the presumed date of ovulation and ending 2 days after ovulation.…”

Section: Methodsmentioning

confidence: 99%

Polychlorinated biphenyl serum concentrations, lifestyle and time-to-pregnancy

et al. 2009

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BACKGROUND Consumption of fish contaminated with polychlorinated biphenyls (PCBs) and prenatal PCB serum concentrations have been associated with a longer time-to-pregnancy (TTP). However, the relationship between preconception serum PCBs concentrations and TTP has not been previously studied. METHODS Eighty-three women (contributing 442 menstrual cycles) planning pregnancies completed daily diaries regarding menstruation, intercourse, home pregnancy test results, and reported use of alcohol and cigarettes. TTP denoted the number of observed menstrual cycles required for pregnancy. Preconception blood specimens underwent toxicologic analysis for 76 PCB congeners via gas chromatography with electron capture; serum lipids were quantified with enzymatic methods. A priori, PCB congeners were summed into a total and three groupings—estrogenic, anti-estrogenic and other— and entered into discrete analogs of Cox models with time-varying covariates to estimate fecundability odds ratios (FOR) and corresponding 95% confidence intervals (CIs). RESULTS Estrogenic and anti-estrogenic PCB concentrations (ng/g serum) conferred reduced FORs in fully adjusted models (0.32; 95% CI 0.03, 3.90 and 0.01: 95% CI < 0.00, 1.99, respectively). Reduced FORs (0.96) were observed for alcohol consumption standardized to a 28-day menstrual cycle in the same adjusted model (FOR = 0.96; 95% CI 0.93, 1.00). CONCLUSIONS These data suggest that environmental exposures including those amenable to change, such as alcohol consumption, may impact female fecundity. The findings are sensitive to model specification and PCB groupings, underscoring the need to further assess the impact of chemical mixtures on sensitive reproductive outcomes, such as TTP, especially in the context of lifestyle factors which are amenable to change, thereby improving reproductive health.

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“…Errors in measuring gestational age may be due to factors such as menstrual cycle irregularities, early vaginal bleeding during pregnancy, or inaccurate recall of when the last menstrual period started (11)(12)(13)(14). Unfortunately, we were unable to assess the validity of these possible explanations because this information is not recorded in vital records.…”

Section: National Trendsmentioning

confidence: 99%

State-Specific Trends in Preterm Delivery: Are Rates Really Declining Among Non-Hispanic African Americans Across the United States?

Vahratian

Buekens

Alexander

2005

Matern Child Health J

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Objectives: This study sought to examine state-specific trends in preterm delivery rates among non-Hispanic African Americans and to assess whether these rates are influenced by misclassification of gestational age. Methods: The sample population consisted of singleton nonHispanic White and non-Hispanic African-American infants born in 1991 and 2001 to U.S. resident mothers. For both time periods, state-specific and national preterm delivery rates were calculated for all infants, stratified by infant race/ethnicity. Next, birth-weight distributions within strata of gestational age were studied to explore possible misclassifications of gestational age. Lastly, state-specific and national preterm delivery rates among infants who weighed less than 2,500 g were separately computed. Results: National analyses showed that the frequency of preterm delivery increased by 15.8% among non-Hispanic Whites but declined by 10.3% among non-Hispanic African Americans over the same period. For both subgroups, a bimodal distribution of birth weights was apparent among preterm births at 28-31 weeks of gestation. The second peak with its cluster of normal-weight infants was more prominent among non-Hispanic African Americans in 1991 than in 2001. After excluding preterm infants who weighed 2,500 g or more, the national trends persisted. State-specific analyses showed that preterm delivery rates increased for both subgroups in 13 states during this period. Of these 13, 6 states had a number of non-Hispanic African-American births classified as preterm that were apparently term births mistakenly assigned short gestational ages. Such misclassification was more frequent in 1991 than in 2001 and inflated 1991 rates. Conclusion: There is heterogeneity in state-specific preterm delivery rates. Such differences are often overlooked when aggregate results are presented.

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Time of ovulation and prolonged pregnancy

Cited by 59 publications

References 14 publications

Postdate pregnancy Part I. A literature review

Postdate pregnancy Part I. A literature review

Polychlorinated biphenyl serum concentrations, lifestyle and time-to-pregnancy

State-Specific Trends in Preterm Delivery: Are Rates Really Declining Among Non-Hispanic African Americans Across the United States?

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