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PubMed1990

Risk factors for breast cancer according to age at diagnosis in a French case-control study.

In a French case-control study of 1010 women with breast cancer and 1950 controls with nonmalignant disease, the variations of the effects of 8 risk factors for breast cancer as a function of age at diagnosis, were analysed by tests of homogeneity and trend. The risks associated with a late age at first full-term pregnancy and with nulliparity were different between age-groups (test of homogeneity: p = 0.03), and the highest risks for these two factors were observed in women 45-54 years old. The risks associated with Quetelet index were also found to vary with age at diagnosis (test for trend: p = 0.008). A high Quetelet index decreased the risk of breast cancer in the younger age-groups; this decrease of risk became progressively less important with advancing age, and no such effect was found in the oldest age-group. Inverse results were observed for a tall stature (test for trend: p = 0.04): a tall stature increased the risk of breast cancer in the younger age-groups, and the figures suggested a reverse effect in the oldest group. No large variation with age was found for the effects of age at menarche, history of breast cancer death in mother or sisters, prior biopsy for benign breast disease, and weight. In conclusion, the relative importance of certain risk factors for breast cancer is closely related to age at diagnosis. Nulliparity and a late age at first birth appear to be major risk factors only for middle-aged women, whereas a low Quetelet index and a tall stature appear to increase the risk of breast cancer only for younger women.

Adult↗
PubMed1990

Identification of high risk groups for breast cancer by means of logistic models.

In order to identify high risk groups for breast cancer, unconditional multiple logistic regression models based on 5 widely recognized and easily identifiable risk factors (age at menarche, at menopause and at first birth, family history of breast cancer and body mass index) were applied to a large dataset including 2085 cases and 1936 controls aged 50 or over derived from two unmatched hospital-based case-control studies conducted in Italy. Although various models provided an excellent fitting, both on the whole dataset and using a training-testing approach to a priori identified separate subset, the observed extent of variation in breast cancer risk between highest and lowest decile of the distribution was limited to a factor 2. This indicates that the 5 variables considered did not allow identification of subgroups with substantially elevated risk of breast cancer to have practical implications for screening/prophylactic treatment purposes.

Adolescent↗
PubMed2004

Managing the production, storage, and delivery of colostrum.

Provision of an adequate immunoglobulin mass to dairy calves is an essential component for survival, health, and future productivity. To prevent FPT of immunity due to suckling of the dam, newborn dairy calves should be removed from the calving area within 30 minutes of birth. First and later lactation cows are suitable colostrum donors, provided they are healthy, well-vaccinated, have had optimal transition management, and an appropriate dry-period length. Early colostrum collection yields an adequate immunoglobulin mass provided that 3 to 4 L of colostrum is fed to the newborn calf. Regular testing for the adequacy of the dairy's colostrum feeding program is an excellent way to prevent calf health problems and identify potential need for CSs or replacement products.

Animals↗
PubMed2006

Effects of infertility insurance mandates on fertility.

Infertility currently affects over 6 million individuals in the United States. While most health insurance plans nationwide do not cover infertility diagnoses or treatments, to date 15 states have enacted some form of infertility insurance mandate. In this paper, I use data from the Vital Statistics Detail Natality Data and Census population estimates to examine whether these state-level mandates were successful in increasing fertility rates. Using a difference-in-differences approach, I exploit variation in the enactment of mandates both across states and over time, and identify treatment and control groups that should have been differentially affected by infertility coverage. My results suggest that the mandates significantly increase first birth rates for women over 35, and these results are robust to a number of specification tests.

Adult↗
PubMed2005

Breast cancer risk in the WHI study: the problem of obesity.

In the climacteric, about 40% of the women have occult breast tumors the growth of which may be stimulated by hormones. Many genetic, reproductive and lifestyle factors may influence the incidence of breast cancer. Epidemiological data suggest that the increase in the relative risk (RR) of breast cancer induced by hormone replacement therapy (HRT) is comparable with that associated with early menarche, late menopause, late first birth, alcohol consumption, etc. One of the most important risk factors is obesity which exceeds the effect of HRT by far, and in overweight postmenopausal women the elevated risk of breast cancer is not further increased by HRT. As in the WHI study the majority of women was overweight or obese, this trial was unsuitable for the investigation of breast cancer risk. In the women treated with an estrogen/progestin combination, the RR of breast cancer rose only in those women who have been treated with hormones prior to the study, suggesting a selection bias. In the women not pretreated with hormones, it was not elevated. In the estrogen-only arm of the WHI study, there was no increase but a steady decrease in the RR of breast cancer during 6.8 years of estrogen therapy. This result was unexpected, as estrogens are known to facilitate the development and growth of breast tumors, and the effect is enhanced by the addition of progestins. Obese women are at high risk to develop a metabolic syndrome including insulin resistance and hyperinsulinemia. In postmenopausal women, elevated insulin levels are not only associated with an increased risk for cardiovascular disease, but also for breast cancer. This might explain the effects observed in both arms of the WHI study: HRT with relative low doses of estrogens may improve insulin resistance and, hence, reduce the elevated breast cancer risk in obese patients, whereas this beneficial estrogen effect may be antagonized by progestins. The principal options for the reduction of breast cancer risk in postmenopausal women are the prevention of overweight and obesity to avoid the development of hyperinsulinemia, the medical treatment of insulin resistance, the use of low doses of estrogens and the reduction of exposure to progestins. The latter might include long-cycles with the sequential use of appropriate progestins every 3 months for 14 days. There are large inter-individual variations in the proliferative response to estrogens of the endometrium. Control by vaginalsonography and progestin challenge tests may help to identify those women who may be candidates for low-dose estrogen-only therapy.

Body Weight↗
PubMed2006

Age at menopause and cause-specific mortality in South Korean women: Kangwha Cohort Study.

OBJECTIVE: The purpose of this study was to examine the relation between age at natural menopause and all-cause and cause-specific mortality among women. METHODS: This study used the data of the Kangwha Cohort that was followed up from 1985 to 2001, in particular, for the group of 55 years or older women (n=2658). We calculated the hazard ratio of mortality by the group of age at menopause using the Cox proportional hazards model with adjustment for age, alcohol consumption, education, age at first birth, self-cognitive health level, chronic disease, marital partner, parity, age at menarche, oral contraceptive use and hypertension. RESULTS: The mean (standard deviation) age at menopause was 46.9 (4.9) years, and the median age was 48 years. After adjusting for the relevant variables, the risk of total death in the early menopause group (<40 years at menopause) was 1.32 times higher than that of the reference group (45-49 years at menopause) (95% confidence interval [CI], 1.05-1.66, p=0.02). For the early menopause group, relative to the reference group, the adjusted hazard ratios of death due to cardiovascular disease and cancer were 1.53 (95% CI, 1.00-2.39, p=0.04) and 2.01 (95% CI, 1.06-3.82, p=0.03), respectively. CONCLUSION: Through this study, the age at menopause was found to be different between Asian and Caucasian women and the association of age at menopause with death, particularly caused by cardiovascular disease and cancer, was validated. Our study is one of rare studies regarding the age at menopause of Asian women and their risk of mortality, which could be considered to be meaningful.

Adult↗
PubMed2004

Epithelial ovarian cancer risk by invasiveness and cell type in the Central Valley of California.

OBJECTIVE: To evaluate epithelial ovarian cancer (EOC) risk factors by level of invasiveness and histology. METHODS: A population-based epidemiologic case-control study of EOC was conducted over a 2-year period (January 2000 to December 2001) in 22 counties of Central California that comprise the reporting area for two regional cancer registries. Telephone interviews were conducted with 256 cases and 1122 control frequencies matched on age and ethnicity. The interview obtained information on demographic factors as well as information pertinent to the respondent's menstrual and reproductive experience, use of exogenous hormones, surgical history, and family history of cancer. Adjusted odds ratios were calculated using stratification as well as Logistic regression methods. Analyses were completed by level of invasiveness and cell type. RESULTS: Strong protective associations were observed for use of oral contraceptives and parity. Risk increased with a family history of ovarian, but not breast cancer and age at first birth was positively associated with increased risk. Hormone replacement therapy was associated with increased risk only in long-term users. Many of the relationships were observed only in specific histologic subtypes of EOC. CONCLUSION: Risk of EOC is associated with several lifestyle and environmental exposures but the impact of these effects appears to be dependent upon level of invasiveness and histologic subtypes of EOC. However, the sample size available for analysis limits our statistical power and our ability to analyze data by histologic subtype, thus limiting interpretation of our results.

Adolescent↗
PubMed1998

Ultrasonographic examination of intrauterine growth for multiple fetal dimensions in a Chinese population. Central-South China Fetal Growth Study Group.

OBJECTIVE: We sought to construct an ultrasonography-based growth curve in a Chinese population. STUDY DESIGN: Routine ultrasonographic examination was performed in 5496 normal pregnancies (>95% first births) in five obstetric ultrasonography laboratories in Central-South China from January 1, 1992, to December 31, 1993. RESULTS: All the fetal growth measures increased with gestational age, whereas the ratios either decreased or remained constant across gestation. Biparietal diameter and cerebral hemispheric width were higher at early gestational ages, whereas femur length, thoracic circumference, and abdominal circumference were lower at later gestational ages in our study than in previous studies. The ratio of lateral ventricular width/cerebral hemispheric width was lower at an early gestational age but higher in later gestational ages in our study. CONCLUSIONS: A different standard of ultrasonography-based fetal growth is needed for different populations. The ultrasonography-based growth curve constructed in this large Chinese population provides an additional tool for the evaluation of fetal growth and development.

Abdomen↗
PubMed2001

Vaginal bleeding patterns among rural highland Bolivian women: relationship to fecundity and fetal loss.

Among the most common reasons given for discontinued use of some contraceptive methods is a disturbance in the menstrual cycle, particularly changes in vaginal bleeding. Work to date suggests marked populational variation in menses duration, but few data have been collected from South America. This longitudinal study of non-contracepting Aymara women (n = 189 providing 837 non-truncated bleeding episodes) identified conceptions and fetal loss via urine tests for human chorionic gonadotropin and classified episodes accordingly to test the hypotheses that (a) vaginal bleeding patterns differ between lactating and non-lactating women, (b) duration of vaginal bleeding accompanying fetal loss differs from that of menstruation, (c) menses preceding a conception are longer than those not followed by a conception. Compared to published values, mean menses duration (3.5 days) in these women was relatively short. Menses duration was not significantly correlated with current age, age at menarche or first birth, parity, time postpartum, or menstrual segment length. Mean menses duration (not preceding a conception) was comparable for lactating and non-lactating women. Mean duration of fetal loss bleeding did not differ from that of menses. Pre-conception episodes were significantly longer than those not followed by conception. Thus, because the rate of conceptions was twice as great among lactating than non-lactating women, the mean duration of all menses (irrespective of conception) was significantly longer in lactating women. Bolivian, and perhaps other South American, women may be particularly disinclined to accept contraceptives (e.g., intrauterine devices) that modify an otherwise relatively brief menses duration. Therefore, a wide variety of contraceptive choices accompanied by population-specific informed counseling is essential. In addition, these findings suggest that studies of fecundability limited to non-lactating women may be biased toward those of relatively lower fecundity and that menses duration may be predictive of risk for some cancers.

Adult↗
PubMed1985

Characteristics of women undergoing induced abortion: results of a case-control study from Northern Italy.

In order to identify subgroups of women at elevated risk of induced abortion, personal characteristics and habits, selected medical histories and contraceptive practices of 873 women undergoing legal abortion in various areas of Northern Italy were compared with those of 504 control subjects identified in family planning clinics of the same hospitals or area health authorities. When age was allowed for, the risk of induced abortion was not strongly influenced by marital status, education or other indicators of social class. However, women who were employed, independently from the type of occupation, showed markedly lower abortion risks than housewives. Among various indicators of sexual habits investigated, the strongest determinant of legal abortion was the frequency of sexual intercourses over the previous six months, women with less frequent intercourses showing a markedly elevated risk estimate (RR = 2.82). Induced abortion was less frequent among ex-smokers and more frequent in heavy smokers, but was not appreciably influenced by several other indicators of lifestyle habits and history of gynaecological or psychiatric complaints. The risk of abortion was not influenced by the number of livebirths, but was lower for women with later age at first birth. Less than 5% of case and control subjects reported more than two previous induced abortions, thus indicating that abortion is more of an "accidental" event rather than a widespread contraceptive practice. However, over three-quarters of abortions occurred in women reporting no contraception at all or coitus interruptus, thus underlining the scope for family planning education in this population.

Abortion, Legal↗
PubMed1989

The effect of therapy initiation day on clomiphene citrate therapy.

Eighty-seven anovulatory patients were treated with clomiphene citrate (CC) to induce ovulation in 414 cycles. Clomiphene citrate was initiated randomly on the 2nd, 3rd, 4th, or 5th day of the menstrual cycle to evaluate the effectiveness of therapy. The results of therapy were assessed in terms of ovarian response and pregnancy outcome. Ovarian response was evaluated employing basal body temperature (BBT) to define follicular, luteal, and cycle lengths, and a midluteal serum progesterone (P) level and the integrated luteal P to define luteal adequacy. Pregnancy outcome was evaluated in the categories of total pregnancy, live birth, first trimester abortion, and fecundity rates. There were no significant differences noted between the groups who started CC on the 2nd, 3rd, 4th, or 5th day of cycle in terms of anovulation rates (12% to 21%), luteal dysfunction (28% to 39%), and normal ovulation rates (42% to 57%). Pregnancy was achieved in 31% (n = 27/87) of patients with a spontaneous abortion rate of 19% (n = 5/27). The fecundity rates ranged between 5.7% and 9.4%. Pregnancy outcomes also were not significantly different between the groups. Significantly shorter luteal phase length and longer follicular phase length were observed in the cycles with luteal dysfunction. The luteal progesterone parameters, including midluteal serum P concentration, the integrated luteal P, and the luteal P amplitude were significantly lower in the cycles with luteal dysfunction.

Abortion, Spontaneous↗
PubMed1998

Obstetric outcome of elderly low-risk nulliparae.

OBJECTIVE: To compare referrals and reasons for referral during pregnancy and labor, mode of delivery and obstetric outcome of first births in women 35 years and older with women 20-30 years old. METHODS: A prospective cohort study was performed of 146 elderly and 306 younger nulliparae in seven independent midwives' practices in and around Amsterdam. RESULTS: No significant differences in referrals were found between the two compared groups. After selection during pregnancy, obstetric outcome was not different between the groups. A higher percentage of episiotomies was found in the elderly group, compared to the younger group. CONCLUSIONS: After proper selection during pregnancy, the elderly nullipara under the care of a midwife does not have an increased risk of fetal distress or other emergency factors, compared to the younger nullipara. However, high referral rates during labor - both of younger and older women - were observed in this study.

Adult↗
PubMed2000

A longitudinal study of electrogastrography in normal neonates.

BACKGROUND/PURPOSE: Gastric motility is partly regulated by an inherent electric control activity (ECA). Electrogastrography (EGG) measures gastric ECA through cutaneous electrodes. Little is known about EGG in neonates. A slow wave frequency of 3 cycles per minute (cpm) accounts for 85% to 100% of gastric ECA in normal adults and children. However, the authors have shown previously a lower percentage of 3 cpm activity in neonates. Abnormal EGG patterns (tachygastria and bradygastria) have been described in adults and children with gastric motility disorders. In neonates, especially premature infants, disorders of gastrointestinal motility are common, especially after gastrointestinal operations. It is necessary to characterise normal ECA before the pathophysiology of these disorders can be studied. The aim of this study was to investigate the pattern of ECA in the developing neonate. METHODS: Nine healthy neonates born at 34 weeks' gestation were studied using Synectics EGG sampling at 4 Hz. Each subject underwent 4 hourly EGG recordings at fortnightly intervals from birth until age 8 weeks, and then every 2 months until age 2 years. The paired sample t test (95% Confidence Interval [CI]) was used to compare recordings. RESULTS: Between birth and age 2 years, 3 cpm activity increased from 38% to 57% of recorded time. The mean percentage recorded time of tachygastria decreased from 47% to 35%, and bradygastria decreased from 15% to 8%. Statistically significant differences were seen between birth, 6 months, and 2 years of age. CONCLUSIONS: The pattern of ECA in the normal neonatal stomach differs from that seen in adult studies. Tachygastria and bradygastria are seen more frequently, with fewer periods of 3 cpm. There is an increase in the percentage of 3 cpm activity over time, with statistically significant differences from the ECA pattern at birth first seen at the age of 6 months. The authors suggest that neonatal ECA undergoes a maturation process and that larger longitudinal and normal range studies are required to investigate this phenomenon.

Child, Preschool↗
PubMed2000

A probabilistic approach to the assessment of some life history pattern parameters in a Middle Pleistocene human population.

Parameters of a Middle Pleistocene human population such as the expected length of the female reproductive period (E(Y)), the expected interbirth interval (E(X)), the survival rate (tau) for females after the expected reproductive period, the rate (phi(2)) of women who, given that they reach first birth, do not survive to the end of the expected reproductive period, and the female infant plus juvenile mortality rate (phi(1)) have been assessed from a probabilistic standpoint provided that such a population were stationary. The hominid sample studied, the Sima de los Huesos (SH) cave site, Sierra de Atapuerca (Spain), is the most exhaustive human fossil sample currently available. Results suggest that the Atapuerca (SH) sample can derive from a stationary population. Further, in the case that the expected reproductive period ends between 37 and 40 yr of age, then 24 less, similarE(Y) less, similar27 yr, E(X)=3 yr, 0.224</=tau</=0.246,0.49<phi(2)</=0.754 and 0</=phi(1)<0.264. When, however, the end of the expected reproductive period occurs after 40 yr of age, it turns out that 24 less, similarE(Y) less, similar30 yr, E(X)=3 yr, 0.204</=tau</=0.246, 0.74<phi(2)</=0.754 and 0</=phi(1)<0.056.

Adult↗
PubMed1998

Normal amniotic fluid index by gestational week in a Chinese population. Central-South China Fetal Growth Study Group.

OBJECTIVE: To construct an ultrasonography-based gestation-specific amniotic fluid index (AFI) curve in a Chinese population. METHODS: Routine obstetric ultrasonography examinations were performed in 5496 normal pregnancies (more than 95% first births) in five obstetric ultrasound laboratories in Central-South China from January 1, 1992, to December 31, 1993. A gestation-specific AFI curve was constructed and compared with previous studies. RESULTS: The gestational ages of the patients included in this study ranged from 16 to 40 weeks. The gestation-specific AFI showed patterns similar to those observed previously, with the median being 72 mm at 16 weeks, increasing to 119 mm at 26 weeks, and then gradually declining to a median of 91 mm at 40 weeks. However, the absolute value of AFI in this Chinese population was consistently and substantially lower than values reported in previous studies in populations with mixed parities. CONCLUSION: Different standards of AFI are needed for different populations.

Amniotic Fluid↗
PubMed2004

Breast cancer and abortion: collaborative reanalysis of data from 53 epidemiological studies, including 83?000 women with breast cancer from 16 countries.

BACKGROUND: The Collaborative Group on Hormonal Factors in Breast Cancer has brought together the worldwide epidemiological evidence on the possible relation between breast cancer and previous spontaneous and induced abortions. METHODS: Data on individual women from 53 studies undertaken in 16 countries with liberal abortion laws were checked and analysed centrally. Relative risks of breast cancer--comparing the effects of having had a pregnancy that ended as an abortion with those of never having had that pregnancy--were calculated, stratified by study, age at diagnosis, parity, and age at first birth. Because the extent of under-reporting of past induced abortions might be influenced by whether or not women had been diagnosed with breast cancer, results of the studies--including a total of 44000 women with breast cancer--that used prospective information on abortion (ie, information that had been recorded before the diagnosis of breast cancer) were considered separately from results of the studies--including 39000 women with the disease--that used retrospective information (recorded after the diagnosis of breast cancer). FINDINGS: The overall relative risk of breast cancer, comparing women with a prospective record of having had one or more pregnancies that ended as a spontaneous abortion versus women with no such record, was 0.98 (95% CI 0.92-1.04, p=0.5). The corresponding relative risk for induced abortion was 0.93 (0.89-0.96, p=0.0002). Among women with a prospective record of having had a spontaneous or an induced abortion, the risk of breast cancer did not differ significantly according to the number or timing of either type of abortion. Published results on induced abortion from the few studies with prospectively recorded information that were not available for inclusion here are consistent with these findings. Overall results for induced abortion differed substantially between studies with prospective and those with retrospective information on abortion (test for heterogeneity between relative risks: chi2(1) =33.1, p<0.0001). INTERPRETATION: Pregnancies that end as a spontaneous or induced abortion do not increase a woman's risk of developing breast cancer. Collectively, the studies of breast cancer with retrospective recording of induced abortion yielded misleading results, possibly because women who had developed breast cancer were, on average, more likely than other women to disclose previous induced abortions.

Abortion, Induced↗
PubMedDate not supplied

Breast cancer.

Breast cancer remains a public-health issue on a global scale. We report new information about the disease from the past 5 years. Early age at first birth, increasing parity, and tamoxifen use are related to long-term lifetime reduction in breast-cancer risk. Ductal carcinomas in situ has been suggested to be renamed ductal intraepithelial neoplasia to emphasise its non-life-threatening nature. An alternative approach, the progenitor/stem cell theory, predicts that only some tumour cells cause cancer progression and that these should be targeted by treatment. Mammography and ultrasonography are still the most effective for women with non-dense and dense breast tissues, respectively. Additionally, MRI, lymphatic mapping, the nipple-sparing mastectomy, partial breast irradiation, neoadjuvant systemic therapy, and adjuvant treatments are promising for subgroups of breast-cancer patients. Although tamoxifen can be offered for endocrine-responsive disease, aromatase inhibitors are increasingly used. Assessment of potential molecular targets is now important in primary diagnosis. Tyrosine-kinase inhibitors and other drugs with anti-angiogenesis properties are currently undergoing preclinical investigations.

Breast Neoplasms↗
PubMed1976

Oestrogen profiles of parous and nulliparous women.

Women who bear their first child at an early age have lower breast-cancer incidence-rates than do women who are older at first birth or who remain nulliparous. The urine "oestriol ratio", the concentration of oestriol relative to the sum of the concentrations of oestrone and oestradiol, is inversely related to a population's breast-cancer rate. To evaluate the relationship between these two breast-cancer risk indicators the urine oestriol ratio was determined for recently delivered uniparous women aged 19-23, 25-27, and 29-34 years and nulliparous women of comparable ages. In the follicular phase, the youngest parous women had an oestriol ratio 40% higher than, and significantly different from, the ratios of all other groups which were otherwise quite similar. In the luteal phase, the oestriol ratio of the youngest parous women was again distinctively raised and generally the oestriol ratios of parous women were higher than those of nulliparae. The results are not explained by differing frequencies of ovulation among the groups or by confounding from several breast-cancer risk indicators. These findings support the hypothesis that oestrogen metabolism, as reflected by the urine oestriol ratio, is a determinant of breast-cancer risk.

Adult↗