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PubMed1999

Risk factors for breast cancer in women under 40 years.

The relation between hormonal and lifestyle factors and breast cancer risk in women younger than 40 years was investigated using data from two case-control studies conducted in Italy between 1983 and 1994. Cases were 579 women with histologically confirmed, incident breast cancer and controls were 668 women admitted to hospital for acute, non-neoplastic, non-hormone-related diseases. Breast cancer risk was inversely related to age at menarche with a multivariate odds ratio (OR) of 0.53 (95% confidence interval, CI, 0.31-0.89) for women reporting menarche at the age of > or = 15 years compared with < 12 years. Breast cancer risk was significantly higher in parae than in nulliparae (OR 1.58), and was directly associated with age at first birth (OR 5.31 among women aged > or = 30 years at first birth compared with those aged < 20), and inversely with time since last birth (OR 3.80 for < 3 years compared with > or = 12). Compared with women reporting no abortion, the OR were 1.10 for any spontaneous, 0.87 for any induced and 0.90 for > or = 2 abortions. With reference to oral contraceptive use, the OR was 1.05 for ever users compared with never users, and no material association was evident with duration, time since first and last use. The OR was 1.79 for more than 13 years of education compared with < 9, 1.85 for a family history of breast cancer and 1.85 for a history of benign breast disease. Breast cancer risk was inversely related to body mass index with an OR of 0.51 (95% CI 0.26-0.97) for > or = 30 kg/m2 compared to < 20. Total energy and alcohol intake were directly related to the risk (OR 1.38 and 1.27 for the highest tertiles of intake compared with the lowest), although the estimates were not significant, whilst raw vegetable and beta-carotene consumption were inversely related to breast cancer risk (OR 0.57 and 0.67 for the highest tertile of intake compared with the lowest). Thus, most risk factors in this large dataset of women aged less than 40 years were similar to those described in breast cancer epidemiology at any age. Of interest are the inverse associations with body mass index, age at menarche and time since last birth, the direct ones with age at first and last birth, and the higher risk of parous women compared with nulliparae.

Abortion, Induced↗
PubMed2003

Correlates of mammogram density in southwestern Native-American women.

Little is known about the breast cancer risk factors or mammogram characteristics among Native-American women. Southwestern Native-American women have a low risk of breast cancer and a high risk of diabetes. Our purpose was to determine the prevalence of known clinical risk factors for breast cancer and their association with mammogram density in a sample of Southwestern Native-American women undergoing breast cancer screening. A retrospective review was performed of screening mammogram examinations in 455 women. Density was classified by American College of Radiology Breast Imaging Reporting and Data System (BIRADS) density patterns 1 to 4 (fat to dense). Clinical data including patient age, weight, body mass index, parity, lactation, age at first birth, menopause status, hormone replacement therapy, diabetes status, and family history of breast cancer were obtained. Multivariate analyses were performed. Among the entire group, 152 women (33.4%) had diabetes. Patient age (P = 0.0012), weight (P < 0.0001), menopause status (P = 0.0134), estrogen use (P = 0.0311), age at first birth (P = 0.0035), and diabetes (P = 0.0015) were associated with mammogram density. Diabetes was associated with mammogram density in premenopausal women (P = 0.0032) but not in postmenopausal women (P = 0.3178) in stratified analyses. Diabetes, hormone replacement therapy, age, weight, menopause status, parity, and age at first birth were significantly associated with mammogram density. The association of mammogram density with diabetes varied by menopause status and was significant only for premenopausal women.

Adult↗
PubMed1976

Quality of care given to first time birth control patients at a free clinic.

In an empirical study of the quality of care at a free clinic, criteria for optimal care for female first visits for birth control were established and 100 charts were reviewed, 50 in April 1974 and 50 in April 1975 with an interval in between of in-service training accompanied by new medical forms and procedures. An encouraging improvement in record keeping was observed. The authors feel it is important that free clinics concentrate on quality as well as quantity and accessibility of care.

Adult↗
PubMed1994

Correlation of cervical cancer mortality with reproductive and dietary factors, and serum markers in China.

BACKGROUND: Cervical cancer is the second leading cause of cancer death among Chinese women. Within China, a considerable geographical variation in mortality rates has been observed, but the reasons are not well understood. METHODS: Cervical cancer rates were examined in relation to indices of reproductive factors, dietary habits, and selected serum biomedical markers in 65 rural Chinese counties. RESULTS: Cervical cancer mortality rates correlated positively and significantly with antibodies to herpes simplex virus type 2 (HSV-2) (r = 0.40, P < 0.01), serum levels of ferritin (r = 0.33, P < 0.01), body mass index (BMI) (r = 0.42, P < 0.01) and cigarette smoking (r = 0.51, P < 0.05) and negatively and significantly with age at first birth (r = -0.51, P < 0.01), consumption of green vegetables (r = -0.40, P < 0.01) and animal foods (r = -0.40, P < 0.01), and serum levels of selenium (r = -0.26, P < 0.05). When these variables were considered in the multiple regression analysis, early age at first birth and higher BMI were positively associated with cervical cancer mortality, while consumption of green vegetables and animal foods were negatively correlated. In the serum model, infection with HSV-2 and low levels of sex hormone binding globulin (SHBG) were positively related to cervical cancer mortality. No relation was found for consumption of fruits. CONCLUSIONS: Although limitations of these ecologic data preclude causal inferences, findings in this study, including associations with HSV-2 infection, early age at first birth, consumption of green vegetables and animal foods, may provide clues to cervical cancer aetiology.

Adult↗
PubMedDate not supplied

Alternative theories of the relationship of schooling and work to family formation: evidence from Mexico.

Role incompatibility, education as an investment in human capital, and schooling as a transformative experience are three mechanisms that link women's education to the timing of marriage and first birth. We simultaneously evaluate these different explanations using retrospective life history data for two cohorts of Mexican women collected in a nationally representative sample. Our analyses provide evidence in support of all three hypotheses. While in school young women are at a substantially lower risk of marriage and of a first birth. We find no evidence that women leave school to enter into unions nor do we find evidence that the effect of being a student diminishes with age. Women who work for a wage are also at a lower risk of marriage and a first birth. Once we control for student and employment status, the direct effects of cumulative education on family formation are relatively modest, although cumulative education is strongly associated with positive attitudes towards women's work and a significant increase in the likelihood of premarital and postmarital employment.

Adult↗
PubMed2002

Childbearing and the risk of leukemia in Sweden.

OBJECTIVE: The possible influence of childbearing on the development of leukemias in females has received little attention, in spite of consistent findings of lower incidence rates in females than in males. A nested case-control study was undertaken to explore if parity and age at first birth affect the risk of developing these malignancies. METHODS: In a nationwide cohort defined by a population-based Fertility Register, we identified 356 women with chronic myeloid leukemia (CML), 819 with acute nonlymphocytic leukemia (ANLL), and 179 with acute lymphocytic leukemia (ALL). For each case, five age-matched controls were selected. Odds ratios were estimated by conditional logistic regression analyses. RESULTS: There was some evidence of weak negative associations between parity and age at first birth for CML. Compared to nulliparous women there was a tendency of a temporal risk reduction of CML for the first 10 years following a delivery. The risk of ANLL was slightly lower in parous compared to nulliparous women. Neither parity nor age at first birth was related to the risk of ALL. CONCLUSIONS: We conclude that if pregnancy-related hormonal or immunological factors have an effect on the development of leukemia, it is minor and confined to the myeloid types, chiefly CML. Our study gives some support for treating the leukemias as separate entities based on both cell lineage and form in future etiologic studies.

Adolescent↗
PubMed1993

Long-term impact of reproductive factors on cancer risk.

The relationship between reproductive variables (parity, age at first birth, number of induced and spontaneous abortions) and cancer risk has been analysed using data from an integrated series of case-control studies conducted in northern Italy between 1983 and 1992. The overall data-set included women below age 75 with histologically confirmed cancers of the following sites: oesophagus, 58; stomach, 280; colon, 405; rectum, 210; liver, 82; gall-bladder, 29; pancreas, 129; breast, 3,415; cervix, 742; endometrium, 725; ovary, 953; bladder, 68; kidney, 56; thyroid, 180; lymphomas, 80; myelomas, 57; and a total of 5,619 controls admitted to hospital for acute non-neoplastic, non-gynaecological, non-hormone-related conditions. Multivariate odds ratios, as estimators of relative risks (RR), were obtained after allowance for age, education, use of oral contraceptives and oestrogen replacement treatments, plus various reproductive factors. Direct significant trends with parity were observed for cancer of the liver (RR for women with > or = 4 births vs. nulliparae = 3.3) and cervix uteri (RR = 4.1). The risk of gall-bladder cancer was also elevated for multiparae (RR = 1.9). No significant inverse trend in risk emerged. However, the RRs in multiparae were significantly below unity for breast (RR = 0.8), endometrium (RR = 0.7), and ovary (RR = 0.8). With reference to age at first birth, a significant trend in risk was observed for breast cancer (RR = 1.4 for 25 to 29 and 1.5 for > or = 30 vs. < 25 years). In contrast, the risk of cervical cancer was inversely related to age at first birth. For spontaneous abortions, the only significant inverse trend was for ovarian cancer (RR = 0.7 for > or = 2 vs. 0 abortions), but also the point estimate for endometrial cancer in women with > or = 2 abortions was below unity. For induced abortions, there was a strong inverse trend in risk for endometrial cancer (RR = 0.5), and the RRs were below unity also for colon and breast cancer. In contrast, cervical cancer was directly associated with the number of spontaneous abortions. Although the underlying aetiological interpretations are different for various cancer sites, this study provides, in a large and uniform data-set, quantitative information on the long-term impact of reproductive factors on cancer risk.

Abortion, Induced↗
PubMedDate not supplied

Delayed childbearing in Canada: trends and factors.

"Using period and cohort birth order statistics, an overview of the phenomenon of delayed childbearing in Canada is presented. Data employed in the period analysis were mainly from the years 1944 to 1985, while women born between the years 1935 and 1960 were the subjects of the cohort analysis. An examination of selected indices, namely, age-specific first-birth fertility rates, median ages of women at first-order birth and cumulative first-order birth rates shows that there is an overall trend for women to postpone the initiation of childbearing until late twenties or early thirties.... The results indicate that work experience, education, occupation and year of marriage are important variables influencing age at first birth and first-birth interval." (SUMMARY IN FRE AND ITA)

Age Factors↗
PubMed1991

Reproductive factors and colorectal cancer.

Descriptive and analytical epidemiology have suggested that cancer of the colorectum may have reproductive correlates similar to those of breast cancer (e.g., protection by parity and early age at first birth), but the evidence is still controversial. We therefore reviewed published data from 15 case-control investigations, two cohort studies, and one cancer registry-based study from seven different countries. With reference to parity, statistically significant protection for colorectal cancer was found in three case-control studies; in four other studies, significant inverse relationships of parity were observed with colon cancer, but not with rectal cancer. Among the remaining 12 studies, relative risks below unity for parous or multiparous women were observed in four. There was no appreciable trend in risk in four others; in two, there was nonsignificant increased risk with parity; and in one, a significant increased risk. Information on age at first birth was available from 12 studies. Three reported significant trends of increased risk with increasing age at first birth--one found a direct association of borderline significance; six indicated no evidence of association; and two reported an inverse trend in risk of borderline significance. Findings on age at menarche were inconsistent and mostly negative, although an inverse significant association was reported, especially regarding colon cancer, in one investigation. In all the six studies, which provided information on age at menopause, there was a hint of protection, although nonsignificant, for women who underwent natural menopause at an older age. Two studies reported a direct association of colorectal cancer with use of oral contraceptives, and another showed an inverse relationship with the use of menopausal estrogens.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMedDate not supplied

Menarcheal age and subsequent patterns of family formation.

We examine whether age at menarche affects age at first marriage or first birth using two samples of U.S. women. Data are drawn from the Tremin Trust, a longitudinal study of menstrual cycles that recruited white women who were students at the University of Minnesota and from a survey of a nationally representative sample of white women born between 1900 and 1910. Regression models with cubic splines were used to analyze the relationship between age at menarche and age at first marriage. Cox proportional hazard models were used to examine the effect of age at menarche on the interval between marriage and first birth. Unlike earlier work, we found that once secular trends in both age at marriage and age at menarche were taken into account, there was no evidence that age at menarche affects either age at marriage or the timing of first births in these U.S. women.

Adolescent↗
PubMed1986

Seroepizootiology of types 3 and 7 adenoviruses and bovine viral diarrhea virus infections of beef cattle from birth to first parturition.

Twenty-nine female Angus cattle were monitored from birth until 24 months of age for infection with types 3 and 7 adenoviruses (AV3, AV7) and bovine viral diarrhea (BVD) virus by virus isolation and neutralization tests. Twenty-seven animals remained in the study for 450 days, whereas 16 animals remained at the conclusion of the tests. Viruses were not isolated from test animals. Seroepizootiologic examination indicated that there were 28 infections with AV3, 33 infections with AV7, and 13 infections with BVD virus. Of these infections, 5 with AV3, 6 with AV7, and 2 with BVD virus were reinfections. All but 1 primary AV3 infection had occurred between 180 and 360 days after parturition. Infection with AV7 occurred earlier than that with AV3, as shown by 6 seropositive animals by 180 days. Most adenovirus infections were documented after animals had left confinement and were turned out to pasture. Most BVD virus infections occurred within the first 90 days after parturition. At completion of the study, only 1 animal had not shown evidence of AV3 infection, 2 animals had not been infected with AV7, and 7 cows had remained free of BVD virus infection.

Adenoviridae↗
PubMed1984

Measurement and replication: evaluating the consistency of eight U. S. fertility surveys.

This paper addresses the comparability of data from eight national fertility surveys conducted in the United States between 1955 and 1980. We examine the extent to which substantive conclusions about the levels and correlates of the timing of first birth vary across these data sources by comparing samples of women who were eligible to be included in more than one study. Results obtained from Ordinary Least Squares (OLS) and logistic regression analyses of several measures of timing indicate few study effects. Thus findings based on data from one survey can be replicated with comparable data from another. One notable exception is the relationship between contraceptive use prior to the first birth and the timing of that birth. The contraceptive variable appears to be poorly measured, leading to unstable estimates of the relationship. In general, our results suggest: (1) the feasibility of pooling data from the various surveys when modeling delayed childbearing; and (2) reasonable accuracy in assessing trends in the timing of first birth from multiple data sources.

Adolescent↗
PubMed2006

Breast cancer risk factors in relation to breast density (United States).

OBJECTIVES: Evaluate known breast cancer risk factors in relation to breast density. METHODS: We examined factors in relation to breast density in 144,018 New Hampshire (NH) women with at least one mammogram recorded in a statewide mammography registry. Mammographic breast density was measured by radiologists using the BI-RADS classification; risk factors of interest were obtained from patient intake forms and questionnaires. RESULTS: Initial analyses showed a strong inverse influence of age and body mass index (BMI) on breast density. In addition, women with late age at menarche, late age at first birth, premenopausal women, and those currently using hormone therapy (HT) tended to have higher breast density, while those with greater parity tended to have less dense breasts. Analyses stratified on age and BMI suggested interactions, which were formally assessed in a multivariable model. The impact of current HT use, relative to nonuse, differed across age groups, with an inverse association in younger women, and a positive association in older women (p < 0.0001 for the interaction). The positive effects of age at menarche and age at first birth, and the inverse influence of parity were less apparent in women with low BMI than in those with high BMI (p = 0.04, p < 0.0001 and p = 0.01, respectively, for the interactions). We also noted stronger positive effects for age at first birth in postmenopausal women (p = 0.004 for the interaction). The multivariable model indicated a slight positive influence of family history of breast cancer. CONCLUSIONS: The influence of age at menarche and reproductive factors on breast density is less evident in women with high BMI. Density is reduced in young women using HT, but increased in HT users of age 50 or more.

Adult↗
PubMed1994

Young African-American multigenerational families in poverty: quality of mothering and grandmothering.

Parenting practices (problem-solving and disciplinary styles) in a sample of 99 young, low-income, African-American multigenerational families were examined, using home-based observations of grandmothers and young mothers (mean age at first birth: 18.3; range = 13.3 to 25.5), interacting separately with 3-year-old children. A risk and resilience approach was applied in studying African-American families' behavior in harsh social contexts, and included a consideration of the role of kin, shared child rearing between mothers and grandmothers, coresidence, and adolescent parenthood. Mothers and grandmothers did not differ in the mean level of the quality of their parenting practices. Similarly, few significant correlations in parenting quality across generations were evident, and these primarily involved negative dimensions of parenting between younger childbearers and grandmothers. No main effect of mothers' age at first birth on mothers' parenting was found. In contrast, there was a main effect of grandmother coresidence on both mothers' and grandmothers' parenting, which was negative. Moreover, the interaction between coresidence and mothers' age at first birth indicated that multigenerational families most likely to provide positive parenting were those where older mothers did not reside with the grandmother. Yet, in families with very young mothers, coresiding grandmothers showed higher quality of parenting than did non-coresiding grandmothers.

Adolescent↗
PubMed2006

Breast cancer incidence trends in deprived and affluent Scottish women.

OBJECTIVE: Breast cancer is commoner in the affluent and breast cancer rates in many countries are rising; it remains unclear whether this incidence rise is consistent across the different socio-economic groups. The rising incidence of breast cancer may be related to changes in population risk factor profiles. This study aimed to determine breast cancer incidence trends in women of different socio-economic categories and whether these trends were related to breast cancer risk factor trends. DESIGN: Data on breast cancer incidence rates by deprivation quintile in Scotland 1991-2000 were analysed using linear regression. Data on first births at late maternal age, BMI trends (based on the Scottish Health Surveys) and breast screening uptake trends in the different categories were also analysed and their relation to breast cancer incidence trends explored. POPULATION AND SETTING: Breast cancer incidence data was based on all women in Scotland. BMI data was based on representative cross-sectional survey data from the Scottish Health Surveys-women in the 1995, 1998 and 2003 surveys were 16-64, 16-74 and aged 16 and over, respectively. First birth data was based on all women aged 35-39 in Scotland. Breast screening uptake data was studied in women of screening age, that is, aged 50-64. RESULTS: Breast cancer incidence rates in Scottish women are rising in parallel across all socio-economic categories and the incidence gap between deprived and affluent still remains. Since the late 1980s, numbers of first birth in Scottish women aged 35-39 have risen dramatically, especially in the affluent, but numbers were stable before this. The prevalence of obesity and mean BMI has increased over time in all socio-economic classes but BMI continues to be higher in the deprived. Uptake of screening invitations has increased in all socio-economic groups. CONCLUSIONS: Breast cancer is rising in women of all socio-economic status in Scotland and the deprived-affluent gap remains. Trends in late age at first pregnancy, prevalence of obesity and screening uptake do not fully explain the observed trends.

Adult↗
PubMed1989

A comparison of low birth weight, perinatal mortality, and infant mortality between first and second births to women 17 years old and younger.

Several studies and vital statistics reports have indicated that second pregnancies in the young adolescent have worse outcomes than first pregnancies. This study compared the birth weights and mortality rates of first and second births to 407 teenagers who were less than or equal to 17 years old at the time of the second delivery. Contrary to previous studies, the mean birth weight was significantly lower for first births than for second births (p = 0.0001), even though patients registered for care earlier with their first pregnancy. The perinatal and infant mortality rates for first births were nearly double the rates for second births.

Adolescent↗
PubMed2004

Do breast-feeding and other reproductive factors influence future risk of rheumatoid arthritis? Results from the Nurses' Health Study.

OBJECTIVE: To explore the contribution of female hormonal factors occurring prior to the onset of rheumatoid arthritis (RA), such as age at menarche, parity, age at first birth, breast-feeding, use of oral contraceptives (OCs), irregular menstrual cycles, and postmenopausal hormone (PMH) use, to the subsequent development of RA in a large female cohort. METHODS: We studied female reproductive and hormonal risk factors for RA in a cohort of 121,700 women enrolled in the longitudinal Nurses' Health Study. The diagnosis of incident RA (between 1976 and 2002) in 674 women was confirmed by a connective tissue disease screening questionnaire and blinded medical record review for American College of Rheumatology criteria. Sixty percent of the patients with RA were rheumatoid factor positive. The relationship between potential risk factors, including age, age at menarche, parity, age at first birth, total lifetime history of breast-feeding, use of OCs, and irregular menstrual cycles and the multivariate-adjusted risk of RA was estimated using Cox proportional hazards models. RESULTS: Using a multivariate model that adjusted for age, body mass index, smoking, parity, and other hormonal factors, we observed a strong trend for decreasing risk of RA with increasing duration of breast-feeding (P for trend = 0.001). For women who breast-fed (compared with parous women who did not breast-feed), the risk ratios (RRs) and 95% confidence intervals (95% CIs) were as follows: breast-feeding for < or =3 total months, RR 1.0 (95% confidence interval [95% CI] 0.8-1.2); for 4-11 total months, RR 0.9 (95% CI 0.7-1.1); for 12-23 total months, RR 0.8 (95% CI 0.6-1.0); and for > or =24 total months, RR 0.5 (95% CI 0.3-0.8). Very irregular menstrual cycles were associated with an increased risk of RA (RR 1.4, 95% CI 1.0-2.0). Age at menarche < or =10 years was associated with an increased risk of seropositive RA (RR 1.6, 95% CI 1.1-2.4) but not significantly associated with risk of RA. Parity, total number of children, age at first birth, and OC use were not associated with an increased risk of RA in this cohort. CONCLUSION: In this large cohort, breast-feeding for >12 months was inversely related to the development of RA. This apparent effect was dose-dependent, with a significant trend toward lower risk with longer duration of breast-feeding. Irregular menstrual cycles and earlier age at menarche increased the risk of RA. Other reproductive hormonal factors were not associated with RA risk.

Adult↗
PubMed2000

Changing paternity and the risk of preeclampsia/eclampsia in the subsequent pregnancy.

To determine whether changing paternity affects the risk of preeclampsia or eclampsia in the subsequent pregnancy and whether the effect depends on a woman's history of preeclampsia/eclampsia with her previous partner, a cohort study was conducted based on 140,147 women with two consecutive births during 1989-1991 identified through linking of annual California birth certificate data. Among women without preeclampsia/eclampsia in the first birth, changing partners resulted in a 30% increase in the risk of preeclampsia/eclampsia in the subsequent pregnancy compared with those who did not change partners (95% confidence interval: 1.1, 1.6). On the other hand, among women with preeclampsia/eclampsia in the first birth, changing partners resulted in a 30% reduction in the risk of preeclampsia/eclampsia in the subsequent pregnancy (95% confidence interval: 0.4, 1.2). The difference of the effect of changing paternity on the risk of preeclampsia/eclampsia between women with and those without a history of this condition was significant (p < 0.05 for the interaction term). The above estimates were adjusted for potential confounders. These findings suggest that the effect of changing paternity depends on the history of preeclampsia/eclampsia with the previous partner and support the hypothesis that parental human leukocyte antigen sharing may play a role in the etiology of preeclampsia/eclampsia.

Adult↗