First birth in a new transport in vitro fertilization program.
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Adult↗
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Results for “First Birth”
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Just another day in a woman's life? Women's long-term perceptions of their first birth experience. Part I.
This study explored and analyzed the long-term impact of the birth experience on a group of 20 women from the natural childbirth culture of the late 1960s and early 1970s. The data consisted of 1) a structured labor and birth questionnaire and an unstructured account of their experiences written shortly after their babies were born; 2) a similar questionnaire and account written 15 to 20 years later; and 3) a transcribed one- to one-and-a-half-hour interview during which each woman's memories and perceptions were discussed. Women reported that their memories were vivid and deeply felt. Those with highest long-term satisfaction ratings thought that they accomplished something important, that they were in control, and that the birth experience contributed to their self-confidence and self-esteem. They had positive memories of their doctors' and nurses' words and actions. These positive associations were not reported among women with lower satisfaction ratings.
Adult↗
First births to older mothers, 1970-86.
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Adolescent↗
Histologic specificity of the effect of age at birth of first child on breast cancer risk.
Slides of 531 breast cancers from Glamorgan, Wales, were classified according to the presence or absence of each of three histologic characteristics: stromal infiltration by linear strands of tumor cells, areas of intraductal carcinoma, and areas of lobular carcinoma in situ. The proportion of tumors with each of these characteristics was positively associated with age at first child-birth. Increasing age at first birth had a strong positive effect on the incidence risk of tumors with any of these features, but only a small effect on risk of tumors with none. For parous women, the rate of breast cancer with or without linear strands, with or without areas of intraductal cancer, and without areas of lobular carcinoma in situ was lower than for nulliparous women. Parity appeared not to reduce the risk of tumors with areas of lobular carcinoma in situ.
Adult↗
Risk factors of breast cancer in Burma.
A hospital-based case-control study of breast cancer was undertaken in Rangoon. The age-standardized incidence rate, 25.1 per 100,000 woman-years and the shape of the age-incidence curve show that Rangoon women have an intermediate level of breast cancer risk compared to women of other countries in the world. The analysis is based on 193 cases and 400 controls. Breast cancer risk was found to be directly related to educational attainment. There was an increased risk associated with early menarche and late menopause. The most striking finding was the strong inverse relationship between risk and parity; women who had six or more children have only one-third the breast cancer risk of married women who had less than four children. This association is not confounded by case-control differences in age at birth of first child. The association of breast cancer risk with age at first birth was not striking; only women with a first birth after age 30 were at increased risk. Breast cancer risk was unrelated to lactation. Overall, the epidemiology of breast cancer in Burma is similar to that in most other countries. However, the possibility of an unusual relationship of risk to parity and age at first parturition warrants further exploration.
Adult↗
Reproductive factors and cancers of the breast and genital organs--are the different cancer sites similarly affected?
Relationships between reproductive factors and cancer of the breast and genital organs were investigated in a prospective study of 63,090 Norwegian women. During followup from 1961 through 1980 1565 cases of breast cancer, 422 cases of cancer of the corpus uteri, and 471 cases of ovarian cancer were diagnosed. High parity was associated with low risk of cancer of the breast, corpus uteri, and ovary in analyses with adjustment for age at first birth. Age at first birth and age at last birth were positively associated with risk of breast cancer and inversely associated with endometrial cancer, whereas no clear associations were observed with ovarian cancer. Results suggest that the effect of a pregnancy on cancer risk is mediated, at least in part, by different mechanisms for these three sites. Age at menarche was inversely and age at menopause positively related to risk of breast and endometrial cancer, whereas no association was observed for ovarian cancer. In analyses of squamous cell carcinoma of the cervix uteri, an association with reproductive factors was expected from the known relationships with sexual habits. However, this cannot account for the high risk observed in this study in women with early age at first birth.
Abortion, Spontaneous↗
Age at last birth and its components.
This paper examines the ways in which the behavior of twentieth century cohorts of American women changed simultaneously in the three components of fertility that determine age at last birth--age at first birth, spacing between subsequent births, and parity progression ratios of subsequent births--to produce changes in the timing of the completion of childbearing. It decomposes changes in the mean age at last birth among cohorts and between whites and nonwhites to changes in these three components. To perform these analyses, we developed and applied a method to estimate the distributions and means of ages and last births, birth intervals, and parity progression ratios from age- and parity-specific fertility rates available from vital statistics data. Results show that the cohorts increased and decreased their age at first birth, birth intervals, and parity progression ratios of lower and higher birth orders in almost every possible combination so as to achieve a relatively young age at final birth.
Birth Intervals↗
The influence of reproductive and hormonal factors on thyroid cancer in women.
We conducted a study on 165 women with thyroid cancer and 214 hospital controls in order to investigate the role of reproductive and hormonal factors in the aetiology of thyroid cancer. Late age at menarche (Relative risk (RR) for menarche at greater than or equal to 14 vs less than or equal to 11 = 2.8), menstrual irregularity (RR = 1.7), late age at first birth (RR for first birth at greater than or equal to 28 vs less than or equal to 21 = 2.4) and at last birth (RR for last birth greater than or equal to 30 vs less than 30 = 2.2) significantly increased the risk of the development of thyroid cancer both in premenopausal and postmenopausal women. Parity was, in the present study rather inconsistently related to disease status whereas voluntary abortions and miscarriages were completely unrelated. A non significant increasing risk was observed with age at menopause older than 50, and with the use of oral contraceptives in premenopausal women. The mechanism of action of female hormones on the thyroid gland remains largely obscure, but the observation that age at first and, perhaps, subsequent pregnancies may be relevant points to an interplay of reproductive factors (and, possibly, their hormonal correlates) more complex than previously suggested.
Abortion, Spontaneous↗
The period between birth and first suckling in dairy calves.
The period between birth and first suckling was recorded for 82 dairy calves. 11 per cent of heifers' calves and 46 per cent of cows' calves had not suckled by 6 h after birth. All calves, whether suckling spontaneously or put to the teat at 6 hr, had adequate 48 h total serum immunoglobulin levels.
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Marital and reproductive experience in a community-wide epidemiological study of breast cancer.
The relationship of marital and reproductive experience to human breast cancer was studied using data collected during 1956-1962 by the Department of Biostatistics and Epidemiology at the Roswell Park Memorial Institute in Buffalo, New York. Information of epidemiological interest was obtained from all women with cancers of the reporductive organs in Buffalo, New York, and the adjoining township of Kenmore. For comparison, a probability sample of the same population was selected. During 1965-1967, an International Collaborative Study with similar objectives found a striking positive relationship between age at first birth and breast cancer risk. This finding can be interpreted as either indicating that an event associated with first birth at an early age protects against the development of breast cancer or that the hormonal status of a women both produces a delay in a woman becoming pregnant and increases the risk of developing breast cancer. The analysis of marital and reproductive histories in the Buffalo population study confirms previous reports of an increasing risk of breast cancer with increasing age at first birth. Attempts to distinguish the two interpretations mentioned by analyzing the interval between first marriage and time of birth in addition to age at first birth were not conclusive. This necessitated a similar analysis of data available in a larger series of 1164 breast cancer patients and 1200 non-neoplastic controls hospitalized at the Roswell Park Memorial Institute during 1957-1965. The results do not show an influence of interval between first marriage and first birth but do show an increased risk of breast cancer with increasing age at first birth. The results are thus consistent with a protective effect of an earyl age at first birth. These findings also have a bearing on recent suggestions that ovulatory failure predisposes to development of breast cancer.
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Risk factors for cervical intraepithelial neoplasia.
To evaluate risk factors for cervical intraepithelial neoplasia (CIN), data were collected in a case-control study based on 366 patients (58 with CIN class 1, 70 with CIN class 2, and 238 with CIN class 3) and 323 control subjects with normal cervical smears interviewed on selected days at the same screening clinics where cases had been identified. No relationship emerged between indicators of socioeconomic status (education and social class) and risk of mild/moderate (considered together) and severe dysplasia. A total of 55 (43%) patients with CIN class 1 or 2, 107 (45%) patients with CIN class 3, and 94 (29%) controls were current smokers. The corresponding relative risk (RR) estimates for current versus never smokers were 1.9 (95% confidence interval [CI] 1.2 to 3.0) for patients with CIN class 1 or 2 and 2.5 (95% CI 1.7 to 3.6) for patients with CIN class 3, and the risk increased with the number of cigarettes smoked per day. No relationship was observed between oral contraceptive use, parity, spontaneous or induced abortions and the risk of CIN, but patients tended to report earlier age at first birth than control subjects. Compared with women reporting their first birth before the age of 20 years, the risk estimates were 0.5 and 0.4, respectively, for patients with CIN 1 or 2 and patients with CIN 3 in women reporting first birth at 20 to 24 years of age. The risk estimates were 0.5 and 0.6 for those reporting their first birth at age 25 or later, but the trends in risk were not statistically significant. The number of sexual partners was directly associated with the risk for both histopathologic subgroups. Compared with women reporting no intercourse or their first intercourse after 22 years of age, women with first intercourse before the age 18 had a RR estimate of CIN class 1 or 2 of 2.3 and of CIN class 3 of 2.4, with the trends in risk being statistically significant. This study confirms considerable similarities in the epidemiology of mild/moderate and severe cervical dysplasia. In addition, it suggests consistency between the epidemiology of intraepithelial and invasive cervical neoplasia for risk factors that are likely to act on one of the first stages of the process of carcinogenesis (i.e., indications of sexual habits) but differences for hormone-mediated factors (i.e., reproductive variables or oral contraceptives).
Abortion, Spontaneous↗
Reproductive factors and breast cancer: an overview.
Despite extensive research, there is still uncertainty on the separate effects of parity and age at first birth on breast cancer risk. Thus, information on these variables from formal epidemiological articles published in English since 1970 is reviewed in the present article. Among 26 studies considered, one found no significant association with either variable, seven showed an association between age at first birth but not parity and breast cancer risk, six an association with parity but not age at first birth, and in twelve studies both variables appeared to be independently related with breast cancer risk. Various reasons for these apparent differences can be considered, including heterogeneity between various populations (for instance, the proportion of multiparous women in studies showing no association with parity tended to be higher than in studies finding an inverse relation with parity), criteria for selection of cases and controls, influence of age and other covariates (among which the interval between pregnancies is of particular interest) and, of course, the role of chance. The data reviewed suggest, from an aetiological viewpoint, that both parity and age at first birth have some independent effect on breast carcinogenesis. From a public health viewpoint, however, it appears that the importance of age at first birth is greater, since the trend is linear across subsequent age levels, while the protection of parity seems to be quantitatively relevant only for women with four or five births or more.
Breast Neoplasms↗
Childbearing in marriage and mortality from breast cancer in Norway.
The relationship between childbearing and mortality from breast cancer has been studied in a cohort of 822,593 currently married Norwegian women with information on parity from the Census in 1970 and follow-up till 1985. All age groups of parous women showed significant trends of decreasing mortality rates with increasing parity. Nulliparous women had the same mortality rates as uniparous women in all age groups. In a stratified analysis, for age group 45-74 years, the relative risk for uniparous women was between 3.8 and 4.5 dependent on age at first birth compared to women with 8-9 children, age at first birth before the age of 25 and last birth after the age of 30 years. In a multivariate analysis age and parity were stronger risk factors than age at first birth, while age at last birth was nonsignificant. Among women 45-74 years the population attributable risk of breast cancer mortality due to childbearing was 72%, using women with 8-9 children as the reference group. The use of different definitions of reference group for parity is discussed.
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Education and timing of parenthood among Canadian women: a cohort analysis.
This research examines factors associated with the timing of first birth in Canada, focusing primarily on the role of women's educational attainment. Proportional hazards modelling techniques are applied to data from the 1984 Canadian Fertility Survey (CFS) in order to determine how educational attainment, estimated as close as possible to the date of first birth, influences the timing of first birth and whether the importance of this variable varies according to age cohorts. The results suggest that among a number of variables useful for distinguishing different levels of risk, educational attainment proves to be the most important predictor in the model. Education exerts a substantial positive influence on birth timing for women of all age groups. As expected, moreover, significant cohort differences are also evident, with the greatest to the smallest impact on the risk from the youngest to the oldest cohorts. These clear-cut cohort differences indicate a fundamental change in the effects of education over time, a trend most likely resulting from substantial changes in both the content and social significance of formal schooling during the past few decades.
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Pooled analysis of 3 European case-control studies: I. Reproductive factors and risk of epithelial ovarian cancer.
The role of reproductive factors in the aetiology of epithelial ovarian cancer has been re-assessed in a meta-analysis of 3 hospital-based case-control studies conducted in Europe (i.e. Italy, the United Kingdom and Greece), providing a total dataset of 1,140 cases and 2,724 controls. Multiple logistic regression models were used to obtain relative risk (RR) estimates adjusted for study centre, age, socio-cultural indicators, age at menopause, and oral contraceptive use. The risk decreased with increasing number of births and the trend in risk was significant (chi 2(1) = 7.50, p less than 0.01). In comparison to nulliparous women, those who reported 4 or more births had a 40% reduction in risk of ovarian cancer (RR = 0.6, 95% confidence interval, CI: 0.4-0.8). An RR estimate of 1.4 (95% CI: 1.1-1.7) as found, overall, for age of 35 or more at first birth compared to age of 25 or less at first birth. In each stratum and overall, nulliparous women did not appear to be at increased risk compared to those who delayed birth of their first child until age 35 or more. In each study, as well as in the overall dataset, an inverse association between number of abortions and ovarian cancer risk emerged. Overall, the inverse relationship was highly significant, RR estimates for 1 and 2 or more abortions, as compared to none, being 0.9 (95% CI: 0.8 and 1.1) and 0.7 (95% CI: 0.6-0.9) respectively. The effects of parity, age at first birth and number of abortions emerged consistently in various strata of study centre and age.
Abortion, Spontaneous↗
Risk factors for epithelial ovarian tumours of borderline malignancy.
A case-control study was conducted on 91 cases with histologically-confirmed borderline ovarian tumours and 237 control subjects in hospital for acute non-gynaecological, hormonal or neoplastic disease. Women reporting three or more births, compared to nulliparae, had a relative risk (RR) estimate of 0.6, but this finding was not statistically significant (95% confidence interval (CI): 0.2-1.4). The risk of borderline tumours increased, although not significantly, with later age at first birth: compared to women reporting first birth at age 24 or before, the RRs were 1.3 and 1.7 in those reporting respectively their first birth at age 25-29 and 30 years or more. No significant relationship emerged between borderline ovarian cancer and age at menarche, menopausal status and lifelong menstrual pattern. Cases tended to report a later age at menopause than controls, but the trend in risk was not statistically significant. Nine cases (9.9%) and 68 controls (24.9%) reported oral contraceptive use: compared with never users the multivariate RR for ever users was 0.3, and the risk dropped with duration of use to 0.2 in users for two years or more (chi 2 (1) trend = 12.70, p less than 0.001). This study provides epidemiological evidence of a pathogenetic continuum between borderline and invasive ovarian tumours.
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Breast cancer mortality and the change in fertility risk factors at menopause: a prospective study of 800,000 married Norwegian women.
I examined breast cancer mortality in relation to fertility factors in a cohort of 800,814 married Norwegian women aged 25-74 years at the start of follow-up. Women aged 25-44 years with a first birth after the age of 35 years had a RR = 2.58 compared with women with a first birth before the age of 20 years. For women aged 45-74 years, the corresponding RR was 1.35. On the other hand, the rate differences between women with a late first birth (35+ years) and an early birth (less than 20 years) were similar for women of different ages. Small rate differences were found for premenopausal women between uniparous women and women with 6-7 children, but postmenopausal women with many children had lower rates of breast cancer mortality than uniparous women. For postmenopausal women the rate differences were stable over age categories. This study points toward a change in fertility risk factors at menopause.
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Colorectal cancer in northeast Italy: reproductive, menstrual and female hormone-related factors.
The role of reproductive and menstrual factors and a few medical conditions linked to female hormones in the aetiology of colorectal cancer was investigated in a case-control study conducted in Pordenone province in northeastern Italy, on 89 women with colorectal cancer and 148 controls admitted to hospital for a wide spectrum of acute, non-digestive nor neoplastic disorders. After adjustment for age and social class, parous women, as compared to nulliparous ones, were significantly protected against colorectal cancer (odds ratio, OR = 0.4, [95% confidence interval, CI:0.2-0.8]) and the risk appeared to decrease with successive pregnancies up to five or more (0.2, [0.04-0.6]). Compared to women who had their first birth at age 24 or less, the OR for those who had it at 30 or older was 2.0, but the inverse trend in risk was not significant. However, among parous women only, age at first birth, but not parity, seemed to retain a certain influence. Late age at menopause seemed to decrease colorectal cancer risk (OR for menopause at age greater than or equal to 50 vs. less than 45 = 0.4, [0.2-1.0] chi 2(1) (trend) = 3.66). Conversely, age at last birth, number of abortions, years between marriage and first birth, age at menarche, pattern of menstrual cycle and occurrence of a few medical conditions potentially linked to female hormones were similarly reported by cases and controls. Due to the very limited number of oral contraceptive (OC) users (9 controls but only 1 case), and the lack of oestrogen replacement therapy users, the influence of exogenous female hormones on colorectal cancer could not be analysed meaningfully.
Age Factors↗