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Risk factors for juvenile onset recurrent respiratory papillomatosis.

BACKGROUND: Children born to condylomatous mothers are at risk for developing juvenile onset recurrent respiratory papillomatosis (JORRP). We inquired whether the triad of vaginal delivery, being firstborn and maternal age of <20 years are also risk factors for JORRP. METHODS: Data for JORRP and adult onset recurrent respiratory papillomatosis cases were obtained from questionnaires answered by patients or their parents for the Recurrent Respiratory Papillomatosis Foundation. The observed numbers of cesarean births, first order births and births to mothers <20 years old were compared with expected numbers for the same variables, which were computed by distributing the cases by year of birth and then applying to them national annual statistics for the year of birth. In addition observed and expected numbers of first order births to mothers <20 years old were compared with corresponding numbers in mothers 20 years old or older. RESULTS: In JORRP cases the relationships be tween observed and expected numbers of cases were as follows: cesarean births, 4.6-fold less; first order births, 1.6-fold greater; maternal age <20 years old, 2.6-fold greater. All these differences were statistically highly significant. The observed parity effect was mediated to a large extent by maternal age. In contrast there were no significant differences between observed and expected numbers of adult onset recurrent respiratory papillomatosis cases with respect to any of the above variables. CONCLUSIONS: Young primiparous mothers with condylomas are at a high risk for transmission of JORRP to their infants. The option of cesarean delivery should be discussed with a mother who has condyloma at the time of delivery.

Adult↗

Relationship between parity and clinical and biological features in patients with systemic sclerosis.

OBJECTIVE: To assess the influence of parity on the clinical and biological features of systemic sclerosis (SSc). METHODS: We recorded the following clinical and biological data of 100 consecutive women with SSc: age, disease duration before diagnosis, cutaneous extension of sclerosis according to LeRoy's classification, pulmonary involvement, and antinuclear antibodies. We compared these features to the number and sex of children who were born before SSc onset. Date of birth of the first children was systematically recorded. RESULTS: Patients with limited SSc had more children before SSc onset than patients with diffuse SSc (2.4 +/- 1.8 vs 1.7 +/- 1.5; p < 0.05). The interval between first birth and SSc onset was shorter for patients with limited SSc than for patients with diffuse SSc (11.0 +/- 9.9 vs 23.5 +/- 14.5 yrs; p < 0.01). Patients with pulmonary fibrosis had more children than patients without pulmonary fibrosis (2.5 +/- 1.9 vs 2.0 +/- 1.6; p < 0.05). Age at first birth was significantly higher when the child was a girl than a boy (26.8 +/- 7.5 vs 22.9 +/- 5.3 yrs; p < 0.05). The interval between the first birth and SSc onset was shorter when the child was a girl than a boy (16.2 +/- 9.6 vs 25.4 +/- 13.4 yrs; p < 0.05). CONCLUSION: Pregnancy related microchimerism could be preferentially associated with limited SSc and pulmonary fibrosis. Microchimerism may be facilitated in cases in which the fetus is female.

Adult↗

Early anthropometric measures and reproductive factors as predictors of body mass index and obesity among older women.

OBJECTIVE: To examine whether early anthropometric measures and reproductive factors were associated with body mass index (BMI), overweight, and obesity. DESIGN: Cross-sectional, observational study. SUBJECTS: In all, 18 109 healthy women who participated in the Swedish Mammography Cohort aged 49-83 y. MEASUREMENTS: Early anthropometric (birthweight and body shape at age 10 y) and reproductive (age at menarche, age at the birth of the first child, and parity) variables were our predictors and current BMI, overweight (BMI 25-29.99 kg/m(2)), and obesity (BMI > or =30 kg/m(2)) were our outcomes. RESULTS: In multivariate-adjusted polytomous logistic regression analysis, risk of overweight and obesity increased with increasing body shape at age 10 y and decreased with increasing age at menarche and age at first birth (P for trend <0.0001). A U-shaped relation with birthweight was observed. In our tests for effect modification of the relation with overweight/obesity (ow/ob; BMI > or =25 kg/m(2)), we detected significant interactions between body shape at 10 y and age (P<0.0001); body shape at 10 y and physical activity (P<0.0001); age at first birth and smoking (P=0.02); and parity and physical activity (P=0.004). The increased risk of ow/ob among women who reported a larger childhood body shape was reduced as women moved from the lowest to highest quartile of physical activity in adulthood. Likewise, the increasing risk of ow/ob among women with greater parity was reduced with increased physical activity. CONCLUSION: Early anthropometric measures and reproductive factors are significantly associated with BMI, overweight, and obesity among older women. The effects of childhood body weight, age at first birth, and parity may be modified by adult lifestyle choices, as well as age.

Age Factors↗

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↗

First cesarean birth and subsequent fertility.

OBJECTIVE: To determine whether cesarean delivery is independently associated with later subfertility. DESIGN: Retrospective cohort study. SETTING: Maternity records kept for Scotland, 1980-1999. PATIENT(S): The study included 109,991 women who had first births between 1980 and 1984, excluding multiple or preterm births and perinatal deaths. INTERVENTION(S): Exposures studied were spontaneous vaginal birth, operative vaginal birth, planned cesarean delivery for breach presentation, planned cesarean delivery for other indications, and emergency cesarean delivery. MAIN OUTCOME MEASURE(S): The relative risk of not having a second pregnancy over the following 15 years, the interpregnancy interval, and the number of spontaneous early pregnancy losses between the first and second birth. RESULT(S): Women who delivered by planned cesarean section for breech presentation had an increased risk of not having a second birth compared with women whose first birth was a spontaneous vertex delivery (relative risk [RR]: 1.21, 95% confidence interval [CI]: 1.14 to 1.29). However, after adjustment for maternal and obstetric characteristics, there was no longer a strong association (adjusted RR: 1.07, 95% CI: 1.00 to 1.15). Operative vaginal delivery (forceps and vacuum extraction) and all types of cesarean delivery were associated with longer interpregnancy intervals. There was no relationship between mode of delivery and the number of spontaneous early pregnancy losses between the first and second birth. CONCLUSION(S): It is unlikely that delivering by cesarean section in a first pregnancy decreases a woman's likelihood of having a second viable pregnancy.

Abortion, Spontaneous↗

Effects on pregnancy outcome of changing partner between first two births: prospective population study.

OBJECTIVE: To compare the effects on pregnancy outcomes of changing partner between the first two births with having the same partner for both births. DESIGN: Prospective population study. SETTING: Norway. PARTICIPANTS: 31 683 women who changed partner between their first two births and 456 458 women with the same partner for both births. RESULTS: After adjustment for maternal age and education, interval between births, and decade of birth, the risk of adverse pregnancy outcomes for the second birth was higher for women who changed partner between the first two births compared with those who had the same partner for both births: preterm birth (< 37 weeks; relative risk 2.0, 95% confidence interval 1.9 to 2.1), low birth weight (< 2500 g; 2.5, 2.3 to 2.6), and infant mortality (1.8, 1.6 to 2.1). For the first birth, the risk of these adverse pregnancy outcomes was only slightly higher for mothers who subsequently had a second birth with another partner. CONCLUSION: Women who change partner between their first two births are at an increased risk of delivering a preterm, low birthweight baby with an increased risk of infant mortality compared with women who have the same partner for both births.

Birth Order↗

Parity and the risk of pancreatic cancer: a nested case-control study.

Smoking is the only generally accepted risk factor for pancreatic cancer. Reproductive history has in recent studies been associated with pancreatic cancer, but with contradictory results. In order to evaluate a possible association between age at first birth and the number of births and pancreatic cancer, we conducted a nested case-control study by linking 2 Swedish nationwide registries: the Cancer Registry and The Fertility Registry. Among women born between 1925 and 1970, 1,015 patients with pancreatic cancer were compared with 5,073 age-matched controls. No association between pancreatic cancer and number of births was found. Age at first birth was inversely related with the risk of pancreatic cancer (OR per 5 years = 0.90; 95% CI 0.83-0.97; p = 0.01), an association mainly confined to women with a diagnosis of pancreatic cancer before 50 years of age (OR per 5 years = 0.85; 95% CI 0.73-1.00; p = 0.04). This trend remained after adjustment for parity, but was less prominent. Young age at first birth and high parity in Sweden are, however, associated with an increased frequency of smoking, thus at least some of the increased risk for pancreatic cancer in women with young age at first birth is likely to be explained by smoking acting as a confounder.

Adolescent↗

Does a traumatic birth experience have an impact on future reproduction?

OBJECTIVE: To investigate whether women's experiences of their first birth affects future reproduction. DESIGN: Prospective cohort study. SETTING: South Hospital, Stockholm, Sweden. POPULATION: Six hundred and seventeen women who gave birth to their first child 1989-1992. METHODS: A global measure of women's experiences of their first birth, assessed two months postpartum, was available from a birth centre trial, together with information on a range of background variables. This information was linked to the Swedish Medical Birth Register, which included information on the number of subsequent births during the following 8-10 years. MAIN OUTCOME MEASURES: Number of births (0 or > or =1) following the first birth. RESULTS: Women with a negative experience of their first birth had fewer subsequent children and a longer interval to the second baby (RR 1.7, 95% CI 1.3-2.3). Being 35 years and older (RR 2.6, 95% CI 1.6-3.7), or single (RR 2.6, 95% CI 1.7-3.9) was also associated with subsequent infertility. CONCLUSION: A negative birth experience was associated with subsequent infertility, and women's experiences should therefore be considered seriously in the provision of maternity care.

Adult↗

Delayed childbearing by education level in the United States, 1969-1994.

OBJECTIVES: Advanced maternal age at first birth, but not at subsequent births, may have detrimental health implications for both mother and child, such as a poor birth outcome and an increased risk of maternal breast cancer. However, positive outcomes may also result such as an improvement in economic measures and offspring's performance on cognitive tests. Research has indicated that women increasingly are delaying their first births beyond the early twenties, but the recent trends in socioeconomic disparity in age at first birth, and the implications for public health, have not been well described. METHOD: This study used national birth certificate data for 1969-1994 to examine age at first birth by maternal education level. Current Population Survey data were also used to examine changes over time in age and educational distribution among women of childbearing age. RESULTS: Age at first birth increased during the time period. Median age at first birth increased from 21.3 to 24.4 between 1969 and 1994, and the proportion of first-time mothers who were age 30 or older increased from 4.1% to 21.2%. Age at first birth increased rapidly among women with 12 or more years of education; nearly half (45.5%) of college graduate women who had their first birth in 1994 were age 30 or older, compared with 10.2% in 1969. However, little change was observed among women with fewer than 12 years of education; among those with 9-11 years of education, only 2.5% of first births in 1994 occurred at age 30 or older. CONCLUSIONS: The trend toward postponed childbearing has occurred primarily among women with at least a high school education. Health services use, such as infertility treatment and cesarean section, may increase as a result of delayed childbearing among higher educated women. Future examinations of the association between maternal age at first birth and health outcomes may need to take greater account of socioeconomic differentials.

Adolescent↗

Phenotypic resemblance in birth weight between first cousins.

Birth weight data on 72,078 liveborn singletons representing 5981 paternal and 7036 maternal single first cousin kinships were assembled by computerized record linkage from all marriages and livebirths registered in Hawaii during a 38-year period from 1942 to 1979. These kinships represented incrosses of five selected racial groups. An additional 15,536 livebirths from 1134 paternal and 1679 maternal cousin kinships provided data on outcrossing between racial groups, and 28,952 livebirths from 2379 paternal and 3538 maternal cousin kinships provided data on both incrossing and outcrossing within kinships. Phenotypic resemblance in birth weight between single first cousins was estimated by the covariance and intraclass correlation. The covariances between maternal cousins were generally much higher than those between paternal cousins. Neither heterogeneity in maternal genotypes nor heterogeneity in newborn genotypes had any significant effect on the resemblance between first cousins. These observations have led to the conclusion that maternal influences of non-hereditary origin are of primary importance in determining birth weight in man. The observed non-zero correlation in several groups of paternal cousins was explained in part by the process of preferential selection of mates within and among racial groups by brothers, and probably by the similarity in some maternal characteristics associated with age at childbearing among their wives.

Asian People↗

Cumulative first live birth after elective cryopreservation of all embryos due to ovarian hyperresponsiveness.

OBJECTIVE: To estimate cumulative chance for first live birth after elective pronuclear stage cryopreservation of all embryos due to ovarian hyperresponsiveness. DESIGN: Retrospective analysis with longitudinal follow-up. SETTING: Academic hospital. PATIENT(S): Thirty subjects with elective cryopreservation of all embryos due to ovarian hyperresponsiveness. INTERVENTION(S): Elective cryopreservation of all embryos at the pronuclear stage (n = 30) and subsequent cryopreserved-thawed ET (n = 51). MAIN OUTCOME MEASURE(S): Cumulative chance for first live birth. RESULT(S): Cumulative chance for first live birth was 77% when analyzed by intention to treat and 82% by treatment with ET. Nearly 40% of live births were multiple. CONCLUSION(S): Cumulative first live birth increased with repetitive ET after elective pronuclear stage cryopreservation of all embryos due to ovarian hyperresponsiveness. Multiple births, however, were frequent. In the context of initial ET attempts in young women, transfer of no more than two cryopreserved-thawed embryos is advised.

Adult↗

Accuracy and reliability of maternal recall of infant birth weight among older women.

PURPOSE: We assessed the accuracy and reliability of maternal recall of infant birth weight 35 to 70 years after delivery. METHODS: A total of 120 well functioning women (mean age 80 years; 45% Black) reported the birth weight for each live birth and then provided documentation of birth weights (n = 22) or reported birth weights a second time (n = 98). RESULTS: Agreement between recalled and documented birth weights was high for first births (ICC = 0.96) but moderate for subsequent births (ICC = 0.59). Maternal recall was highly reliable for first births (r = 0.95) and subsequent births (r = 0.87), and reliability remained high when considered separately by race, education, income, and age. CONCLUSION: Women report accurate and reliable infant birth-weight data an average of 57 years after delivery, and recall is particularly precise for first births.

Age Factors↗

Subsequent childbearing among teenage mothers: the determinants of a closely spaced second birth.

Data from the National Longitudinal Survey of Youth reveal that approximately one-quarter of teenage mothers have a second child within 24 months of their first birth. The prevalence of closely spaced second births is greatest (31%) among young women whose first birth occurred prior to age 17. Teenage mothers' characteristics before the first birth (such as race or ethnicity and parents' level of education) and at the time of the first birth (such as years of schooling completed and whether their first birth was wanted) influence whether they have a rapid second birth. For example, those with more educated parents are less likely than others to have had a closely spaced second birth. In addition, young mothers who obtain additional schooling in the period after their first birth are less likely to have a closely spaced second birth, while those who marry are more likely to have a rapid second birth.

Adolescent↗

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↗

A case-control study of reproductive factors and risk of lymphomas and myelomas.

The relationship between reproductive factors and risk of lymphoid neoplasms was investigated in a hospital-based case-control study conducted in northern Italy on women with histologically confirmed incident Hodgkin's disease (HD) (n = 68), non-Hodgkin's lymphomas (NHL) (n = 180) and multiple myelomas (MM) (n = 71), and 448 controls admitted to hospitals, for acute, non-neoplastic, non-immunological and non-gynecological conditions. The odds ratios (OR) of HD were 0.6 for > or = 3 pregnancies compared to nulligravidae, and 0.5 for > or = 1 total (spontaneous and induced) abortions compared to women reporting no abortions. Compared to nulliparae, the OR of HD was 0.9 in parae and 0.3 in those with first birth when aged < 20 years. The OR of NHL and MM in relation to number of pregnancies, abortions and births, age at first birth and time since last birth were close to unity. Results were similar for the relation between reproductive factors and HD in women younger than 50 years. The OR of NHL was above unity (OR 2.2, 95% CI 1.0 to 4.9) for women aged < 50 years reporting one or more pregnancies as compared to nulliparae, and for women reporting the last birth since less than 10 years (OR 2.9, 95% CI 1.1 to 7.4). Early events in pregnancy, including changes in immunological status, rather than exposure to female sex hormones are likely mechanisms for the protection of pregnancies and abortions on the risk of HD.

Abortion, Induced↗

Reproductive factors and breast cancer risk according to joint estrogen and progesterone receptor status: a meta-analysis of epidemiological studies.

INTRODUCTION: Although reproductive factors have been known for decades to be associated with breast cancer risk, it is unclear to what extent these associations differ by estrogen and progesterone receptor (ER/PR) status. This report presents the first meta-analysis of results from epidemiological studies that have investigated parity, age at first birth, breastfeeding, and age at menarche in relation to ER+PR+ and ER-PR- cancer risk. MATERIALS AND METHODS: We calculated summary relative risks (RRs) and corresponding 95% confidence intervals (CIs) using a fixed effects model. RESULTS: Each birth reduced the risk of ER+PR+ cancer by 11% (RR per birth = 0.89, 95% CI = 0.84-0.94), and women who were in the highest age at first birth category had, on average, 27% higher risk of ER+PR+ cancer compared with women who were in the youngest age at first birth category (RR = 1.27, 95% CI = 1.07-1.50). Neither parity nor age at first birth was associated with the risk of ER-PR- cancer (RR per birth = 0.99, 95% CI = 0.94-1.05; RR of oldest versus youngest age at first birth category = 1.01, 95% CI = 0.85-1.20). Breastfeeding and late age at menarche decreased the risk of both receptor subtypes of breast cancer. The protective effect of late age at menarche was statistically significantly greater for ER+PR+ than ER-PR- cancer (RR = 0.72 for ER+PR+ cancer; RR = 0.84 for ER-PR- cancer, p for homogeneity = 0.006). CONCLUSION: Our findings suggest that breastfeeding (and age at menarche) may act through different hormonal mechanisms than do parity and age at first birth.

Age Factors↗

Parity and cancers of the gall bladder and the extrahepatic bile ducts.

The relation of parity and age at first birth to cancers of the gall bladder and extrahepatic bile ducts in women was studied using a database generated by linking 2 Swedish national registries; the Fertility Registry and the Cancer Registry. Among women born between 1925 and 1960, 257 cases of gall-bladder cancer recorded in the Cancer Registry between 1958 and 1984 were compared with 1,285 controls, age-matched to cases in a 5:1 ratio. In addition, 60 cases of extrahepatic-bile-duct cancer were matched with 300 controls. There was a positive association between number of live births and risk of gall-bladder cancer (p 0.06), but simultaneous consideration of parity and age at first birth revealed a more complex picture. Parity increases the risk for cancer of the gall bladder when the first birth occurs before the age of about 25 years, whereas parity associated with first birth after the age of about 30 years is associated with reduced risk for the disease. Thus, among parous women there is a highly significant inverse association of age at first birth with risk for gall-bladder cancer after adjustment for number of live births. Variable levels of pregnancy estrogens according to maternal age and variable effects of parity on non-pregnancy estrogens by age, may explain the observed pattern. The results on extrahepatic-bile-duct cancer, parity and age at first birth did not indicate the existence of an association in either direction.

Adult↗