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PubMed1999

Variability of breast sucking, associated milk transfer and the duration of lactational amenorrhoea.

Quantitative relationships between physical parameters of sucking, milk transfer and the duration of amenorrhoea were examined in normal mother-baby pairs under exclusive breastfeeding. Sucking pressures were recorded twice on the second and once on the fifth month after birth, during complete breastfeeding episodes, by means of a catheter attached to the nipple and connected to a pressure transducer, the signals of which were analysed by computer. Babies were weighed before and after each sucking episode to estimate milk transfer. In the first nursing episode after noon, 2-month-old babies sucked from 140 to > 800 times during 4-15 min from the first breast, obtaining from 20 to > 100 g milk. The physical parameters of sucking and milk transfer exhibited high inter-individual but low intra-individual variabilities. There were significant differences in the physical parameters of sucking and milk transfer efficiency between first and second breast and between the second and fifth months after birth. Milk transfer efficiency was inversely correlated with time occupied by non-sucking pauses > or = 1.5 s, and was directly correlated with mean intersuck intervals in the first breast and with duration of the sucking episode, number of sucks, mean pressure and area under the pressure curve in the second breast. There was no correlation between the physical parameters of sucking and duration of lactational amenorrhoea (n = 62). However, significantly more mothers had amenorrhoea lasting > 180 days among those whose babies spent a longer proportion of the nursing episode in non-sucking pauses > or = 1.5 s. This finding indicates that sensory stimulation of the nipple produced during a nursing episode by stimuli other than sucking itself may have an important role in sustaining lactational amenorrhoea. It is concluded that nursing episodes have a complex structure that allows the development of a breastfeeding phenotype in each mother-baby pair, exhibiting important inter-individual variability. The present analysis does not support the contention that this source of variability accounts for the variability in the duration of lactational amenorrhoea.

Amenorrhea↗
PubMed2004

Development of lung function in early life: influence of birth weight in infants of nonsmokers.

This study aimed to compare lung growth and development during the first year of life in healthy term infants of low or appropriate birth weight for gestation. Paired measurements of forced expiratory volume in 0.4 second, FVC, and forced expiratory flow when 75% of FVC has been exhaled were obtained, using the raised volume technique, at about 7 weeks and 9 months of age in 80 infants (32 low and 48 appropriate birth weight for gestation) of white, nonsmoking mothers. Forced flows and volumes increased with growth. Longitudinal trends in results were compared between the two groups, using random effects modeling and adjusted for potential confounding factors. After adjustment for sex, age, and length, forced expiratory volume was significantly reduced by an average (95% confidence interval) of 9% (2 to 16%) in low birth weight compared with appropriate birth weight for gestation infants throughout the first year of life, with a similar trend in forced expiratory flow (8% [-2 to 17%]) and FVC (4% [-3 to 11%]). These findings suggest that lung function is reduced in low birth weight for gestation infants born to nonsmoking white mothers and that this is independent of somatic growth during infancy.

Birth Weight↗
PubMed2005

Birth outcomes and prenatal exposure to ozone, carbon monoxide, and particulate matter: results from the Children's Health Study.

Exposures to ambient air pollutants have been associated with adverse birth outcomes. We investigated the effects of air pollutants on birth weight mediated by reduced fetal growth among term infants who were born in California during 1975-1987 and who participated in the Children's Health Study. Birth certificates provided maternal reproductive history and residence location at birth. Sociodemographic factors and maternal smoking during pregnancy were collected by questionnaire. Monthly average air pollutant levels were interpolated from monitors to the ZIP code of maternal residence at childbirth. Results from linear mixed-effects regression models showed that a 12-ppb increase in 24-hr ozone averaged over the entire pregnancy was associated with 47.2 g lower birth weight [95% confidence interval (CI), 27.4-67.0 g], and this association was most robust for exposures during the second and third trimesters. A 1.4-ppm difference in first-trimester carbon monoxide exposure was associated with 21.7 g lower birth weight (95% CI, 1.1-42.3 g) and 20% increased risk of intrauterine growth retardation (95% CI, 1.0-1.4). First-trimester CO and third-trimester O3 exposures were associated with 20% increased risk of intrauterine growth retardation. A 20-microg/m3 difference in levels of particulate matter < or = 10 microm in aerodynamic diameter (PM10) during the third trimester was associated with a 21.7-g lower birth weight (95% CI, 1.1-42.2 g), but this association was reduced and not significant after adjusting for O3. In summary, O3 exposure during the second and third trimesters and CO exposure during the first trimester were associated with reduced birth weight.

Adult↗
PubMed1989

Pregnancy characteristics and outcomes of Cambodian refugees.

This study describes the perinatal characteristics of Cambodian refugees in Massachusetts. Data were abstracted from the records of 452 consecutive pregnancies among Cambodian women and 110 low-income Whites receiving obstetrical services at the same clinic and hospital in Lowell, Massachusetts. Pregnancies of Cambodian women were marked by a higher proportion of older mothers, grand multiparas, previous adverse birth outcomes, and short interpregnancy intervals. We identified maternal anemia (29.9 percent with hemoglobin less than 110 g/L) and inadequate utilization of prenatal care (32.3 percent with first visit in the 3rd trimester) as possible risk factors for the Cambodians. The prevalence of primary cesarean birth was only 6.3 percent in the Cambodians, compared to 15.6 percent in the comparison group, largely due to the infrequent occurrence of prolonged labor among multiparas. Despite the prominence of several risk factors for adverse birth outcomes in this population, major pregnancy complications were less common and the prevalence of low birthweight (6.4 percent) was close to the state average. Logistic regression analysis of risk factors for low birthweight identified young maternal age and short stature as the strongest factors operative in this community. Many of our findings are consistent with a strong cultural emphasis on managing the size of the baby to avoid a difficult labor and delivery.

Adult↗
PubMedDate not supplied

The pace of repeated childbearing among young American mothers.

Women who first give birth at ages 16 and younger are more likely to bear a second child within the next two years (26 percent) than are women who have their first child at ages 17-18 (20 percent) or at ages 19-22 (22 percent). However, there are important racial and ethnic differences in the likelihood of rapid repeated childbearing: Among whites, age at first birth has little effect on the proportions who have a second birth quickly; but among blacks, it has a significant inverse effect, with younger women more likely than older women to have a second child quickly. At nearly all ages at first birth, Hispanic mothers are more likely than either whites or blacks to have a second birth soon after the first. While the youngest black mothers (those 16 and under) are more likely than the youngest whites to have a rapid second birth, the oldest white mothers (those 19-22) are more likely than the oldest blacks. Socioeconomic background (represented by level of parental education), marital status at first birth and wantedness of the first birth also affect the pace of repeated childbearing. Compared with young mothers whose own mothers are high school graduates, those whose mothers are dropouts are more likely to have a second child within two years. Teenage mothers who are married at their first birth appear somewhat more likely than their unmarried counterparts to bear another child quickly; and mothers who wanted their first child at the time of conception are generally more likely to do so than are mothers whose first births were unwanted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2002

Metoclopramide for nausea and vomiting of pregnancy: a prospective multicenter international study.

Nausea and vomiting are very common during pregnancy, mainly throughout the first trimester. Metoclopramide is a dopamine receptor blocking drug that is commonly used to treat nausea and vomiting. The aim of this prospective study was to investigate the effect on the fetus of intrauterine exposure to metoclopramide. One hundred and seventy-five women who received metoclopramide and consulted 6 teratogen information centers in Israel, Italy, Brazil, and Canada were studied. Women exposed to metoclopramide were paired for age, smoking and alcohol consumption habits with women exposed to nonteratogens. Women in the metoclopramide group had a significantly higher rate of premature births (8.1%) as compared with the control group (2.4%) ( p = 0.02, relative risk = 3.37, 95% confidence interval 1.12-10.12). Rates of major malformations in the metoclopramide group (4.4%) did not differ from controls (4.8%) ( p = 0.84, relative risk = 0.91, 95% confidence interval 0.34-2.45). According to our findings, metoclopramide use during the first trimester of pregnancy does not appear to be associated with an increased risk of malformations, spontaneous abortions, or decreased birth weight, however, larger studies are needed to confirm these observations.

Adolescent↗
PubMed2006

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↗
PubMed2002

Birth size, growth, and blood pressure between the ages of 7 and 26 years: failure to support the fetal origins hypothesis.

The "fetal origins hypothesis" asserts that birth weight is inversely related to later blood pressure. Data from a cohort of 891 infants born in Dunedin, New Zealand, in 1972-1973 whose blood pressure was measured at 2-year intervals from age 7 years to age 15 years and at ages 18 and 26 years were used to test this hypothesis. Three regression models based on standardized scores for weight and height were used. The first showed that at any of the ages at which the cohort was assessed, an increase in birth weight of one z score (one standard deviation) was commensurate with a decrease of 0.29 mmHg (95% confidence interval: -0.17, 0.76) in blood pressure. The second model showed that a one-z-score increase in weight between birth and a subsequent age was associated with an increase in systolic blood pressure of 0.96 mmHg (95% confidence interval: 0.53, 1.38). This estimate applied to all ages. The third model showed that the effect of an interaction between birth weight and later weight was not significant; thus, there was no evidence to suggest that children with a low birth weight who became overweight or obese had extra high blood pressure. Similar results were obtained for height. These results fail to support the fetal origins hypothesis.

Adolescent↗
PubMed1987

Congenital dislocation of the knee: a description of four cases in rural Kenya.

Four infants with congenital dislocation of the knee seen in rural Kenya are described. All presented in the first 5 days after birth. Three were treated with a posterior plaster slab, renewed at 2 weekly intervals for 6 weeks. One infant was treated by passive exercises, taught to the mother. At the last follow-up at 6 weeks, all the infants had almost normal knee flexion and hyperextension of the joint was no longer possible. The need for early treatment, which can be quite simple and is highly effective, is emphasized.

Casts, Surgical↗
PubMed1995

Proportion of breast cancer cases in the United States explained by well-established risk factors.

BACKGROUND: Few estimates of the fraction of cases of breast cancer attributable to recognized risk factors have been published. All estimates are based on selected groups, making their generalizability to the U.S. population uncertain. PURPOSE: Our goal was to estimate the fraction of breast cancer cases in the United States attributable to well-established risk factors (i.e., later age at first birth, nulliparity, higher family income, and first-degree family history of breast cancer), using data from the first National Health and Nutrition Examination Survey (NHANES I) Epidemiologic Follow-up Study (NHEFS), the survey and follow-up of a probability sample of the U.S. population. METHODS: From a cohort of 7508 female participants surveyed in the early 1970s, and followed up between 1982 and 1984 and again in 1987, 193 breast cancer cases were accrued for study. We calculated incidence rates, relative risks (RRs), and population attributable risks (PARs) for breast cancer risk factors and extended our results to the U.S. female population by using sample weights from the NHANES I survey. RESULTS: Our PAR estimates suggest that later age at first birth and nulliparity accounted for a large fraction of U.S. breast cancer cases, 29.5% (95% confidence interval [CI] = 5.6%-53.3%); higher income contributed 18.9% (95% CI = -4.3% to 42.1%), and family history of breast cancer accounted for 9.1% (95% CI = 3.0%-15.2%). Taken together, these well-established risk factors accounted for approximately 47% (95% CI = 17%-77%) of breast cancer cases in the NHEFS cohort and about 41% (95% CI = 2%-80%) in the U.S. population. CONCLUSIONS: The RRs for most of these risk factors were modest, but their prevalence as a group was high, leading to estimates that suggest that a substantial proportion of breast cancer cases in the United States are explained by well-established risk factors. IMPLICATIONS: Elucidation of the determinants underlying recognized factors and study of other factors that may confer risk or protection are needed in efforts to advance understanding of breast cancer etiology and to aid in devising strategies for prevention.

Adult↗
PubMed1997

Condom use and first-time urinary tract infection.

We evaluated the effects of condom use, lubricated condom use, and spermicide use on risk of acquiring first urinary tract infection in a case-control study of sexually active college women ages 18-39 years. Cases (N = 144) were women with first urinary tract infection that was confirmed by culture recruited at the student health service; controls (N = 286) were women without a history of urinary tract infection who were randomly sampled from all women enrolled at the university. Participants completed a self-administered questionnaire regarding type and frequency of condom use during the previous 2 weeks. Condoms and spermicides usually were used in combination with each other or oral contraceptives. After adjusting for frequency of vaginal intercourse, using unlubricated condoms compared with using no birth control method strongly increased the risk of first urinary tract infection (odds ratio = 29.1; 95% confidence interval = 3.1-1,335). Using a lubricated condom (with or without spermicide in the lubricant) or a spermicidal cream or gel with an unlubricated condom was associated with two- to eightfold risk of first urinary tract infection. Unlubricated condom use was strongly associated with risk of first urinary tract infection, but this effect was largely neutralized by using a spermicidal cream or gel with the unlubricated condom or by using a lubricated condom.

Adolescent↗
PubMed2002

Oral contraceptive use and mammographic patterns.

High-risk mammographic patterns represent an increased risk of contracting breast cancer and may be used as a surrogate endpoint for the disease. We examined the relationship between oral contraceptive (OC) use and mammographic patterns among 3218 Norwegian women, aged 40-56 years. Information on ever OC use, duration, and age of first OC use and other epidemiological data were obtained through questionnaires. The mammograms were categorized into five groups. Patterns I-III were combined into a low-risk group and patterns IV and V into a high-risk group. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression and adjusted for age, menopausal status, parity, age at first birth, and body mass index. Women who reported ever having used OCs were 20% more likely (OR 1.27, 95% CI 1.0-1.6) to have high-risk mammographic patterns compared with those reporting never having used OCs. There was no dose response between different measures of OC use and high-risk patterns. Among nulliparous women, ever OC users were four times more likely (OR 4.65, 95% CI 2.1-10.3) to have high-risk patterns compared with never users. Our findings suggest that, especially among nulliparous women, ever OC use may exert its effect on breast cancer risk through changes in breast tissue, which can be observed on a mammogram.

Adult↗
PubMed1994

Patterns of fantasy play engagement across the transition to becoming a sibling.

Patterns of spontaneous dyadic fantasy play among 30 3- to 5-year-old first-born children who were becoming siblings were evaluated at two pre- and three post-birth intervals for its length, thematic content and social quality. Children who interacted more positively with their sibling played longer, engaged in fantasy play that was thematically relevant to becoming a sibling and had more positive interactions with best friends than low-sibling acceptance children. High-sibling acceptance children also experienced a suppression in fantasy immediately following their sibling's birth; thus, a temporary disruption in fantasy play may indicate adaptive coping.

Adaptation, Psychological↗
PubMed2001

Modification of BRCA1- and BRCA2-associated breast cancer risk by AIB1 genotype and reproductive history.

Women who have inherited a germ-line mutation in the BRCA1 or BRCA2 (BRCA1/2) genes have a greatly increased risk of developing breast cancer compared with the general population. However, there is also substantial interindividual variability in the occurrence of breast cancer among BRCA1/2 mutation carriers. We hypothesize that genes involved in endocrine signaling may modify the BRCA1/2-associated age-specific breast cancer penetrance. We studied the effect of alleles at the AIB1 gene using a matched case-control sample of 448 women with germ-line BRCA1/2 mutations. We found that these women were at significantly higher breast cancer risk if they carried alleles with at least 28 or 29 polyglutamine repeats at AIB1, compared with women who carried alleles with fewer polyglutamine repeats [odds ratio (OR), 1.59; 95% confidence interval (CI), 1.03-2.47 and OR, 2.85; 95% CI, 1.64-4.96, respectively]. Late age at first live birth and nulliparity have been associated with increased breast cancer risk. We observed increases in BRCA1/2-associated breast cancer risk in women who were either nulliparous or had their first live birth after age 30 (OR, 3.06; 95% CI, 1.52-6.16). Women were at significantly increased risk if they were nulliparous or had a late age at first live birth and had AIB1 alleles no shorter than 28 or 29 or more AIB1 polyglutamine repeats (OR, 4.62; 95% CI, 2.02-10.56 and OR, 6.97; 95% CI, 1.71-28.43, respectively) than women with none of these risk factors. Our results support the hypothesis that pathways involving endocrine signaling, as measured through AIB1 genotype and reproductive history, may have a substantial effect on BRCA1/2-associated breast cancer risk.

Adult↗
PubMed1990

Proposals for epidemiological surveys of helminthoses aimed at the improvement of livestock production in the tropics.

As the major contagious epidemics in the tropics are today more or less under control, the most important diseases of livestock are due to parasitic infections. Precise knowledge concerning the biology of parasites and their seasonality is a prerequisite for any control strategy. Therefore, epidemiological investigations into the effect of helminths on ruminant livestock production must include I. A vertical section through the age dependent helminthic burden of a representative number of animals of a given population, i.e. the sampling of faeces at regular intervals during the first 18 months of life. II. Investigations into the horizontal development of the helminthic situation, whether soil-transmitted and/or vector-transmitted. a. The seasonal fluctuation of egg excretion from gastrointestinal nematodes. b. The seasonal incidence of nematode larvae on pastures. c. The seasonal survival time of nematodes larvae on pastures. III. The seasonal fluctuation of vector snails and their incidence of infection with trematode larvae. For the economic evaluation of control measures it is necessary that the following parameters should be recorded: The age dependent mortality rate, the development of the average body weight, the birth/slaughter weight, the age at first calving and the calving intervals.

Age Factors↗