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PubMed1973

Influence of pregnancy spacing on outcome of pregnancy.

To assess the significance of the length of time between two pregnancies on the outcome of the second we used information collected by the British Perinatal Mortality Survey of 1958. From questionnaires on the 16,994 singleton births in the first week of March 1958 and the 7,117 singleton stillbirths and neonatal deaths in March, April, and May 1958 we abstracted information on the date and outcome of any preceding pregnancy. The interpregnancy interval was taken as the length of time between this preceding pregnancy and the last menstrual period before the index pregnancy. The most important factors influencing pregnancy spacing were outcome of the preceding delivery, social class, and maternal age. When these variables had been taken into account we found that the length of interpregnancy interval had little effect on stillbirth rates. High neonatal death rates, however, occurred when interpregnancy intervals were less than six months (P <0.005), though longer intervals had no significant effects.

Adolescent↗
PubMed2006

Correlates of hepatitis C virus (HCV) RNA negativity among HCV-seropositive blood donors.

BACKGROUND: Approximately 20 percent of persons infected with hepatitis C virus (HCV) clear viremia. Factors associated with resolution of viremia are not well defined. Implementation of routine nucleic acid testing (NAT) of blood donors has yielded a large data set for analysis of demographic correlates of resolved viremia. STUDY DESIGN AND METHODS: HCV antibody and NAT data, liver enzyme (alanine aminotransferase [ALT]) results, and donor demographic characteristics were compiled for 2,579,290 allogeneic donations given at five large blood centers after NAT implementation in 1999 through December 2001. Donation HCV RNA status was compared between first-time donors categorized by ALT levels, sex, age, race and/or ethnicity, country of birth, level of education, blood center location, and blood group, with chi-square tests and multivariable logistic regression methods. RESULTS: Of 35 confirmed-seropositive repeat donors, 19 (54.3%) tested negative for the presence of HCV RNA; there was no association between RNA status and preseroconversion intervals (p = 0.74). Of 2105 RIBA-positive, first-time donors, 402 (19.1%) tested negative for the presence of HCV RNA by NAT (presumptive resolved infections). There were significant differences in the frequency of RNA negativity among first-time donors categorized by ALT levels and by race and/or ethnicity. ALT levels were more likely to be elevated in RNA-positive, first-time donors (p < 0.0001). Viremia was less likely to resolve in Asian (8.2%) and black non-Hispanic (14.4%) donors than in white non-Hispanic (20.7%), Hispanic (22.1%), and other race and/or ethnicity (22.1%) donors (p = 0.02). No significant associations were found for age, sex, country of origin, level of education, blood type, and donor center location. CONCLUSION: These results confirm that the frequency of HCV RNA negativity among seropositive persons differs by race and/or ethnicity. Follow-up studies of donors with resolved viremia are warranted to further elucidate viral, immunologic, and genetic factors underlying spontaneous viral clearance.

Adult↗
PubMed1988

Preterm or small-for-gestational-age infants. Neurological and behavioural development at the age of 6 years.

In 166 full term, small-for-gestational-age (FT-SGA), 53 preterm, appropriate-for-gestational-age (PT-AGA), 27 PT-SGA and 206 FT-AGA infants a neurological examination at the age of 6 years was carried out. Data were collected on behaviour and school achievement. Major and minor neurological abnormalities were more frequent in the three low birth weight groups, especially in the PT-SGA group. Multivariate analysis showed that the development of major and minor neurological abnormalities was explained by a varying set of risk factors, in which besides prematurity and growth retardation, neonatal neurological condition, social class, neonatal course and interval complications were preponderant. The results suggest a temporal difference in potentially harmful factors: for neurological handicap early in pregnancy, for minor neurological dysfunction (MND) the second half of gestation and the first 2 years of life. No striking behavioural differences were found between the three low birth weight groups and the FT-AGA group; behaviour was related to neonatal and follow-up neurological condition, sex, gestational age and birth weight to a limited extent only. Three (4%) of the preterms entered a special school (already at the age of 6). School achievement was mainly related to the present neurological condition and social class, which underlines the importance of the latter.

Child↗
PubMed1998

Trends in low birth weight: a comparison of two birth cohorts separated by a 15-year interval in Ribeirão Preto, Brazil.

The incidence and some determinants of low birth weight (LBW) were studied in two population-based cohorts of singletons born live to families in Ribeirão Preto, São Paulo State, Brazil. The first cohort comprised infants born between June 1978 and May 1979 (6750 births--population survey) and the second, infants born between May and August 1994 (2990 births--sample survey). The incidence of LBW was 7.2% in 1978-79 and 10.6% in 1994. After adjustment for confounding factors, the following determinants remained significant in 1978-79: female sex, maternal age > or = 35 years, preterm delivery, < four antenatal health visits, maternal smoking, lower level of maternal education, and manual work/unemployment. In 1994, the significant determinants were preterm delivery, maternal smoking and caesarean section. The adjusted percentage population attributable risk (PAR%) fell for the majority of risk factors but increased for caesarean section, preterm birth, multiparity (> or = 5), primiparity and non-cohabitation. The increase in the rate of LBW from 1978-79 to 1994 was higher for families with more qualified occupations, and occurred only for infants delivered at 36-40 weeks' gestational age and weighing 1500-2499 g, i.e. those most likely to be born by elective caesarean section. The caesarean section rate rose from 30.3% in 1978-79 to 51.1% in 1994. The increase in LBW was probably due to iatrogenic practices associated with elective caesarean section.

Adult↗
PubMed2004

Identifying children at high risk for overweight at school entry by weight gain during the first 2 years.

OBJECTIVE: To assess the best anthropometric predictor from birth to 2 years for later overweight, based on recent studies reporting that large infant weight or length gain predicts subsequent overweight. DESIGN: Retrospective cohort study. SETTING: Southern Germany. PARTICIPANTS: German children (n = 4235) aged 5.0 to 6.9 years. MAIN OUTCOME MEASURES: Overweight at school entry was defined according to sex- and age-specific body mass index cutpoints proposed by the International Obesity Task Force. Weight, length, body mass index, and ponderal index differences between birth, 6 months, 12 months, and 24 months of age were compared by receiver operating characteristic curves and predictive values. RESULTS: For all variables, the largest area under the receiver operating characteristic curve was observed with a 24-month follow-up: 0.76 (95% confidence interval [CI], 0.74-0.79) for weight, 0.70 (95% CI, 0.67-0.72) for body mass index, and 0.58 (95% CI, 0.55-0.61) for length gain. The highest Youden index ([sensitivity plus specificity] minus 1) for weight gain from birth to 24 months (41%) was attained for a cutpoint of 9764 g, with a corresponding positive likelihood ratio of 2.39 (95% CI, 2.20-2.59) and positive predictive value of 19% (95% CI, 17%-21%), despite an odds ratio of 5.7 (95% CI, 4.5-7.1). CONCLUSIONS: Weight gain from birth to 24 months was the best overall predictor of later overweight compared with other anthropometric markers and intervals. However, the corresponding poor positive predictive value suggests that only 1 of 5 children with a large weight gain in the first 2 years is overweight at school entry and reflects an insufficient predictability in the general population.

Body Mass Index↗
PubMed2002

Ascertaining women's choice of title during pregnancy and childbirth.

METHODS: A questionnaire was administered to 958 women attending the antenatal clinic at Mercy Hospital for Women, Melbourne, to ascertain their choice of title during pregnancy Midwifery, nursing and medical staff (376 in total) were also invited to respond to a similar questionnaire. RESULTS: The response rate was 73.6% from the survey of all women who were overwhelmingly in favour of being called 'patient' as their first choice (34%), followed by 'other' (20%) and then 'mother' (19%). Virtually all women requesting 'other' wished to be called by their name. Women wishing to be called 'patient' for first choice did not significantly differ from the remainder of the study group in age, gestation, number of previous pregnancies, or number of children. When women from the Family Birth Centre (FBC) were analysed as a separate group, they had a clear preference to be called 'other' (unanimously, by their name) than the general antenatal population (odds ratio (OR) 5.1; 95% confidence interval (CI) 3.1, 8.3; p < 0.0001). The staff survey, with a response rate of 84%, also demonstrated that 'patient' was the most popular first choice for patient title. Medical staff were significantly more likely to choose 'patient' (OR 4.2, 95% CI 2.3, 7.7; p < 0.0001), though the term 'patient' was the preferred choice of all staff.

Adult↗
PubMed1992

Dietary folate and nonneural midline birth defects: no evidence of an association from a case-control study in Western Australia.

In a population-based case-control study of dietary folate and neural tube defects, information was collected by interview and self-administered questionnaires from the mothers of cases with only neural tube defects, from the mothers of matched control infants with defects other than neural tube defects, and from the mothers of matched live-born infants with no birth defects. The association of midline birth defects (excluding neural tube defects) with dietary folate intake in the first 6 weeks of pregnancy was assessed by restricting the analysis to the 59 mothers of infants with midline defects in the first control group and comparing them with their matched control infants in the second control group. The crude and adjusted odds ratios for dietary folate and for folic acid supplementation were close to one, and all confidence intervals embraced unity. These data do not provide evidence of an association between midline birth defects (excluding neural tube defects) and either dietary folate or folic acid supplementation.

Australia↗
PubMed2005

Reproductive and hormonal factors and risk of brain tumors in adult females.

Causes of brain tumors are largely unknown, and there is an urgent need to identify possible risk factors. Several observations point to a possible role of reproductive hormones, but few epidemiologic studies have examined whether reproductive factors, such as age at menarche and parity, are associated with brain tumor risk. We conducted a multi-center case-control study of newly diagnosed glioma (n = 212) and meningioma (n = 151) and frequency-matched controls (n = 436) in women from hospitals in Phoenix, Arizona; Boston, Massachusetts; and Pittsburgh, Pennsylvania between 1994 and 1998. Research nurses interviewed patients regarding potential risk factors for brain tumors, including reproductive factors and hormone use. Unconditional logistic regression analyses were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Risk of glioma increased with older age at menarche [OR = 1.90 (95% CI = 1.09-3.32) for age at menarche > or =14 vs. <12 years]. Early age at first birth was associated with reduced risk of glioma [OR = 0.43 (95% CI = 0.23-0.83) for a first birth before age 20 vs. nulliparity], but there was little effect of number of births. Exogenous hormone use was also associated with a lower risk of glioma, but risks did not vary systematically according to duration of use or age at first use. Possibly owing to low statistical power, there were few noteworthy associations between meningioma and reproductive factors, other than a nonsignificant (p = 0.09) trend of increasing risk with increasing age at menopause. The findings suggest that hormonal exposures early in life may be associated with risk of glioma, but the evidence is inconsistent and does not point clearly to a specific causal or protective hypothesis.

Adolescent↗
PubMed1993

Reproductive factors and risk of brain, colon, and other malignancies in Iowa (United States).

The influence of parity on the risk of cancers of the female breast and reproductive organs is well established. However, non-reproductive sites have received less attention. Mail questionnaire data gathered from incident female cases (169 brain; 332 colon; 260 rectal; 145 kidney; and 169 pancreas cancers), and 821 population-based controls in Iowa (United States) were used to measure the effect of parity and age at first birth on risk of these malignancies. Relative to nulliparous women, ever-parous women were at significantly decreased risk of brain cancer (odds ratio [OR] = 0.44, 95 percent confidence interval [CI] = 0.3-0.7) and of colon cancer (OR = 0.67, CI = 0.5-0.97), after adjustment for age and other risk factors. The OR for the other sites did not differ significantly from 1.0. The lower risk of brain cancer among parous women was similar in younger and older age groups, in patients diagnosed with glioblastoma and astrocytoma, and among ever- and never-smokers. The findings for colon cancer are consistent with observations from other studies. In the context of limited laboratory and clinical evidence implicating hormones in brain neoplasia, these findings may suggest a role for hormonal factors in brain cancer etiology. Hormonal factors deserve more detailed future consideration as risk factors in brain cancer.

Adult↗
PubMed1999

Progressive disease of the atrioventricular conduction axis in an infant of an anti-Ro positive mother.

A child of a mother with maternal anti-Ro and anti-La antibodies presented antenatally with abnormal myocardial function, and was found to have a first degree heart block at birth. The extent of the abnormality in the conduction system progressed, with appearance of left bundle branch block in addition to further prolongation of PR interval. A pacemaker was implanted prophylactically, but patient has remained well, with no further deterioration in her atrioventricular conduction.

Antibodies, Antinuclear↗
PubMed2006

Cancer risk among users of neuroleptic medication: a population-based cohort study.

It has been suggested that neuroleptic medication may decrease cancer risk. We compared cancer risks in a population-based cohort study of 25,264 users (>or=2 prescriptions) of neuroleptic medications in the county of North Jutland, Denmark, during 1989-2002, with that of county residents who did not receive such prescriptions. Statistical analyses were based on age-standardisation and Poisson regression analysis, adjusting for age, calendar period, COPD, liver cirrhosis or alcoholism, use of NSAID, and, for breast cancer, additionally for use of hormone therapy, age at first birth, and number of children. Use of neuroleptic medications was associated with a decreased risk for rectal cancer in both women and men (adjusted IRRs of 0.61 (95% confidence interval, 0.41-0.91) and 0.82 (0.56-1.19), respectively) and for colon cancer in female users (0.78; 0.62-0.98). Some risk reduction was seen for prostate cancer (0.87; 0.69-1.08), but breast cancer risk was close to unity (0.93; 0.74-1.17). Overall, treatment with neuroleptic medications was not related to a reduced risk of cancer, but for cancers of the rectum, colon and prostate there were suggestive decreases in risk.

Adolescent↗
PubMedDate not supplied

Dynamic ultrasound assessment for monitoring of treatment of congenital dislocation of the hip.

Of the 7,827 babies born in Sheffield between March 1989 and August 1991, a total of 114 (1.4%) who had either clinical abnormality of the hip or high-risk factors for congenital dislocation of the hip (CDH) were examined by ultrasound at birth and at regular intervals. Dynamic ultrasound assessment of both hips was done to diagnose instability and to monitor the treatment. Abnormal findings were recorded in 55 babies at the first visit, and 31 of these subsequently required treatment with the Pavlik harness (3.9 per 1,000). Only one case of late CDH has been seen among the babies who were not examined by ultrasound. There were no cases of avascular necrosis in our series. Dynamic ultrasound examination of high-risk infants' hips is a reliable method of screening for CDH. Monitoring of hips treated with the Pavlik harness, by dynamic ultrasound examination, can identify failure to obtain a concentric reduction, and in such cases, splintage can be abandoned in favour of other modes of treatment. It can, therefore, reduce the chances of overtreatment and its associated complications.

Cohort Studies↗
PubMed2001

Injury related infant death: the impact of race and birth weight.

OBJECTIVE: To examine the effect of race and birth weight independent of other sociodemographic factors on injury related infant death using national data. SETTING: Infants born in the United States to mothers who were white (non-Hispanic), African American, Mexican American, and Native American. METHODS: Linked infant birth and death data from the National Center for Health Statistics for 1989-91 were analyzed to calculate unadjusted and adjusted odds ratios for death due to homicide or unintentional injury within the first year of life. In addition to maternal race and birth weight, the risk of death was adjusted for maternal age, prenatal care, maternal education, paternal education, marital status, birth order, interval since last pregnancy, smoking during pregnancy, and alcohol intake during pregnancy. RESULTS: Among 10.7 million births during 1989-91, 821 homicides and 2397 unintentional deaths were reported in infants. Relative to whites, African Americans were at highest risk for homicides (unadjusted and adjusted odds ratios = 3.6 (95% confidence interval = 3.1 to 4.2) and 1.6 (1.3 to 1.9), respectively) and Native Americans at highest risk for unintentional injuries (unadjusted and adjusted odds ratios = 3.8 (3.0 to 4.8) and 2.1 (1.7 to 2.6), respectively). After accounting for other sociodemographic factors, Mexican American infants appeared protected from injury (adjusted odds ratio = 0.7 (0.6 to 1.0) for homicides and 0.7 (0.6 to 0.8) for unintentional injuries). An inverse effect of birth weight was seen-as birth weight decreased, risk of homicides and unintentional injuries increased. After adjustment for the sociodemographic factors, very low birthweight babies were still at substantially increased risk of homicides with an odds ratio of 2.1 (1.4 to 3.1) and unintentional injuries with an odds ratio of 2.9 (2.4 to 3.7). CONCLUSIONS: Using a large national data-set, the effect of race as a risk factor for fatal infant injuries was mostly explained by birth weight and other sociodemographic factors. Preventable risk factors need to be identified for African Americans and Native Americans, in particular. Birth weight is an important independent risk factor; very low birthweight babies should be monitored for both homicide and unintentional injury.

Accidents↗
PubMed1987

Methyl tertiary butyl ether inhalation in rats: a single generation reproduction study.

Male rats exposed to target concentrations of methyl tertiary butyl ether (MtBE) at 300, 1300 and 3400 ppm for 6 hours/day, 5 days/week for 12 weeks were mated to female rats exposed to the same concentrations for a 3-week period. Exposures continued through the mating period and the females continued exposures during gestation and from days 5-21 lactation of the litters (F1a) (no exposures days 0-4 lactation). A second litter (F1b) was produced under the same mating and post mating exposure regimen. No adverse effect of treatment was observed with the adult animals (Fo) throughout the in-life portion of the study. The only remarkable finding was an increased incidence of dilated renal pelves in the low- and high-dose females (Fo). All gonad weights, male accessory reproductive organ weights, organ-to-body weight ratios and reproductive organ histopathology were unremarkable upon comparison of treated animals with air sham controls. The mating indices and fertility indices in exposed animals for both mating intervals (F1a and F1b) were not significantly different from controls. Pregnancy rates were comparable between treated and control females for the first litter interval (F1a) but were slightly lower (not statistically significant) than control on the second litter interval (F1b). Treated animal mean gestation length and the mean number of pups at birth were not statistically different from controls. The pup viability indices at birth were comparable for control and treated groups for the F1a generation, but the mid- and high-dose groups displayed a slight statistically significant decrease in the F1b generation; the decrease was not considered to be biologically significant and perhaps not treatment-related. Litter survival indices were comparable between control and treated groups for both litter intervals. Pups of mid- and high-dose females had slightly lower (not statistically significant) mean weights at days 14 and 21 of lactation but this was not considered treatment-related. The most frequent post-mortem observation for pups sacrificed at day 21 of lactation was dilated renal pelves. This did not appear to be related to treatment. It is concluded that MtBE inhalation in rats results in little adverse reproductive toxicity as shown in a two litter, one generation reproduction assay in rats.

Administration, Inhalation↗
PubMed1999

Lack of association between duration of breast-feeding or introduction of cow's milk and development of islet autoimmunity.

The hypothesis that early exposure to cow's milk or lack of breast-feeding predisposes to type 1 diabetes remains controversial. We aimed to determine prospectively the relationship of, first, duration of exclusive breast-feeding and total duration of breast-feeding, and second, introduction of cow's milk protein as infant formula, cow's milk, or dairy products, to the development of islet antibodies in early life. Some 317 children with a first-degree relative with type 1 diabetes were followed prospectively from birth for 29 months (4-73). Mothers kept a home diary and answered infant feeding questionnaires at 6-month intervals. No systematic feeding advice was given. Insulin autoantibodies (normal range <5.5%), anti-GAD antibodies (<5.0 U), and anti-IA2 antibodies (<3.0 U) were measured at 6-month intervals. Cox proportional hazards model of survival analysis detected no significant difference between children who did not develop islet antibodies (225 of 317 [71%]), children with one islet antibody raised once (52 of 317 [16.4%]), children with one antibody raised repeatedly (18 of 317 [5.7%]), or children with two or more antibodies raised (22 of 317 [6.9%]), in terms of duration of exclusive breast-feeding, total duration of breast-feeding, or introduction of cow's milk-based infant formulas, cow's milk, or dairy products (relative risk: 0.91-1.09). Four of the children with two or more islet antibodies developed type 1 diabetes. We conclude that there is no prospective association between duration of breast-feeding or introduction of cow's milk and the development of islet autoimmunity in high-risk children.

Aging↗
PubMed1982

Effects of intrauterine growth and gestational age upon infants' early psychomotor development in Brazil.

In a sample of 245 Brazilian infants, the effects of intrauterine growth and gestational age upon psychomotor development were studied through ages 4 to 18 mo. Gestational age was more important than intrauterine growth in determining psychomotor development in the first 18 mo. of life. Intrauterine growth had a significant but smaller and more stable effect than gestational age upon psychomotor development at all ages. Maternal parity, interval between the birth of the child studied and the next oldest sibling, 5-min. Apgar score, and socioeconomic status were also relevant to psychomotor development at these early ages.

Birth Weight↗
PubMed2003

Timing of pregnancy and the risk of epithelial ovarian cancer.

Recent animal studies suggest that progestagen-induced apoptosis of transformed ovarian surface epithelial cells may underlie the observed protective effect of pregnancy on the risk of ovarian cancer. Assuming that increasing numbers of cells are transformed with advancing age, we postulated that the benefits of pregnancy would be greater for older than younger women and tested this hypothesis in a population-based case-control study. We conducted interviews with 620 parous women, ages 18-79 years, with histologically confirmed incident ovarian cancer and 723 parous controls of the same age. Detailed information was collected on reproductive history, as well as hormonal exposures, smoking, medical history, and other factors. We estimated the relative risk of ovarian cancer associated with births at different ages through multiple logistic regression models. After adjusting for parity, older age at first and last births, and shorter time since last birth were all associated with significantly reduced risks of ovarian cancer. Age at first birth and time since last birth were not associated with ovarian cancer when adjusted for each other, whereas age at last birth remained strongly protective [odds ratio (OR), 0.57; 95% confidence interval (CI), 0.36-0.90] among women >35 years versus women less than 25 years. The effect was independent of total parity (per year of age among women with one birth: OR, 0.93; 95%CI, 0.87-1.01; among women with four or more births: OR, 0.96; 95%CI, 0.90-1.02). Our finding that ovarian cancer risk is reduced by pregnancy at older ages is further evidence that pregnancy confers a benefit beyond anovulation and is consistent with the theory that ovarian surface epithelial cell apoptosis induced by pregnancy hormones may be the underlying protective mechanism.

Adolescent↗
PubMed2006

Captive breeding of the white rhinoceros, Ceratotherium simum, and the Cape buffalo, Syncerus caffer.

Breeding records of 40 white rhinoceros and 155 Cape buffalo were analysed. Three rhinoceros cows bred in captivity, themselves conceived for the first time at 84, 87 and 95 months of age, respectively. Rhinoceros cows breed throughout the year. There is no evidence of a relationship between calving interval and month of birth. Calving intervals were normally distributed about the mean of 34 months and there were no significant differences between bulls, cows or sex of calf. There was no difference in the sex ratio of calves born to young cows nor older cows. The male:female ratio of the calves was 1:1. Younger cows did not have shorter birth intervals. Although captive Cape buffaloes breed throughout the year, there is a preponderance of births in midsummer. There was some evidence that larger cows produce heavier calves and that season of birth may influence birth weight. Male calves weighed 41.20 +/- 0.68 kg vs 39.00 +/- 0.73 kg (range 24-60 kg) for female calves but this difference was not significant. Calving intervals were normally distributed about the mean of 395 days and the male:female ratio of the calves was 1:1.2.

Age Factors↗