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PubMed1995

Age at menarche and breast cancer risk in nulliparous women.

Early age at menarche is a known risk factor for breast cancer, some inconsistency in the literature not withstanding. Relative risks for an early menarcheal onset as compared to a late onset vary from 1.0 to 1.9. To avoid (residual) confounding by parity-related factors a case-control study was conducted among nulliparous women. 135 cases and 540 controls were selected from two population-based screening projects for breast cancer in The Netherlands. Four controls were matched to each case for year of birth, for screening-centre, and for number of screening examinations. Women with a menarcheal age of 10 or 11 years showed a 2.2 times (95% confidence interval: 1.2-4.0) higher risk for breast cancer compared to women who had their first menstrual period at 12 years of age or older.

Adolescent↗

PubMed1994

Exogenous hormones, reproductive history, and colon cancer (Seattle, Washington, USA).

The associations between exogenous hormones, reproductive history, and colon cancer were investigated in a case-control study among women aged 30-62 years. The study was conducted in the Seattle, Washington (USA) metropolitan area between 1985 and 1989 and included 193 incident cases of colon cancer and 194 controls. There was little overall association between colon cancer and oral contraceptive use, parity, age at first birth, hysterectomy or oophorectomy status, or age at menopause. Use of noncontraceptive hormones at or after age 40, most likely hormone replacement therapy (HRT), was associated with decreased risk of colon cancer (adjusted odds ratio [OR] = 0.60, 95 percent confidence interval [CI] = 0.35-1.01), particularly among women with more than five years of use (OR = 0.47, 95 percent CI = 0.24-0.91). While results from previous studies have not been consistent, any protective effect of HRT against colon cancer would be important given the continuing debate over its potential risks and benefits.

Adult↗

PubMed1996

The role of reproductive and menstrual factors in cancer of the breast before and after menopause.

The aim of the study was to elucidate the role of reproductive and menstrual factors in the aetiology of breast cancer, overall and by menopausal status. A cooperative case-control study was conducted between 1991 and 1994 in six different Italian areas (including three from the centre and the south). The study included 2569 histologically confirmed incident cases of breast cancer (median age 55 years, range 23-78 years) and 2588 control women (median age 56 years, range 20-79 years) admitted to the same hospitals for a variety of acute conditions unrelated to the hypotheses in study. A trend of increasing risk with increasing age at menopause (odds ratio (OR) for age at menopause > or = 53 versus < 45 years = 1.8; 95% confidence interval (CI) = 1.4-2.2). High parity reduced cancer risk (OR for > or = 4 versus 1 birth = 0.7; 95% CI = 0.5-0.9). Overall, nulliparous women showed a 20% lower risk than uniparous ones (OR = 0.8; 95% CI = 0.7-1.0). Late age at first birth (or pregnancy) had an independent adverse effect (OR for first birth at > or = 32 versus < 20 years = 1.7; 95% CI = 1.3-2.1) both before and after menopause. An approximately 2-fold elevation of breast cancer risk was evident up to 10 years after the last birth. No trend in risk was evident for induced abortions (OR = 1.2 for 1 and 1.1 for > or = 2 induced abortions versus 0). Other examined menstrual and reproductive characteristics did not seem important. Multiparity, early age at first birth and early age at menopause were therefore the most important determinants of breast cancer risk. The effects of the timing of births was significantly heterogeneous in pre- and postmenopausal women because of the transient adverse effect of such events, evident only in premenopausal women.

Adult↗

PubMedDate not supplied

Dose minimization study of oxytocin in early labor in sows: uterine activity and fetal outcome.

Two hundred sows were randomly assigned to intramuscularly receive 0.9% NaCl (group 1) or oxytocin 0.083, 0.11 or 0.17 IU/kg (groups 2, 3 and 4, respectively) immediately after the expulsion of the first piglet. The overall duration of labor was decreased in a dose-dependent relationship. Time interval between piglets was decreased approximately 5 min in groups 3 and 4 while sows in these groups exhibited approximately 10-20 contractions x 10 births more than controls (P<0.005). Duration and intensity of uterine contractions also showed a positive dose-response relationship. As an indicative of fetal distress, approximately 2.5 times more meconium-stained piglets were born to sows receiving the higher doses of oxytocin, but in the lowest dose significantly decreased. Oxytocin 0.083 IU/kg significant decreased the mortality rate of piglets [OR 0.49 (95%CI, 0.26-0.92)]. In conclusion, we recommend the intramuscular administration of the lowest possible dose of oxytocin, which still decreases the duration of labor in sows.

Animals↗

PubMed2000

The reality of unsafe abortion in a rural community in South India.

Though the law in India has permitted medical termination of pregnancy on broad legal grounds for over two decades, unsafe abortions carried out by unqualified providers show no signs of decreasing. A community-based study was undertaken in rural South India to determine the prevalence of induced abortion, women's reasons for seeking abortion, who was providing abortions and whether the procedures were safe or unsafe. A cross-sectional study design was used that included focus group discussions with 88 women and a quantitative survey with 195 married women who had a birth interval of two or more years since their last pregnancy. There was a high prevalence of induced abortion (28 per cent) among the study population, mainly among women who were not using contraception. Most abortions were carried out in the first trimester of pregnancy and unqualified practitioners performed 65 per cent of terminations. The preference for illegal, untrained providers in a country where abortion is legally available exposes the ambiguity in the status of abortion and how inadequacies in legal service provision have served to promote and sustain unsafe providers and practices. An integrated approach to family planning and reproductive health which includes abortion is imperative if the reproductive health status of Indian women is to be improved. The poor utilisation of existing government facilities suggests the need for improving the quality of services, expansion of abortion facilities and the introduction of safer methods of abortion. To do this, a re-examination and re-framing of aspects of the 1971 abortion law is needed.

Abortion, Induced↗

PubMed2003

Non-obstetric surgery during gestation: risk factors for lower birthweight.

OBJECTIVE: To assess the risk for preterm birth and low birthweight for women undergoing non-obstetric surgery during gestation. DESIGN: Two perinatal tertiary care centres. POPULATION: Women undergoing non-obstetric surgery during gestation between January 1989 and June 1999. MATERIALS AND METHODS: A chart review was carried out. Cervical cerclages, procedures carried out under local anaesthesia or intravenous sedation, or carried out in combination with Caesarean delivery were excluded. MAIN OUTCOME MEASURES: Preterm birth (<37 weeks), birthweight. RESULTS: A total of 116 of 69 800 women (0.2%) underwent non-obstetric surgery, with 96 women delivering under our care. Procedures were more commonly carried out in the second trimester (53%), versus the first (23%) or third trimester (24%). Surgery in the second trimester resulted in the lowest rate of preterm birth (11%). The overall preterm birth rate was 21% (20/96), with 13 out of 20 (65%) occurring between 35 and 37 weeks. The mean interval from surgery to delivery was 18.7 weeks. Rates of preterm birth were similar for either intra- versus extra-abdominal procedures, or general versus regional anaesthetic. Use of a general anaesthetic was associated with a significant decrease in birthweight (3053 vs 3515 g, P = 0.01) despite similar gestational ages at delivery (37.6 vs 38.6 weeks, P = 0.08). Multiple linear regression controlled for gestational age showed that general anaesthesia, longer surgery duration, and intra-abdominal procedures were all significant independent risk factors for lower birthweight. CONCLUSION: While non-obstetric surgery appears to be relatively safe during gestation, general anaesthesia, longer surgery time, and intra-abdominal procedures are associated with lower birthweights.

Anesthesia, General↗

PubMed2002

Comparison of two gentamicin dosing schedules in very low birth weight infants.

BACKGROUND: Several dosing schedules for gentamicin have been recommended for very low birth weight infants during the early neonatal period. We conducted a prospective, randomized, controlled trial to compare efficacy and pharmacokinetics of two dosing schedules in preterm neonates. METHODS: Fifty-eight very low birth weight infants (600 to 1500 g), prescribed gentamicin for treatment of suspected sepsis during the first week after birth, were randomized to receive either the new dosing schedule [every 48 h (q48h)] or the existing dosing schedule [every 24 h (q24h)]. Infants in the "q48h" group received gentamicin at 5.0 or 4.5 mg/kg/dose q48h depending on weight group and infants in the "q24h" group received 2.5 or 3.0 mg/kg/dose q24h. Peak and trough serum gentamicin concentrations were monitored. RESULTS: Peak serum gentamicin concentrations after the first dose were significantly higher in the q48h infants than in q24h infants (8.19 +/- 1.3 vs. 6.04 +/- 2.2, P = 0.00001). Ninety percent of all peak serum gentamicin concentrations in the q48h group were in a higher therapeutic range of 6 to 12 microg/ml as compared with 55% of q24h (P = 0.0005). None of the q48h infants had subtherapeutic serum gentamicin concentrations immediately after administration of the first dose as compared with 36% of q24h infants (P < 0.005). Eighteen percent of q24h infants continued to have peak serum gentamicin concentrations in subtherapeutic range even after the third dose at 48 h. Trough serum gentamicin concentrations were significantly lower in q48h infants than in q24h infants. However, 9 of 30 (30%) q48h infants had trough serum gentamicin concentrations of < or = 0.5 microg/ml before the dose at 48 h and 4 of the 9 had serum gentamicin concentrations of <1 microg/ml at 24 h after the first dose. CONCLUSIONS: The q48h dosing schedule of gentamicin given to very low birth weight infants during the first week after birth achieved therapeutic serum gentamicin concentrations and potentially higher peak to MIC ratios for microorganisms in all infants. However, nearly one-third of the infants had extremely low serum gentamicin concentrations before the next dose. A dosing interval of 36 h might be optimal for bactericidal activity and avoid bacterial growth during prolonged periods of extremely low serum gentamicin concentrations; this dosing interval warrants study.

Anti-Bacterial Agents↗

PubMed2004

Socioeconomic risk factors for breast cancer: distinguishing individual- and community-level effects.

BACKGROUND: Women are at higher risk of breast cancer if they have higher socioeconomic status (SES) or live in higher SES or urban communities. We examined whether women living in such communities remained at greater risk of breast cancer after controlling for individual education and other known individual-level risk factors. METHODS: Data were from a population-based, breast cancer case-control study conducted in Wisconsin from 1988 to 1995 (n = 14,667). Data on community SES and urbanicity come from the 1990 census, measured at the census tract and zip code levels. We evaluated relationships between individual- and community-level variables and breast cancer risk using multilevel logistic regression models with random community intercepts. RESULTS: After controlling for individual education and other individual-level risk factors (age, mammography use, family history of breast cancer, parity, age at first birth, alcohol intake, body mass index, hormone replacement use, oral contraceptive use, and menopausal status), women living in the highest SES communities had greater odds of having breast cancer than women living in the lowest SES communities (1.20; 95% confidence interval = 1.05-1.37). Similarly, the odds were greater for women in urban versus rural communities (1.17; 1.06-1.28). CONCLUSIONS: Community SES and urbanicity are apparently not simply proxies for individual SES. Future research should examine why living in such communities itself is associated with greater risk of breast cancer.

Adult↗

PubMed1994

Well health care and the sudden infant death syndrome.

The aim of this study was to examine whether poor attendance at routine antenatal and postnatal 'well child' health services was associated with a higher risk of sudden infant death syndrome (SIDS, or cot death). A nationwide case-control study of SIDS in New Zealand enrolled 485 postneonatal deaths due to SIDS and 1800 control infants who were selected randomly. The risk for SIDS was found to be higher for infants whose mothers attended their first antenatal check later than 3 months into the pregnancy, made fewer antenatal visits, and did not go to antenatal education classes. However, this increased risk was largely explained by high parity, maternal smoking, the mother not being married, mother being < 20 years old at the birth of her first child, and delivery during the winter months. Infants not attending a 6 week postnatal check had an almost three-fold increased risk of SIDS compared with those who did attend (odds ratio [OR] 2.86; 95% confidence interval [CI] 1.93, 4.24). Similarly, infants not attending well child clinics were at increased risk of SIDS (OR 2.75; 95% CI 2.09, 3.62). These differences persisted when adjusted for likely confounders. This study demonstrates that infants who miss child health nurse clinics are those most at risk for SIDS and are those who warrant increased surveillance.

Case-Control Studies↗

PubMed1993

The position of the tongue during rooting reflexes elicited in newborn infants before the first suckle.

A common breast-feeding problem is when the infant "places its tongue in its palate" and has difficulties in attaching to its mother's nipple. The aim of this study was to document the position of the tongue in the mouth cavity during rooting reflexes elicited in newborn infants before the first suckle. Eleven healthy, full-term infants were videotaped 101 +/- 31 min after birth during an evoked distinct rooting reflex before the first suckle. The videotaped rooting reflex was analyzed in detail concerning the degree of turning of the head, mouth opening and position of the tongue, in pictures that were "frozen" at specific intervals. "Licking movements" preceded and followed the rooting reflex in the alert infants. In 10 of the 11 infants the tongue was placed in the bottom of the mouth cavity during a distinct rooting reflex (p = < 0.05). It is suggested that forcing the infant to the breast might abolish the rooting reflex and disturb placement of the tongue. A healthy infant should have the opportunity of showing hunger and optimal reflexes, and attach to its mother's nipple by itself.

Breast Feeding↗

PubMed1993

Effects of prematurity and intrauterine growth on respiratory health and lung function in childhood.

OBJECTIVE: To determine whether birth weight and gestational age are associated with respiratory illness and lung function in children aged 5-11 years. DESIGN: Cross sectional analysis of parent reported birth weight, gestational age, and respiratory symptoms; parental smoking and social conditions; forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory rates between 25% and 75% and 75% and 85% (FEF25-75 and FEF75-85), and height. SETTING: Primary schools in England and Scotland in 1990. SUBJECTS: 5573 children aged 5-11 (63.3% of eligible children) had respiratory symptoms analysed and 2036 children (67.1% of eligible children) had lung function measured. MAIN OUTCOME MEASURES: Symptoms of asthma, bronchitis, occasional and frequent wheeze, cough first thing in the morning, and cough at any other time and lung function. RESULTS: Birth weight adjusted for gestational age was significantly associated with all lung function measurements, except FEF25-75. The association remained for FVC (b = 0.475, 95% confidence interval 0.181 to 0.769) and FEV1 (b = 0.502, 0.204 to 0.800) after adjustment for gestational age, parental smoking, and social factors. FEF75-85 was the only lung function related to gestational age. Respiratory symptoms, especially wheeze most days (adjusted odds ratio 0.9, 0.84 to 0.97) were significantly associated with prematurity. Every extra week of gestation reduced the risk of severe wheeze by about 10%. CONCLUSIONS: Lung function is affected mainly by intrauterine environment while respiratory illness, especially wheezing, in childhood is related to prematurity.

Birth Weight↗

PubMed1975

Sequential patterns of circulating LH and FSH in female sheep during the early postnatal period: effect of gonadectomy.

To determine the basis for the marked daily variability in circulating luteinizing hormone (LH) in the female lamb shortly after birth and to determine whether circulating follicle-stimulating hormone (FSH) exhibits similar variability during this period of life, serum levels of both gonadotropins were monitored frequently (20-min intervals) over a 3- or 6-hr period each week for the first 9 weeks of life. Similar measurements of circulating LH and FSH were made in lambs ovariectomized at 2 weeks of age to assess whether the ovary influences the secretion of these gonadotropins. Pulsatile release of LH, but not FSH, was observed in both groups of lambs. Although mean concentrations of circulating FSH in intact female lambs were similar to basal levels of the cyclic adult, mean concentrations of serum LH were much higher. Because of the discontinuous release of LH in intact lambs after 4-5 weeks of age, patterns of LH were often indistinguishable from those of the long-term ovariectomized adult. At 9 weeks of age the frequency of episodic LH release in intact lambs ranged from 0.33-1.1 pulses/hr. Castration at 2 weeks of age produced a concomitant, but delayed, rise in mean serum LH and FSH beginning 4-5 weeks later. By 9 weeks of age serum LH, but not FSH, had attained levels comparable to those of the castrated adult, and the mean frequency of LH release (about hourly) was similar for both groups. The results indicate that by 9 weeks of age the ovary of the lamb influences the secretion of LH and FSH. Because in the 9-week-old intact female lamb episodic release of LH occurs producing high (castrate) levels of this gonadotropin while circulating concentrations of FSH remain stable and within basal levels of the adult cycling female, it is suggested that acute concomitant release of LH and FSH does not occur at this age and that separate negative feedback loops for the control of LH and FSH secretion may exist during early postnatal life.

Aging↗

PubMed1989

Biochemical timing of peri-intraventricular hemorrhage assessed by perinatal CPK-BB isoenzyme measurements.

Precise diagnosis of peri-intraventricular hemorrhage (PIVH) requires brain real-time ultrasound imaging procedure (US). However, maximal diagnostic efficiency of US lies between day 4 and 14 since fresh blood may initially appear sonolucent. Because of this supposed interval required for clot formation to become visible on US, serum CPK-BB estimations were performed in the first 60 hours of life to determine precise biochemical timing of PIVH. A group of 50 preterm infants less than 1500 g birth weight (1120 +/- 320 g) and 34 weeks gestation (30 +/- 3.7 weeks) was studied. Serial CPK-BB measurements were performed in serum immediately after birth (T0), then serially at time T1 (6-10 h), T2 (20-30 h), T3 (40-60 h). The incidence of PIVH diagnosed on the third day of life was 30%. Total CPK-BB values at T0 in infants who developed PIVH were significantly higher than those of patients without cerebral bleeding (70.8 +/- 30.5 vs 20.9 +/- 10.7 U/l) (p less than 0.05). The same statistically significant results were not observed analysing the CPK-BB values at T1, T2 and T3. These results suggest that most pathological conditions responsible for enzyme release occur in the pre- or perinatal period.

Brain↗

PubMed1977

Sex of listener and hormonal correlates of auditory thresholds.

The present study investigates changes in auditory threshold during 4-6 week intervals for men, women on birth control pills, and normal cycling women not on birth control pills. Thresholds were determined at 250, 500, 1,000, 2,000, 4,000, 6,000, 8,000 Hz. Normal cycling females had significantly lower thresholds during first half of the menstrual cycle than during the second half. Females on birth control pills showed significantly and consistently lower thresholds than other listeners at several frequencies. Explanations for the phenomena are proposed.

Adolescent↗

PubMed2004

Genetic correlations among production, body size, udder, and productive life traits over time in Holsteins.

Genetic correlations among milk, fat, and protein yields; body size composite (BSC); udder composite (UDC); and productive life (PL) in Holsteins were investigated over time. The data set contained 25,280 records of cows born in Wisconsin between 1979 and 1993. The multiple trait random regression (MT-RR) animal model included registration status, herd-year, age group, and stage of lactation as fixed effects; additive genetic effects with random regressions (RR) on year of birth using the first-order Legendre polynomial; and residual effects. Heterogeneous residual variances were considered in the model. Estimates of variance components and genetic correlations among traits from MT-RR were compared with those estimated with a multiple trait interval (MT-I) model, which assumed that every 3-yr interval was a separate trait and included the same effects as in the MT-RR model except for the RR. Genetic correlations estimated with MT-RR and MT-I models over time among all traits were compared with correlations among breeding values predicted with the single trait (ST) model without RR. Correlations among breeding values predicted with MT-RR, ST, and MT models were also calculated. Additive genetic and residual variances for all traits except PL increased over time; those for PL were constant. As a result, heritability estimates had no significant changes during the 15 yr. Genetic correlations of PL with milk, fat, protein, and BSC declined to zero or negative; those with UDC remained positive. Correlations among breeding values predicted with ST, MT, and MT-RR models were relatively high for all traits except PL. Genetic correlations between PL and other traits varied over time, with some correlations changing sign. For accurate indirect prediction of PL from other traits, the genetic correlations among the traits need to be re-estimated periodically.

Animals↗

PubMedDate not supplied

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↗

PubMed1993

The effects of diarrhoea on food intake in piglets weaned on the day of birth.

Large White x Landrace piglets (23 animals) weaned on the first day after birth were reared individually in a thermoneutral environment on a liquid diet having a macronutrient content similar to that of sow's milk. They were offered the diet from sucking bottles nine times a day at 2-h intervals. According to the appearance of the faeces the animals were divided into two groups: diarrhoeic piglets and clinically healthy animals. Their consumption of the diet, energy (GE) and macronutrients was assessed from the 3rd to the 10th day after birth; a total of 514 and 441 measurements were made in diarrhoeic piglets and healthy controls, respectively. With advancing age the intake of the diet by animals of the two groups changed in the same way as we described in previous studies. In diarrhoeic piglets, however, both the actual and the relative food intake, expressed in relation to live body mass and metabolic mass, was lower on days 3, 5 and 6 than in the healthy controls. In the period of the earlier described transient decrease in food consumption this difference disappeared and was observed again in piglets 9 (actual diet intake) and 10 (both actual and relative diet intake) days of age. Impairment of their enteral functions manifested by decreased ingestion of the liquid diet, GE, N substances and lipids was also observed after ontogenic shift of regulatory mechanisms of food intake control to a higher integrative level.

Animals↗

PubMed1996

Specific IgE and IgG4 immune responses to tetanus and diphtheria toxoid in atopic and nonatopic children during the first two years of life.

BACKGROUND: In order to investigate, whether atopic and nonatopic children show differences in their specific IgE and IgG4 immune responses to tetanus (T) and diphtheria (D) antigens, we studied 538 children who had been followed from birth on and from whom records had been kept of all immunizations. METHODS: The prevalence of eczema and asthma was registered at regular intervals and the cumulative incidence of symptoms was determined at 24 months of age. Total serum IgE and specific IgE to a panel of nine allergens as well as T- and D-specific IgE and IgG4 were determined from the 24-months blood samples. RESULTS: Our results show that both atopic and nonatopic children are capable of mounting high levels of toxoid-specific IgE antibody responses. Children with cord blood IgE > 0.9 kU/1, serum IgE 10-100 kU/1 and > 100 kU/1 and at least one sensitization to an allergen at 24 months of age have significantly higher IgE responses to T and D (p < 0.001). In contrast, specific IgG4 antibody concentrations to T and D were not significantly different in children with elevated total IgE levels at 24 months. No differences in subgroups of children with or without early symptoms of atopy were observed. CONCLUSIONS: Our data indicate that IgE responses to toxoids such as T and D are not limited to infants with clinical manifestations of atopy in the first 2 years of life but are related to immunological parameters of atopy.

Asthma↗