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PubMed1995

Breast cancer in Swedish women before age 50: evidence of a dual effect of completed pregnancy.

We set out to detect a transient increase in risk of breast cancer following childbirth, the existence of which has been postulated, but for which empirical evidence is contradictory. Breast cancers and births occurring among the cohort of Swedish women born after 1939 were linked, yielding 3,439 cases and 25,140 age-matched controls with at least two children. Within three years of their last childbirth, women had an estimated rate of breast cancer of 1.21 (95 percent confidence interval [CI] = 1.02-1.44) times that of women whose last birth was 10 or more years earlier, after adjustment for parity and age at first birth. Further analyses suggested that this effect reflected, in part, a small transient increase in breast cancer risk that lasts for about three years following completed pregnancy. The effect of age at first birth on breast cancer risk appears to be confounded by time since last birth; the parity-adjusted rate ratio for having a first birth at age 35 years or more compared with under 20 years is reduced from 1.72 (CI = 1.14-2.58) to 1.36 (CI = 0.88-2.09) on additional adjustment for time since last birth. A transient increase in breast cancer risk after childbirth appears thus appears to account for part of the effect of age at first birth on breast cancer risk.

Adult↗
PubMed2002

Risk of breast cancer in women exposed to diethylstilbestrol in utero: prelimiinary results (United States).

BACKGROUND: A synthetic estrogen, diethylstilbestrol (DES), was widely prescribed to pregnant women during the 1950s and 1960s but was later discovered to be associated with an increased risk of clear-cell carcinoma of the vagina and cervix in female offspring. DES has not been linked to other cancers in female offspring, but studies of other prenatal factors such as twin gestation and pre-eclampsia have indicated that in-utero estrogen levels may influence breast cancer risk. We evaluated the relation of in-utero DES exposure to the risk of adult breast cancer. METHODS: A cohort of 4821 exposed women and 2095 unexposed women, most of whom were first identified in the mid-1970s, were followed by mailed questionnaires for an average of 19 years. Reported cancer outcomes were validated by medical record review. Breast cancer incidence in DES-exposed daughters was compared with cancer incidence in unexposed daughters with use of Poisson regression analysis, adjusting for year of birth, age at menarche, age at first birth, and number of births. FINDINGS: The rate ratio for incidence of invasive breast cancer in exposed versus unexposed women was 1.4 (95% confidence interval (CI) = 0.7-2.6). DES exposure was not associated with an increased risk of breast cancer in women under 40 years, but among women aged 40 and older the rate ratio was 2.5 (95% CI = 1.0-6.3). The rate ratio for the association of DES exposure with estrogen receptor-positive tumors was 1.9 (95% CI = 0.8-4.5). INTERPRETATION: While not statistically significant, the overall 40% excess risk, arising exclusively from the subset of estrogen receptor-positive cases, raises a concern calling for continued investigation.

Adult↗
PubMed1997

Offspring birth weights after maternal intrauterine undernutrition: a comparison within sibships.

The authors examined the effects of maternal intrauterine undernutrition on offspring birth weights in a cohort of women born between August 1944 and April 1946 in Amsterdam, The Netherlands. This period included the Dutch Hunger Winter, a war-induced famine. Undernutrition was defined separately for each trimester of pregnancy as an average supply of less than 1,000 calories per day from government food rations. For maximum control of potential maternal confounding factors related to offspring birth weight, the authors performed a within-family analysis, including 437 families with two siblings and 107 families with three siblings born between 1960 and 1985. As in other studies of the famine, maternal birth weight itself was decreased after third trimester intrauterine exposure but not after first trimester exposure. The expected increase in offspring birth weights with increasing birth order was not seen after maternal intrauterine exposure in the first trimester of pregnancy. In this group, second born infants weighed, on average, 252 g less at birth than their firstborn siblings (95% confidence interval (CI) -419 to -85), and thirdborn infants weighed 419 g less (95% CI -926 to 87), even after adjustment for trimester of maternal intrauterine exposure, maternal birth weight, smoking during pregnancy, and sex of infants in the sibling pairs. Additional adjustment for the birth weight of the elder sibling did not materially change this abnormal pattern. There were no abnormal patterns in offspring birth weights after maternal intrauterine exposure in the second or third trimester of pregnancy. The study outcomes could not be explained by other selected determinants of birth weight, by lack of control for socioeconomic status, or by loss to follow-up of the 1944-1946 birth cohort. This study suggests that there may be long-term biologic effects, even into the next generation, of maternal intrauterine undernutrition which do not correspond to the effects on the mothers' own birth weights.

Birth Order↗
PubMed1983

Mice selected for age of puberty: reverse selection and reproductive characteristics.

Previous investigations have hypothesized a link between regulation of population size in various rodent species and changes in allele frequencies for certain loci that exert their effects on particular behaviors or processes related to reproduction. Drickamer (1981a) has shown that age of first vaginal estrus can be shifted by artificial selection and that there is a relatively high heritability for this trait in laboratory Mus. This paper reports on two related experiments, one a test of reverse selection on strains of mice previously selected for early and late first vaginal estrus, and the other a compilation of data for a variety of traits related to reproduction for the original base stock and four artificially selected stocks. The original selection for early and late onset of puberty did not result in fixation of the trait-enough residual variation remained so that in eight generations of selection it was possible to significantly reverse the timing of first estrus. Traits related to reproduction including litter size, pup weight, survival of pups to 21 days, weight at 21 days, fertility and birth intervals all were not affected by the selection process across all five stocks tested. These results are discussed with regard to changes in puberty and generation time in Mus as a factor in population regulation.

Animals↗
PubMed1992

Tap or bottled water consumption and spontaneous abortion: a 1986 case-control study in California.

To investigate whether drinking tap or bottled water during pregnancy affects the risk of spontaneous abortion, we asked questions about water consumption in a large case-control study (626 cases, 1,300 controls). The study ascertained cases from hospital pathology laboratory reports of pregnancies that began in 1986 and obtained controls from birth certificates. The crude odds ratio for consumption of any vs no cold tapwater at home during the first trimester was 1.2 (95% confidence interval = 1.0-1.5), with no dose-response effect. The crude odds ratio for any bottled water consumption was 0.79 (95% confidence interval = 0.65-0.96), with a downward trend by amount consumed. Adjusting for many potential confounders did not alter these associations appreciably, although some variables appeared to be effect modifiers. The point estimates were stronger among women who were more difficult to contact, suggesting the possibility of bias.

Abortion, Spontaneous↗
PubMed1997

DDT (dicophane) and postmenopausal breast cancer in Europe: case-control study.

OBJECTIVE: To examine any possible links between exposure to DDE (1,1-dichloro-2,2-bis (p-chlorophenyl)ethylene), the persistent metabolite of the pesticide dicophane (DDT), and breast cancer. DESIGN: Multicentre study of exposure to DDE by measurement of adipose tissue aspirated from the buttocks. Laboratory measurements were conducted in a single laboratory. Additional data on risk factors for breast cancer were obtained by standard questionnaires. SETTING: Centres in Germany, the Netherlands, Northern Ireland, Switzerland, and Spain. SUBJECTS: 265 postmenopausal women with breast cancer and 341 controls matched for age and centre. MAIN OUTCOME MEASURE: Adipose DDE concentrations. RESULTS: Women with breast cancer had adipose DDE concentrations 9.2% lower than control women. No increased risk of breast cancer was found at higher concentrations. The odds ratio of breast cancer, adjusted for age and centre, for the highest versus the lowest fourth of DDE distribution was 0.73 (95% confidence interval 0.44 to 1.21) and decreased to 0.48 (0.25 to 0.95; P for trend = 0.02) after adjustment for body mass index, age at first birth, and current alcohol drinking. Adjustment for other risk factors did not materially affect these estimates. CONCLUSIONS: The lower DDE concentrations observed among the women with breast cancer may be secondary to disease inception. This study does not support the hypothesis that DDE increases risk of breast cancer in postmenopausal women in Europe.

Adipose Tissue↗
PubMed2002

Day care attendance in early life, maternal history of asthma, and asthma at the age of 6 years.

Among children not selected on the basis of a parental history of atopy, day care attendance in early life is inversely associated with asthma at school age. We examined the relation between day care in the first year of life and asthma, recurrent wheezing, and eczema at the age of 6 years and wheezing in the first 6 years of life among 453 children with parental history of atopy followed from birth. Among all study participants, day care in the first year of life was inversely associated with eczema (odds ratio [OR] = 0.3, 95% confidence interval [CI] = 0.1-0.8). Day care attendance in early life was associated with a decreased risk of asthma (OR = 0.3, 95% CI = 0.1-0.7) and recurrent wheezing (OR = 0.3, 95% CI = 0.1-0.9) at the age of 6 years and with a decreased risk of any wheezing after the age of 4 years only among children without maternal history of asthma. Among children with maternal history of asthma, day care in early life had no protective effect on asthma or recurrent wheezing at the age of 6 years but was instead associated with an increased risk of wheezing in the first 6 years of life. Our findings suggest that maternal history of asthma influences the relation between day care-related exposures and childhood asthma.

Age Distribution↗
PubMed1996

Mother's health-seeking behaviour and childhood mortality in Pakistan.

"The paper examines the mother's health-seeking behaviour and childhood mortality in Pakistan. This is based on the 1990-91 Pakistan Demographic and Health Survey (PDHS).... It was found that neonatal, infant, and child mortality rate is the highest among children of mothers aged less than 20 years. Infant and child mortality rate is likewise higher among first and higher order births than among births of second or third order. It was further found that mortality declines as the length of the birth interval increases. The results reveal that the education of mother has significant effect on the neonatal, infant and child survival.... Health care factors such as antenatal care, place of delivery, assistance at delivery and immunisation also influenced neonatal, infant and child mortality."

Age Factors↗
PubMed1995

Pregnancy in renal transplant recipients: the Christchurch experience.

AIM: Assess the pregnancies of our female renal transplant recipients and to document long term maternal and fetal outcome. METHODS: Between 7 June 1972 and 31 December 1992 112 females had at least one renal transplant. Sixty-four of these 112 women were in the reproductive age and had a functioning graft. RESULTS: Nine women had 16 pregnancies which resulted in 11 live births and three first trimester abortions. Two unplanned pregnancies were terminated. Mean age at transplantation was 17.2 yr [range 16-22.5 yr] and mean interval from transplant to pregnancy was 6.8 yr [range 1.8-9.0 yr]. Prednisone and azathioprine were used in all patients and cyclosporin in five. For seven of the successful pregnancies plasma creatinine remained < or = 0.10 mmol/L. One of these women developed allograft nephropathy 5 years after delivery and returned to dialysis 9 years later. For the other four successful pregnancies the preconception plasma creatinine was 0.12-0.14 mmol/L. The woman with two successful pregnancies had a halving of glomerular filtration rate during the second pregnancy, but it has remained stable for 15 years; one was poorly compliant with her immunosuppressive regimen and reached endstage renal failure two years after delivery; one developed cyclosporin nephrotoxicity, but 18 months later renal function was stable after a dosage reduction. Ten infants were delivered by caesarean section, four of them urgently. Three babies were preterm and five growth retarded. One died of sudden infant death syndrome at four months. All other infants developed normally. CONCLUSION: There is no contraindication to pregnancy in female transplant recipients who have stable graft function and controlled blood pressure. Management of such pregnancies should be by shared obstetrical/nephrological/paediatric care.

Adolescent↗
PubMed1993

Does midline episiotomy increase the risk of third- and fourth-degree lacerations in operative vaginal deliveries?

OBJECTIVE: To explore the association between midline episiotomy and the risk of third- and fourth-degree lacerations during operative vaginal delivery with either vacuum extractor or forceps. METHODS: This retrospective cohort study analyzed all operative vaginal deliveries at a university hospital in 1989 and 1990. Univariate analysis of the relationships between perineal lacerations and obstetric variables was performed. Stratified analysis using the relevant variables was used to calculate relative risk (RR) estimates. RESULTS: Episiotomy, birth weight, and whether the index birth was the first vaginal birth were associated with third- and fourth-degree perineal lacerations. Stratified analysis demonstrated an RR of 2.4 with a 95% confidence interval of 1.7-3.5 for rectal injury with episiotomy, adjusting for parity and birth weight. CONCLUSION: Midline episiotomy is associated with an increased risk of third- and fourth-degree perineal lacerations in operative vaginal deliveries.

Birth Weight↗
PubMedDate not supplied

[Risk factors for neonatal death in Recife: a case-control study]

OBJECTIVE: Neonatal mortality is the main cause of infant mortality in the city of Recife. The objective of the present study was to determine the major risk factors for neonatal death in Recife in 1995. METHODS: This is a case control study. Information was obtained from the mortality and live birth databases after validation of the data set, between January and December 1995. A sample of 456 cases and 2,280 controls was obtained after using the linkage technique between the two data sets. The difference in proportion was analyzed by the chi square test. The odds ratio was calculated as a risk measure, with a 95% confidence interval. The logistic regression technique was used to adjust potential confounding factors. RESULTS: 212 deaths (46.6%) occurred in the first 24 hours of life. We found that 358 (79.7%) of the cases presented low birth weight, with a 46-fold higher risk of death (CI =33.8-59.0 P<0.001) than those weighing >/= 2,500g. The major risk factors observed in the logistic regression analyses of the measure, listed in descending order, were: birth weight < 1,500g (OR= 49.6 CI= 22.6-108.7 P<0.001), 5-minute Apgar score < 7 (OR = 44.1 CI= 25.1-77.2 P<0.001), birth weight between 1,500 and 2,500g (OR= 8.2 CI= 4.8-14.0 P<0.001), gestational age < 37 weeks (OR= 4.3 CI= 2.6-7.1 P<0.001). CONCLUSIONS: Among the studied variables, birth weight, gestational age, and Apgar score should be considered the main risk factors for the surveillance of neonatal death.

Journal Article↗
PubMed1992

Naloxone prevents interruption of parturition and increases plasma oxytocin following environmental disturbance in parturient sows.

Experiments in rodents have suggested that environmental disturbance can disrupt parturition through an opioid-mediated inhibition of oxytocin secretion. To test this hypothesis in a large animal model, 14 primiparous female pigs were allowed to commence parturition in a strawed pen. Five of these gilts were allowed to continue parturition undisturbed in this pen, while the remainder were moved to a farrowing crate immediately after the birth of the first piglet. At this time, pigs were injected subcutaneously with either the opioid antagonist naloxone (n = 4; dose 1 mg/kg body weight) or saline (n = 5). Whereas the undisturbed pigs all gave birth to a second piglet within 53 min, in three of the five disturbed and saline-treated pigs no further births occurred for 2 h, at which time oxytocin was administered subcutaneously to restart parturition. By contrast, all of the naloxone-treated pigs gave birth spontaneously within 2 h, although mean interbirth intervals were still prolonged compared to undisturbed pigs. In a second experiment, nine primiparous female pigs with chronic catheters preplaced in the external jugular vein were similarly moved after the birth of their first piglet and either injected with naloxone (n = 5) or saline (n = 4). Again, parturition was interrupted in three out of four saline-treated animals for at least 2.5 h, but resumed promptly when exogenous oxytocin was administered. Plasma concentrations of oxytocin in these pigs were significantly lower than in naloxone-treated pigs, five out of six of which gave birth spontaneously to one or more piglets within 2.5 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Epidemiology of frontoethmoidal encephalomeningocoele in Burma.

One hundred and thirty nine patients suffering from encephalomeningocoele and myelomeningocoele who had attended the neurosurgical outpatients department of the Rangoon People's Hospital were interviewed. A predominance of frontal encephalomeningocoele was found; a low proportion of these patients had been conceived in the cold season and an increased interval separated the index patients from the previous full term pregnancy of their mothers; no first degree relatives were affected. It is suggested that an environmental factor is implicated in the developmental aetiology.

Adolescent↗
PubMed2004

Planning a family: priorities and concerns in rural Tanzania.

A fertility survey using qualitative and quantitative techniques described a high fertility setting (TFR 5.8) in southern Tanzania where family planning use was 16%. Current use was influenced by rising parity, educational level, age of last born child, breastfeeding status, a preference for longer than the mean birth interval (32 months), not being related to the household head, and living in a house with a tin roof. Three principal concerns amongst women were outlined from the findings. First, that there is a large unmet need for family planning services in the area particularly among teenagers for whom it is associated with induced abortion. Second, that family planning is being used predominantly for spacing but fears associated with it often curtail effective use. Third, that service provision is perceived to be lacking in two main areas--regularity of supply, and addressing rumours and fears associated with family planning. Reproductive health interventions in the area should ultimately be more widespread and, in particular, abortion is highlighted as an urgent issue for further research. The potential for a fast and positive impact is high, given the simplicity of the perceived needs of women from this study.

Abortion, Legal↗
PubMed1997

Immunogenicity of hepatitis B vaccine in preterm infants.

OBJECTIVE: To determine the immunogenicity of hepatitis B vaccine in preterm infants when the first dose of vaccine is delayed until hospital discharge. METHODS: One hundred two preterm infants (23 to 36 weeks gestational age) born to hepatitis B surface antigen-negative mothers were enrolled. Immunization was initiated just before hospital discharge with subsequent doses 1 and 6 months later. Serum specimens were obtained before the administration of each vaccine dose and 3 months after the last dose and were tested for antibody to hepatitis B surface antigen (antiHBs). RESULTS: Eighty-seven infants (85%) completed the study. Ninety percent (n = 78) of infants who completed the study seroconverted (antiHBs > or = 10 mIU/mL); 10% (n = 9) remained seronegative at study completion. The geometric mean antibody titer to hepatitis B surface antigen for infants who seroconverted was 200 mIU/mL. Nonresponders (NR) differed from responders (R) in birth weight (NR = 2090 g, R = 1560 g) gestational age (NR = 33 weeks, R = 31 weeks), and weight gain before vaccine initiation (NR = 244 g, R = 633 g). There were no differences in weight or age at vaccine initiation, Apgar scores, interval between vaccine doses, or bacterial infections, steroid use, or transfusions before vaccine initiation. CONCLUSIONS: Ninety percent of preterm infants responded to hepatitis B vaccine when the first dose of vaccine was delayed until hospital discharge. Nonresponders were more likely to be preterm infants of higher birth weight and higher gestational age, and to have gained less weight before vaccine initiation.

Gestational Age↗
PubMed2000

Effect of crambe meal on performance, reproduction, and thyroid hormone levels in gestating and lactating beef cows.

Crambe meal was compared to a combination of sunflower and soybean meal as a protein supplement for mature beef cows in two experiments. In Exp. 1, cows (n = 80, average BW 651+/-14.4 kg) were fed crambe meal at 9.86% of dry matter intake (DMI) during the last trimester of gestation. No differences (P < .05) were detected due to treatment for cow weight, condition score, thyroid hormones, calf birth weight, or calving interval. In Exp. 2, cows (n = 100, average BW 566+/-6.82 kg) were fed crambe meal at 7.44% of DMI during the last trimester of gestation and at 8.33% of DMI during early lactation (53+/-6 d of lactation). Gains were greater during gestation (P = .09) and throughout the supplementation period (P = .06), and days to first estrus were reduced (P < .01) for cows fed crambe meal. During lactation, serum triiodothyronine (T3) concentrations did not decline as much (P = .03) in cows fed crambe meal as in cows fed sunflower-soybean meal-based supplements. No differences (P > .10) were apparent for condition score, birth weight, calf growth rate, weaning weight, thyroid hormones during gestation, or calving interval. These data indicate that crambe meal fed at the levels used in this experiment can be used as a protein supplement for beef cows without negatively affecting cows' performance.

Animal Feed↗
PubMed2006

Survival of infants with neural tube defects in the presence of folic acid fortification.

OBJECTIVE: Neural tube defects (NTDs) are preventable through preconceptional and periconceptional folic acid intake. Although decreases in the prevalence of NTDs have been reported since folic acid fortification of United States grain products began, it is not known whether folic acid plays a role in reducing the severity of occurring NTDs. Our aim was to determine whether survival among infants born with spina bifida and encephalocele has improved since folic acid fortification and to measure the effects of selected maternal, pregnancy, and birth characteristics on first-year (infant) survival rates. METHODS: A retrospective cohort study was conducted and included 2841 infants with spina bifida and 638 infants with encephalocele who were born between 1995 and 2001 and were registered in any of 16 participating birth defects monitoring programs in the United States. First-year survival rates for both spina bifida and encephalocele cohorts were measured with Kaplan-Meier estimation; factors associated with improved chances of first-year survival, including birth before or during folic acid fortification, were measured with Cox proportional-hazards regression analysis. RESULTS: Infants with spina bifida experienced a significantly improved first-year survival rate of 92.1% (adjusted hazard ratio: 0.68; 95% confidence interval: 0.50-0.91) during the period of mandatory folic acid fortification, compared with a 90.3% survival rate for those born before fortification. Infants with encephalocele had a statistically nonsignificant increase in survival rates, ie, 79.1% (adjusted hazard ratio: 0.76; 95% confidence interval: 0.51-1.13) with folic acid fortification, compared with 75.7% for earlier births. CONCLUSIONS: Folic acid may play a role in reducing the severity of NTDs in addition to preventing the occurrence of NTDs. This phenomenon contributes to our understanding of the efficacy of folic acid. Additionally, as survival of NTD-affected infants improves, health care, education, and family support must expand to meet their needs.

Dietary Supplements↗