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PubMed1995

Epidemiology of preterm delivery in two birth cohorts with an interval of 20 years.

The occurrence and determinants of preterm delivery were studied in two population-based birth cohorts from northern Finland. In the first cohort of 1966 there were 11,475 singleton deliveries and in the later cohort of 1985-1986, 8,888. The overall incidence (percentage) of preterm deliveries fell from 9.1 to 4.8, including a reduction from 8.8 to 3.4 for spontaneous preterm deliveries. For iatrogenic ones, however, there was an increase from 0.3 to 1.4. The relative risks, associated with such known maternal determinants as unmarried status, smoking, low educational level, age over 34 years, unwantedness of the pregnancy, and poor earlier obstetric history, had about the same level in these two series. However, despite a favorable change in the distribution of most of these determinants over the 20 years, only a small part of the decrease of the total incidence of preterm delivery could be attributed to these changes, as a consistent and substantial reduction occurred in the incidence of spontaneous preterm birth in all categories of each single determinant. The increase in the proportion of iatrogenic preterm deliveries was accompanied by these being more common at lower than at higher socioeconomic levels in 1985-1986, whereas the social gradient appeared to be reversed in 1966.

Cohort Studies↗
PubMed2003

Moderate alcohol drinking and risk of preterm birth.

OBJECTIVE: We have analysed the association between alcohol drinking before and during the three trimesters of pregnancy and risk of preterm birth of babies with normal weight for gestational age or with low weight for gestational age (SGA). DESIGN: Case-control study. SETTING: General and university hospitals in Italy. SUBJECTS: Cases were 502 women who delivered preterm births <37 weeks gestation. The controls included 1966 women who gave birth at term (>/=37 weeks of gestation) to healthy infants of normal weight (ie between 10th and 90th centile according to the Italian standard) on randomly selected days at the hospitals where cases had been identified. INTERVENTIONS: Interview. RESULTS: No increased risk of preterm birth was observed in women drinking one or two drinks/die in pregnancy, but three or more drinks/die increased the risk (multivariate odds ratios (OR) 2.0 for >/=3 drinks during the first trimester, 1.8 during the second and 1.9 during the third). When the analysis was conducted separately for preterm births with normal weight or SGA, the increased risk was observed in preterm SGA only (multivariate OR for >/=3 drinks/die during the first trimester=3.6, 95% confidence interval (CI) 1.3-11.1); the estimated multivariate OR for >/=3 drinks/die during the first trimester of preterm babies with normal weight for gestational age was only slightly above unity and not statistically significant (multivariate OR 1.4, 95% CI 0.5-3.7). CONCLUSIONS: The study shows an increased risk in mothers who drink >/=3 die units alcohol in pregnancy of preterm births.

Adult↗
PubMed2005

Effect of the interpregnancy interval after an abortion on maternal and perinatal health in Latin America.

OBJECTIVE: To investigate whether the length of the interval between an abortion and the next pregnancy is associated with increased risks of adverse maternal and perinatal outcomes in Latin America. METHOD: Retrospective cross-sectional study using information from 258,108 women delivering singleton infants and whose previous pregnancy resulted in abortion recorded in the Perinatal Information System database of the Latin American Centre for Perinatology and Human Development, Montevideo, Uruguay, between 1985 and 2002. Adjusted odds ratios were obtained through logistic regression analysis. RESULT: Compared with the post-abortion interpregnancy intervals of 18 to 23 months, intervals shorter than 6 months were significantly associated with increased risks of maternal anemia, premature rupture of membranes, low birth weight, very low birth weight, preterm delivery, and very preterm delivery. CONCLUSION: In Latin America, post-abortion interpregnancy intervals shorter than 6 months are independently associated with increased risks of adverse maternal and perinatal outcomes in the next pregnancy. DEFINITION: Post-abortion interpregnancy interval (PAII): the time elapsed between the day of the abortion and the first day of the last menstrual period for the index pregnancy.

Abortion, Induced↗
PubMed1995

Multiple births and risk of breast cancer.

Data from a large, multicenter, population-based case-control study were analyzed to investigate the relation between multiple birth pregnancies and subsequent breast-cancer risk in the gravidas. Women less than 75 years old who had breast cancer were identified from statewide tumor registries in Wisconsin, western Massachusetts, Maine and New Hampshire. Controls aged less than 65 years were selected randomly from lists of licensed drivers, and controls aged between 65 and 74 were selected randomly from lists of Medicare beneficiaries. Information on reproductive history and other factors was obtained by means of telephone interviews. After excluding nulliparous women, 5,880 case subjects and 8,217 controls remained for analysis. Multiple birth pregnancies occurred in 146 cases and 218 controls. Adjusted for the number of full-term pregnancies and other confounders, the odds ratio (OR) for any multiple birth pregnancy was 0.94 (95% confidence interval, 0.75 to 1.17). The null association between multiple birth pregnancies and breast cancer remained if the mother's first pregnancy or last pregnancy resulted in a multiple birth. In addition, no trend in risk emerged for age at first multiple birth or time since last multiple birth. While other investigators have suggested biological mechanisms to explain both protective and detrimental effects of multiple births and subsequent development of breast cancer, this study does not support either assertion.

Adult↗
PubMed2005

Reproductive factors and subtypes of breast cancer defined by hormone receptor and histology.

Reproductive factors are associated with reduced risk of breast cancer, but less is known about whether there is differential protection against subtypes of breast cancer. Assuming reproductive factors act through hormonal mechanisms they should protect predominantly against cancers expressing oestrogen (ER) and progesterone (PR) receptors. We examined the effect of reproductive factors on subgroups of tumours defined by hormone receptor status as well as histology using data from the NIHCD Women's Contraceptive and Reproductive Experiences (CARE) Study, a multicenter case-control study of breast cancer. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) as measures of relative risk using multivariate unconditional logistic regression methods. Multiparity and early age at first birth were associated with reduced relative risk of ER + PR + tumours (P for trend=0.0001 and 0.01, respectively), but not of ER - PR - tumours (P for trend=0.27 and 0.85), whereas duration of breastfeeding was associated with lower relative risk of both receptor-positive (P for trend=0.0002) and receptor-negative tumours (P=0.0004). Our results were consistent across subgroups of women based on age and ethnicity. We found few significant differences by histologic subtype, although the strongest protective effect of multiparity was seen for mixed ductolobular tumours. Our results indicate that parity and age at first birth are associated with reduced risk of receptor-positive tumours only, while lactation is associated with reduced risk of both receptor-positive and -negative tumours. This suggests that parity and lactation act through different mechanisms. This study also suggests that reproductive factors have similar protective effects on breast tumours of lobular and ductal origin.

Adult↗
PubMed2006

Established breast cancer risk factors by clinically important tumour characteristics.

Breast cancer is a morphologically and clinically heterogeneous disease; however, it is less clear how risk factors relate to tumour features. We evaluated risk factors by tumour characteristics (histopathologic type, grade, size, and nodal status) in a population-based case-control of 2386 breast cancers and 2502 controls in Poland. Use of a novel extension of the polytomous logistic regression permitted simultaneous modelling of multiple tumour characteristics. Late age at first full-term birth was associated with increased risk of large (> 2 cm) tumours (odds ratios (95% confidence intervals) 1.19 (1.07-1.33) for a 5-year increase in age), but not smaller tumours (P for heterogeneity adjusting for other tumour features (Phet) = 0.007). On the other hand, multiparity was associated with reduced risk for small tumours (0.76 (0.68-0.86) per additional birth; Phet = 0.004). Consideration of all tumour characteristics simultaneously revealed that current or recent use of combined hormone replacement therapy was associated with risk of small (2.29 (1.66-3.15)) and grade 1 (3.36 (2.22-5.08)) tumours (Phet = 0.05 for size and 0.0008 for grade 1 vs 3), rather than specific histopathologic types (Phet = 0.63 for ductal vs lobular). Finally, elevated body mass index was associated with larger tumour size among both pre- and postmenopausal women (Phet = 0.05 and 0.0001, respectively). None of these relationships were explained by hormone receptor status of the tumours. In conclusion, these data support distinctive risk factor relationships by tumour characteristics of prognostic relevance. These findings might be useful in developing targeted prevention efforts.

Breast Neoplasms↗
PubMed2003

Reliability of maternal recall and reporting of child births and deaths in rural Egypt.

Demographic indicators such as fertility rates and infant mortality rates are often measured in census surveys by interviewing mothers to obtain their pregnancy histories and child deaths. The validity of such surveys depends upon accurate recall of histories, truthful reporting of events and understanding of the questions posed. To measure the reliability of maternal reporting, two census surveys conducted in a rural Egyptian population were compared. Women between 15 and 55 years of age residing in 20 villages were asked their histories of live births, stillbirths and child deaths. An identical set of questions was posed 2 years later. Twice-monthly home visits were conducted in the intervening 2-year interval to identify accurately any new births, stillbirths and deaths occurring in the population. The maternal reports from the first census were combined with the prospectively identified births, stillbirths and deaths and compared with the maternal reports from the second census. For 1502 women, the discrepancies in the total number of births, stillbirths and child deaths reported between the two surveys were 0.6%, 4% and 0.6% respectively. However, when the consistency of responses was analysed, the proportion of women with discordant responses was 10%, 6% and 7% for the same measures. These results suggest that, despite the large number of births and deaths that women may experience in developing countries, maternal interviews provide reliable responses that can be used to estimate mortality and fertility rates in settings where vital records are incomplete or unreliable.

Adolescent↗
PubMed2006

A case-control study to determine risk factors for hospitalization for rotavirus gastroenteritis in U.S. children.

OBJECTIVE: The objective of this case-control study nested within a surveillance study conducted at 3 hospitals (Cincinnati Children's Hospital Medical Center, Cincinnati, OH; Children's Hospital of New Orleans, New Orleans, LA; and Hasbro Children's Hospital, Providence, RI) was to identify risk factors for rotavirus gastroenteritis requiring hospitalization. PATIENTS: Cases were children < or =59 months of age who were admitted with acute gastroenteritis (AGE) and found to have rotavirus infection. Controls were selected from a birth certificate registry (Cincinnati and Providence) or a registry of patients from a large practice consortium in 11 locations (New Orleans). RESULTS: Three hundred forty-nine rotavirus-infected cases and 1242 control subjects were enrolled. Breast feeding was protective against hospitalization for rotavirus AGE for infants <6 months of age. (odds ratio [OR], 5.1; 95% confidence interval [CI], 1.2-13.2). Low-birth-weight (<2500 g) infants had increased risk for hospitalization even beyond the first few months of life (OR, 2.8; 95% CI, 1.6-5.0). Children in child care were more likely to be hospitalized for rotavirus AGE than those cared for at home, particularly those > or =24 months of age (OR, 3.0; 95% CI, 1.8-5.3). Other characteristics associated with rotavirus AGE hospitalization were children <24 months of age covered by Medicaid or without insurance (OR, 2.1; 95% CI, 1.4-3.2) and having another child in the house <24 months of age (OR, 1.6; 95% CI, 1.1-2.3). The data suggest that maternal age <25 years (OR, 1.4; 95% CI, 1.0-2.0) and a mother with less than a high school education (OR, 1.5; 95% CI, 1.0-2.3) may also increase risk of rotavirus hospitalization. CONCLUSION: There are socioeconomic and environmental factors and aspects of the child's medical and dietary history that identify children at risk for hospitalization with rotavirus AGE.

Age Factors↗
PubMed1982

[Intra-uterine detection of atrio-ventricular block in two children whose mother had Sjögren's syndrome].

A woman with isolated juvenile Sjögren's syndrome gave birth, at 3 years' interval, to two children with complete atrio-ventricular heart block (AVB). This is the first published case of AVB in children of mothers with Sjögren's syndrome without any clinical and laboratory evidence of connective tissue disease, notably lupus. Ultrasonography showed that the AVB was acquired in utero and occurred during the 23rd week of gestation. In both children the AVB was isolated, without any symptom of congenital malformation of the heart; there were no abnormalities of conduction in the mother. Early corticosteroid treatment of the mother's disease had no beneficial effect on AVB in the foetuses. Attempts to reproduce the condition experimentally met with failure.

Adult↗
PubMed1984

The development of physiological responses of the piriform cortex in rats to stimulation of the lateral olfactory tract.

Extracellular recording techniques in rats were used to follow the postnatal development of the evoked response of the piriform cortex to electrical stimulation of the lateral olfactory tract (LOT) from birth to adulthood. As in other species, LOT shock in adult rats produces short-latency activation of units in piriform cortex and an extracellular field potential consisting of three components: a surface-negative component, the A1 wave (corresponding to the cortical monosynaptic EPSP evoked by the LOT fibers); a second surface-negative component, the B1 wave (corresponding to reactivation of layer I dendrites by intracortical fibers); and a late surface-positive component, the period 2 wave. A conditioning shock 20-150 msec before the test shock profoundly inhibits both evoked unit activity and the B1 wave, while it facilitates the A1. At birth, units can be orthodromically activated by LOT stimulation in association with the A1 wave. There is also a surface-positive spikelike wave, the S wave, which represents the summation of cortical unit activity. The B1 wave is apparent early in the first postnatal week. However, in contrast to the prominent inhibition in the adults, for the first few days after birth, single-unit responses, multiple-unit activity, and the S wave are all facilitated by a preceding conditioning shock with intervals of 200 msec or less, in association with the facilitation of the A1 wave. A shift to inhibition is apparent with longer intershock intervals of 300-700 msec, which exceed the period during which paired shocks facilitate the A1 wave. During the remainder of the first two postnatal weeks,, partial suppression of evoked activity with intervals of less than 200 msec appears and progressively increases in strength, but inhibition at very long intershock intervals remains greater in magnitude. During this time, the duration of the inhibitory period also decreases to near the adult value of 200-300 msec. In the third postnatal week the pattern was similar to that in the adult, but the inhibition was still clearly weaker than in adults. These results suggest a delayed maturation of the cortical inhibitory circuitry; this conclusion has also been suggested by previously published observations in the developing neocortex and hippocampus. In addition, the acceleration with age of the conduction velocity of axons in the LOT was analyzed. The adult value of 9.6 m/sec was not achieved until some time after postnatal day 15, which parallels the myelinization of the tract as observed with the light microscope.

Aging↗
PubMed2001

Hormonal factors and pancreatic cancer in women.

PURPOSE: The aim of the study was to evaluate hormonal risk factors for carcinoma of the exocrine pancreas among postmenopausal women. METHODS: Mailed questionnaire data from 52 cases and 233 population-based controls in Ontario were used to assess parity, age at first birth, and other hormonal factors on pancreatic cancer risk. RESULTS: Reduced risk was seen with three or more pregnancies [adjusted odds ratio (OR) = 0.22, 95% confidence interval (CI) = 0.07-0.65] and use of oral contraceptives (adjusted OR = 0.36, 95% CI = 0.13-0.96), whereas no significant associations were found for age at menarche or menopause, or estrogen replacement therapy. Among parous women, later age at first full-term pregnancy significantly increased the risk of this cancer (adjusted OR = 4.05, 95% CI = 1.50-10.92 for ages 25-29 years, adjusted OR = 3.78, 95% CI = 1.02-14.06 for ages 30+ years). CONCLUSIONS: Our data support the hypothesis that pancreatic cancer is, at least in part, an estrogen-dependent disease; there is growing epidemiological evidence that aspects of reproductive history and hormonal exposure are associated with risk of this disease.

Adolescent↗
PubMed1999

Social differences of very preterm birth in Europe: interaction with obstetric history. Europop Group.

Social differences of very preterm birth (22-32 completed weeks of amenorrhea) were studied using data from a large case-control survey in Europe between 1994 and 1997; 1,675 very preterm births and 7,965 full-term births were included. The relation between social factors and very preterm birth was studied according to obstetric history and the mode of delivery onset. Very preterm birth was significantly related to low educational level among women with no previous adverse pregnancy outcome (odds ratio (OR) = 2.67, 95 percent confidence interval (CI) 1.66-4.28) and among primigravid women and those with previous first-trimester abortion (OR = 2.01, 95 percent CI 1.56-2.58). In this group, unemployment of all household members was associated with a double risk of very preterm birth. No significant association between very preterm birth and socioeconomic status was observed among women with previous second-trimester abortion or preterm birth. Socioeconomic indicators remained significantly associated with both spontaneous and induced very preterm births among women with no previous late fetal loss or preterm birth. The results are consistent with social factors affecting the risk of very preterm birth, but the relation differs according to obstetric history.

Adolescent↗
PubMed1999

Cotinine in meconium indicates risk for early respiratory tract infections.

1. In order to identify potential risks for lower respiratory tract symptoms during early infancy, the concentration of cotinine was measured in meconium of 91 newborns as a parameter of prenatal exposure to tobacco, and a questionnaire was performed with parents at birth. Infants were followed up for the first year of life by monthly telephone interviews. 2. Lower respiratory tract infections during the first 6 months of life were associated with a high concentration of cotinine in meconium (cotinine higher than median vs lower than median; odds ratio 4.9, 95% confidence interval 1.2 to 20.3), while none of the other variables tested including selfreport of parental, prenatal or postnatal tobacco consumption, parents history of atopy, maternal age, presence of siblings, socio-economic status, duration of gestation, birth weight, gender, and duration of breast feeding were identified as independent risks. The occurrence of a lower respiratory tract infection during the first 6 months of life was predicted correctly in 77% of the infants by a cotinine excretion in meconium exceeding the group median. 3. In conclusion, quantification of cotinine in meconium is preferred to historical parameters as an estimate of the risk for early respiratory tract infections.

Adult↗
PubMed1997

Comparison of platelet counts in first and second newborns of mothers with immune thrombocytopenic purpura.

OBJECTIVE: This study was designed to estimate the predictive value of the first neonatal platelet count for the second neonate in women with immune thrombocytopenic purpura (ITP). METHODS: Data of 34 patients, repeatedly pregnant while they had ITP, were prospectively collected in two study centers between 1984 and 1995. The main outcome measure was neonatal thrombocytopenia. RESULTS: Early neonatal platelet counts (i.e., umbilical cord count or count during the first 24 hours of life) between siblings were correlated (r = .73; 95% confidence interval (CI) for the correlation coefficient 0.52, 0.86). Severe thrombocytopenia (less than 50 x 10(9)/L) at birth did not occur in any of the 27 siblings of infants with birth platelet levels above 50 x 10(9)/L. Also the second sibling's nadir neonatal platelet counts during the first 2 weeks of life were correlated with those of the first sibling (r = .76; 95% CI for the correlation coefficient 0.58, 0.88). In those cases in which the first sibling had a lowest platelet count above 100 x 10(9)/L (n = 19), the second sibling never became thrombocytopenic. CONCLUSION: The platelet count of the first sibling can be used to counsel women with ITP, and may be helpful in their management.

Female↗
PubMedDate not supplied

Expanded Medicaid coverage for pregnant women to 100 percent of the federal poverty level.

Our objective was (1) to identify the subgroup of women most affected by the regulatory change expanding Tennessee Medicaid eligibility for pregnant women from 45% of the federal poverty level to 100% and (2) to examine whether increased enrollment correlated with greater use of prenatal care and improved reproductive outcomes. We linked Tennessee birth and fetal death certificates to Medicaid enrollment files. We compare outcome rates in the 12-month period before the change in the Medicaid regulations with similar rates for the 10-month period after the change had been in effect nine months. We found the increase in Medicaid enrollment that occurred after the expansion was greatest for teenage mothers. Among teens, Medicaid enrollment increased 18%, and the odds of receiving no prenatal care or only late (third-trimester) care were reduced 16% (95% confidence interval = 8%, 24%) after we controlled for potential confounders. However, there was no improvement in first-trimester use of prenatal care or in birth outcomes. This finding suggests the need to evaluate carefully subsequent regulatory changes, which sought to promote early prenatal care by removing barriers to early Medicaid enrollment in pregnancy.

Adolescent↗
PubMed1999

Childbearing at older age and endometrial cancer risk (Sweden).

OBJECTIVES: Several studies have found an inverse association between older age at last birth and endometrial cancer risk. A nested case-control study was undertaken to examine the influence of this and other aspects of reproductive patterns on the risk of developing endometrial cancer. METHODS: Among women born in 1925 and later, 4,839 eligible patients were identified in the Swedish Cancer Register. For each case, five individually age-matched controls were randomly selected from a population-based Fertility Register. Relative risks were estimated from odds ratios obtained from conditional logistic regression analyses. RESULTS: Compared to uniparous women, childless women were at a higher risk of endometrial cancer (odds ratio [OR] = 1.38, 95% confidence interval [CI] = 1.25-1.52). This association was stronger in younger (< 50 years) than in older (50+ years) women. At all ages of first birth, a delivery was associated with a reduced risk of endometrial cancer that slowly diminished with time. Among parous women, the risk decreased by almost 20% for each additional live birth (OR = 0.81, CI = 0.78-0.84). In an analysis limited to women with two or more births that compared the independent effects of age at first and at last birth, only older age at last birth was associated with a lowered risk of endometrial cancer. The risk decreased at a rate of about 15% per five-year delay of last birth. CONCLUSIONS: Endometrial cancer is often referred to as the prototype hormonally-determined disease in women. However, our findings give further support to the hypothesis that a birth may not only affect risk through hormonal influences, but possibly also through mechanical shedding of cells that have undergone malignant transformation.

Adult↗
PubMed2004

The sex ratio of pregnancies complicated by hospitalisation for hyperemesis gravidarum.

OBJECTIVE: To evaluate the sex ratio among pregnancies complicated by first trimester hyperemesis gravidarum and extend previous findings to include a measure of severity. DESIGN: Population-based case control study. SETTING: All non-federal hospitals in Washington State. POPULATION: Two thousand and one hundred and ten pregnant women hospitalised for hyperemesis gravidarum and 9783 pregnant women without hyperemesis gravidarum. METHODS: The infant sex ratio for pregnant women admitted to the hospital for hyperemesis gravidarum was evaluated using the Washington State hospital discharge database linked to the birth certificate database for years 1987-1996. Cases were pregnant women hospitalised for hyperemesis gravidarum (International Classification for Diseases-9th edition [ICD-9] diagnosis code 643) in the first trimester. Controls were women who experienced a singleton live birth and were not hospitalised for hyperemesis in Washington State during the same time period. Regression analysis with general estimating equations was used to calculate an odds ratio (OR) and 95% confidence interval (CI) to assess the association of hyperemesis gravidarum with infant sex ratio. MAIN OUTCOME MEASURE: Infant sex ratio. RESULTS: Pregnant women hospitalised for hyperemesis gravidarum in the first trimester had a 50% increased odds of having a female infant compared with controls (OR 1.5, 95% CI 1.4, 1.7). Women hospitalised for three or more days had the greatest odds of having a female infant compared with control women (OR 1.8, 95% CI 1.5, 2.0). CONCLUSION: Hyperemesis gravidarum is associated with an increase in female live births and may be a marker for high oestrogen levels in utero.

Adolescent↗
PubMed1992

Correlated responses in reproduction accompanying selection for milk yield in Jerseys.

Reproductive traits of heifers and primiparous cows from a long-term selection project were analyzed to determine correlated response to single-trait selection for milk yield. Data were from 1056 daughters (765 selection, 291 control) of 37 bulls (17 selection, 20 control). Traits in heifers were ages at first observed estrus and at first breeding, services to conception, interval from first service to conception, and length of first gestation. Traits in primiparous cows were ages at first calving and at first breeding, after calving; services to conception; length of second gestation; and intervals from calving to first observed estrus, to first breeding, and to conception, from first service to conception, and from first to second calving. Analyses for services to conception in heifers and primiparous cows were categorical using models containing genetic group and generation. Analyses of other traits were by linear mixed models using fixed effects of genetic group, generation within group, and year-season of birth. Sires were assumed random and nested within genetic group. The mean square for sires within group was used to test for group differences. No significant differences were found between genetic groups in traits measured in heifers; however, the interval from first service to conception approached significance (control superior). In primiparous cows, differences between genetic groups were significant for the intervals of calving to first breeding and calving to conception and for length of second gestation (control superior). For other traits, reproductive performance of the control was better but not significantly different from that of the selected group. Reproductive performance should be monitored during selection for high milk yield.

Age Factors↗