Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “First Birth Intervals”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
PubMed1977

Rodent brain growth stages: an analytical review.

Study of data in the literature on rat and mouse brain growth from birth to weaning reveals a stagewise growth in average brain weight. Rapid growth occurs in the intervals between days 0-6, 8-12, and 17-23 after birth. Slow growth periods then lie in the intervals 6-8, 12-17, and after 23 days. The first slow growth period is signalled by events occurring at its end: substantial acceleration of synthesis of RNA, DNA, protein, and myelin. The second slow growth period is characterized by at least a 3-day interval during which there is very little increase in average brain weight compared with what occurs just before and just after that period; the correlation among 12 studies is highly significant. Implications are discussed for cross-species' extrapolation of findings about brain development.

Age Factors↗
PubMed1985

Risk factors for benign breast disease and their relation with breast cancer risk. Pooled information from epidemiologic studies.

Information from published case-control studies on benign breast disease was pooled using standard statistical methods to obtain single, overall risk estimates. This analysis showed that higher socio-economic status (pooled relative risk, RR = 1.24, 95% confidence interval, CI = 1.13-1.37), later menopause (pooled RR = 1.87, 95%, CI = 1.67-2.11) and late age at first birth (pooled RR = 1.30, 95%, CI = 1.13-1.50) were associated with an increased risk of benign breast disease, whereas an apparent protection was given by greater body mass index (pooled RR = 0.58, 95%, CI = 0.50-0.67) and the use of oral contraceptives (pooled RR = 0.75, 95%, CI = 0.67-0.83). The role of these factors did not appear to be materially different in the various histopathologic categories considered, although available information allowed only a general distinction between breast dysplasia (fibrocystic disease) and benign tumors, chiefly fibroadenoma. In conclusion, the general evidence from published studies indicates that benign breast lumps appear to share a number of important risk factors with breast cancer.

Adolescent↗
PubMed2006

Relationship between blood pressure, cerebral electrical activity, cerebral fractional oxygen extraction, and peripheral blood flow in very low birth weight newborn infants.

There is uncertainty about the level of systemic blood pressure required to maintain adequate cerebral oxygen delivery and organ integrity. This prospective, observational study on 35 very low birth weight infants aimed to determine the mean blood pressure (MBP) below which cerebral electrical activity, peripheral blood flow (PBF), and cerebral fractional oxygen extraction (CFOE) are abnormal. Digital EEG, recorded every day on the first 4 d after birth, were analyzed a) by automatic spectral analysis, b) by manual measurement of interburst interval, and c) qualitatively. CFOE and PBF measurements were performed using near-infrared spectroscopy and venous occlusion. MBP was measured using arterial catheters. The median (range) of MBP recorded was 32 mm Hg (16-46). The EEG became abnormal at MBP levels below 23 mm Hg: a) the relative power of the delta (0.5-3.5 Hz) frequency band was decreased, b) interburst intervals were prolonged, and c) all four qualitatively abnormal EEG (low amplitude and prolonged interburst intervals) from four different patients were recorded below this MBP level. The only abnormally high CFOE was measured at MBP of 20 mm Hg. PBF decreased at MBP levels between 23 and 33 mm Hg. None of the infants in this study developed cystic periventricular leukomalacia. One infant (MBP, 22 mm Hg) developed ventricular dilatation after intraventricular hemorrhage. The EEG and CFOE remained normal at MBP levels above 23 mm Hg. It would appear that cerebral perfusion is probably maintained at MBP levels above 23 mm Hg.

Blood Pressure↗
PubMed1999

Perinatal mortality in Taiwan.

Information on perinatal deaths was obtained from 310 women by collecting detailed obstetric histories dating from marriage to the start of the survey. These histories were compared to those of 688 age matched controls. Potential risk factors, levels and time trends of perinatal mortality in Taiwan were examined and factors underlying stillbirths and early neonatal deaths were also compared using conditional logistic regression analyses. A nearly 56% decline of the perinatal mortality rate during the 35 y, approximately, prior to the survey was observed. Risk of stillbirths was increased among those who had abused illegal drugs during pregnancy, those who reported that the pregnancy was unwanted and those with Thalassemia trait. Body mass index was log-linearly related with stillbirths, with higher body mass associated with higher risk. For early neonatal deaths, those mothers aged 19 y or less, those giving birth to either their first children or to their fifth or later child, those who had their first prenatal care visit after the first three months of pregnancy were associated with increased risk in the logistic model. Those with a birth interval of less than two years and those with less education were associated with increased risk in both perinatal death groups. While some of these factors have already been associated with perinatal deaths, others have not; the new associations provide clues to mechanisms by which the risk of death increases before or after delivery.

Age Factors↗
PubMed2000

Predicting preeclampsia in the second pregnancy from low birth weight in the first pregnancy.

OBJECTIVE: To evaluate the effect of low birth weight adjusted for gestational age in first pregnancies on preeclampsia in second pregnancies and to estimate the proportion of preeclampsia in second pregnancies attributable to histories of LBW for gestational age. METHODS: We conducted a cohort study based on linked data from the Medical Birth Registry of Norway, which covered all births in 1967-1992. RESULTS: Women who delivered infants under the third percentile birth weight were three times more likely to have initial or recurrent preeclampsia in second pregnancies than those who delivered infants at or above the tenth percentile. After adjusting for maternal age, year of birth, interpregnancy interval, education, chronic hypertension, diabetes mellitus, and change of partner, the increased risk persisted. Birth weight below the tenth percentile in the first delivery accounted for 10% of the total cases of preeclampsia in the second pregnancy and 30% of recurrent cases. CONCLUSION: A history of low birth weight adjusted for gestational age is associated significantly with subsequent occurrence as well as recurrence of preeclampsia. These findings are consistent with the hypothesis of a shared etiologic factor or recurrent pathophysiologic mechanism for preeclampsia and fetal growth restriction. A history of fetal smallness for gestational age is found in a substantial proportion of all cases of preeclampsia and thus seems to be important in the etiology of preeclampsia.

Adult↗
PubMedDate not supplied

Infant feeding and growth--a longitudinal study in three Swedish communities.

In a prospective longitudinal study of 312 Swedish infants physical growth was analysed in relation to breast feeding, artificial feeding and some other possible determinants of growth. Weight and length at eight ages, from birth to 19.5 months as well as weight and length velocities for the corresponding intervals are reported. Almost all infants were breastfed during the first month of life and 50% were still breastfed at six months of age. The attained weights and lengths of these infants were generally above the national or international standards in early infancy and around the standard from six months of age. In a regression analysis the weight and length velocities are analysed in relation to feeding habits, birth weight, birth length and some other factors. Entirely breast-fed infants were shown to have a higher weight and length velocity than mixed- or formula-fed infants during the first three months of life. The artificially fed infants showed a catch-up in growth during the next three months and there was no difference in attained weight or length from six months of age due to previous feeding habits. The higher initial weight and length velocities of breast-fed infants were not caused by any catch-up due to unfavourable intra-uterine factors. Entirely breast-fed infants were heavier at birth; a difference which could be explained by differences in smoking habits during pregnancy. The consequences for the interpretation of individual growth patterns in early infancy and the need of an appropriate growth standard for the first six months of life are discussed.

Anthropometry↗
PubMedDate not supplied

Visual evoked potentials in preterm infants during the first hours of life.

Flash evoked cortical potentials (VEPs) were studied in 33 preterm infants with gestational ages from 27 to 33 weeks. During the first 12 h after birth a visual response was evoked in all infants. Better estimates of the VEP latency and amplitude were obtained by using the values of 3 VEPs recorded at 30 sec intervals. The VEP latency decreased during the first hours of life, which was accounted for by an increase in core temperature; the latency decreased 6 msec/degrees C increase. Changes in amplitude were less influenced by changes in temperature. Both VEP latency and amplitude were inversely related to gestational age, but there was no association between head circumference and latency. The flash intensity could be reduced from 155 cd to 39 cd without any effect on VEP latency or amplitude. Similarly, a variation of background illumination below 200 lux did not cause VEP changes. The VEP was not affected by development of minor subependymal haemorrhages but it was severely attenuated during a short episode of hypoxia. It is suggested that when taking core temperature into account the VEP can be used to determine changes in the cerebral function in preterm infants.

Cerebral Hemorrhage↗
PubMed2001

The association between perineal trauma and spontaneous perineal tears.

OBJECTIVE: We assessed whether women who had a perineal trauma (episiotomy or spontaneous tear of the second degree or higher) at the first delivery were at increased risk for spontaneous perineal tears at the next delivery, and whether the risk increases with the severity of previous perineal trauma. DESIGN: Retrospective cohort study. POPULATION: We included data from 1895 women who had their first and second deliveries at Saint-Sacrement Hospital, Quebec City, Canada, between 1985 and 1994. Our study was restricted to women who gave birth vaginally to a single living neonate at their first 2 deliveries and who did not have an episiotomy at the second delivery. We extracted the data from the Department of Obstetrics computerized database. OUTCOMES MEASURED: Spontaneous perineal tears (of second degree or higher) at the second delivery. RESULTS: Having a perineal trauma at the first delivery more than tripled the risk (relative risk=3.3; 95% confidence interval, 2.6-4.2) of spontaneous perineal tears at the second delivery. The risk of spontaneous perineal tears at the second delivery increased with the severity of previous perineal trauma at birth. CONCLUSIONS: Our results show that the risk of spontaneous perineal tears at subsequent deliveries increases with the presence and the severity of perineal trauma at the first delivery.

Adult↗
PubMed1992

Reproductive factors in breast cancer epidemiology.

There is abundant epidemiologic evidence showing that early menarche, late menopause, low parity and late age at first birth are related to increased risk of breast cancer. However, in younger age groups, uniparous women seem to be at higher risk than nulliparous, and the effect of later pregnancies is less clear in this group. Intervals between pregnancies may modify the general protective effect. Some studies have indicated an adverse effect of late age at pregnancies after the first. Further studies are necessary to determine if the general protective effect of pregnancies after the first is preceded by a transient increase in breast cancer risk. No clear association has been established with number of abortions. Results from two large prospective studies suggest that breast feeding is not strongly related to risk of breast cancer among Western populations.

Abortion, Induced↗
PubMed1994

Cumulative conception and live-birth rates after in vitro fertilization with and without the use of long, short, and ultrashort regimens of the gonadotropin-releasing hormone agonist buserelin.

OBJECTIVE: Our purpose was to compare cumulative conception and live-birth rates after in vitro fertilization with and without the use of the long, short, and ultrashort regimens of the gonadotropin-releasing hormone agonist buserelin. STUDY DESIGN: Life-table analysis of conception and live-birth rates in relation to ovarian stimulation regimen used in 2893 women who had one of five stimulation regimens exclusively throughout all treatment cycles, namely, human menopausal gonadotropin with or without clomiphene citrate; follicle-stimulating hormone with or without clomiphene citrate; and long, short, and ultrashort protocols of buserelin, plus follicle-stimulating hormone or human menopausal gonadotropin; and in an additional 347 women who had been administered both human menopausal gonadotropin and follicle-stimulating hormone with or without clomiphene citrate. RESULTS: The cumulative conception rate and cumulative live-birth rate were significantly higher in those women treated exclusively with the long buserelin regimen (59% and 55%, respectively, after three cycles) compared with those who only had human menopausal gonadotropin or follicle-stimulating hormone with or without clomiphene citrate (39% and 29%, respectively, after three cycles) (p = 0.001 and p = 0.0001) or compared with those who had only short or ultrashort buserelin regimens (22% and 17% after two cycles) (p = 0.0001 and p = 0.005). The pregnancy failure rate in patients on the long buserelin regimen was 22.4% (95% confidence interval 14.8% to 30.0%) compared with 33.3% (95% confidence interval 29.6% to 37.0%) in those who had human menopausal gonadotropin or follicle-stimulating hormone with or without clomiphene citrate (p = 0.03). When the probabilities of first conception and first live birth were examined by treatment regimen, after we allowed for the effects of age, cause of infertility, calendar year of treatment, and treatment cycle number (with a multiple logistic regression model), it was found that, relative to human menopausal gonadotropin or follicle-stimulating hormone with or without clomiphene citrate, the odds of conceiving with the long buserelin regimen was 1.63 (95% confidence interval 1.31 to 2.03) (p < 0.001) and the odds of a live birth was 1.97 (95% confidence interval 1.53 to 2.54) (p < 0.001). Similarly, relative to short or ultrashort buserelin the odds of conceiving with long bureselin was 1.88 (95% confidence interval 1.39 to 2.55) (p < 0.001) and the odds of a live birth was 1.79 (95% confidence interval 1.25 to 2.56) (p = 0.001). CONCLUSION: Pituitary desensitization with the long protocol of buserelin significantly increases the probabilities of conception and live birth after in vitro fertilization.

Adult↗
PubMed2001

Teenage pregnancy and risk of adverse perinatal outcomes associated with first and second births: population based retrospective cohort study.

OBJECTIVE: To determine whether first and second births among teenagers are associated with increased risk of adverse perinatal outcomes after confounding variables have been taken into account. DESIGN: Population based retrospective cohort study using routine discharge data for 1992-8. SETTING: Scotland. MAIN OUTCOME MEASURES: Stillbirth, preterm delivery, emergency caesarean section, and small for gestational age baby among non-smoking mothers aged 15-19 and 20-29. RESULTS: The 110 233 eligible deliveries were stratified into first and second births. Among first births, the only significant difference in adverse outcomes by age group was for emergency caesarean section, which was less likely among younger mothers (odds ratio 0.5, 95% confidence interval 0.5 to 0.6). Second births in women aged 15-19 were associated with an increased risk of moderate (1.6, 1.2 to 2.1) and extreme prematurity (2.5, 1.5 to 4.3) and stillbirth (2.6, 1.3 to 5.3) but a reduced risk of emergency caesarean section (0.7, 0.5 to 1.0). CONCLUSIONS: First teenage births are not independently associated with an increased risk of adverse pregnancy outcome and are at decreased risk of delivery by emergency caesarean section. However, second teenage births are associated with an almost threefold risk of preterm delivery and stillbirth.

Adolescent↗
PubMed1988

Effects of salinomycin on sow weight change during lactation and on sow reproductive performance.

Forty-five gravid cross-bred sows (mean parity 3.3 +/- .3) were randomly allotted to two dietary treatments: corn-soybean mean (CS) or CS plus 60 mg salinomycin per kilogram of diet (CSS). Sows were fed their respective diets through two successive parities with dietary treatment initiated at 100 d postcoitum and continued until weaning of the second successive litter. Therefore, sows fed CSS received salinomycin for 14 d before the first parturition and for approximately 153 d before the second parturition. Daily feed intake was restricted to 2 kg.hd-1.d-1 during gestation and to 3 kg.hd-1.d-1 from weaning to breeding. All sows. had ad libitum access to feed during lactation. Sows were weighed 7 d prior to parturition, at weaning and at breeding. Weaning-to-estrus interval and farrowing interval were recorded for all sows. Litters were weighed at birth and weaning. There were no differences (P greater than .05) between dietary treatments in sow weights before parturition, at weaning or at breeding for either first or second farrowing. The CSS-fed sows lost more weight from weaning to breeding after the first (P less than .03) and second (P less than .05) lactation periods than CS-fed sows. The CSS-fed sows tended to gain more (P = .06) weight during lactation than CS-fed sows. There were no differences (P greater than .05) between treatments in lactation feed intake, weaning-to-estrus interval, farrowing interval, litter size born or weaned, litter weights at birth or at weaning, or in sow culling rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2002

Intrapartum fetal head position II: comparison between transvaginal digital examination and transabdominal ultrasound assessment during the second stage of labor.

OBJECTIVE: To test the null hypothesis that no correlation exists between transvaginal digital examination compared with the gold standard technique of transabdominal suprapubic ultrasound assessment of fetal head position during the second stage of labor. A secondary objective was to compare the performance of attending physicians vs. senior residents in depicting fetal head position by transvaginal digital examination in comparison with ultrasound assessment. METHODS: Consecutive patients in the second-stage of labor at term with normal singleton cephalic-presenting fetuses and ruptured membranes were included. Transvaginal digital examinations were performed by either attending physicians or senior residents and were followed immediately by transverse suprapubic transabdominal sonographic assessments performed by a single sonographer. Examiners were blinded to each other's findings. Power analysis dictated sample size. Exact binomial confidence intervals around observed rates were compared with chi 2 and Cohen's kappa-tests. Logistic regression was applied. P < 0.05 was considered significant throughout. RESULTS: One hundred and twelve patients were studied. The absolute error of transvaginal digital examinations was recorded in 65% of patients (95% confidence interval, 56-74%). Parity, pelvic station, combined spinal epidural anesthesia, length of first or second stages of labor, use of oxytocin augmentation, gestational age, mode of delivery, birth weight, and examiner experience did not significantly affect examination accuracy. Stratification, when the transvaginal digital examination was recorded as correct if occurring within +/- 45 degrees of the ultrasound assessment, reduced the error of the transvaginal digital examinations to 39% (95% confidence interval, 30-49%). Independent variables again did not affect examination accuracy in this assessment modality. Rates of agreement between the two methods for attending physicians compared with residents were not significantly different. The overall degrees of agreement were 40% (95% confidence interval, 26-55%) and 68% (95% confidence interval, 53-80%) (kappa = 0.25 and 0.30) for the absolute agreement and +/- 45 degrees assessment modalities, respectively, for attending physicians, and 31% (95% confidence interval, 20-44%) and 55% (95% confidence interval, 42-68%) (kappa = 0.14 and 0.12) for senior residents. CONCLUSION: Using ultrasound assessment as the gold standard, our data demonstrate a high rate of error (65%) in transvaginal digital determination of fetal head position during the second stage of labor. The performance of senior residents in transvaginal digital examinations did not differ significantly from that of attending physicians. Intrapartum ultrasound increases the accuracy of fetal head position assessment during the second stage of labor.

Adolescent↗
PubMed1992

Epidemiology of isotretinoin exposure during pregnancy.

BACKGROUND: Exposure to isotretinoin during pregnancy is associated with a high risk of major fetal malformations. OBJECTIVE: Our purpose was to determine the reasons for and outcomes of in utero isotretinoin exposure. METHODS: On the basis of 433 spontaneous reports, we describe the likely reasons these exposures occurred and the outcomes of these pregnancies. In our analysis of the outcomes of pregnancy, we separately consider the pregnancies known to us before their outcomes were determined as prospective cases. RESULTS: Timing of conception in relation to initiation of therapy with isotretinoin was known for 396 women. Of these, 130 patients (33%) were already pregnant when they started isotretinoin. An additional 65 patients (16%) became pregnant in the first 3 weeks of isotretinoin use. Pregnancy outcomes were known on 409 pregnancies. Among these, 222 (54%) ended in elective abortion and 29 (7%) in spontaneous or missed abortion. Of 151 births, 72 (48%) were normal, 71 (47%) had congenital malformations, and 8 (5%) had abnormalities other than malformations. Of 94 prospectively ascertained pregnancies that ended in births, 28% had congenital malformations (95% confidence interval 19% to 37%). Exposure to isotretinoin during any time and for as little as one capsule within the first trimester have been associated with congenital malformations. CONCLUSION: The high proportion of exposures in already or recently pregnant women illustrates the importance of obtaining a negative pregnancy test before the initiation of isotretinoin therapy and of delaying the commencement of isotretinoin therapy until the onset of the next menstrual period. Furthermore, the importance of reliable contraceptive methods should be emphasized to patients when isotretinoin is prescribed. Young women seem to be at an especially high risk of pregnancy exposure to isotretinoin. There is a substantial risk of congenital malformation at all therapeutic doses of isotretinoin, even when the duration of exposure is brief.

Abnormalities, Drug-Induced↗
PubMed2004

Low birth weight infants and Calmette-Guérin bacillus vaccination at birth: community study from Guinea-Bissau.

BACKGROUND: In developing countries, low birth weight (LBW) children are often not vaccinated with Calmette-Guérin bacillus (BCG) at birth. Recent studies have suggested that BCG may have a nonspecific beneficial effect on infant mortality. We evaluated the consequences of not vaccinating LBW children at birth in Guinea-Bissau. METHODS: Between 1989 and 1999, 7138 children born at the central hospital had a birth weight registered. We assessed BCG coverage until 3 years of age. Data on tuberculin skin test (TST) for 297 children and BCG scar for 1319 children in the study population were reanalyzed for differences between normal birth weight (NBW) children and LBW children. We assessed the effect of early BCG vaccination on mortality to 12 months of age. RESULTS: Among LBW children there were 1.5- to 3-fold more unvaccinated individuals than among NBW children up to 4 months of age. There was no overall difference between LBW and NBW children in TST or BCG scarring; LBW children vaccinated early may have had slightly reduced reactions to tuberculin. Among 845 LBW children, 182 had received BCG within the first week of life. Controlling for background factors and censoring at first diphtheria-tetanuspertussis vaccination, measles vaccination or at 6 months of age (whichever came first), the mortality rate ratio for BCG-vaccinated versus -unvaccinated LBW children was 0.17 (95% confidence interval, 0.06-0.49), with an even stronger effect for LBW children vaccinated in the first week of life (mortality rate ratio, 0.07; 95% confidence interval, 0.01-0.62). CONCLUSIONS: The policy of not vaccinating with BCG at birth had a negative impact on vaccination coverage for LBW children. Early BCG vaccination had no large negative impact on TST and BCG scarring. Mortality was lower for BCG-vaccinated than for unvaccinated LBW children controlling for available background factors. BCG vaccination of LBW children may have a beneficial effect on survival that cannot be explained by protection against tuberculosis. Future studies should examine possible adverse effects from equalizing BCG policy for LBW and NBW children.

BCG Vaccine↗
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↗