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Associations of seafood and elongated n-3 fatty acid intake with fetal growth and length of gestation: results from a US pregnancy cohort.

Previous studies, mainly among populations with high consumption of seafood, have suggested that increased marine n-3 polyunsaturated fatty acid (PUFA) intake during pregnancy promotes longer gestation and higher birth weight. Few studies have isolated the contribution of fetal growth to birth weight. Using data from 2,109 pregnant women in Massachusetts enrolled in Project Viva from 1999 to 2002, the authors examined associations of marine n-3 PUFA and seafood intake with birth weight and birth-weight-for-gestational-age z value (fetal growth) using linear regression; length of gestation using median regression; and low birth weight, preterm delivery, and being small for gestational age using logistic regression. After adjustment for maternal and child factors, birth weight was 94 (95% confidence interval: 23, 166) g lower and fetal growth z value 0.19 (95% confidence interval: 0.08, 0.31) units lower in the highest compared with the lowest quartile of first-trimester n-3 PUFA intake. Results for the second and third trimesters were similar, and findings for seafood paralleled those for n-3 PUFA. Elongated n-3 PUFA intake and seafood intake were not associated with length of gestation or risk of preterm birth. Results from this US cohort support the conclusion that seafood intake during pregnancy is associated with reduced fetal growth.

Birth Weight↗

Is the reduction of birth intervals an efficient reproductive strategy in traditional Morocco?

Birth interval lengths are analysed from reproductive life histories of 517 Berber peasant women of the region of Marrakesh (Southern Morocco), whose fertility developed in a full traditional context. The high mortality rates associated with short birth intervals indicate that a rapid succession of births is detrimental to the progeny. The reproductive efficiency of the traditional propensity to a large family size is therefore examined by means of two different evaluations of reproductive success: the 'absolute' reproductive success (the absolute number of offspring surviving to maturity) and the 'relative' reproductive success (the proportion of live born surviving to maturity). The first shows that close pregnancies increase the fertility rate to such an extent that the associate higher number of deaths is more than compensated for, so that the women practising short birth intervals produce more surviving offspring than the others by the end of their reproductive life. The second shows that the probability of survival is directly associated with birth interval length, the efficiency of the reproductive process being therefore greater as birth intervals grow. It is suggested that these two behaviours are not contradictory, and that they represent two successive steps of the same reproductive adjustment to evolving environmental conditions.

Aged↗

Gail model for prediction of absolute risk of invasive breast cancer: independent evaluation in the Florence-European Prospective Investigation Into Cancer and Nutrition cohort.

BACKGROUND: The Gail model 2 (GM) for predicting the absolute risk of invasive breast cancer has been used for counseling and to design intervention studies. Although the GM has been validated in US populations, its performance in other populations is unclear because of the wide variation in international breast cancer rates. METHODS: We used data from a multicenter case-control study in Italy and from Italian cancer registries to develop a model (IT-GM) that uses the same risk factors as the GM. We evaluated the accuracy of the IT-GM and the GM using independent data from the Florence-European Prospective Investigation Into Cancer and Nutrition (EPIC) cohort. To assess model calibration (i.e., how well the model predicts the observed numbers of events in subsets of the population), we compared the number of expected incident breast cancers (E) predicted by these models with the number of observed incident breast cancers (O), and we computed the concordance statistic to measure discriminatory accuracy. RESULTS: The overall E/O ratios were 0.96 (95% confidence interval [CI] = 0.84 to 1.11) and 0.93 (95% CI = 0.81 to 1.08) for the IT-GM and the GM, respectively. The IT-GM was somewhat better calibrated than GM in women younger than 50 years, but the GM was better calibrated when age at first live birth categories were considered (e.g., 20- to 24-year age-at-first-birth category E/O = 0.68, 95% CI = 0.53 to 0.94 for the IT-GM and E/O = 0.75, 95% CI = 0.58 to 1.03 for the GM). The concordance statistic was approximately 59% for both models, with 95% confidence intervals indicating that the models perform statistically significantly better than pure chance (concordance statistic of 50%). CONCLUSIONS: There was no statistically significant evidence of miscalibration overall for either the IT-GM or the GM, and the models had equivalent discriminatory accuracy. The good performance of the IT-GM when applied on the independent data from the Florence-EPIC cohort indicates that GM can be improved for use in populations other than US populations. Our findings suggest that the Italian data may be useful for revising the GM to include additional risk factors for breast cancer.

Breast Neoplasms↗

Birth defects and parental consanguinity in Norway.

The study compares frequencies of birth defects between immigrant groups and the rest of the Norwegian population in Norway and estimates the influence of consanguinity and socioeconomic factors on these frequencies. The authors studied all 1.56 million births in Norway from 1967 to 1993. Of these, 7,494 children had two Pakistani parents, 84,688 had one Norwegian and one immigrant parent, and 25,891 had two immigrant parents from countries other than Pakistan. The risk of birth defects relative to the Norwegian group was 0.98 (95% confidence interval 0.92-1.03) in the group with one foreign and one Norwegian parent, 1.39 (95% confidence interval 1.22-1.60) in the group with two Pakistani parents, and 1.04 (95% confidence interval 0.95-1.14) in the group with two parents from other foreign countries; 0.1% of the Norwegian and 30.1% of the Pakistani children had parents who were first cousins. There was no difference in risk between children of nonconsanguineous Pakistani parents and the other groups. The relative risk of birth defects among children whose parents were first cousins was about 2 in all groups. Among the Pakistani, 28% of all birth defects could be attributed to consanguinity. Low paternal educational level was associated with a slightly increased risk in the Norwegian group, while independent effects of parental educational levels were not found in any other groups.

Confidence Intervals↗

Vocal fundamental frequency characteristics of infant hunger cries: birth to 12 months.

The vocal fundamental frequency (Fo) characteristics of four infants' hunger cries are reported. The infants were audio recorded at monthly intervals during the first year of life. In general, each infant's Fo increased across the one-year period. The increase in Fo was attributed to the transition from early reflexive crying to intentional vocalization behavior, rather than anatomical and physiological growth influences. Discussion focuses on the regulation of infant crying behavior across the first year of life, as well as the diagnostic implications of these findings.

Aging↗

The association of ambient outdoor temperature throughout pregnancy and offspring birthweight: findings from the Aberdeen Children of the 1950s cohort.

BACKGROUND: We assessed the effect of mean ambient outdoor temperature during gestation on birthweight. OBJECTIVE: To assess the effect of mean ambient outdoor temperature during gestation on birth weight. DESIGN: Birth cohort study with record linkage to climate databases. SETTING: Aberdeen, Scotland. SAMPLE: A total of 12,150 individuals born in Aberdeen, Scotland between 1950 and 1956. METHODOLOGY/PRINCIPAL FINDINGS: Perinatal data from a cohort of 12,150 individuals born in Aberdeen, Scotland between 1950 and 1956 were linked to daily outdoor temperature data. Birthweight was seasonally patterned, with lowest birthweights among those born in the winter months (December-February) and highest birthweights among those born in the autumn months (September-November); P= 0.01 for joint sine-cosine functions. Mean ambient outdoor temperature during the first trimester of pregnancy was inversely associated with birthweight and mean ambient outdoor temperature during the third trimester of pregnancy was positively associated with birthweight. In fully adjusted (for sex, maternal age, birth year, birth order and social class) models a 1 degrees C increase in mean ambient outdoor temperature in the mid 10-day period of the first trimester was associated with a 5.4-g (95% confidence interval [CI] 2.9, 7.9 g) decrease in birthweight, whereas a 1 degrees C increase in the mid 10-day period of the third trimester was associated with a 1.3-g (95% CI 0.50, 2.1 g) increase in birthweight. Ambient outdoor temperature in the first trimester of pregnancy explained the seasonal patterning of birthweight. MAIN OUTCOME MEASURE: Birthweight. RESULTS: Birthweight was seasonally patterned, with lowest birthweights among those born in the winter months (December-February) and highest birthweights among those born in the autumn months (September-November); P= 0.01 for joint sine-cosine functions. Mean ambient outdoor temperature during the first trimester of pregnancy was inversely associated with birthweight and mean ambient outdoor temperature during the third trimester of pregnancy was positively associated with birthweight. In fully adjusted (for sex, maternal age, birth year, birth order and social class) models a 1 degrees C increase in mean ambient outdoor temperature in the mid 10-day period of the first trimester was associated with a 5.4 g (95% confidence interval 2.9, 7.9 g) decrease in birthweight, whereas a 1 degrees C increase in the mid 10-day period of the third trimester was associated with a 1.3 g (95% confidence interval 0.50, 2.1 g) increase in birthweight. Ambient outdoor temperature in the first trimester of pregnancy explained the seasonal patterning of birthweight. CONCLUSION: Higher ambient outdoor temperature in the first trimester of pregnancy and/or lower ambient outdoor temperature in the third trimester are associated with reduced offspring birthweight. With the increasing occurrence of temperature extremes, in particular, heat waves, these findings, if replicated in other studies, have important public health implications.

Adolescent↗

Neonatal characteristics in rapidly progressive perinatally acquired HIV-1 disease. The French Pediatric HIV Infection Study Group.

OBJECTIVE: To identify clinical and laboratory parameters at birth that are associated with the rapidly progressive form of human immunodeficiency virus type 1 (HIV-1) disease in children born to infected mothers. DESIGN: Multicenter, prospective study of infants born to HIV-seropositive mothers. SETTING: A total of 62 obstetric and pediatric centers in France. PARTICIPANTS: Of 1386 children born to HIV-1-seropositive mothers at least 18 months before the cutoff date, 267 were infected. Infection was defined as serological positivity at 18 months or death from HIV disease before the age. MAIN OUTCOME MEASURE: Category C events (including opportunistic infections, recurrent severe bacterial infections, cancers, specific encephalopathy, and wasting syndrome) in the new pediatric Centers for Disease Control and Prevention classification during the first year of life, according to clinical, immunological, and virological findings at birth. RESULTS: The risk of category C manifestations at 12 months was significantly higher when an infected newborn had liver and/or spleen enlargement and/or adenopathies (38.1% vs 15.1%; relative risk [RR], 2.5; 95% confidence interval [CI], 1.4 to 6.0; P<.02) or a low proportion (<30%) of CD4+ cells at birth (45.5% vs 15.0%; RR, 3.0; 95% CI, 1.4 to 6.4; P<.005). Similarly, HIV-1 culture and/or polymerase chain reaction positivity during the first week of life was associated with a higher risk of the early, severe form of HIV infection (26.4% vs 9.3%; RR, 2.8; 95% CI, 1.3 to 6.1; P<.006). In case of positive antigenemia at birth, the risk was 50.0% vs 14.4% (RR, 3.5; 95% CI, 1.9 to 6.2; P<.001). These parameters, determined at birth, were strongly interrelated and could reflect active disease onset in utero in some cases of early, severe HIV-1 disease in childhood. CONCLUSIONS: These prognostic markers, particularly virological parameters, are of value in monitoring children infected by HIV and might serve as a basis for early therapeutic intervention.

AIDS Serodiagnosis↗

Reproductive career after breech presentation: subsequent pregnancy rates, interpregnancy interval, and recurrence.

OBJECTIVE: To assess subsequent pregnancy rates and recurrence of breech, as well as interpregnancy interval after a breech presentation. METHODS: We conducted a national population registry-based study using data from 1967 to 1994, with maternal record linkage of sibships, comprising the first to the fourth birth of a mother. RESULTS: The subsequent pregnancy rate after a surviving breech birth was lower than after a surviving nonbreech birth. Women with two births, of which one was a perinatal loss, had a higher subsequent pregnancy rate, compared with those who had surviving infants. The subsequent pregnancy rate was lower after a cesarean delivery irrespective of presentation. The interpregnancy interval was shorter if the previous infant died, whereas presentation did not influence the interval. The adjusted odds ratio of recurrence of breech increased from 4.32 (95% confidence interval [CI] 4.08, 4.59) after one previous breech delivery to 28.1 (95% CI 12.2, 64.8) after three. CONCLUSION: Breech and cesarean delivery lowered the subsequent pregnancy rate, probably because of the women's decision not to reproduce. Thus, preconceptional counseling with information, support, and reassurance regarding future pregnancies and deliveries might reduce the discouraging effect. A high odds ratio of recurrence of breech suggests effects of recurring specific causal factors of either genetic or more permanent environmental origin.

Adult↗

Development of circadian rhythmicity of temperature in full-term normal infants.

Twelve full-term infants (7 girls and 5 boys) with normal neurological, behavioral and somatic development were followed at regular intervals during the first 5 months of life to appreciate the development of circadian rectal temperature rhythmicity. Activity and temperature (oral at birth, rectal thereafter) were monitored for a minimum of 60 hours on seven separate occasions: at birth, 3 weeks, 6 weeks, 8 weeks, 10 weeks, 16 weeks and 20 weeks of age. Activity was measured using an actigraph worn on the infant's wrist, and rectal temperature was measured using a rectal probe attached to a portable microprocessor (Vitalog TM). Data points were collected every 2 minutes. No fewer than ten infants were monitored at each session, and no infant missed more than one session. Missing recordings were due to equipment malfunctions, probe expulsions and minor health problems. Six infants out of 12 were successfully monitored at each of the first four sessions, from birth to 8 weeks of age inclusively, and two subjects were successfully monitored at all seven sessions. Periodic regression analysis was performed by least squares curve fit with secondary analysis of variance. Analysis of covariance was performed on repeated measures. There was no evidence of rectal temperature circadian rhythmicity at 3 weeks. Two infants demonstrated a circadian rhythmicity at 6 weeks, and all infants had a circadian rhythmicity at 10 weeks post-natal age. At the time of the first observance of circadian rhythmicity of rectal temperature, the mean delta in temperature from peak to trough was 0.6 +/- 0.3 degrees C. This delta was greater at the 16th week, with a mean value of 1.2 +/- 0.3 degrees C. The trough was seen during the first part of the long nocturnal inactivity period. Circadian rhythmicity of rectal temperature was always observed in the studied subjects before the establishment of a consolidated, long daytime wake period.

Body Temperature Regulation↗

Body weight in mouse embryos specifies staging of tooth development.

Great intra- and interlitter variation in morphological stages is known to exist among mouse embryos of the same strain at a similar chronological stage. With the aim of searching for an easily measurable parameter that correlates well with tooth development, the morpho- and histodifferentiation of teeth were compared in embryos classified according to the embryonic day (ED) specified by wet body weight. The embryos and fetuses were harvested at 12-h intervals from ED12.5 until birth, weighed, fixed, and processed histologically. The tooth age was determined according to the developmental progress of the first molar, evaluated based on morpho- and histodifferentiation criteria. The data documented a better correlation between tooth morpho-histodifferentiation with the age/weight staging than with only the embryonic day. The cyto-differentiation of odontoblasts exhibited a high interlitter variability and was similar within specimens of the same litter, regardless of their body weight differences.

Animals↗

The impact of chorionicity on umbilical cord acid-base values in twin gestations.

OBJECTIVE: To evaluate the impact of chorionicity on inter-twin differences in acid-base status at birth. METHODS: Records for twin pregnancies delivered at > or = 24 weeks' gestation from 1 January 1990 to 31 June 2000 were reviewed. Collected data included maternal demographics, gestational age, fetal presentation, anesthesia, delivery mode, inter-twin interval, umbilical artery (UA) and venous (UV) acid-base values, Apgar scores and birth weights. The influence of chorionicity on umbilical cord biochemistry was evaluated. (p < 0.05 was considered significant.) RESULTS: Analysis was carried out in 87 twin pairs (29 monochorionic, MC; and 58 dichorionic, DC). MC and DC twins were similar in maternal age (25.5 vs. 28.2 years), estimated gestational age (33.7 vs. 33.6 weeks), Cesarean delivery (55.2 vs. 52.6%), delivery interval (10 vs. 5 min) and respective birth weights (twin A, 1882 vs. 1981; and twin B, 1828 vs. 1872 g). MC first twins had a higher UA pH (7.31 +/- 0.05 vs. 7.26 +/- 0.08; p = 0.0005) than DC first twins. MC first and second twins had higher UA and UV bicarbonate levels than their DC counterparts (DeltapH = 21.7 +/- 5.1 vs. 18.5 +/- 3.1 mmol/l and 22.0 +/- 3.5 vs. 19.6 +/- 2.5 mmol/l, respectively; p = 0.003). MC twins were more discordant in UA pH than DC twins (DeltapH = 0.043 +/- 0.09 vs. 0.003 +/- 0.07; p = 0.009). MC and DC twins had a similar venous pH (DeltapH = 0.01 +/- 0.06 vs. 0.02 +/- 0.06; p = 0.5). CONCLUSIONS: There is a significant association between placental chorionicity and umbilical cord biochemistry in twins. Although it is possible that the mechanism of this finding is related to placental angioarchitecture, it is unlikely to be a result of simple mixing of blood volumes between twins. The physiology of underlying processes requires further study.

Adult↗

When did bovine spongiform encephalopathy (BSE) start? Implications on the prediction of a new variant of Creutzfeldt-Jakob disease (nvCJD) epidemic.

BACKGROUND: Knowing the starting date of the BSE epidemic and its size at the very beginning is crucial to interpret the timing of the nvCJD cases and to forecast the nvCJD epidemic. The first cases occurred in 1985. The models devised by Anderson (back-calculation) and Dealler (age-period-cohort) led to an estimate of less than 50 cases in 1983, and none earlier. Here, we applied age-cohort models to the BSE data in order to estimate the earliest possible date of the first unrecognized BSE cases. METHODS: The numbers of confirmed BSE cases in the UK, by age group and by calendar year from 1988 to 1996, were analysed by Poisson regression. The cases' age distribution was considered as constant between the different birth cohorts. The herd's age structure was taken into account. RESULTS: According to the models, BSE cases may have occurred as early as 1980. The expected number of cases before 1990 is almost twice the number of confirmed cases and exceeds by more than 20% the expected value of Anderson's model. The scenario of first human exposure in 1980 leads to fewer future nvCJD cases than predicted by Cousens with exposure patterns starting in 1983 or 1985. CONCLUSION: The first birth cohort available, consisting of two cases older than 10 in 1988, does not allow any projections before 1980. Moreover, confidence intervals are wide and the power of the study is limited by the great dispersion of the data; the precision of the estimations would be improved by considering geographical incidence. Nevertheless, our projections are consistent with Wilesmith's survey of rendering plants relating the emergence of BSE to the dramatic fall in the proportion of meat and bone meal following solvent extraction, initiated in the late 1970s (65% in 1977 to 10% in 1983).

Animals↗

Employment as a welder and Parkinson disease among heavy equipment manufacturing workers.

OBJECTIVE: We investigated whether employment as a welder with potential exposure to manganese and other substances is associated with Parkinson disease (PD), parkinsonism or related neurological disorders, or accelerates the age of onset of PD. METHODS: We selected cases and controls from 12,595 persons ever employed at three Caterpillar Inc. (CAT) plants between 1976 and 2004 with potential to make a medical insurance claim between 1998 and 2004. Cases had filed a claim for 1) PD, 2) "secondary parkinsonism", 3) "other degenerative diseases of the basal ganglia" or 4) "essential and other specific forms of tremor". Cases were grouped by claims: Group 1-claims 1 and 2 and Group 2-claims 1 to 4, and as study period incident (SPI) or prevalent. Each case was matched to two series of 10 controls each on date of case's first claim, year of birth, race and sex. Series I was also matched on plant. RESULTS: Odds ratios (OR) and 95% confidence intervals (CI) for the variable, "ever welder in any CAT plant" were: Group 1-SPI Cases: Series I (OR = .76, CI = .26-2.19), Series II (OR = .81, CI = .29-2.25); Group 1- Prevalent Cases: Series I (OR = .82, CI = .36-1.86), Series II (OR = .97, CI = .42-2.23); Group 2- SPI Cases: Series I (OR = 1.03, CI = .57-1.87), Series II (OR = 1.21, CI = .67-2.20) Group 2-Prevalent Cases: Series I (OR = 1.02, CI = .62-1.71), Series II (OR = .86, CI = .51-1.43). Our finding of no statistically significant associations for welding employment was maintained following adjustment for potential confounding and evaluation of possible effect modification. Employment as a welder did not accelerate the age of onset of PD. CONCLUSIONS: Our study supported the conclusion that employment as a welder is not associated with Parkinson disease, parkinsonism or a related neurological disorder.

Adult↗

Juvenile granulosa cell tumor of the testis:: contemporary clinical management and pathological diagnosis.

PURPOSE: Juvenile granulosa cell tumor (JGCT) of the testis is a rarely diagnosed subset of testicular stromal tumors. Although this variant of testicular stromal tumor is predominantly a benign entity in prepubertal patients, limited experience precludes a complete understanding of its clinical presentation and pathological diagnosis. MATERIALS AND METHODS: We reviewed all cases of testicular tumors at Children's Hospital of Philadelphia between 1976 and 2002 in males younger than 18 years. We specifically reviewed our experience with JGCT in terms of presentation, surgical treatment and long-term outcome. We also reviewed the microscopic findings and histochemical techniques used to confirm the diagnosis. RESULTS: We identified 77 tumors during the defined interval, of which 3 (3.9%) were JGCTs. All 3 patients with JGCT were first noted to have a testis mass soon after birth. All presented with a firm, unilateral testicular mass. Ultrasonographic findings were consistent with a complex, multiseptated, hypoechoic mass. Two of the 3 patients underwent radical orchiectomy. Testis sparing mass excision was performed in 1 patient. Grossly the tumors were partially cystic masses. Histologically positive immunostaining with inhibin-alpha and negative staining for alpha-fetoprotein (AFP) reliably differentiated JGCTs from yolk sac tumors. At a mean followup of 8.5 years (range 5 to 14) no metastases or local tumor recurrences have been diagnosed. CONCLUSIONS: To our knowledge we report the first case of testis sparing enucleation of a JGCT with a 5-year recurrence-free followup. Testis sparing enucleation is now our procedure of choice for tumors in neonates and prepubertal children with serum AFP in the normal range for age. JGCT should be suspected in neonates presenting at birth with a complex, cystic mass of the testis. Positive immunostaining for inhibin-alpha and a lack of AFP staining have consistently corroborated the pathological diagnosis in our experience and they should be applied for pediatric testis tumors that may mimic yolk sac tumor pathology.

Adolescent↗

Routine ultrasound screening in the third trimester: a population-based study.

BACKGROUND: No population-based study has evaluated the effects of third trimester ultrasound screening on prognosis. OBJECTIVE: To study the effects of routine ultrasound screening in the third trimester on perinatal/infant mortality, prevalence of small for gestational age infants (SGA) and low Apgar score. STUDY DESIGN: Two university clinics using routine ultrasound screening in the third trimester were compared with seven county or district hospitals with no routine screening. Deliveries between 1985 and 1996 were included. In all, 16 municipalities including 56 371 pregnancies with routine screening were compared with 59 municipalities and 153 355 pregnancies without third trimester screening. An observational design was applied, using data stored during pregnancy, delivery, and during the first year (infant mortality) at the Swedish Medical Birth Registry, The National Board of Health and Welfare. Odds ratio with 95% confidence interval was used in the evaluation. End-points included incidence of SGA, perinatal/infant mortality, Apgar score at 5 min, cesarean section and instrumental delivery in areas with versus without routine third trimester screening. RESULTS: No significant difference was seen in the prevalence of the most extreme SGA (< -3 SD from the mean), perinatal complications including cesarean section or instrumental delivery, or perinatal/infant mortality between units with versus without routine ultrasound screening in the third trimester. CONCLUSION: Added to the findings of previous small randomized studies, it seems as if routine third trimester ultrasound screening in an unselected population does not reduce perinatal mortality or early neonatal morbidity, expressed as Apgar scores or SGA.

Apgar Score↗

Epidemiology of SIDS and explained sudden infant deaths. CESDI SUDI Research Group.

OBJECTIVES: To establish whether epidemiologic characteristics for sudden infant death syndrome (SIDS) have changed since the decrease in death rate after the "Back to Sleep" campaign in 1991, and to compare these characteristics with sudden and unexpected deaths in infancy (SUDI) from explained causes. DESIGN: Three-year, population-based, case-control study. Parental interviews were conducted soon after the death and for 4 controls matched for age and date of interview. All sudden unexpected deaths were included in the study and the cause of death was established by a multidisciplinary panel of the relevant health care professionals taking into account past medical and social history of the mother and infant, the circumstances of death, and a full pediatric postmortem examination. Contributory factors and the final classification of death were made using the Avon clinicopathologic system. SETTING: Five regions in England, with a total population of >17 million people, took part in the study. The number of live births within these regions during the particular time each region was involved in the study was 473 000. STUDY PARTICIPANTS: Three hundred twenty-five SIDS infants (91.3% of those available), 72 explained SUDI infants (86.7% of those available), and 1588 matched control infants (100% of total for cases included). RESULTS: Many of the epidemiologic features that characterize SIDS infants and families have remained the same, despite the recent decrease in SIDS incidence in the United Kingdom. These include the same characteristic age distribution, few deaths in the first few weeks of life or after 6 months, with a peak between 4 and 16 weeks, a higher incidence in males, lower birth weight, shorter gestation, and more neonatal problems at delivery. As in previous studies there was a strong correlation with young maternal age and higher parity and the risk increased for infants of single mothers and for multiple births. A small but significant proportion of index mothers had also experienced a previous stillbirth or infant death. The majority of the SIDS deaths (83%) occurred during the night sleep and there was no particular day of the week on which a significantly higher proportion of deaths occurred. Major epidemiologic features to change since the decrease in SIDS rate include a reduction in the previous high winter peaks of death and a shift of SIDS families to the more deprived social grouping. Just more than one quarter of the SIDS deaths (27%) occurred in the 3 winter months (December through February) in the 3 years of this study. In half of the SIDS families (49%), the lone parent or both parents were unemployed compared with less than a fifth of control families (18%). This difference was not explained by an excess of single mothers in the index group. Many of the significant factors relating to the SIDS infants and families that distinguish them from the normal population did not distinguish between SIDS and explained SUDI. In the univariate analysis many of the epidemiologic characteristics significant among the SIDS group were also identified and in the same direction among the infants dying as SUDI attributable to known causes. The explained deaths were similarly characterized by the same infant, maternal, and social factors, 48% of these families received no waged income. Using logistic regression to make a direct comparison between the two index groups there were only three significant differences between the two groups of deaths: 1) a different age distribution, the age distribution of the explained deaths peaked in the first 2 months and was more uniform thereafter; 2) more congenital anomalies were noted at birth (odds ratio [OR] = 3.14; 95% confidence intervals [CI]: 1.52-6. (ABSTRACT TRUNCATED)

Age Distribution↗

Effects of sow-crate design on sow and piglet behavior.

The effects of sow-crate design on certain behaviors of sows and piglets at farrowing and again approximately 3 wk later were evaluated with a 2 x 2 x 4 factorial arrangement of crate width (narrow [N = 55 cm] or wide [W = 64] between lowest horizontal pipes), length (short [S = 183 cm] or long [L = 198] from rump stop to front gate) and side type (lower side of sow crate "fingered" [F], "bowed" bottom bar 20 cm above the floor [B], or straight bottom bar 20 cm [S20] or 25 cm above the floor [S25]). Farrowing-crate design influenced both sow and piglet behaviors both during and immediately after parturition and during nursing-suckling bouts approximately 3 wk later. Activities of 51 sows and their piglets were videorecorded during and immediately following parturition. Sow-crate design affected neither the interval between births of successive piglets in a litter nor the frequency of standing by the sow during parturition. Latency from birth to first mammary contact (LMC) was greater with S25-sided and S sow crates, and especially with S, W crates. A significant interaction occurred between sow-crate side type and dimensions; LMC was longer when S25 sides were combined with S or W crates. Data on suckling behavior were collected from 113 litters over three successive sucklings approximately 3 wk after farrowing. Sow-crate design had no effect either on the consistency with which a piglet suckled a particular teat or teat pair or on the frequency of multiple-teat use. Piglets maintained fewer functional teats with S, S20 crates. The distribution of functional teats between rows was less symmetric with S crates. Piglets nursed with their bodies over a side bar more frequently with B- and S20-sided crates. The sow permitted her piglets to suckle while she was in a vertical stance more frequently with S and N crates, and especially with S, N crates. Sow-crate design affected important behaviors of sows and piglets both during and immediately after parturition as well as during nursing-suckling bouts about 3 wk later.

Animal Husbandry↗

Large bowel cancer in women in relation to reproductive and hormonal factors: a case-control study.

A community-based case-control study of the effect of reproductive factors on risk of large bowel cancer in Australia is described. The study involved 155 cases (99 colon cancer, 56 rectal cancer) and 311 controls who were interviewed with regard to pregnancies and their outcomes, lactation, menstrual history, and oral contraceptive (OC) use. Increasing parity was associated with a decreasing risk of colon cancer; para 0, relative risk (RR)=1; para 1-2, RR=0.9, 95% confidence interval (CI)=0.4-1.8; para greater than or equal to 3, RR=0.4, 95% CI=0.2-0.8; later age at first live birth (AFLB) was associated with increasing risk (AFLB less than or equal to 21 yr, RR=1; 22-25 yr, RR=2.3, 95% CI=1.0-5.5; greater than or equal to 26 yr, RR=2.7, 95% CI=1.2-6.2). These effects were independent of each other. Parity appeared to exert its predominant effect on risk of cancer of the right colon. OC use was more common among controls than cases (RR=0.5; 95% CI=0.3-1.2 for ever vs. never users) and showed a dose-response effect in multiple logistic analysis. The pattern of point-estimate RR for rectal cancer was largely congruent with those for colon cancer but was not significantly different from 1.0.

Adult↗