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PubMed1997

The relationship of calfhood morbidity with survival after calving in 25 New York Holstein herds.

The association of owner-diagnosed calfhood diseases with the length of herd life after calving was evaluated using data collected prospectively over a ten-year period in 25 New York Holstein dairy herds. Herds selected for the study were milking between 35 and 200 Holstein cows, used dairy herd improvement records, bred cows by artificial insemination unless they needed three or more services, and had regularly-scheduled herd health visits by clinicians from the Cornell University College of Veterinary Medicine. Owners recorded occurrences of dullness, respiratory disease, and scours from birth through 90 days of age for all heifer calves that lived at least 24 h and were to be kept as replacements. Milking herd life was measured as the difference between the age at first calving and the age at death or sale. Data on cows sold when the herd went out of business or still in the herd at the end of the study were censored observations. Cox's proportional hazards model was used for statistical analysis of the data. Controlling for age at first calving, study month of birth, and sire predicted difference for milk, there was no statistically significant association of calfhood morbidity with length of herd life. The estimated hazard rate ratios for leaving the milking herd and 95% confidence intervals for dullness, respiratory disease, and scours within 90 days of birth were 1.3 (0.9, 1.9), 0.9 (0.6, 1.3), and 1.0 (0.8, 1.3), respectively. Dullness was the only disease category with an estimated hazard rate ratio greater than 1, and although it was not statistically significant, may warrant evaluation in future studies of long term effects of calfhood morbidity.

Animals↗
PubMed1998

Influence of consanguinity and maternal education on risk of stillbirth and infant death in Norway, 1967-1993.

To analyze the influence of consanguinity and maternal education on stillbirth and infant death for children born in Norway between 1967 and 1993, the authors studied 7,274 children of ethnic Pakistani origin and 1,431,055 children of Norwegian ethnic origin. Of these children, 31.0% of the Pakistani children and 0.1% of the Norwegian children had parents who were first cousins. Consanguinity increased the relative risk of stillbirth (odds ratio (OR) = 1.3, 95% confidence interval (CI) 1.0-1.6) and infant death (OR = 2.4, 95% CI 2.0-3.0), after adjustment for maternal education, maternal age, parity, and year of birth. In 1985-1993, 29% (95% CI 13-45) of stillbirths and infant deaths among the Pakistani group were attributable to consanguinity. In the Norwegian group, 17% (95% CI 13-21) of the deaths were attributable to factors associated with low maternal education, while in the Pakistani group, the corresponding estimate was nonsignificant. The risks of stillbirth and infant death were similar for children with non-consanguineous parents in both populations. This is an important observation considering the differences in socioeconomic status between the two groups. The authors conclude that consanguinity influenced stillbirth and infant death independent of maternal education, and that a large proportion of deaths could be attributed to consanguinity in the Pakistani group due to high frequencies of consanguinity.

Consanguinity↗
PubMed1995

Periconceptional multivitamin use in relation to the risk of congenital urinary tract anomalies.

To study the relation of maternal periconceptional vitamin use to the risk of a congenital urinary tract anomaly (CUTA), we conducted a case-control study using the Washington State Birth Defect Registry. We identified CUTA cases with no known chromosomal abnormality in seven counties in western Washington State occurring between January 1, 1990, and December 31, 1991. We randomly selected a sample, as controls, of all infants delivered in five large hospitals in King County who did not have a birth defect and who were born in the same year as the cases. About 55% of all infants in King County and a smaller proportion of infants in the other six counties are delivered in these five hospitals. We interviewed mothers of 118 cases and 369 controls to obtain information about their vitamin use during the pregnancy and during the year before the conception. After adjustment for maternal race, family income, county of maternal residence, and birth year, we found that women who used multivitamins during the first trimester had only 15% the risk of bearing a child with a CUTA compared with women who did not take vitamins [odds ratio (OR) = 0.15; 95% confidence interval (CI) = 0.05-0.43]. The reduction was smaller for use restricted to the second or third trimesters (OR = 0.31; 95% CI = 0.09-1.02). Among women who used vitamins during the first trimester, vitamin use before conception was not associated with any further reduction in the risk, nor did there appear to be an association with the amount or brand of vitamin used.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2001

Increased breast cancer risk among women who work predominantly at night.

Irregular working hours, including working at night, have serious psychological and physiological effects. In a nationwide population-based case-control study, we investigated the breast cancer risk among 30- to 54-year-old Danish women who worked predominantly at night. Individual employment histories were reconstructed back to 1964 for each of 7035 women with breast cancer and their individually matched controls from the records of a nationwide pension scheme with compulsory membership. Odds ratios, including 5 years of induction time and adjusted for socio-economic status, age at the birth of first and last child and number of children, were estimated by conditional logistic regression analysis. The odds ratio for breast cancer among women who worked at night at least half of a year was 1.5 (95% confidence interval, 1.2 to 1.7), and there was a tendency to increasing odds ratio by increasing duration of nighttime employment.

Adult↗
PubMed2000

Effect of vitamin E sources (RRR- or all-rac-alpha-tocopheryl acetate) and levels on sow reproductive performance, serum, tissue, and milk alpha-tocopherol contents over a five-parity period, and the effects on the progeny.

Two dietary sources of vitamin E (DL-alpha-tocopheryl acetate [DL-beta-TAc], or D-alpha-tocopheryl acetate [DL-alpha-TAc]) at two dietary supplemental levels (30 vs 60 IU/kg) were evaluated in reproducing sows over a five-parity period. The experiment was a 2 x 2 factorial arrangement of treatments conducted as a randomized complete block in two replicates. A total of 48 gilts were fed their treatment diets from 40 kg BW through five parities, reflecting a total of 171 farrowings. Reproductive measurements of litter size, sow weight, and back-fat thickness were collected. The incidence of mastitis-metritis-agalactia (MMA) and fluid discharge from the vagina were evaluated for each sow on each of the first 3 d postpartum. Sows were bled at periodic intervals during gestation and at weaning (21 d) and serum was frozen. After the fifth parity, two to four sows from each treatment group were killed and tissues collected. At birth, two to three neonatal pigs were killed from each sow treatment group within each parity and livers were collected and frozen. In addition, three pigs from each litter from three to four sows per treatment group within each parity were bled at weaning and serum was saved. Six pigs from each sow group at weaning of Parity 5 were also killed and livers were collected and frozen. Sow and pig sera and tissues were analyzed for a-tocopherol. There was no effect (P > .15) of vitamin E source or level on the various sow reproductive measurements, litter size, or the incidences of MMA or fluid discharges from the vagina. Feeding D-alpha-TAc compared with DL-alpha-TAc or 60 IU compared with 30 IU vitamin E/kg diet resulted in higher (P < .01) sow serum, colostrum, and milk alpha-tocopherol contents at each measurement period. Sow liver, adipose, lung, and heart alpha-tocopherol contents were also higher (P < .01) when the 60 IU vitamin E level had been fed. Both serum and liver a-tocopherol contents in 21-d-old nursing pigs were higher (P < .01) when the sow had been fed D-alpha-TAc compared with the DL-alpha-TAc source or when the 60 IU level had been fed. There were no vitamin E source x vitamin E level interactions (P > .15) for the various alpha-tocopherol measurements. Although the supplemental vitamin E sources were provided on an equivalent IU basis, these results suggest that D-alpha-TAc has a higher equivalency than DL-alpha-TAc on an IU basis, but higher dietary levels also resulted in higher sow and pig alpha-tocopherol contents.

Animals↗
PubMed1995

[Presence of Campylobacter spp., Clostridium difficile, C. perfringens and salmonellae in litters of puppies and in adult dogs in a shelter].

In order to ascertain the importance of Campylobacter spp., C.difficile, C.perfringens and Salmonella as agents of bacterial gastroenteritis in dogs, two groups of animals were studied prospectively. The first group consisted of 77 puppies in 14 litters, with fecal cultures performed weekly for 10 weeks, starting at birth. The second group consisted of a kennel population with every dog cultured at entry, and at two-month intervals thereafter. Incidence of Campylobacter spp. was 32 and 31 per 100 dog-month of observation for healthy pups and healthy adult dogs respectively, 46 and 0 for C.difficile, 51 and 36 for C.perfringens and 6.5 and 1.3 for Salmonella. The incidence of Campylobacter spp. in pups peaked at 8 weeks of age. This incidence (43 per 100 dog-months) was higher in pups reared together with older dogs than in pups reared without contact to other dogs (0 per 100 dog-months). Toxigenic strains of C.difficile were found in 61.5% of the healthy neonate dogs. None of the cases of non-watery and non-inflammatory diarrhea we observed was associated with any of the pathogens studied. Furthermore newly acquired colonization with Campylobacter spp. or Salmonella was never associated with episodes of diarrhea. No conclusions could be drawn about the role of bacterial pathogens for causation of watery or inflammatory diarrhea which were not observed in our study.

Animals↗
PubMed1998

Clinical effects of porcine reproductive and respiratory syndrome virus on pigs during the early postnatal interval.

OBJECTIVE: To determine the effect of congenital and early postnatal infection of pigs with porcine reproductive and respiratory syndrome virus (PRRSV) on postnatal survival and growth. ANIMALS: 20 pregnant gilts and their pigs and fetuses. PROCEDURE: 16 pregnant gilts (principals) comprising 4 groups (4 gilts/group) were exposed oronasally to 4 strains of PRRSV (a vaccine strain, and 3 field strains) at or about day 90 of gestation. Four pregnant gilts (controls) were kept under similar conditions, except for exposure to PRRSV. Samples collected from pigs before ingestion of colostrum and samples and specimens collected from pigs at selected times thereafter were tested for PRRSV and homologous antibody. Pigs were observed for clinical signs and were weighed at birth and at weekly intervals until they were euthanatized and necropsied at about 3 weeks of age. RESULTS: At least some members of all litters of principal gilts were infected congenitally. Most noninfected, liveborn littermates became infected within the first week of life. Infection of pigs with field strains did, and infection of pigs with the vaccine strain did not, adversely affect postnatal survival and growth rate. All infected pigs had generalized lymph node enlargement. CONCLUSION: Exposure of pregnant gilts to either attenuated (vaccine) or virulent (field) strains of PRRSV can result in congenital infection. Vaccine as well as field strains can be transmitted postnatally from infected to noninfected littermates. Pigs infected with field strains have a poorer rate of survival and growth than do noninfected pigs. CLINICAL RELEVANCE: Because attenuated (vaccine) PRRSV can cause congenital infection and be transmitted postnatally from congenitally infected to immune-naive pigs, the use of attenuated virus during gestation is, at best, questionable.

Animals↗
PubMed1987

Does a vigorous feeding style influence early development of adiposity?

A prospective study of a cohort of healthy infants observed from birth to 2 years of age was carried out to investigate factors influencing the development of early adiposity. Infant suckling was measured in the laboratory twice during the first month of life. Multiple regression analyses revealed that parental educational level and a measure of feeding behavior, the interval between bursts of suckling, accounted for 18% of the variance in triceps skinfold measures at 1 year of age. A lower level of education and shorter interburst interval were associated with increased adiposity. Two feeding variables, pressure of suckling and the number of reported feeds per day, accounted for 21% of the variance in skinfold thickness at 2 years of age. Fewer, but larger, feeds and a higher sucking pressure were associated with a greater degree of adiposity. It seems that a vigorous infant feeding style, consisting of sucking more rapidly, at higher pressure, with a longer suck and burst duration, and a shorter interval between bursts of sucking, is associated with higher caloric intake and greater adiposity. The early development of this feeding style suggests that it may be a genetically endowed behavior. Breast-feeding protected against early adiposity only to the age of 6 months in this cohort of infants.

Birth Weight↗
PubMed1998

Adaptation in neonatology of the once-daily concept of aminoglycoside administration: evaluation of a dosing chart for amikacin in an intensive care unit.

BACKGROUND: The bactericidal efficacy of aminoglycosides is directly related to peak serum concentration (Cmax), particularly the first one. Transitory high concentrations of aminoglycosides do not result in such a high drug uptake by renal and cochlear tissues because of the saturation of cell binding sites. These observations have led to the concept that less frequent administration of relatively larger doses of aminoglycosides would be of interest in treating infectious diseases. OBJECTIVE: Prospective evaluation of a dosing chart of amikacin (Ak) in high-risk neonates suspected of infection within the first 2 days of life. This dosing chart was based on a previous pharmacokinetic population study published elsewhere, treated accordingly to the new once-daily concept of aminoglycoside administration. STUDY DESIGN: One hundred and seventy-seven neonates (69 females and 108 males; mean gestational age (GA +/-SD: 33.6 +/- 4.1 weeks (W) received Ak regimen dosage according to the following dosing chart: Group (Gr) 1a GA <28 W: 20 mg/kg/42 h; Gr 1b GA 28 </= 31 W: 20 mg/kg/36 h; Gr 2 GA 31 </= 34 W: 18.5 mg/kg/30 h; Gr 3 GA 34 </= 37 W: 17 mg/kg/24 h; Gr 4 GA >/= 37 W: 15.5 mg/kg/24 h. In case of asphyxia, hypoxic episode and intercourse treatment with indomethacin, the interval was systemically increased by 6 h whatever the GA groups. The mean duration time of Ak treatment (+/- 1 SD) was 5.00 +/- 2.01 days (range 2-13). Ak serum concentrations 1 h after completion of 30 min infusion (C1h), and successive Ak serum concentrations just before next administration depending on the difference of interval between each group (so defined minimum serum concentration (Cmin)), were determined in each neonate. Creatininemia during the fist postnatal weeks was used as an index of glomerular filtration rate; brainstem auditory evoked potentials (BEAPs) were used in 139 babies when reaching a postconceptional age of >/= 36 weeks to assess possible ototoxicity, and were compared to values from a group of term and a group of preterm babies, previously defined as our reference control groups. RESULTS: At day 1 of treatment, there was no correlation between the Ak C1hS and the GA at birth (mean 27.8 +/- 5.21 microgram/ml (+/- 1 SD); median 28; r = -0.003; range 10-40). In the same way, there was no correlation between the first Ak CminS and the GA at birth (mean 3.7 +/- 2.0 microgram/ml (+/- 1 SD); median 3.0; r = -0.33; range 0-10). The lack of correlation between these first observed C1hS and CminS and the GA at birth suggests the validity of our previous established dose regimen recommendations. Analyzing the data between groups, the mean value +/- 1 SD of Ak C1hS at day 1 of treatment was not significantly different (p > 0.05). Concerning the first Ak CminS, a significant difference (p < 0.01) was only observed when comparing groups 1a, 1b and 2 to group 4. However, this significant difference disappeared when comparing the successive next Ak CminS between groups while each interval remained the same, suggesting a positive postnatal maturation of the renal clearance. In the same way, creatininemia showed a significant and normal decrease (p < 0.01) in each group during the first postnatal weeks. Threshold values of BEAPs at 30 dB showed no significant difference (p > 0.05) between the treated groups (preterm group and term group) and the corresponding control groups. While the primary aim of the study was not to test the bactericidal efficacy of this new regimen, the recovery was excellent in 37 babies with proven or highly suspected infectious disease, except in 1 of them who died from septic shock (group B Streptococcus). After 5 years of using this kind of Ak administration in the unit, minimal inhibitory concentration profiles tested in 43 successive bacterial strains collected from inborn patients remained adequate. (ABSTRACT TRUNCATED)

Aminoglycosides↗
PubMed1983

Birth of a sibling: effect on mother-first born child interaction.

This study examined the effects of the birth of a sibling on the first born child-mother interaction. First born children-mother dyads were observed in a playroom setting at 12 and 24 months. At 12 months all first born children had no siblings born, while at 24 months a group of children had acquired a sibling. In general, the findings suggested that first born children who acquire a sibling before they are 2 years old show more dependency behavior to mother and are more upset during a free play session than their counterparts of first born children who have not acquired a sibling. Mothers of first borns with a sibling show a tendency to increase their attention to the first born, but exhibit less playful kinds of interaction. These results from a laboratory setting are consistent with the home observations made by others, and suggest that the mother-first born child interaction may temporarily become less playful and more strained after a sibling is born.

Birth Intervals↗
PubMed1997

Testicular cancer and cryptorchidism in relation to prenatal factors: case-control studies in Denmark.

To explore prenatal risk factors that are common to testicular cancer and cryptorchidism, two parallel case-control studies were conducted in Denmark. Information about characteristics of the mother, the pregnancy, and the birth were obtained from the mothers of cases and controls, using a mailed self-administered questionnaire. A maternal age above 30 years was associated with odds ratios (OR) of 1.9 (95 percent confidence interval [CI] = 1.2-3.0) for cryptorchidism and 2.0 (CI = 1.2-3.6) for testicular seminoma; the latter effect was particularly high when the boy was the first child of the mother (OR = 4.1, CI = 1.1-14.6). Birthweights below 3,000 g or above 4,000 g were associated with increased risks of testicular cancer, with ORs up to 2.6 (CI = 1.1-5.9) for birthweight below 2,500 g. For cryptorchidism, there was a monotonous trend in the OR from 0.4 in birthweights above 4,500 g to 2.3 in birthweights below 2,500 g. The association between cryptorchidism and testicular cancer was not attenuated by adjustment for maternal age and birthweight, indicating that all three variables are independent risk factors for testicular cancer. With the exception of high maternal age, which consistently is associated more strongly with seminoma than with non-seminoma, it remains most likely that seminoma and non-seminoma have similar causes.

Adolescent↗
PubMed1997

Low birth weight and serum lipid concentrations at age 7-11 years in a biracial sample.

The relation between birth weight and serum lipid concentrations at age 7 through 11 years was examined in a sample of 1,411 black children and white children in Washington Parish, Louisiana. Two data sets of the Bogalusa Heart Study were merged: 1) newborn cohort participants (n = 225) initially examined at birth, 1973-1974, and reexamined in 1984-1985 at age 9 through 11 years; and 2) subjects examined at ages 7 through 11 years in 1987-1988 (n = 1,186) whose birth weight was collected from birth certificates in 1991. The prevalence ratios for being in the race-, sex-, and age-specific upper decile of serum lipid concentrations in children born with low birth weight (< 2,500 g) versus those with birth weight > or = 2,500 g were calculated per race-sex group. Among white boys with low birth weight, higher than expected percentages of subjects were in the highest decile group of triglyceride concentrations (0.01 < p < 0.05). The prevalence ratio was 2.42 (95% confidence interval 1.19-4.91). When premature infants were excluded, only for white girls was a greater than expected percentage of subjects with low birth weight found to be in the highest decile group of triglyceride concentrations. The corresponding prevalence ratio for white girls was 3.23 (95% confidence interval 1.16-9.00). In analyses that either included or excluded premature infants, prevalence infants, prevalence ratios for triglyceride concentrations in black boys and black girls and for the low density lipoprotein cholesterol/high density lipoprotein cholesterol ratio, total cholesterol concentration, and very low density lipoprotein cholesterol concentration in all race-sex groups were not significantly different from one. To our knowledge, this is the first study finding associations between low birth weight and elevated triglyceride concentrations in later childhood. A follow-up study among adults is recommended.

Black or African American↗
PubMed2005

Dynamics of Helicobacter pylori infection in a US-Mexico cohort during the first two years of life.

BACKGROUND: The Pasitos Cohort Study has followed children in El Paso, Texas and Ciudad Juarez, Mexico since 1998 to identify determinants of Helicobacter pylori infection. This paper describes patterns of acquisition and elimination of H. pylori infection in 468 children from birth to 24 months. METHODS: Mothers were recruited during pregnancy at maternal-child clinics; children were targeted for follow-up examinations every 6 months after birth. H. pylori infection was detected using the 13C-urea breath test, corrected for age-dependent variation in CO2 production. RESULTS: Test results were available for 359, 341, 269, and 215 children around target ages of 6, 12, 18, and 24 months, respectively. The person-time at risk of a first detectable infection was 7742 person-months; 128 first infections were detected, thus the incidence rate was 1.7% per month (95% confidence interval 1.4-2.0%). Rates were similar in boys and girls and on both sides of the border; evidence suggests, however, that this similarity could be due to selection bias. Among children with follow-up after a positive test, 77% tested negative at a later visit. CONCLUSIONS: The initial acquisition of detectable H. pylori infection occurred at a rate of 20% per year among Pasitos Cohort children from birth to 24 months of age. A key finding, with implications for clinical, community health, and research settings, is that most of these infections did not persist. The transient nature of early H. pylori infection should be considered when designing research or contemplating therapeutic intervention for this age group.

Breath Tests↗
PubMed2002

Factors influencing alcohol consumption during pregnancy and after giving birth.

AIMS: This study explored the demographic profile of women consuming alcohol during pregnancy and after giving birth, as part of a larger cohort study of smoking during pregnancy. METHODS: This was a prospective study of a cohort of 665 women registered with a maternity care provider organisation for antenatal care in Wellington. Data were collected from postal questionnaires sent at intervals during gestation and the postnatal period. The questionnaires elicited information about smoking, alcohol consumption and demographic data. RESULTS: At 24 weeks gestation, 74% of women reported not consuming any alcohol in the preceding seven days. Women who were pregnant for the first time, women who experienced nausea, women who were socio-economically deprived and women who smoked were less likely to report having consumed alcohol. At six weeks after giving birth the number of women reporting not consuming any alcohol in the preceding seven days decreased to 46%. Socio-economic deprivation was associated with abstention and tertiary education with alcohol consumption. CONCLUSIONS: Approximately a quarter of women continue to drink alcohol during pregnancy. Health education aiming to reduce alcohol consumption in pregnancy needs to take into account the profile of women who drink during pregnancy.

Adult↗
PubMed2000

Prenatal exposure to valproic acid during pregnancy and limb deficiencies: a case-control study.

We conducted a case-control study using data from the Spanish Collaborative Study of Congenital Malformations (ECEMC) on the relationship between prenatal exposure to valproic acid (VPA) and the presence of limb deficiencies in newborn infants. Among a total of 22,294 consecutive malformed infants (once we excluded genetic syndromes) and 21,937 control infants with specified data on antiepileptic drugs during gestation, 57 malformed infants and 10 control infants were exposed to VPA during the first trimester of pregnancy. Of the total of malformed infants exposed to VPA, 36.8% (21/57) presented with congenital limb defects of different types (including overlapping digits, talipes, clubfoot, clinodactyly, arachnodactyly, hip dislocation, pre- and postaxial polydactyly, etc.), three of them having limb deficiencies. The result of the case-control analysis shows a risk for limb deficiencies of odds ratio = 6.17 [confidence interval (CI) 1.28-29.66, P = 0.023], after controlling for potential confounder factors. If we consider that in our population the prevalence at birth of this type of defect is 6.88 per 10,000 livebirths (95% CI 6.43-7.36) we can estimate that the risk for women treated with VPA of having a baby with limb deficiencies would be around 0.42%. The limb deficiencies in the three patients exposed to VPA were the following: the first case was a newborn infant with hypoplasia of the left hand, the second patient was a newborn infant with unilateral forearm defect and hypoplastic first metacarpal bone in the left hand, and the third patient presented with short hands with hypoplastic first metacarpal bone, absent and hypoplastic phalanges, retrognathia, facial asymmetry, hypospadias, teleangiectatic angioma in skull, and hypotonia.

Anticonvulsants↗
PubMed1999

Leukocyte counts in relation to the method of delivery during the first five days of life.

The goal of the present study was to evaluate total and differential leukocyte counts during the first 5 days of life in relation to the method of delivery. We included 203 healthy term infants; of these, 114 were born by vaginal delivery, and 89 by elective cesarean section. Total and differential leukocyte counts were evaluated at the following intervals: 0-6, 7-12, 13-24, 25-48, 49-72, 73-96, and 97-120 h after birth. The cord serum cortisol level was measured as an indicator of the degree of delivery-related stress. Mean leukocyte and neutrophil counts were higher in infants born by vaginal delivery in cord blood and up to 12 h of life. No significant differences were observed in the immature: total neutrophil ratios between the two groups of infants. The cord serum cortisol level was higher in vaginally delivered infants. A significant correlation was found between cortisol and leukocyte, neutrophil, or lymphocyte counts. The method of delivery produces significantly different total leukocyte and neutrophil counts during the first 12 h after birth; after this time, there appears to be no more variation of leukocyte counts during the first 5 days of life.

Cesarean Section↗
PubMed2005

Paternity following treatment for testicular cancer.

BACKGROUND: Studies of fertility in men treated for testicular cancer have mainly addressed serum follicle-stimulating hormone levels and sperm parameters. We assessed post-treatment paternity among long-term survivors of testicular cancer. METHODS: Men (n = 1814) who had been treated for unilateral testicular cancer in Norway during 1980 through 1994 were invited to participate in a national multi-center follow-up survey in 1998 through 2002. The participants were allocated to five groups according to the treatment received after orchiectomy, including treatment at relapse (surveillance, retroperitoneal lymph node dissection, radiotherapy, low-dose chemotherapy [i.e., < or = 850 mg cisplatin], and high-dose chemotherapy [i.e., > 850 mg cisplatin]). Cox proportional hazards analysis was used to assess predictive factors for post-treatment paternity. Statistical tests were two-sided. RESULTS: A total of 1433 men were assessable, of whom 827 were fathers at diagnosis. Post-treatment conception was attempted by 554 men, among whom the overall 15-year actuarial post-treatment paternity rate was 71% (95% confidence interval [CI] = 66% to 75%) without the use of cryopreserved semen. This rate ranged from 48% (95% CI = 30% to 69%) in the high-dose chemotherapy group to 92% (95% CI = 78% to 98%) in the surveillance group (P < .001). The median actuarial time from diagnosis to the birth of the first child after treatment was 6.6 years overall but varied according to treatment. Assisted reproductive technologies were used by 22% of the couples who attempted conception after treatment. Dry ejaculation, treatment group, pretreatment fatherhood, and marital status were statistically significant independent predictors for post-treatment fatherhood, with dry ejaculation as the most important negative factor. CONCLUSIONS: Although the overall paternity rate after treatment for testicular cancer was high, the ability to conceive and the time to conception reflected the intensity of treatment. These data may help inform patients about their future ability to father biological children.

Actuarial Analysis↗
PubMed1986

On the process of stabilization in the renewal model: approximations for the time to convergence.

The transient behaviour of the renewal model leading to the stable age distribution is studied for weakly skewed net maternity functions (found in human as well as in some animal populations). The study, which is partly based on heuristic arguments, first provides approximate expressions for the damping constant and the circular frequency (in terms of the moments of the net maternity function) belonging to the principal oscillatory component of the birth trajectory. The time to stability (defined as the time interval after which the principal oscillatory component has become less than a certain fraction of the stable solution) is then determined in two cases: For the genesis model and for a stable population in which the net reproduction rate is reduced to one. The results are applied to a problem which arises in the mass rearing of pest insects.

Animals↗