Threshold-linear estimation of genetic parameters for farrowing mortality, litter size, and test performance of Large White sows.
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Up to 109,447 records of 49,656 Large White sows were used to evaluate the genetic relationship between number of pigs born dead (BD) and number born alive (BA) in first and later parities. Performance data (n = 30,832) for ultrasound backfat (BF) at the end of the test and days to reach 113.5 kg (AD) were used to estimate their relationships with BD and BA at first parity in a four-trait threshold-linear analysis (TL). Effects were year-farm, contemporary group (CG: farm-farrowing year-farrowing month) and animal additive genetic. At first parity, estimates of heritability were 0.09, 0.09, 0.37, and 0.31 for BA, BD, AD, and BF, respectively. The estimate of genetic correlation between BD and litter size was -0.04 (BD-BA). Corresponding values with test traits were both -0.14 (BD-AD, BD-BF). Estimates of genetic correlation between BA and performance traits were 0.08 (BA-AD) and 0.05 (BA-BF). The two test traits were moderately negatively correlated (-0.22). For later parities, a six-trait (BD, BA in three parities) TL model was implemented. The estimates of additive genetic variances and heritability increased with parity for BD and BA. Estimates of heritabilities were: 0.09, 0.10, and 0.11 for BD, and 0.09, 0.12, and 0.12 for BA in parities one to three, respectively. Estimates of genetic correlations between different parities were high (0.91 to 0.96) for BD, and slightly lower (0.74 to 0.95) for BA. Genetic correlations between BD and BA were low and positive (0.02 to 0.17) for BA in Parities 1 and 2, but negative (-0.04 to -0.10) for BA in Parity 3. Selection for increased litter size should have little effect on farrowing piglet mortality. Intense selection for faster growth and increased leanness should increase farrowing piglet mortality of first-parity sows. A repeatability model with a simple correction for the heterogeneity of variances over parities could be implemented to select against farrowing mortality. The genetic components of perinatal piglet mortality are independent of the ones for litter size in the first parity, and they show an undesirable, but not strong, genetic association in second parity. (+info)
The placental RCAS1 expression during stillbirth.
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BACKGROUND: Independently of the fetal death cause the beginning and course of stillbirth is closely related with the growing cytotoxic activity at the maternal-fetal interface. RCAS1 participates in the inhibition of maternal immune response during pregnancy. The alterations of RCAS1 protein expression in placental cells seem to determine the beginning of the labor and participate in the placental abruption. The aim of the present study was to investigate RCAS1 expression in placentas obtained following stillbirths or normal term births. METHODS: RCAS1 expression was evaluated by Western blot method with the use of monoclonal anti-RCAS1 antibody in 67 placental tissue samples. Pregnant women were divided into four groups according to the mode of labor onset--spontaneous or induced, and the type of labor, stillbirth or labor at term. Placental beta-Actin expression was chosen as a control protein. Relative amounts of placental RCAS1 were compared with the use of Student's t-test, whereas beta-Actin control data were compared with the use of Mann-Whitney U test. RESULTS: The average relative amount of RCAS1 was significantly lower in women with induced stillbirths than in women with induced labor at term. Similarly, significantly lower RCAS1 placental levels were observed in patients with spontaneous stillbirths than in women with spontaneous labor at term. Significant differences in RCAS1 expression were also observed with the respect to the beginning of the stillbirth: spontaneous and induced. Lowest RCAS1 placental levels were observed in women with spontaneous stillbirth. CONCLUSIONS: These preliminary results indicate that the alterations of RCAS1 expression in the human placenta may be involved in the changes of maternal immune system that take place during stillbirth. (+info)
Minor physical anomalies are not increased in the offspring of mothers with systemic lupus erythematosus.
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OBJECTIVE: To determine the incidence and type of minor physical anomalies (MPAs) in infants born to mothers with systemic lupus erythematosus (SLE). METHODS: Each trimester, pregnant women with SLE were assessed for disease activity, prescribed drug use, and exposure to tobacco, alcohol, and illicit drugs through a self reported questionnaire. Infant examinations were performed on 30/39 (77%) live births in women with SLE and the incidence of MPAs determined. RESULTS: 2/30 (7%) patients had three or more MPAs; 4 (13%) had two; 7 (23%) had one; and 17 (57%) had none. One in three women reported alcohol, tobacco, and illicit drug use. Facial anomalies were the most common MPAs. The relative risk and 95% confidence interval for any MPA were 2.05 (0.99 to 4.26) for tobacco use; 1.95 (0.92 to 4.11) for alcohol use; 1.36 (0.165 to 11.23) for maternal disease flare; 0.63 (0.27 to 1.47) for prednisone use; and 0.72 (0.21 to 2.44) for aspirin use. CONCLUSION: 13/30 (43%) infants had minor anomalies-a similar incidence to that of the general population. Counselling for preventable self reported exposure is advisable in addition to counselling specifically for lupus management during pregnancy. (+info)
Can all neonatal resuscitation be managed by nurse practitioners?
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AIM: To assess the ability of nurse practitioners to manage the care of all babies requiring resuscitation at birth in a unit without on site medical assistance. METHOD: A prospective review, and selective external audit, of the case records of all 14 572 babies born in a maternity unit in the north of England during the first eight years after nurse practitioners replaced resident paediatric staff in 1996. RESULTS: Every non-malformed baby with an audible heart beat at the start of delivery was successfully resuscitated. Twenty term babies and 41 preterm babies were intubated at birth. Eight term babies only responded after acidosis or hypovolaemia was corrected following umbilical vein catheterisation; in each case the catheter was in place within six minutes of birth. Early grade 2-3 neonatal encephalopathy occurred with much the same frequency (0.12%) as in other recent studies. Independent external cross validated review found no case of substandard care during the first hour of life. CONCLUSION: The practitioners successfully managed all the problems coming their way from the time of appointment. There was no evidence that their skill decreased over time even though, on average, they only found themselves undertaking laryngeal intubation once a year. It remains to be shown that this level of competence can be replicated in other settings. (+info)
The distribution of apolipoprotein E alleles in Scottish perinatal deaths.
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BACKGROUND: The apolipoprotein E (ApoE) polymorphism has been well studied in the adult human population, in part because the e4 allele is a known risk factor for Alzheimer's disease. Little is known of the distribution of ApoE alleles in newborns, and their association with perinatal brain damage has not been investigated. METHODS: ApoE genotyping was undertaken in a Scottish cohort of perinatal deaths (n = 261), some of whom had prenatal brain damage. The distribution of ApoE alleles in perinatal deaths was compared with that in healthy liveborn infants and in adults in Scotland. RESULTS: ApoE e2 was over-represented in 251 perinatal deaths (13% v 8% in healthy newborns, odds ratio (OR) = 1.63, 95% confidence interval (CI) 1.13 to 2.36 and 13% v 8% in adults, OR = 1.67, 95% CI 1.16 to 2.41), both in liveborn and stillborn perinatal deaths. In contrast, the prevalence of ApoE e4 was raised in healthy liveborn infants (19%) compared with stillbirths (13%, OR = 1.59, 95% CI 1.11 to 2.26) and with adults (15%, OR = 1.35, 95% CI 1.04 to 1.76). However, no correlation was found between ApoE genotype and the presence or absence of perinatal brain damage. CONCLUSIONS: This study shows a shift in ApoE allelic distribution in early life compared with adults. The raised prevalence of ApoE e2 associated with perinatal death suggests that this allele is detrimental to pregnancy outcome, whereas ApoE e4 may be less so. However, ApoE genotype did not appear to influence the vulnerability for perinatal hypoxic/ischaemic brain damage, in agreement with findings in adult brains and in animal models. (+info)
Uterine artery Doppler at 11-14 weeks of gestation to screen for hypertensive disorders and associated complications in an unselected population.
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OBJECTIVES: To establish reference values for the first-trimester uterine artery (UtA) pulsatility index (PI) and to investigate the role of UtA Doppler in the early prediction of hypertensive disorders and their associated complications in an unselected Mediterranean population. METHODS: A prospective study including 1091 consecutive singleton pregnancies undergoing routine early ultrasound screening at 11-14 weeks of gestation was performed. The left and right UtA were examined by color and pulsed Doppler transvaginally. The mean PI and the presence of bilateral protodiastolic notching were cross-sectionally recorded. Reference ranges were calculated and the pregnancies were followed for occurrence of pre-eclampsia, gestational hypertension, intrauterine growth restriction, placental abruption and stillbirth. The sensitivity and predictive values of a mean UtA-PI>95th percentile and the presence of bilateral notching in the prediction of these pregnancy complications were calculated. RESULTS: A total of 999 women were finally included. Both the mean UtA-PI and the prevalence of bilateral notches showed a significant linear decrease between 11 and 14 weeks' gestation. Sixty-seven (6.7%) pregnancies developed at least one of the formerly described complications, including 22 (2.2%) cases of pre-eclampsia and 37 (3.7%) cases with intrauterine growth restriction. Compared with women with a normal outcome, complicated pregnancies showed a significantly higher mean PI (2.04 vs. 1.75; P<0.05, t-test) and a higher prevalence of bilateral notching (58% vs. 41%; P<0.05, Chi-square test). Using the 95th percentile in mean UtA-PI as a cut-off, 23.9% (95% CI, 13.7-34.1) of complicated pregnancies and 30.8% (95% CI, 5.68-55.85) of severe cases were identified. CONCLUSIONS: Our results suggest that pregnancies with an increased risk of developing hypertensive disorders and related complications already have an abnormally increased UtA-PI in early pregnancy. However, the use of a single uterine Doppler measurement for screening purposes in unselected early pregnancy populations has limited clinical value. The use of UtA-PI combined with other screening tests needs to be determined by further investigation. (+info)
Validity of maternal and perinatal risk factors reported on fetal death certificates.
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We sought to estimate the accuracy, relative to maternal medical records, of perinatal risk factors recorded on fetal death certificates. We conducted a validation study of fetal death certificates among women who experienced fetal deaths between 1996 and 2001. The number of previous births, established diabetes, chronic hypertension, maternal fever, performance of autopsy, anencephaly, and Down syndrome had very high accuracy, while placental cord conditions and other chromosomal abnormalities were reported inaccurately. Additional population-based studies are needed to identify strategies to improve fetal death certificate data. (+info)
Coffee and fetal death: a cohort study with prospective data.
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The authors conducted a cohort study within the Danish National Birth Cohort to determine whether coffee consumption during pregnancy is associated with late fetal death (spontaneous abortion and stillbirth). A total of 88,482 pregnant women recruited from March 1996 to November 2002 participated in a comprehensive interview on coffee consumption and potentially confounding factors in pregnancy. Information on pregnancy outcome was obtained from the National Hospital Discharge Register and medical records. The authors detected 1,102 fetal deaths. High levels of coffee consumption were associated with an increased risk of fetal death. Relative to nonconsumers of coffee, the adjusted hazard ratios for fetal death associated with coffee consumption of 1/2-3, 4-7, and > or =8 cups of coffee per day were 1.03 (95% confidence interval (CI): 0.89, 1.19), 1.33 (95% CI: 1.08, 1.63), and 1.59 (95% CI: 1.19, 2.13), respectively. Reverse causation due to unrecognized fetal demise may explain the association between coffee intake and risk of fetal death prior to 20 completed weeks' gestation but not the association with fetal loss following 20 completed weeks' gestation. Consumption of coffee during pregnancy was associated with a higher risk of fetal death, especially losses occurring after 20 completed weeks of gestation. (+info)