Costs and benefits of non-invasive fetal RhD determination.

OBJECTIVE: Non-invasive fetal Rhesus (Rh) D genotyping, using cell-free fetal DNA (cffDNA) in the maternal blood, allows targeted antenatal anti-RhD prophylaxis in unsensitized RhD-negative pregnant women. The purpose of this study was to determine the cost and benefit of this approach as compared to routine antenatal anti-RhD prophylaxis for all unsensitized RhD-negative pregnant women, as is the current policy in the province of Alberta, Canada. METHODS: This study was a decision analysis based on a theoretical population representing the total number of pregnancies in Alberta over a 1-year period (n = 69 286). A decision tree was created that outlined targeted prophylaxis for unsensitized RhD-negative pregnant women screened for cffDNA (targeted group) vs routine prophylaxis for all unsensitized RhD-negative pregnant women (routine group). Probabilities at each decision point and costs associated with each resource were calculated from local clinical and administrative data. Outcomes measured were cost, number of women sensitized and doses of Rh immunoglobulin (RhIG) administered. RESULTS: The estimated cost per pregnancy for the routine group was 71.43 compared with 67.20 Canadian dollars in the targeted group. The sensitization rates per RhD-negative pregnancy were equal, at 0.0012, for the current and targeted programs. Implementing targeted antenatal anti-RhD prophylaxis would save 4072 doses (20.1%) of RhIG over a 1-year period in Alberta when compared to the current program. CONCLUSIONS: These data support the feasibility of a targeted antenatal anti-RhD prophylaxis program, at a lower cost than that of the existing routine prophylaxis program, with no increased risk of sensitization.

Using a family-based structure to detect the effects of genomic inbreeding on embryo viability in Holstein cattle.

Recent evidence has suggested that some of the decline in reproductive ability in dairy cattle has been caused by embryonic death. The current study compared expected genomic inbreeding from sire-dam mating pairs to genomic inbreeding from live progeny in an attempt to determine how embryonic inbreeding may affect fertility. A total of 11,484 Holstein cattle with 43,485 SNP markers and pedigree information were available for analysis. A total of 412 sire-dam-progeny trios in which all animals had reliable genotypes were discovered. After removal of trios because of parentage errors, 374 remained for analysis. Additionally, a total of 3,031 animals comprising 3,906 genotyped full-sibling pairs were available for comparison. Expected genomic inbreeding measures were calculated by predicting homozygosity independently per SNP (FPHE) in sire-dam mating pairs and by simulating progeny using phased haplotype information (FROHE and FPHE). Actual genomic inbreeding measures were calculated using the percent homozygosity of all SNP (FPH) and using runs of homozygosity (FROH). Average FPHE values (62.8±0.78%) were slightly lower than FPH (63.1±1.12%), when considering each SNP independently. After phasing haplotypes, FPHE (62.5±0.83%) was again slightly lower than FPH (62.7±1.16%), and FROHE (3.46±1.54%) was slightly lower than FROH (3.53±2.17%). Results suggest increases in expected genomic inbreeding do not explain a large effect on embryo viability at average levels of expected inbreeding. Higher variation in FROH values was present with sire-dam mating pairs exhibiting high FROHE, which may suggest high levels of genomic inbreeding are required for a noticeable effect on overall embryo viability. Genomic inbreeding between full siblings was also compared with moderate correlations (0.47-0.52) present. Overall, expected genomic inbreeding measures were calculated, but results did not suggest a large effect of expected inbreeding on embryo viability.

Maternal folic acid and multivitamin supplementation: International clinical evidence with considerations for the prevention of folate-sensitive birth defects.

More evidence is available for maternal intake, absorption, distribution, tissue specific concentrations, and pregnancy outcomes with folic acid (fortification/supplementation) during preconception - first trimester. This Quality Improvement prevention review used expert guidelines/opinions, systematic reviews, randomized control trials/controlled clinical trials, and observational case control/case series studies, published in English, from 1990 to August 2021. Optimization for an oral maternal folic acid supplementation is difficult because it relies on folic acid dose, type of folate supplement, bio-availability of the folate from foods, timing of supplementation initiation, maternal metabolism/genetic factors, and many other factors. There is continued use of high dose pre-food fortification 'RCT evidenced-based' folic acid supplementation for NTD recurrence pregnancy prevention. Innovation requires preconception and pregnancy use of 'carbon one nutrient' supplements (folic acid, vitamin B12, B6, choline), using the appropriate evidence, need to be considered. The consideration and adoption of directed personalized approaches for maternal complex risk could use serum folate testing for supplementation dosing choice. Routine daily folic acid dosing for low-risk women should consider a multivitamin with 0.4 mg of folic acid starting 3 months prior to conception until completion of breastfeeding. Routine folic acid dosing or preconception measurement of maternal serum folate (after 4-6 weeks of folate supplementation) could be considered for maternal complex risk group with genetic/medical/surgical co-morbidities. These new approaches for folic acid oral supplementation are required to optimize benefit (decreasing folate sensitive congenital anomalies; childhood morbidity) and minimizing potential maternal and childhood risk.

Outcomes in a cohort of patients with Stage I twin-to-twin transfusion syndrome.

OBJECTIVE: To determine pregnancy outcomes of patients who present with Stage I twin-to-twin transfusion syndrome (TTTS). METHODS: This was a retrospective review of all patients with TTTS referred to our institution between January 2005 and December 2006. Quintero criteria were used for staging. Laser ablation was not offered to patients with Stage I disease. RESULTS: A total of 155 twin pregnancies were evaluated for TTTS during this period. Forty-two met the criteria for Stage I and were included in the analysis. The overall survival to discharge was 82%. The mean gestational age at the time of consultation was 20.9 +/- 0.4 weeks. A total of 23 cases (54.8%) underwent amnioreduction. Progression of TTTS requiring invasive therapy occurred in four cases. The mean gestational age at delivery was 32.5 +/- 0.62 weeks. When divided according to use of amnioreduction, there were no statistically significant differences between the groups for gestational age at delivery or for birth weight. Those Stage I cases with a CHOP cardiovascular score of 5 or higher delivered almost 3 weeks earlier than the remainder of the cohort. CONCLUSIONS: Progression of TTTS beyond Stage I occurred in only 9.5% of the cohort. Mean gestational age at delivery and survival to discharge did not differ between Stage I patients and those treated with placental laser ablation for more advanced stages of TTTS.

Natural marine oil seepage.

The probable range of seepage into the marine environment is 0.2 x 10(6) to 6.0 x 10(6) metric tons per year. Within this range the best estimate for the present marine seepage worldwide is on the order of 0.6 x 10(6) metric tons per year. This estimate is based on the presumption that only a few other areas around the world are as seepage-prone as southern California. Measurements of seeps and seepage rates are too few to allow an accurate estimation by observation and measurement techniques alone. Seepage potential can, however, be related to geologic criteria, and these provide sound bases for marine seepage assessment. On the basis of this estimate, areas of high seepage potential contribute about 45 percent of the worldwide seepage, areas of moderate seepage about 55 percent, and areas of low seepage less than 1 percent. The situation varies somewhat from ocean to ocean. In the Pacific Ocean, areas of high seep potential are by far the major contributors. In the Atlantic, Indian, Arctic, and Southern oceans, areas of moderate seep potential are most significant because areas of high seep potential are relatively rare in these realnis. The circum-Pacific area is the area of greatest seepage; it contributes about 40 percent of the world's total.

In vitro production of bovine embryos using sex-sorted sperm.

The objective of this study was to investigate the suitability of sex-sorted sperm for producing viable in vitro embryos for subsequent transfer into recipient cows and heifers on commercial dairy farms. From August 2002 to June 2003, ovaries were collected from 104 producer-nominated Holstein donor cows on seven Wisconsin farms via colpotomy or at slaughter. Oocytes (N=3526) were aspirated from these ovaries, fertilized 22+/-0.2h later, and cultured to the morula or blastocyst stage. The fluorescence-activated cell sorting ("Beltsville") approach was used to produce (primarily) X-bearing sperm from the ejaculates of three young Holstein sires, and 365 transferable embryos were produced. On average, 3.6+/-0.3 (means+/-S.E.M.) transferable embryos were produced per donor, including 1.4+/-0.2 (Grade 1), 1.5+/-0.2 (Grade 2), and 0.7+/-0.1 (Grade 3) embryos. Number of usable oocytes per donor (33.9+/-3.3) and percent cleavage (51.1+/-1.9) were significant predictors of the number of blastocysts that developed. Mean conception rates for the resulting in vitro embryos were 34.2+/-1.6% in yearling heifer recipients and 18.2+/-0.7% in lactating cow recipients. Additional oocytes (N=3312) from ovaries of anonymous donors (N unknown) collected at a commercial abattoir were fertilized using unsorted sperm, and the percentage of these that developed to blastocyst stage (20.1+/-2.9) was greater (P<0.05) than the corresponding percentage (12.2+/-2.3) achieved with sex-sorted sperm using oocytes (N=1577) from the same source. In summary, we inferred that in vitro embryo production may be a promising application of sex-sorted sperm in dairy cattle breeding, but that the biological causes of impaired embryo development in vitro and compromised conception rates of transferred embryos should be further investigated.

Congenital stationary night blindness: an animal model.

Electroretinographic studies of myctalopic Appaloosa horses demonstrated photopic and scotopic abnormalities similar to those in humans with congenital stationary night blindness (CSNB) of the Schubert-Bornschein type. The phototopic abnormalities consisted of reduced b-wave amplitudes and slower than normal b-wave implict time. The dark-adapted ERG's consisted of a simple negative potential; the scotopic b-wave was nonrecordable. However, a normal c-wave was present in the dark-adapted response. Histologic studies demonstrated no structural abnormalities that could explain the functional defect.

Bilateral renal agenesis in twins.

We present the second report of like-sex twins concordantly affected with bilateral renal agenesis (BRA). Mode of inheritance is proposed to be autosomal dominant. Screening of first-degree relatives of the BRA proband by ultrasound of the GU system is recommended. Prenatal diagnosis with second-trimester ultrasound screening is recommended when a previous fetus has been affected by bilateral renal agenesis.

Renal agenesis in British Columbia.

We review the incidence of bilateral and unilateral renal agenesis occurring in more than 625,000 consecutive births in British Columbia from 1952 to 1982. In total, 92 cases of bilateral renal agenesis and 117 cases of unilateral renal agenesis were identified. Congenital anomalies occurring in association with these conditions were also analyzed. The findings of the study support a mechanism in at least a proportion of cases of a primary developmental defect involving multiple systems within the fetus, with oligohydramnios being the result of the syndrome not the cause. Oligohydramnios no doubt contributes to the anomalies of the face, musculoskeletal system, and genitalia. No trends in changing incidence over time were identified.

Fetal ultrasound abnormalities: correlation with fetal karyotype, autopsy findings, and postnatal outcome--five-year prospective study.

A 5-year prospective prenatal study in 151 pregnancies with 152 malformed fetuses detected by ultrasound was evaluated cytogenetically. Thirty-five fetuses (23%) had abnormal karyotypes. Specific anatomical fetal malformations identified by ultrasound increase the risk for fetal chromosome abnormalities. Risks of abnormal chromosomes in the fetus are present with both single and multiple anomalies including amniotic fluid volume although the risk is increased with specific anatomical systems and multiple malformations. An abnormal fetal karyotype was present in 17% with a single anatomical abnormality and 30% when two or more anatomical systems were involved. Fetal hydrops, duodenal atresia, and omphalocele were the most specific single ultrasound anomalies; fetal hydrops, IUGR, holoprosencephaly, congenital heart disease, diaphragmatic hernia, duodenal atresia, and omphalocele were the most specific multiple anomalies with abnormal amniotic fluid volume. Termination of pregnancy occurred in 32/58 patients diagnosed prior to the 20th week of pregnancy with most (31/32) having a chromosomal anomaly or severe fetal anomaly. Fetuses terminated after the 20th week had chromosomal (7/18) or lethal fetal anomalies (11/18). The most common aneuploidies were trisomy 21, trisomy 18, and 45,X. The decision to terminate the pregnancy was based in most cases on the fetal ultrasound findings. Correlation of ultrasound and clinical findings is important for accurate genetic counselling.

Comparative genomic hybridization: a new approach to screening for intrauterine complete or mosaic aneuploidy.

In the practice of clinical genetics chromosomal aneuploidy in both mosaic and nonmosaic forms has long been recognized as a cause of abnormal prenatal and postnatal development. Traditionally, cytogenetic analysis of cultured lymphocytes has been used as a standard test for detection of constitutional aneuploidies. As lymphocytes represent only one lineage, chromosomal mosaicism expressed in other tissues often remains undetected. The purpose of this study was to assess the utilization of molecular cytogenetic analysis for detection of chromosomal aneuploidy in placental tissues. Using placentas from 100 pregnancies with viable nonmalformed livebirths, both trophoblast and chorionic stroma were analyzed using comparative genomic hybridization (CGH). In all cases with an indication of chromosomal imbalance by CGH, fluorescence in situ hybridization (FISH) analysis was performed to confirm the presence of aneuploidy. To differentiate between constitutional aneuploidy and confined placental mosaicism (CPM), amniotic membrane was analyzed by CGH and FISH techniques. Our results demonstrated five placentas with CPM for chromosomes 2, 4, 12, 13, and 18, respectively, and two constitutional nonmosaic aneuploidies (47,XXX and 47,XXY). Molecular cytogenetic studies of human placental tissues enables easy analysis of both embryonic (amnion) and extraembryonic (chorion) cell lineages. Detection at birth of chromosomal defects affecting intrauterine placental and fetal development is important because these chromosomal defects may continue to have an influence on postnatal development.

Trisomy 7 CVS mosaicism: pregnancy outcome, placental and DNA analysis in 14 cases.

Prenatal diagnosis by chorionic villus sampling (CVS) documents placental chromosomal mosaicism in approximately 2% of viable pregnancies at 9-12 weeks of gestation and can involve various chromosomes and placental cell lineages. Confined placental mosaicism (CPM) is the result of postzygotic mitotic errors occurring in either diploid or trisomic zygotes. With trisomic zygote rescue, depending on the parental origin of the chromosome which is lost, uniparental disomy (UPD) or biparental disomy (BPD) may arise [Kalousek et al., Am J Hum Genet 52: 8-16, 1993]. In this paper, we present 14 pregnancies which were diagnosed by CVS as mosaic trisomy 7. All follow-up amniocenteses showed a normal diploid karyotype. Using both classical cytogenetics and interphase analysis, studies of term placentae showed variable levels of trisomy 7. DNA analysis was performed in nine cases to determine whether the diploid fetus had BPD 7 or UPD 7. Fetal UPD 7 was present only in one case; in eight other cases biparental inheritance was demonstrated. DNA analysis to establish the origin of trisomy 7 in the placenta was fully informative in six cases. One trisomy resulted from a meiotic error and was associated with fetal UPD 7, while the rest were somatic in origin. It is difficult to compare the effect of CPM for trisomy 7 to other trisomies confined to the placenta, as for most chromosomes there are few available cases. It appears that intrauterine fetal growth is not greatly affected by the presence of a trisomy 7 cell line in the placenta. This finding is in contrast to the serious effect of high levels of trisomy 16 within the placenta on fetal intrauterine growth in a series of well-documented cases of CPM 16 [Kalousek et al. 1993].

Spontaneous abortion and pregnancy outcome after normal first-trimester ultrasound examination.

The aim of the study was to assess the spontaneous abortion rate and pregnancy outcome in a population of women with a normal first-trimester ultrasound examination. Gestational age or bleeding was the indication for 90% of the ultrasound scans. The spontaneous abortion rate increased with advancing maternal age. Other factors affecting the rate were indication for the scan and gestational age at the time of the scan. In the overall group, disregarding maternal age, the spontaneous abortion rate was 2.3%. This background rate of spontaneous abortion can be used to assess the added risk of chorionic villus sampling or other first- or second-trimester procedures. The incidence of antepartum and intrapartum complications in these pregnancies corresponded well with published figures.

Late first-trimester invasive prenatal diagnosis: results of an international randomized trial.

OBJECTIVE: To assess, in a randomized trial, the safety and accuracy of amniocentesis and transabdominal chorionic villus sampling (CVS) performed at 11-14 weeks of gestation, given that this time frame is increasingly relevant to early trisomy screening. METHODS: We compared amniocentesis with CVS from 77 to 104 days of gestation in a randomized trial in a predominantly advanced maternal age population. Before randomization, the feasibility of both procedures was confirmed by ultrasonography, and experienced operators performed sampling under ultrasound guidance; conventional cytogenetic analysis was employed. The primary outcome measure was a composite of fetal loss plus preterm delivery before 28 weeks of gestation in cytogenetically normal pregnancies. RESULTS: We randomized 3,775 women into 2 groups (1,914 to CVS; 1,861 to amniocentesis), which were comparable at baseline. More than 99.6% had the assigned procedure, and 99.9% were followed through delivery. In contrast to previous thinking, in the cytogenetically normal cohort (n = 3,698), no difference in primary study outcome was observed: 2.1% (95% confidence interval 1.5, 2.8) for CVS and 2.3% (95% confidence interval, 1.7, 3.1) for amniocentesis. However, spontaneous losses before 20 weeks and procedure-related, indicated terminations combined were increased in the amniocentesis group (P =.07, relative risk 1.74). We found a 4-fold increase in the rate of talipes equinovarus after amniocentesis (P =.02) overall and in week 13 (P =.03, relative risk = 4.65), but data were insufficient to determine this risk in week 14. CONCLUSION: Amniocentesis at 13 weeks carries a significantly increased risk of talipes equinovarus compared with CVS and also suggests an increase in early, unintended pregnancy loss. LEVEL OF EVIDENCE: I

Developmental toxicity studies in rats and rabbits on 2,4-dichlorophenoxyacetic acid and its forms.

The potential for 2,4-D and its salts and esters to induce developmental toxicity was investigated in rats (8 studies) and rabbits (7 studies). Maternal toxicity associated with exposure was dependent on the dose level expressed as 2,4-D acid equivalents. The severity of the maternal effect was correlated to the 2,4-D acid-equivalent dose, with increasing dose levels that exceeded renal clearance causing increasingly more severe maternal effects. In both species, maternal body weight effects began to be manifested at dose levels of 30 mg 2,4-D acid equivalent/kg/day. At higher dose levels (50-75 mg/kg/day in rats and 75-90 mg/kg/day in rabbits), body weights and feed consumption were more severely affected. At dose levels > or =90 mg/kg/day in rats, clinical signs of toxicity (ataxia, muscular stiffness, and decreased motor activity) and mortality were noted. The no-observed-adverse-effect level (NOAEL) for maternal toxicity in both species across the family of 2,4-D salts and esters was approximately 10 mg/kg/day. Significantly decreased fetal body weights and increased fetal variations were seen in rats only at maternally toxic dose levels in excess of 90 mg/kg/day acid equivalent. At maternally toxic doses in rabbits, embryonal and fetal development were essentially unaffected. There were no effect on maternal reproductive measures such as litter size, resorption rates, or fetal body weights, and there was no evidence of teratogenic activity. In summary, equivalent toxicity of the salts and esters is consistent with rapid and complete metabolic conversion to 2,4-D acid. No adverse fetal effects were noted at dose levels that did not also produce evidence of maternal toxicity or exceed renal clearance of 2,4-D indicating that the developing rat and rabbit fetus were not uniquely sensitive to 2,4-D and its forms.

Oculocerebrocutaneous syndrome.

A female infant was found at birth to have an oculocerebrocutaneous syndrome in which the main clinical features include orbital cyst, cerebral malformations, accessory skin tags, and focal hypoplasia or "punched-out" skin lesions. This case, like the four previously reported, was sporadic.

First trimester prenatal diagnosis: amniocentesis.

Twenty years after midtrimester genetic amniocentesis was first used, first trimester invasive prenatal procedures were introduced. Chorionic villous sampling presents some disadvantages that entitled many centers to look into an alternative for first trimester diagnosis. Early amniocentesis (EA) can be performed effectively, as shown over the years in many observational studies and partially randomized and randomized trials. Recently, a multicenter randomized trial (Canadian Early and Midtrimester Amniocentesis Trial) reported a higher total pregnancy loss, a significant increased incidence of musculoskeletal foot deformities, a significant increased culture failure rate, and an increased postamniocentesis rate of leakage in the EA group compared with midtrimester amniocentesis. These results concerning EA procedures from 11w(+0) to 12w(+6) should be included in any pre-EA counseling. However, further trials have started to evaluate EA procedures between 13w(+0) to 14w(+6).

Identification of enterococci by ribotyping with horseradish-peroxidase-labelled 16S rDNA probes.

Enterococci are frequently associated with hospital-acquired infection. Identification of enterococci using conventional biochemical tests are often tedious to perform in a routine diagnostic laboratory and may give equivocal results. This study evaluates the usefulness of ribotyping by DNA hybridisation to identify 68 members of the bacterial genus Enterococcus characterised by a conventional test scheme. DNA probes (830 bp in size) were derived from the 16S rRNA gene of E. coli or E. faecalis by PCR, labelled with horseradish peroxidase and used in Southern blot hybridisations of enterococcal DNA digested with EcoRI. Unique ribotypes were obtained for 11 different species using 12 Enterococcus type strains. Ribotyping identified 44 E. faecalis isolates, 19 E. faecium isolates, two E. durans isolates and one E. avium isolate in concordance with results of the biochemistry tests. Two isolates that had ribotype patterns identical to the E. faecium type strain were unable to be definitively identified by biochemical tests. The results show that ribotyping is able to differentiate between E. faecium and E. faecalis and may be useful for identifying other enterococci in the hospital setting. In addition, ribotyping using DNA probes and enhanced chemiluminescence is a safe and more reproducible alternative to radiolabelling RNA in a clinical microbiology laboratory.

Antibiotic resistance and genomic analysis of enterococci in an intensive care unit and general wards.

Fifty-nine enterococci isolated from 18 patients in an intensive care unit (ICU) and 21 patients in general wards (GW) at Royal Perth Hospital (RPH) during a period of 14 months were examined for antibiotic resistance by susceptibility testing and DNA polymorphism by pulsed-field gel electrophoresis. The study showed that penicillin-resistant Enterococcus faecium is a common nosocomial isolate in ICU. The DNA patterns of various strains of E. faecium and E. faecalis were closely related in most consecutive isolates from the same patients but were generally different for isolates from different patients. Thirty two different DNA patterns were identified for 59 isolates from 39 patients. Identical or similar DNA patterns were also identified for some isolates from different patients, suggesting that cross-infection had occurred between patients in ICU and GW. These data suggest that cross-infection occurred more commonly in ICU than in GW and are consistent with the known higher risk of ICU patients for nosocomial infection.

The effects of comfrey derived pyrrolizidine alkaloids on rat liver.

Three groups of young adult rats were fed pyrrolizidine alkaloids derived from Russian comfrey to study the effects of the herb on the liver. Group I animals received a single dose of 200 mg/kg body wt, Group II 100 mg/kg three times a week for 3 weeks and Group III 50 mg/kg three times a week for 3 weeks. All rats showed light and electron-microscopic evidence of liver damage, the severity of which was dose dependent. There was swelling of hepatocytes and hemorrhagic necrosis of perivenular cells. There was a concomitant loss of sinusoidal lining cells with disruption of sinusoidal wall and the sinusoids were filled with cellular debris, hepatocyte organelles and red blood cells. Extravasation of red blood cells was evident. Terminal hepatic venules were narrowed by intimal proliferation, and in Group II and III, reiculin fibres radiated from these vessels. These appearances have been described in veno-occlusive disease due to pyrrolizidine alkaloids from other plant sources such as Senecio and Crotalaria. The safety of comfrey, a widely used herb, in relation to human consumption requires further investigation.