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Biomedical subjects

M E D'Alton

Publications and source records attributed to M E D'Alton.

At least 19 recordsLinked to original sources
PubMed2006

First- and second-trimester Down syndrome screening markers in pregnancies achieved through assisted reproductive technologies (ART): a FASTER trial study.

OBJECTIVE: To determine whether first- and second-trimester Down syndrome screening markers and screen-positive rates are altered in pregnancies conceived using assisted reproductive technologies (ARTs). METHODS: ART pregnancies in the multicenter FASTER trial were identified. Marker levels were evaluated for five types of ART: in vitro fertilization with ovulation induction (IVF-OI), IVF with OI and egg donation (IVF-OI-ED), IVF with ED (IVF-ED), and intrauterine insemination with OI (IUI-OI) or without OI (IUI). Each group was compared to non-ART controls using Mann-Whitney U analysis. RESULTS: First-trimester marker levels were not significantly different between ART and control pregnancies, with the exception of reduced PAPP-A levels in the IUI-OI group. In contrast, second-trimester inhibin A levels were increased in all ART pregnancies, estriol was reduced and human chorionic gonadotropin (hCG) was increased in IVF and IUI pregnancies without ED, and alpha-fetoprotein (AFP) was increased in ED pregnancies. Second-trimester screen-positive rates were significantly higher than expected for ART pregnancies, except when ED was used. CONCLUSIONS: These data show that ART significantly impacts second-, but not first-, trimester markers and screen-positive rates. The type of adjustment needed in second-trimester screening depends on the particular type of ART used.

Adult↗
PubMed2001

Maternal and neonatal outcome of 100 consecutive triplet pregnancies.

The objective of this study is to determine the maternal and neonatal outcome of a large group of triplet gestations. A retrospective review of 100 triplet gestations managed and delivered between January 1992 and September 1999 by a single perinatal group is examined. These pregnancies were managed on an outpatient basis. Prophylactic interventions were not utilized. Ninety-six percent of the pregnancies had at least one complication, with preterm labor the most common. The median gestational age at delivery was 33 weeks (range 20.4 to 37, SD 4.1 weeks) with 14% of pregnancies delivering prior to 28 weeks' gestation. The corrected perinatal mortality rate was 97/1000. Minimal long-term morbidity was seen with delivery after 27 weeks' gestation. Pregnancy outcome did not vary with birth order or mode of conception. Triplet pregnancy is associated with a high rate ofantenatal complications. Favorable neonatal outcome can be obtained without the use of prophylactic interventions.

Adult↗
PubMed2000

Congenital heart disease: the impact of delivery in a tertiary care center on SNAP scores (scores for neonatal acute physiology).

OBJECTIVE: It has been hypothesized that delivery in a tertiary care center might improve the clinical condition and outcome of infants born with congenital heart disease. The purpose of this study was to determine the effect of delivery in a tertiary care center on SNAP scores (scores for neonatal acute physiology) of infants admitted to the neonatal intensive care unit with major structural cardiac defects. STUDY DESIGN: This retrospective cohort study included 195 infants with major congenital heart disease admitted to the neonatal intensive care unit at the New England Medical Center between July 1, 1992, and June 30, 1998. SNAP scores were abstracted from the medical record. The values of 97 neonates with major cardiac defects born at the New England Medical Center were compared with those of 98 neonates transferred to our center after delivery in a community setting. A 2-tailed Student t test for independent samples was used to compare the mean SNAP scores between the 2 cohorts. RESULTS: The SNAP scores for infants with major cardiac defects who were born at the New England Medical Center ranged from 0 to 41, with a mean of 10.6 +/- 8.8. The values for infants with congenital heart disease who were transferred to our center after birth in community-based hospitals ranged from 0 to 34, with a mean of 11.1 +/- 7.0. There was no significant difference between the 2 populations (P =.646). A comparison of the mean SNAP scores of infants with prenatally diagnosed disease who were delivered at our center versus infants with postnatally diagnosed disease who were delivered in community hospitals was also statistically not significant (P =.824). CONCLUSION: Delivery in a tertiary care center does not improve SNAP scores of infants with major structural cardiac defects.

Alprostadil↗
PubMed2000

Isolated clubfoot diagnosed prenatally: is karyotyping indicated?

OBJECTIVE: To evaluate the appropriateness of fetal karyotyping after prenatal sonographic diagnosis of isolated unilateral or bilateral clubfoot. METHODS: We retrospectively reviewed a database of fetal abnormalities diagnosed by ultrasound at a single tertiary referral center from July 1994 to March 1999 for cases of unilateral or bilateral clubfoot. Fetuses who had additional anomalies diagnosed prenatally, after targeted sonographic fetal anatomy surveys, were excluded. Outcome results included fetal karyotype diagnosed by amniocentesis, or newborn physical examination by a pediatrician. RESULTS: During the 5-year period, 5,731 fetal abnormalities were diagnosed from more than 27,000 targeted prenatal ultrasound examinations. There were 51 cases of isolated clubfoot. The mean maternal age at diagnosis was 30.5 years. The mean gestational age at diagnosis was 21.6 weeks. Twenty-three of the women (45%) were at increased risk of fetal aneuploidy, on the basis of advanced maternal age or abnormal maternal serum screening. Six women (12%) had positive family histories of clubfoot; however, no cases of aneuploidy were found by fetal karyotype evaluation or newborn physical examination. All cases of clubfoot diagnosed prenatally were confirmed at newborn physical examination, and no additional malformations were detected. CONCLUSION: After prenatal diagnosis of isolated unilateral or bilateral clubfoot, there appeared to be no indication to offer karyotyping, provided that a detailed sonographic fetal anatomy survey was normal and there were no additional indications for invasive prenatal diagnoses.

Adult↗
PubMed2000

Anomalies peculiar to multiple gestations.

Congenital anomalies occur twice as often in twin pregnancies as in singletons. In addition to the large range of structural malformations that are described in singleton fetuses, multiple gestations are at risk for additional anomalies that are unique to the twinning process. These unique anomalies include twin-twin transfusion syndrome, twin-reversed-arterial-perfusion syndrome, and conjoined twinning. This article reviews and describes each of these unique abnormal conditions in detail.

Diagnosis, Differential↗
PubMed2000

First-trimester screening for aneuploidy: research or standard of care?

First-trimester screening for Down syndrome has been proposed as a significant improvement with respect to second-trimester serum screening programs, the current standard of care, because of apparently higher detection rates and an earlier gestational age at diagnosis. First-trimester nuchal translucency on ultrasonography forms the basis of this new form of screening, although studies of its efficacy have yielded widely conflicting results, with detection rates ranging from 29% to 91%. Studies of first-trimester serum screening with measurements of pregnancy-associated plasma protein A and free beta-human chorionic gonadotropin serum concentrations have been much more consistent, with Down syndrome detection rates of 55% to 63% at a 5% false-positive rate. The combination of first-trimester ultrasonographic and serum screening has the potential to yield a Down syndrome detection rate of 80% at a 5% false-positive rate, although this approach has not been adequately studied. There have been no studies performed to date to directly compare the performance of first-trimester and second-trimester methods of screening. Two major trials are underway that will address this issue, one in the United Kingdom and one in the United States. Until the results of these trials are available, the current standard of care with respect to Down syndrome screening should not be changed, and first-trimester screening should remain investigational.

Aneuploidy↗
PubMed1999

Latent class analysis applied to patterns of fetal sonographic abnormalities: definition of phenotypes associated with aneuploidy.

The aim of the present study was to generate different latent variables that classify the major chromosome aneuploidies using frequency and patterns of fetal sonographic abnormalities in a large database. A total of 1867 fetuses with sonographic abnormalities recorded in a database at New England Medical Center from January 1995 to March 1998 were available for the statistical analysis. Included within this group were 61 aneuploid fetuses, including 11 with 45,X, 30 with trisomy 21, 14 with trisomy 18 and 6 with trisomy 13, 40 structural malformations and/or sonographic markers were detected in these 61 aneuploid fetuses. The ability of malformations and sonographic markers to generate different groups of phenotypes was evaluated by means of latent class analysis, using the 61 affected cases. Four different classes were generated with the hypothetical assumption that each of them could satisfactorily identify a respective fetal aneuploidy represented in the study group. Among 40 fetal malformations and/or sonographic markers, the most important findings in generating specific karyotypic groups were cystic hygroma (class 1), duodenal atresia (class 2), holoprosencephaly (class 3) and omphalocele (class 4), respectively. Accuracy of the classification was 72 per cent for Turner syndrome (class 1), 74 per cent for Down syndrome (classes 1 and 2), 88 per cent for trisomy 13 (class 3) and 93 per cent for trisomy 18. The frequency of associated malformations detected sonographically can help to define a phenotype that is likely to be representative of a specific aneuploidy. Before the definitive karyotype is available or, in cases in which patients refuse an invasive prenatal diagnostic procedure, this may improve antenatal clinical management.

Aneuploidy↗
PubMed1998

Acute fatty liver of pregnancy in triplet gestation.

BACKGROUND: Acute fatty liver is reported to be more common in twin than in singleton pregnancies. We report three cases of biopsy-proven acute fatty liver in triplet gestations. CASES: In all three cases of acute fatty liver complicating triplet pregnancies, the presenting features were vague abdominal complaints with elevated hepatic aminotransferase levels. A liver biopsy was performed in each case, and cesareans were performed immediately after the diagnosis was confirmed histologically. Clinical resolution occurred in all cases, and all infants did well in the neonatal period. CONCLUSION: Patients with triplet gestations should be monitored closely for the early signs of acute fatty liver. Triplet gestations may contribute to the onset of acute fatty liver by further stressing the fatty acid oxidation capabilities of the susceptible woman.

Acute Disease↗
PubMed1998

Neonatal morbidity and mortality associated with triplet pregnancy.

OBJECTIVE: To compare neonatal morbidity and mortality in a large cohort of triplet pregnancies with singleton and twin neonates managed at a single tertiary center over a short time. METHODS: Records from all triplet pregnancies managed and delivered from 1992 to 1996 were reviewed for neonatal outcome data. Pregnancies delivered before 20 weeks' gestation and neonates with lethal congenital anomalies were excluded. The comparison group comprised all singleton and twin neonates managed in the same neonatal intensive care unit (NICU) during the same period. RESULTS: During the 5-year period, 55 triplet pregnancies and their resulting 165 neonates were managed and delivered at this center. Their outcomes were compared with those of 959 singleton and 357 twin neonates born at similar gestational ages. The median gestational age at delivery for triplets was 32.1 weeks, and 149 of the 165 infants were admitted. Sixteen triplet neonates were not admitted to our neonatal intensive care unit, 12 because of previable gestational age, three because of stillbirth, and one because of a lethal congenital anomaly. The crude perinatal mortality rate in triplets was 121 per 1000 births, and there was no significant difference in outcome based on triplet birth order. There were no significant differences in survival rates between singleton, twin, and triplet neonates, with an overall neonatal survival of 95%, 95%, and 97%, respectively. The only significant differences in morbidity were an increased incidence of mild intraventricular hemorrhage (relative risk [RR] 6.20; 95% confidence interval [CI] 2.64, 14.61), mild retinopathy of prematurity (RR 20.05; 95% CI 3.59, 111.79), and severe retinopathy of prematurity (RR 46.69; 95% CI 6.25, 348.85) in triplets compared with singletons, and severe retinopathy of prematurity (RR 6.83; 95% CI 1.24, 37.56) in triplets compared with twins. CONCLUSION: When stratified by gestational age, triplet neonates delivered at 24-34 weeks' gestation have similar outcomes as singleton and twin neonates, with the only clinically significant difference being an increased incidence of retinopathy of prematurity in triplets.

Female↗
PubMed1998

Factors affecting fellowship satisfaction, thesis completion, and career direction among maternal-fetal medicine fellows.

OBJECTIVE: To determine fellowship satisfaction through a survey of maternal-fetal medicine fellows. METHODS: We constructed a survey using multiple choice, Likert scale, ordinal, and categorical scale questions. The questions focused on faculty involvement, mentorship, research time and productivity, education, fellowship selection, ultimate goals of fellows, and satisfaction. We sent the survey in two mailings to all maternal-fetal medicine fellows during April and May 1996. RESULTS: One hundred thirty-eight surveys were mailed, and 136 were returned (98.5% return rate). Twenty-seven percent of fellows did not believe they would complete their thesis by the end of their fellowship. No statistically significant relationship was noted between the fellows' predicted thesis completion and the availability of funding, support for statistical analysis, the presence of animal research facilities, age, number of dependents, or year of fellowship. The presence of a mentor on the maternal-fetal medicine faculty increased the likelihood of thesis completion from 52.3% to 83.5% (P < .001). Similarly, the presence of a faculty advisor increased the likelihood of thesis completion from 58.9% to 83.5% (P = .001). Thirty-two percent of the respondents did not have a mentor on the faculty, and 41% did not have a faculty advisor. Forty percent indicated that they were too involved in clinical pursuits to perform research. This group was significantly more likely to believe that their theses would not be completed (63% versus 80%, P = .029). Overall, 22% of the fellows would not recommend their fellowships. Fellows with a mentor (88.2% versus 55.8%; P < .001) or faculty advisor (87.3% versus 64.9%; P = .002) were more likely than those without to recommend their fellowship. CONCLUSION: A mentor or faculty advisor plays a significant role in the training of maternal-fetal medicine fellows and is associated with a higher incidence of satisfaction with the fellowship program, thesis completion, and entrance into academic practice.

Academic Dissertations as Topic↗
PubMed1998

Cardiac dysfunction in twin-twin transfusion syndrome: a prospective, longitudinal study.

OBJECTIVE: To use serial echocardiography to evaluate prospectively the cardiac dysfunction in twin-twin transfusion syndrome and determine its clinical course and outcome. METHODS: Twin pregnancies presenting in the second trimester with sonographic evidence of twin-twin transfusion syndrome were managed with therapeutic reduction amniocenteses. Gestational age at diagnosis and delivery, number of amniocenteses performed, volume of amniotic fluid withdrawn, placentation, birth weight, hemoglobin at delivery, and perinatal outcome were recorded. Serial fetal echocardiography was carried out in a single tertiary center. Echocardiographic assessments included cardiac anatomy, chamber size, cardiothoracic ratio, interventricular septal thickness, ventricular systolic function, and the presence and severity of atrioventricular valve regurgitation. Postnatal echocardiograms were obtained on the surviving twins. RESULTS: Twelve cases of twin-twin transfusion syndrome were evaluated with serial echocardiography. Evidence of cardiac dysfunction was present prenatally in 10 recipient twins. All of the donor twins had normal fetal echocardiographic assessments. The most common abnormalities detected prenatally in recipient twins were decreased ventricular function, tricuspid regurgitation, and cardiac chamber enlargement. A deterioration of cardiac function was observed in seven recipient twins with increasing gestational age. Four of the eight surviving recipient twins had persistent postnatal echocardiographic abnormalities on follow-up examinations after the first 28 days of life. CONCLUSION: Prenatal cardiac dysfunction is common in recipient twins and can be transient, progressive, or persistent beyond the neonatal period.

Female↗
PubMed1998

Suggested ultrasound parameters for the assessment of fetal well-being during chronic hemodialysis.

There are no published guidelines on how to assess fetal well-being during hemodialysis. We have developed a specific protocol of renal and obstetric interventions to ensure that hemodialysis is associated with minimal changes in fetal status. We tested this protocol serially over a 9-week period in a pregnant patient who was undergoing chronic hemodialysis for end-stage renal disease. Testing involved serial assessments of uterine and umbilical artery blood flow with Doppler velocimetry and continuous fetal heart rate tracings, before, during and after each hemodialysis session. We found that, by strict adherence to these guidelines, there were no significant alterations in maternal mean arterial blood pressure, continuous fetal heart rate tracings, uterine artery systolic/diastolic ratios, or umbilical artery systolic/diastolic ratios. We conclude that stable uteroplacental and fetal perfusion can be maintained during chronic hemodialysis in pregnancy by adhering to a specific set of precautions.

Adult↗
PubMed1998

Cost issues surrounding the use of computerized telemedicine for obstetric ultrasonography.

OBJECTIVE: The purpose of this study was to describe the cost implications of converting an established videotape review network for obstetric ultrasonography to one based on telemedicine technology. DESIGN: Retrospective review of fixed and non-fixed costs associated with interpreting obstetric ultrasound examinations using both videotape and telemedicine transmission. SUBJECTS: A network of three community offices transmitting 600 obstetric ultrasound examinations per month to a central tertiary level facility. METHODS: Sonographers at the community offices record ultrasound examinations onto videotape, which are then sent by courier to a central facility for interpretation. At the completion of this videotaped examination, sonographers repeat the ultrasound scan while transmitting real-time images over a telemedicine link to the central facility. Costs associated with the videotape review technique that can be avoided by converting to telemedicine interpretation were derived and compared with the fixed and non-fixed costs associated with establishing the telemedicine network. RESULTS: For this network, the fixed costs for establishing telemedicine are $101,750. Monthly non-fixed cost savings by eliminating videotape review include $1620 to $2700 for printing still images, $1200 for courier charges and $7000 for fewer repeat ultrasound examinations. Monthly non-fixed costs for the telemedicine network are $2415. Net monthly savings in non-fixed costs for a telemedicine network are therefore $7405 to $8585, which may pay for the initial fixed costs in 12 to 14 months. CONCLUSIONS: The high cost of a telemedicine network may be offset by possible savings in non-fixed costs compared with alternative systems for interpreting obstetric ultrasonography.

Costs and Cost Analysis↗
PubMed1998

Maternal morbidity associated with triplet pregnancy.

The objective of this article is to describe maternal morbidity in a large cohort of triplet pregnancies managed by a single Maternal-Fetal Medicine group over a short period of time. Records from all triplet pregnancies managed and delivered from 1992 to 1996 were reviewed for maternal outcome data. Pregnancies delivered prior to 20 weeks were excluded. During the 4-year study period, 55 triplet pregnancies were managed and delivered at this center. The most common maternal complication was preterm labor, which occurred in 42 cases (76%). Preterm premature rupture of membranes occurred in 11 cases (20%). Pregnancy-induced hypertensive complications occurred in 15 cases (27%), which included severe preeclampsia 13 (24%), hemolysis, elevated liver function tests, and low platelets (HELLP) syndrome 5 (9%), and eclampsia 1 (2%). Other maternal antenatal complications included anemia 15 (27%), acute fatty liver of pregnancy 4 (7%), gestational diabetes 4 (7%), supraventricular tachyarrhythmias 2 (4%), dermatoses 2 (4%), urinary tract infection 2 (4%), and acute disc prolapse requiring surgery in 1 case (2%). Postnatal complications occurred in 18 cases (33%), including endometritis 13 (24%), postpartum hemorrhage 5 (9%), pneumonia 2 (4%), urinary tract infection 2 (4%), and diastasis of rectus muscles requiring surgery in 1 (2%). There were no maternal deaths. Antenatal and postnatal maternal complications occur in almost all triplet gestations, suggesting that such pregnancies be managed at centers that have appropriate multidisciplinary expertise available.

Cohort Studies↗
PubMed1998

Effect of ISDN bandwidth on image quality for telemedicine transmission of obstetric ultrasonography.

OBJECTIVE: To evaluate objectively the effect of different bandwidths on the ability to interpret obstetric ultrasound scans transmitted live over a commercial telephone network. MATERIALS AND METHODS: An integrated services digital network (ISDN) was established from three satellite offices to our central prenatal diagnostic center. In the first half of the study, the network was based on four ISDN channels transmitting at a bandwidth of 256 kbits per second (kbps), while in the second half of the study, this was increased to six ISDN channels transmitting at 384 kbps. A physician trained in obstetric ultrasonography provided an interpretation of fetal anatomy using a live, real-time telemedicine link. A scoring system consisting of 33 anatomic items was used to evaluate image quality objectively. The number of transmissions complicated by motion artifact was also recorded. RESULTS: One hundred patients had a fetal anatomy survey performed using the 256 kbps system, and these interpretations were compared with those from another group of 100 patients who were examined using the 384 kbps system. Although the visibility of the 33 anatomic items was similar using the two systems, significantly more examinations at 256 kbps were complicated by motion artifact (12% vs. 3%; P = 0.02). CONCLUSIONS: Remote sonographic viewing of fetal anatomy was adequate using both 256 and 384 kbps systems, although motion artifact was significantly more likely to occur using the slower system. This problem may affect the ability of the lower-bandwidth system to allow optimal detection when fetal anomalies are present.

Artifacts↗
PubMed1997

Validation of fetal telemedicine as a new obstetric imaging technique.

OBJECTIVE: Our purpose was to establish whether obstetric ultrasonography interpreted by a live video telemedicine link is comparable to interpretation by videotape review in a low-risk patient population. STUDY DESIGN: An Integrated Services Digital Network (ISDN 6) was established from three satellite offices to our central prenatal diagnostic center. Patients seen at these satellite offices had a complete fetal anatomic survey recorded onto videotape by a trained ultrasonographer. A live interactive video telemedicine link was then established to our center by the digital network, and a perinatologist directed the ultrasonographer through the anatomy survey. Subsequently a different perinatologist, blinded to the telemedicine interpretation, reviewed the videotaped examination. The reports from the videotaped and telemedicine scans were then compared on the basis of a score of 33 anatomic items. RESULTS: The first 200 patients seen at the satellite offices were included. Telemedicine and videotape interpretations provided similar scores in 84% of scans. In 17 of the 33 anatomic categories telemedicine provided significantly better scores than videotape, whereas in the remaining 16 anatomic categories the scores were equivalent. More videotape than telemedicine examinations required repeat ultrasonography because of suboptimal imaging (10% vs 3%, p = 0.003). CONCLUSIONS: The interpretation of obstetric ultrasonography with use of live video telemedicine is comparable to videotape review. Fetal telemedicine may prove to be a useful tool for providing ultrasonographic interpretation of fetal anatomy to a network of low-risk obstetric practices.

Feasibility Studies↗