Biomedical subjects
J L Ecker
Publications and source records attributed to J L Ecker.
The sonographic diagnosis of Dandy-Walker and Dandy-Walker variant: associated findings and outcomes.
Outcomes of pregnancies with sonographically diagnosed Dandy-Walker (DW) or Dandy-Walker variant (DWV) syndromes vary widely. We examined our own experience with these diagnoses in an effort to identify those sonographic features that best predicted neonatal outcome. We identified 50 fetuses with DW and 49 with DWV diagnosed sonographically. Eighty-six per cent of fetuses with DW and 85% of fetuses with DWV had other sonographically identifiable anomalies, the most common being ventriculomegaly (DW: 32%; DWV: 27%) and cardiac defects (DW:38%; DWV: 41%). Forty-six per cent and 36% of available karyotypes in cases of DW and DWV, respectively, were abnormal. 50 out of 99 women in our series elected pregnancy termination. Only three pregnancies with DW resulted in a living infant, and only one of these had a normal paediatric examination at six-week follow-up. Thirteen out of 49 infants with DWV survived the neonatal period and 7 of 13 were reported initially as normal infants, including six with an isolated finding of DWV. We conclude that overall, the prognosis for these posterior fossa defects is grim but not uniformly fatal. The presence of other anomalies is associated with the worst prognosis. Isolated Dandy-Walker variant has the highest chance of leading to a normal neonate.
Obstetric evaluation of fetal acid-base balance.
Several techniques may be used to evaluate fetal acid-base status during the ante- and intrapartum periods. Percutaneous blood sampling (cordocentesis) may be used to measure standard blood-gas parameters while the fetus is still in utero, but because of the risks associated with such procedures and the limited clinical utility of the results, this procedure is recommended for blood gas analysis only as part of a research protocol. Intrapartum blood specimens may be safely obtained via fetal scalp sampling, but the need for such sampling has been dramatically reduced by the use of other noninvasive tests such as fetal scalp stimulation or vibroacoustic stimulation. Finally, assay of blood obtained from a segment of umbilical cord collected at delivery indicates acid-base status at birth, but the range of normal values is wide, and only the most abnormal results have any prognostic significance.
Routine ultrasound screening in low-risk pregnancies: imperatives for further study.
The benefits of screening ultrasonography in low-risk pregnancies are uncertain and require further investigation. As researchers organize future trials, however, they will need to define clearly the structure and content of the screening ultrasound examination and explicitly detail those outcomes considered important. Such studies must examine the effectiveness of screening sonography in comparison with and in the context of other available prenatal tests and screens. Until studies showing efficacy are available, screening ultrasound in low-risk pregnancies should be considered only when patients, guided by clinicians, consider the potential benefits to be of value.
The clinical utility of serum uric acid measurements in hypertensive diseases of pregnancy.
OBJECTIVE: Our purpose was to evaluate the clinical utility of serum uric acid measurements in the hypertensive diseases of pregnancy. STUDY DESIGN: We performed a nested case-control study to assess the clinical utility of serum uric acid measurements in women with hypertensive diseases of pregnancy. We identified 344 women who had serum uric acid measurements at term and categorized them into five diagnostic groups according to definitions of hypertensive diseases in pregnancy published by the National Working Group on Hypertension in Pregnancy: transient hypertension of pregnancy (n = 69), preeclampsia (n = 130), chronic hypertension (n = 23), chronic hypertension with superimposed preeclampsia (n = 29), and normal (n = 93). We compared the mean uric acid concentration for each group with use of a one-way analysis of variance and Scheffe's post hoc test and calculated the sensitivities and specificities in diagnosing preeclampsia as well as the likelihood ratios for serum uric acid values of 5.5, 6.0, and 6.5 mg/dl. We also examined the correlation between serum uric acid levels and several clinical outcome measures in women with hypertensive diseases of pregnancy. RESULTS: The mean serum uric acid values for women with preeclampsia (6.2 +/- 1.4 mg/dl) and transient hypertension (5.6 +/- 1.7 mg/dl) were significantly higher than those of controls (4.3 +/- 0.8 mg/dl, p < 0.05). The difference in mean serum uric acid values between women with chronic hypertension (4.9 +/- 1.0 mg/dl) and superimposed preeclampsia (5.8 +/- 1.4 mg/dl) were not statistically significant. The likelihood ratio of having preeclampsia with a serum uric acid value of 5.5 mg/dl was 1.41 in gestational hypertension of pregnancy and 2.5 in chronic hypertension. With use of a receiver-operator characteristic curve, we were unable to identify a serum uric acid value that could be used to differentiate various hypertensive diseases of pregnancy. There was a weak correlation between serum uric acid values and several clinical outcome measures of preeclampsia (r = 0.06 to 0.26). CONCLUSION: Although mean serum uric acid values are elevated in women with preeclampsia, the clinical utility of serum uric acid values in differentiating various hypertensive diseases of pregnancy appears to be limited. In the setting of chronic hypertension, however, a serum uric acid level of > or = 5.5 mg/dl could identify women with an increased likelihood of having superimposed preeclampsia.
Chorionicity inaccurately predicted by early ultrasound: a case report.
Ultrasound has been found to be extremely accurate in diagnosing the chorionicity of multiple gestations. Prenatal counselling and/or planning for selective termination is most often based on the sonographic prediction of chorionicity. We present a case of triplet pregnancy in which early sonographic prediction of chorionicity did not match the pathological diagnosis at delivery.
A decline in myometrial nitric oxide synthase expression is associated with labor and delivery.
The mechanisms that maintain relative uterine quiescence during pregnancy remain largely unknown. A possible role for nitric oxide has recently emerged, however, the expression of nitric oxide synthase within human myometrium at midgestation, a time when the uterus is normally quiescent, has not been investigated. The purpose of this study was to identify cell types in human myometrium that contain inducible nitric oxide synthase (iNOS), and to examine changes in its expression during pregnancy and labor. We found that iNOS is expressed in smooth muscle cells of pregnant myometrium. Expression of iNOS was highest in myometrium of preterm not-in-labor patients. At term, iNOS expression fell by 75%, and was barely detectable in preterm in-labor or term in-labor specimens. There was no staining in the myocytes of nonpregnant myometrium. Western blotting also revealed a similar pattern of changes in iNOS expression. In summary, iNOS expression in the myocytes of human myometrium is increased greatly during pregnancy, and declines towards term or with labor. Significantly, preterm inlabor patients also had a large decline in iNOS expression. These data suggest that changes in myometrial iNOS expression may participate in the regulation of uterine activity during human pregnancy.
Is there a benefit to episiotomy at operative vaginal delivery? Observations over ten years in a stable population.
OBJECTIVE: Our purpose was to examine the association between maternal vaginal and perineal morbidity and episiotomy performed at operative vaginal delivery. STUDY DESIGN: We obtained data from 2041 consecutive operative vaginal deliveries and compared yearly rates of episiotomy, lacerations, and potential confounders with linear regression and stratified analyses. RESULTS: Between 1984 and 1994 the use of episiotomy for operative vaginal deliveries fell significantly (93.4% to 35.7%, R2 = 0.85, p = 0.0001). This change was associated with a rise in the rate of vaginal lacerations (16.1% to 40.0%, R2 = 0.80, p = 0.0002), a decrease in the rate of fourth-degree lacerations (12.2% to 5.4%, R2 = 0.62, p = 0.004), but no significant change in the rate of third-degree lacerations. These associations held in separate analyses stratified by parity and type of instrument used for delivery. The prevalence of other previously reported risks for perineal morbidity did not change during the study period. CONCLUSION: At our institution a statistically and clinically significant reduction in the use of episiotomy for operative vaginal deliveries was not associated with a change in the rate of third-degree lacerations but was associated with an increase in the rate of vaginal lacerations and a decrease in the rate of fourth-degree lacerations.
Birth weight as a predictor of brachial plexus injury.
OBJECTIVE: To examine the relationship between birth weight and brachial plexus injury and estimate the number of cesareans needed to reduce such injuries. METHODS: All 80 neonatal records coded for brachial plexus injury from October 1985 to September 1993 at the Brigham and Women's Hospital in Boston, Massachusetts, were studied along with linked maternal files. Birth weight, method of delivery, presence or absence of shoulder dystocia, and any diagnosis of maternal gestational or nongestational diabetes were abstracted. Data for the group with brachial plexus injury were compared with data for live-born infants without this injury during the same period. The sensitivity and specificity of birth weight as a predictor of brachial plexus injury were calculated. Further, the number of cesarean deliveries necessary to prevent a single brachial plexus injury was estimated using various weight cutoffs (4000, 4500, and 5000 g) for elective cesarean delivery. RESULTS: Among 77,616 consecutive deliveries, there were 80 brachial plexus injuries identified, for an incidence of 1.03 per 1000 live births. The incidence of brachial plexus injury increased with increasing birth weight, operative vaginal delivery, and the presence of glucose intolerance. In the group of women without diabetes, between 19 and 162 cesarean deliveries would have been necessary to prevent a single immediate brachial plexus injury. Among women with diabetes, between five and 48 additional cesareans would have been required. CONCLUSION: Although birth weight is a predictor of brachial plexus injury, the number of cesarean deliveries necessary to prevent a single injury is high at most birth weights. Because of the large number of cesarean deliveries needed to prevent a single brachial plexus injury in infants born to women without diabetes, it is difficult to recommend routine cesarean delivery for suspected macrosomia in these women.
Treatment of thyroid disease in pregnancy.
With appropriate therapy, complications related to thyroid disease in pregnancy can be minimized. Although the diagnosis of thyroid endocrinopathy may be difficult in pregnancy, few therapies are contra-indicated. Because medications may cross the placenta, however, clinicians need always to be mindful of potential fetal effects and should work to use the minimal dose necessary to achieve maternal euthyroidism. Thyroid function tests, in particular free T4 and TSH, remain good measures of thyroid function and therapy in pregnancy.
Prelabor rupture of the membranes at term.
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Blood glucose monitoring in gestational diabetes mellitus.
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The cost-effectiveness of human immunodeficiency virus screening in pregnancy.
OBJECTIVE: My purpose was to evaluate the cost-effectiveness of screening for human immunodeficiency virus during pregnancy as part of a protocol in which zidovudine was used to reduce the risk of vertical transmission. STUDY DESIGN: This mathematic model used decision analysis to calculate the marginal cost-effectiveness of screening for human immunodeficiency virus in pregnancy and treating human immunodeficiency virus-positive women with zidovudine. Cost and probability assumptions were drawn from a literature review. Sensitivity analyses were performed for important costs and probabilities. RESULTS: When baseline cost and probability assumptions were used, the marginal cost-effectiveness of human immunodeficiency virus screening was $436,927 when the prevalence of human immunodeficiency virus in the population was low (0.00075) and $198,510 when the prevalence was average (0.0015). Above a prevalence of human immunodeficiency virus of 0.009, testing is both cheaper and more effective than not testing. Of the cost variables examined, the charge for a negative testing sequence had the greatest impact on cost-effectiveness. CONCLUSION: Human immunodeficiency virus testing in pregnancy is cost-effective in populations in which the prevalence of human immunodeficiency virus exceeds 9 per 1000 population. Depending on how individual lives saved are valued, screening may also be warranted in populations with lower prevalences of infection.
Is there a benefit to episiotomy at spontaneous vaginal delivery? A natural experiment.
OBJECTIVE: Our purpose was to examine the association between maternal vaginal and perineal morbidity and episiotomy performed at spontaneous vaginal delivery. STUDY DESIGN: We obtained data from 17,483 consecutive spontaneous vaginal deliveries and compared the yearly rates of episiotomy, lacerations, and potential confounders with linear regression and stratified analyses. RESULTS: Between 1976 and 1994 the use of episiotomy fell significantly (86.8% to 10.4%, R2 = 0.92, p = 0.0001). This change was associated with a fall in the rate of third- and fourth-degree lacerations (9.0% to 4.2%, R2 = 0.59, p = 0.0001) and a rise in the rate of intact perinea (10.3% to 26.5%, R2 = 0.68, p = 0.0001) and vaginal lacerations (5.4% to 19.3%, R2 = 0.77, p = 0.0001). These associations held in separate analyses stratified by parity and birth weight, except for the subgroup of nulliparous women with macrosomic infants. CONCLUSION: At our institution a large reduction in the use of episiotomy in spontaneous vaginal deliveries was associated with a significant reduction in perineal trauma in all groups of women except for nulliparous women with macrosomic infants.
Mandatory disclosure of human immunodeficiency virus status by surgeons is philosophically and practically counterproductive.
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Measurement of embryotoxic factors is predictive of pregnancy outcome in women with a history of recurrent abortion.
OBJECTIVE: To determine whether the production of embryotoxic factors in early pregnancy is predictive of pregnancy outcome in women with a history of two or more unexplained recurrent abortions. METHODS: Between July 1987 and June 1991, 450 nonpregnant women were evaluated for recurrent abortion. Embryotoxic factors were found in 328 of 346 women with an otherwise unexplained etiology. These women were given progesterone immunosuppressive therapy in a subsequent conception cycle, and embryotoxic factors were measured at 5 weeks' gestation. RESULTS: Data on embryotoxic factors and pregnancy outcome were available for 141 of 208 reported subsequent pregnancies. Of women still positive for embryotoxic factors, 40 had a repeat first-trimester spontaneous abortion whereas 16 delivered a viable infant; of women who no longer produced embryotoxic factors, only 11 had a repeat first-trimester abortion and 74 delivered a viable infant. CONCLUSIONS: The embryotoxic factor assay may be useful in predicting pregnancy outcome in women with a history of unexplained recurrent abortion. Further work is needed to evaluate the effectiveness of immunosuppression for this condition.
Hirschsprung's disease: associated abnormalities and demography.
We here examine the demographic parameters of patients with Hirschsprung's disease. The study population includes all patients with histologically confirmed disease treated at the Children's Hospital Medical Center of Boston over the 25-year period extending from 1961 through the first quarter of 1986. There were 179 cases. Overall, children with Hirschsprung's disease were found less likely to be first born (P less than .01). This relationship was seen to persist irrespective of maternal age, maternal race, or type of disease. The implications of this finding are discussed. Overall, 22% of these children had one or more associated abnormalities involving the neurological, cardiovascular, urological, and gastrointestinal systems. Many of the disorders appeared to be related to neurocrestopathies. Frequent associations included Down's syndrome, defects in cardiac septation, tetralogy of Fallot, and Dandy-Walker syndrome. These conditions occurred more frequently than would have been predicted through chance alone. This study found no association between an increased maternal age and the occurrence of Hirschsprung's disease. This study also found that approximately 7% of the affected children had been born prematurely.