John W. Seeds

Impaired growth and risk of fetal death: Is the tenth percentile the appropriate standard?☆☆☆★

OBJECTIVE Our purpose was to determine whether the 10th percentile of birth weight for gestational age is appropriate to identify fetuses at risk of death associated with impaired growth. STUDY DESIGN All live births recorded in Virginia from Jan. 1, 1991, through Dec. 31, 1993, were examined. Percentile growth curves were constructed, and fetal, neonatal, and perinatal mortality rates were calculated for births within various percentile intervals. RESULTS Significantly elevated fetal mortality was found for birth weights through the 15th percentile. The odds ratio for fetal mortality relative to the baseline for births < or = 5th percentile was 5.6, for the 5th through the 10th percentile 2.8, and for the 10th through the 15th percentile 1.9. These were all significant. CONCLUSION Fetuses with birth weights between the 10th and 15th percentiles are at a significantly increased risk for fetal death. Therefore the use of the 15th percentile as a diagnostic threshold for the identification of the fetus at increased risk associated with impaired growth is recommended.

Ligation of the umbilical cord of an acardiac-acephalus twin with an endoscopic intrauterine technique

Background: Fetal acardia is a rare entity that complicates twin gestation. Reported survival of the normal or “pump” twin is below 50%. Perinatal mortality and morbidity typically result from heart failure in the pump twin caused by the circulatory demands of perfusion of the abnormal twin. Conservative management has not improved perinatal survival. Case: A 30‐year‐old woman with a twin gestation at 18 weeks was diagnosed with acardia acephalus. Congestive heart failure of the pump twin led to an intrauterine endoscopic attempt to ligate the umbilical cord of the acardiac twin. Both twins ultimately died. Conclusion: A variety of invasive techniques have been reported to accomplish occlusion of the acardiac twins umbilical cord, with inconsistent results. Maternal morbidity was minimal and technical success was achieved with an endoscopic intrauterine technique of umbilical cord ligation. Despite the poor fetal outcome in this case, endoscopic ligation of the acardiac twins umbilical cord should be considered for treating this unusual complication of twinning. (Obstet Gynecol 1993;82:708‐11)

Fetal and neonatal cardiovascular complications from β-sympathomimetic therapy for tocolysis

beta-Sympathomimetic drugs cross the placenta freely. Just as these agents cause serious cardiovascular changes in the mother, they may cause severe cardiovascular complications in the fetus. beta-Sympathomimetic agents for tocolysis have been associated with fetal heart rate and rhythm disturbances, hydrops, stillbirth, neonatal cardiac failure, myocardial ischemia and infarction, and neonatal death. Prospective studies have documented changes in interventricular septa of babies exposed to these drugs. Histologic changes have been reproduced in animal models and in vitro similar to those seen in infants with myocardial disease caused by beta-mimetic therapy. The mechanism of beta-mimetic toxicity appears to be increased myocardial intracellular calcium leading to overexcitation and cell necrosis. Since serious fetal cardiovascular effects may occur with beta-mimetic use, benefits should clearly outweigh risks before these drugs are administered.

Prevention of fetal movement during invasive procedures with pancuronium bromide

The use of fetal intramuscular pancuronium (0.5 mg) to temporarily arrest fetal movement during antenatal intervention in six instances is reported. Successful arrest of movement without adverse side effects was observed. The use of this technique eliminates the need for the excessive and potentially dangerous maternal sedation currently used to minimize fetal movement.

THE ROUTINE OR SCREENING OBSTETRICAL ULTRASOUND EXAMINATION

The debate concerning the value of routine screening ultrasound in the low-risk patient continues. The most likely benefits are obstetrical, with confirmation of dates, detection of multiple gestation, baseline growth data, and location of the placenta being primary advantages gained from such an examination. The detection of the unexpected major fetal malformation has always been the least likely benefit of routine ultrasound. Furthermore, the majority of reports have been retrospective, uncontrolled, and too small to resolve the question. The RADIUS study was intended to solve these problems, but suffered from such intense selection that the final population for study had little need for medical care at all and little relevance to the average population. The rate of adverse outcomes among the control group was so low that few interventions would appear useful. Furthermore, the analysis of the RADIUS data appeared to suggest bias by underestimating the diagnostic sensitivity of ultrasound for major anomalies, and de-emphasizing those statistically significant obstetrical benefits that were recorded. An attempt at cost-benefit analysis by the RADIUS study misrepresented the cost of routine ultrasound by overestimating the size of the low-risk population, arbitrarily costing out two scans instead of one, and therefore overestimated the cost savings of omitting these examinations. Diagnostic sensitivity of the screening obstetrical ultrasound examination appears to be highest in high-risk patients examined by highly specialized ad experienced personnel that may be of limited availability. diagnostic sensitivity may be quite good, however, even in low-risk patients with a basic or routine examination if recognized guidelines for content are followed and referral to experienced referral resources for unclear or suspicious images is liberally practiced. Optimal service and minimum liability exposure will result if the following guidelines are followed: 1. The obstetric population should be carefully screened for historical or clinical risk factors that might indicate increased probability of fetal abnormality. Identification of such increased risk should cause consideration of referral. 2. The screening ultrasound examination should be methodical and complete and include examination of each of several recommended scanplane views to maximize diagnostic sensitivity. 3. The performance of a complete and methodical examination should be carefully documented with both descriptive text and image records to show that a standard of care service was provided. 4. Referral for second opinion should be easily considered and easily obtained in the case of any suspicious finding. Should every obstetrical patient have an ultrasound examination? Only if it is competently performed, properly recorded, and if the patient is aware of appropriate goals and limitations. The ideal gestational age is between 18 and 22 completed weeks.

Disseminated herpes simplex in pregnancy: two cases and a review.

Documented disseminated infection with herpes simplex virus has been reported only five times in pregnancy. All cases have been severe and demonstrated common clinical features, including hepatitis and adenopathy. These reports are reviewed and two new cases added. Dissemination is undoubtedly more common, and commonly less dramatic in presentation then previously suspected. Hepatocellular dysfunction and generalized adenopathy should be clues to dissemination. Dissemination has occurred only in the second half of pregnancy, and even with infected amniotic fluid, has not always resulted in an infected infant. Transplacental maternal IGG has been documented, but is not protective, though newer antiviral drugs do show therapeutic potential. The clinician should be aware of the possibility of dissemination in any patient with oral or genital herpes and generalized signs or symptoms of disease.

Prenatal Diagnosis of Unilateral Hydronephrosis with Early Postnatal Reconstruction

Real-time ultrasound systems, being used extensively now in obstetrical practice for fetal monitoring, are providing the urologist with more opportunities for early recognition and intervention of congenital hydronephrosis. Thorough postnatal investigation to confirm a diagnosis is advocated. An early postnatal surgical repair can be performed successfully.

The Relationship of Obstetric Ultrasound to Parent and Infant Behavior

&NA; There is inconsistency in the obstetric literature regarding the relationship between the mothers knowledge of fetal health gained by ultrasound and maternal psychological attachment to the fetus. To evaluate the relationship more precisely, this study assessed variables of physician‐patient interaction, parental mental health in pregnancy and infancy, and 3‐month infant and parent behavior. The results show that maternal mental health scores increased as a function of the stress associated with an “at risk” pregnancy necessitating ultrasound assessment. As the parent received more definitive information, scores on measures of anxiety, depression, and hostility decreased. There was no significant relationship, however, between definitive information gained through ultrasound and later parent and infant behavior in play interaction. Shifts in fetal and neonatal health status and the positive interaction between physician and parent suggest the need for further analysis.

Elevated Maternal Serum Alpha-Fetoprotein, Second-Trimester Oligohydramnios, and Pregnancy Outcome

Although the primary purpose of maternal serum alpha-fetoprotein (AFP) screening is to detect open neural tube defects, the technique is of value in the diagnosis of other fetal abnormalities. Six patients from the Alpha-Fetoprotein Screening Program, Perinatal Region IV, were found to have twice elevated maternal serum AFP levels associated with severe early second-trimester oligohydramnios. Five of the fetuses were found to have urinary tract abnormalities. The source of the elevated maternal serum AFP is not clear. Pregnancy prognosis appears poor. These cases should be thoroughly studied so that patients may be accurately informed of the recurrence risk.

Maternal and fetal effects of exchange transfusion with a red blood cell substitute

Recent reports have demonstrated the efficacy of Fluosol-DA (20%) as a temporary erythrocyte substitute. We investigated two groups of pregnant ewes that underwent exchange transfusion. In group 1, the animals underwent a nearly total isovolemic exchange of Fluosol-DA (20%) for maternal whole blood; in group 2, the red blood cells were removed and the plasma along with Ringers lactate was replaced isovolumetrically. Although group 1 animals received 100% oxygen and Fluosol-DA (20%), the maternal arterial P02 increased to 350 to 400 torr. However, the maternal blood oxygen content decreased during the exchange, with no change in fetal pH, Pco2, or hematocrit. Maternal blood pressure remained stable and there was a 40% to 50% increase in cardiac output and mean pulmonary arterial pressure. During the exchange, the maternal hematocrit decreased from a mean of 32% to 5.5%; the maternal fluorocrit at the end of the exchange was 9%. Throughout the Fluosol-DA (20%) exchange, the proportion of fetal brain oxyhemoglobin as estimated from infrared transcranial transmittance increased, as did the fetal blood P02 and oxygen content. In group 2, the maternal mean blood pressure decreased, and the hematocrit decreased from a mean of 32% to 8%. Despite an increase in the maternal P02 to 250 torr, the fetal P02 and oxygen content decreased in group 2. This investigation demonstrated that Fluosol-DA (20%) exchange of the mother does not impair delivery of oxygen to the fetus under the conditions of the study.