Does augmented growth impose an increased risk of fetal death?

OBJECTIVE: Our purpose was to examine the risk of fetal death associated with augmented fetal growth. STUDY DESIGN: All live births recorded in Virginia between January 1, 1991, and December 31, 1993, were examined. Mortality rates were examined for infants born at or beyond 24 weeks' gestational age with weights between the 75th and 90th percentiles, from the 90th to the 95th percentile, and >95th percentile. RESULTS: Mortality rates were found to rise only slightly with birth weights >90th percentile. A recorded diagnosis of maternal diabetes, however, was associated with a significant risk in the presence of augmented fetal growth. Augmented fetal growth without maternal glucose intolerance showed no increase in mortality. CONCLUSION: Augmented fetal growth in the absence of maternal glucose intolerance appeared not to be associated with a significant increase in the risk of death among these births. Increased risk was found when augmented fetal growth was associated with maternal diabetes.

Borderline genitourinary tract abnormalities.

The ability to detect major malformations of the fetal urinary tract using diagnostic antenatal ultrasound is well-known. Serious obstructive or dysgenetic abnormalities are often clearly seen and their implications well-known. Less clear is the meaning of mild or minimal pyelectasis, unilateral renal agenesis, nonvisualization of the fetal bladder, and pelvic kidneys. Fetal pyelectasis rarely, if ever, is associated with a need for neonatal intervention if the diameter of the pelvis is less than 10 mm. Although mild pyelectasis occurs in up to 25% of Down syndrome fetuses, the risk of Down syndrome in the case of isolated pyelectasis in a low-risk population is less than 1 in 340. Mild pyelectasis by itself does not seem to justify invasive testing for fetal karyotype. Nonvisualization of the fetal bladder carries a high risk of renal agenesis or dysplasia, whereas unilateral renal agenesis and a fetal pelvic kidney seem to carry limited, if any, negative implications.

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.

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.

The relation between pulmonary hypoplasia and amniotic fluid volume: lessons learned from discordant urinary tract anomalies in monoamniotic twins.

BACKGROUND: Adequate amniotic fluid (AF) volume is one of several factors felt to be essential for normal lung development. Renal agenesis and urinary tract obstruction usually result in oligohydramnios and pulmonary hypoplasia. CASE: Two sets of monoamiotic twins with discordant urinary tract anomalies were seen. One twin in each set had anomalies that in a singleton or diamiotic pregnancy would likely have resulted in fetal pulmonary hypoplasia and subsequent death. However, neither of these infants had pulmonary hypoplasia. One infant is unique in being the first case reported of normal pulmonary function and survival despite the anomaly. CONCLUSION: Adequate AF provided by a monoamniotic twin environment may prevent pulmonary hypoplasia, which usually results from oligohydramnios due to certain fetal urinary tract anomalies.

Acute maternal and fetal cardiovascular effects of caffeine ingestion.

Little data exist regarding the acute maternal and fetal cardiovascular effects of caffeine ingestion. The purpose of this study is assess the cardiovascular effects of caffeine ingestion in pregnant subjects and their fetuses. We examined seven caffeine-naive gravidas longitudinally at 25.7 (SE +/- 0.7) and 36.1 (+/- 0.7) weeks' gestation, before and after ingestion of a caffeine citrate solution (100 mg/m-2 body surface area). Maternal pulse, blood pressure, fetal heart rate, and fetal heart rate accelerations were determined before and after caffeine ingestion. Uterine artery, fetal aorta, and umbilical artery flow velocity waveforms were examined at similar intervals. Significant before and after caffeine differences, regardless of gestational age, were noted for maternal pulse (85.1 vs 74.2 beats/min), diastolic blood pressure (65.9 vs 73.8 torr), mean arterial blood pressure (81.5 vs 87.5 torr), uterine artery systolic-to-diastolic (S/D) ratio (1.9 vs 2.4), fetal heart rate (144.6 vs 135.4 beats/min), and fetal heart rate accelerations (1.6 vs 4.2 per 30 minutes). Differences for fetal aortic and umbilical artery S/D ratios were not significant with respect to caffeine administration. Fetal aortic peak velocities increased with caffeine (85.5 vs 130.2 cm/sec) and the increase was augmented with advancing gestational age. We conclude that maternal ingestion of modest amounts of caffeine citrate in caffeine-naive subjects significantly affects both the fetal and maternal cardiovascular systems.

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 twin's 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 twin's umbilical cord should be considered for treating this unusual complication of twinning.

Oligohydramnios: problems and treatment.

Oligohydramnios is a severe and common complication of pregnancy. The finding of oligohydramnios can be associated with fetal anomalies, PROM, uteroplacental insufficiency (eg, growth retardation, postdatism, abruptio placenta, significant maternal illness), abnormalities of twinning, and idiopathic oligohydramnios. Ultrasound detection of this complication should prompt the clinician to thoroughly evaluate the gravida for hypertension, diabetes, or other significant illness. In addition, a thorough fetal anatomic survey focusing on the genitourinary tract and an attempt at visualizing free amniotic bands should be performed with ultrasound. Karyotype should be considered. The role of amnioinfusion to assist in diagnosis should be considered. Once diagnosed, oligohydramnios with or without associated conditions should lead to intensive fetal biophysical surveillance including frequent ultrasound evaluation. Delivery in the term patients must be considered. The role of amnioinfusion as an adjunct to continuous fetal monitoring in labor to improve neonatal outcome appears beneficial in select series. The role of repetitive amnioinfusion in the preterm patient remote from term may offer marginal clinical benefit to neonatal outcome and is considered experimental at this time.

Route of delivery of infants with congenital anomalies.

Obstetric delivery may be accomplished by only two methods, vaginally or abdominally. In the management of the pregnancy complicated by a fetal malformation, the choice of delivery method may be made on obstetrical grounds or in belief that one method offers the fetus benefit over the other. That choice must be based on knowledge of the nature of the individual malformation in question, the presence or absence of associated fetal malformations, the presence or absence of fetal karyotype abnormalities, fetal maturity, and fetal presentation. Clear evidence of benefit from cesarean delivery is not available in the case of many malformations that are often considered for abdominal delivery. The infrequency of many of these anomalies typically precludes the accumulation of sufficient experience in any one center or successful completion of randomized trials to evaluate treatment modalities. Most studies therefore are retrospective or flawed by small numbers of patients. Logic dictates that certain malformations that produce sufficient enlargement of fetal structures are at probable risk for dystocia of labor (e.g., severe hydrops, severe hydrocephalus, large sacrococcygeal teratoma) and may benefit from abdominal delivery. Other malformations may predispose the affected fetus to trauma or decompensation during labor and vaginal delivery. It is these anomalies that have the most controversy surrounding the "best" mode of delivery and of which we have attempted to address. Table 4 includes proposed criteria for choosing abdominal versus vaginal delivery in the gestation complicated by congenital anomaly. The birth method in the context of a fetal malformation is a choice optimally made after careful discussions with the patient, pediatrician, and pediatric surgeons. Such discussion should include a careful review of the nature of the anomaly, the optimal prognosis, and the evidence of benefit for a specific birth method. Once the pregnancy in question has been evaluated, appropriate consultations obtained, and the available data reviewed with the patient, the obstetrician again assumes a role of patient advocate. The obstetrician is the counselor, the educator, and the friend the patient needs during such a difficult time. The discussion of birth method in the case of a fetal malformation creates a conflict of interest for the patient, but typically a paradoxic result of this conflict occurs. The patient's welfare, which is usually best served by vaginal delivery, may be in conflict with the fetal concerns, which might benefit from abdominal delivery. The data might be clear but more often the data are less than convincing.(ABSTRACT TRUNCATED AT 400 WORDS)

A practical approach to umbilical artery pH and blood gas determinations.

The use of the Apgar score as a means of identifying birth asphyxia has been challenged. Routine umbilical cord blood pH has been recommended as a more objective measure of the condition of the newborn. The purposes of this study were to evaluate a simplified and selective method of umbilical artery pH blood sampling and to determine the effect of delay in sampling upon umbilical artery pH, carbon dioxide pressure (PCO2), and oxygen pressure (PO2). Umbilical arterial blood of 25 patients was sampled from clamped umbilical cord segments every 15 minutes for 1 hour after delivery. The clamped umbilical cord segments were left at room temperature with no special care given. The blood samples were collected in non-heparinized and non-iced plastic syringes and processed promptly after sampling. During the 60 minutes after delivery, there were no statistically significant changes in pH, PCO2, or PO2 of umbilical arterial blood. Our results indicate that umbilical arterial blood may be obtained simply and reliably from clamped umbilical cord segments for pH and gas determinations for up to an hour after delivery.

Sonographic diagnosis of advanced ectopic pregnancy. A case report.

The diagnosis of advanced extrauterine pregnancy is made most often sonographically by identification of a uterus separate from the fetus. Leiomyomas or other pelvic masses can make the sonographic diagnosis more difficult. In a woman with an advanced ectopic pregnancy and uterine leiomyoma, the sonographic diagnosis was made by passing a sterile probe through the endocervix with simultaneous, real-time ultrasound observation.

Sonographic evaluation of growth discordance and chorionicity in twin gestation.

Ninety-four twin gestations had serial ultrasound examinations for evaluation of fetal growth, with special attention to prediction of weight discordance and chorionicity. Fetal weight estimations were made a mean of 3.2 days before birth and then compared to actual birthweights. The average error in intertwin discordance prediction was 1 +/- 9%. In 56 patients ultrasonic detection of membrane thickness was compared with placental pathologic conditions. If a membrane was seen between twins, it was confirmed by placental pathologic study in all cases. No membrane was seen in four twin pairs, but only one of these actually had monochorionic monoamniotic membranes. The three cases with false-positive diagnoses of monoamniotic twin gestation were initially seen late in pregnancy. If clinical decisions in twin gestations are based on ultrasound determination of discordance and chorionicity, the level of accuracy demonstrated by these data must be considered.

Counseling and care for the pregnancy complicated by gastroschisis.

Twenty-one consecutive cases of fetal and neonatal gastroschisis were retrospectively reviewed. There was 100% survival if major nonintestinal malformations did not coexist; however, 28.6% of these patients had other major malformations and 66% of them died. There were significantly fewer small for gestational age infants if the defect was diagnosed prenatally (20% versus 75%, p less than 0.003). There was a 60% cesarean delivery rate in prenatally diagnosed infants and 0% if diagnosis occurred at delivery (p less than 0.01).

Extremely high maternal serum alpha-fetoprotein levels at second-trimester screening.

Maternal serum alpha-fetoprotein (MSAFP) screening is widely used for the detection of open neural tube defects (NTDs) and a variety of other anomalies and complications. We examined the outcomes of 44 pregnancies with MSAFP elevations of 8 or more multiples of the median (MoM) from among 40,676 screened pregnancies. At the initial evaluation by ultrasound, 82% of the patients had at least one finding that may have accounted for the elevation. Approximately 45% of the fetuses had a major fetal anomaly, 25% died, 16% had an identifiable placental abnormality, and 5% had an underestimation of gestational age; 18% of the elevations remained unexplained after ultrasound. In follow-up of the pregnancies, all of those with an unexplained elevation after initial ultrasound had at least one obstetric complication or placental abnormality. The overall positive predictive value of an MSAFP value of 8 or more MoM for NTDs was 22.7%. The proportion of infants born alive in the overall group was low, with only 16 live births among 46 fetuses. The majority of the nonviable outcomes were associated with a fetus with a major anomaly that was terminated or died before 20 weeks. Of the live-born infants, 31% had a major anomaly, 19% had intrauterine growth retardation (IUGR) and an anomaly, 12.5% had IUGR without an anomaly, and 25% were preterm. Eighty-eight percent of those pregnancies with a live-born infant had at least one obstetric complication. Among pregnancies with MSAFP of 8 or more MoM, the majority are associated with large structural fetal anomalies or fetal death before 20 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of ultrasound in evaluation of patients with elevated maternal serum alpha-fetoprotein: a review.

Accumulated experience with the sonographic detection of spina bifida and its associated fetal cranial changes indicates that nearly all these fetuses may be identified by ultrasound examination alone. A review of data from multiple centers shows that a complete and detailed, normal ultrasound is an appropriate basis for a reduction of at least 95% in the maternal serum alpha-fetoprotein (MSAFP)-based risk for neural tube defects. The use of this adjusted risk in patient counseling before amniocentesis may lower the rate of the procedure with no significant loss of diagnostic sensitivity. Among patients with elevated MSAFP, the rate of abnormal cytogenetic findings in fetuses with no abnormalities detected at ultrasound appears to be near 0.61%. Furthermore, the spectrum of abnormal cytogenetic results appears to differ from that associated with increased maternal age, in that the incidence of sex chromosome abnormalities is higher and that of Down syndrome is lower.