Fetal intracardiac echogenic foci: visualization depends on the orientation of the 4-chamber view.

OBJECTIVE: To compare the frequency of visualization of echogenic intracardiac foci in different cardiac views. METHODS: Women having ultrasonographic examinations between October 1997 and July 1998 were prospectively evaluated if a fetal echogenic intracardiac focus was seen in either ventricle. RESULTS: Echogenic intracardiac foci were seen in 89 fetuses in whom both the apical and lateral 4-chamber heart views were obtained. Eight-six fetuses (97%) had a single focus (83 in the left ventricle and 3 in the right ventricle), and 3 (3%) had 2 foci. Echogenic intracardiac foci were seen in the apical 4-chamber view in 89 (100%) and in the lateral 4-chamber view in only 26 (29%; P = .001). CONCLUSIONS: Echogenic intracardiac foci are not easily seen in the lateral 4-chamber view. Studies that suggest an increased risk of aneuploidy when echogenic foci are seen should specify the orientation of the 4-chamber view used.

Ultrasonography of the fetal thyroid: nomograms based on biparietal diameter and gestational age.

OBJECTIVE: To describe gestational age-dependent and -independent nomograms for fetal thyroid size. METHODS: Two hundred fetuses were evaluated between 16 and 37 weeks' gestation in this cross-sectional study. RESULTS: Nomograms of fetal thyroid size were created by using the 5th, 10th, 50th, 90th, and 95th percentiles based on biparietal diameter and gestational age. A second-order polynomial fit for biparietal diameter and a linear fit for gestational age best described thyroid circumference measurements. Variations in thyroid circumference measurements increased with both larger biparietal diameter and advancing gestational age. There was no intraobserver or interobserver variability in thyroid circumference measurements (P > .20). CONCLUSIONS: Both biparietal diameter and gestational age serve as good predictors of fetal thyroid circumference. When the biparietal diameter is difficult to measure, gestational age can be used to assess thyroid size.

Prenatal sonographic diagnosis of uterine rupture following open fetal surgery.

BACKGROUND: Reported cases of uterine rupture diagnosed by ultrasound have shown fetal membranes ballooning through uterine rupture sites, or adjacent areas of hemorrhage. CASE: A 27-year-old gravida 3, para 2 had open fetal surgery to repair a fetal myelomeningocele at 28 weeks' gestation. Her postoperative course was complicated by threatened preterm labor and anhydramnios. At 33 weeks' gestation, with maternal symptoms of bowel obstruction, ultrasound showed a fetal leg and section of umbilical cord protruding through the uterine wall. CONCLUSION: Even in the presence of anhydramnios, uterine wall rupture was identified, because ultrasound evaluation of the uterine wall showed prolapsed fetal parts and umbilical cord. Persistent anhydramnios after open fetal surgery should prompt a search for uterine rupture.

Comparison of three sonographic circumference measurement techniques to predict birth weight.

OBJECTIVE: To compare the accuracy of three different sonographic circumference measurement techniques in predicting birth weight in term fetuses, using a standard equation for estimating fetal weight. METHODS: Fifty-three singleton, term fetuses were examined sonographically within 24 hours of scheduled elective cesarean delivery. The biparietal diameter (BPD) and femur length (FL) were measured using standard techniques, and head circumference (HC) and abdominal circumference (AC) were measured using three separate circumference measurement techniques (Two-diameter, ellipse, and trace). With the use of each circumference method, estimated fetal weights were determined for each fetus according to a weight-estimation formula incorporating BPD, HC, AC, and FL. The accuracy of the formula using each circumference measurement technique for predicting actual birth weight was calculated. RESULTS: The mean (+/- standard deviation [SD]) gestational age was 38.1 +/- 0.9 weeks and the mean actual birth weight was 3536 +/- 472 g. The two-diameter and ellipse circumference measurements allowed more accurate birth weight prediction than did the trace method, with mean (+/- SD) percent deviations from the actual birth weight of -0.5 +/- 7.8%, 1.9 +/- 8.0%, and 8.2 +/- 11.6% (P < .05), respectively. The trace method was the least accurate, with a mean birth weight overestimation of 266 g and measurements within 10% of the actual birth weight only 49.1% of the time. The two-diameter and ellipse method yielded predicted birth weights within 10% of actual birth weights in 77.4 and 79.2% of cases, respectively. CONCLUSION: Two-diameter and ellipse circumference measurement techniques are similarly accurate in predicting birth weight and both are significantly better than the trace technique.

Sonographic identification of fetuses with Down syndrome in the third trimester: a matched control study.

OBJECTIVE: To determine sonographic findings in Down syndrome fetuses in the third trimester. METHODS: Down syndrome fetuses who had third-trimester ultrasound examinations between 25 and 41 weeks' gestation were matched for gestational age with three controls each. Fetal structural anomalies, Down syndrome dysmorphology markers (abnormal facial profile, sandal gap, tongue thrusting, clinodactyly, or hypoplastic middle phalanx of the fifth finger), and abnormal long-bone biometry (femur, humerus, tibia, and fibula; femur length to biparietal diameter ratio; and femur length to abdominal circumference ratio were abstracted from the ultrasound reports. The fetal face, hands, feet, profile, and cardiac outflow tracts are routinely evaluated in our center. RESULTS: Seventeen fetuses with Down syndrome who had third-trimester ultrasound evaluations were identified. Anomalies included cardiac defects (five), tongue thrusting (three), clinodactyly (three), abnormal profile (three), sandal gap (two), and duodenal atresia (two). Of the 17 fetuses, at least one long-bone abnormality was found in 13, at least one structural or biometric anomaly was found in 15, and at least two abnormal findings existed in 11. Abnormal ultrasound findings, including structural anomalies, short bones, and Down syndrome dysmorphology markers, were more common in cases than in matched controls. CONCLUSION: At least one abnormal ultrasound finding was present in 15 of 17 fetuses, and abnormal bone measurements or ratios were discovered in 13 of 17. Abnormal long-bone biometry at third-trimester ultrasound should raise the suspicion of fetal Down syndrome.

Prenatal sonographic appearance of hemorrhagic cerebellar infarction.

To date, the prenatal diagnosis of cerebellar hemorrhage has been limited to isolated case reports, which have demonstrated either a hyperechoic cerebellar hemisphere or a hyperechoic mass within the cerebellum in near-term fetuses. We demonstrate the ultrasonographic findings of intracerebellar hemorrhagic infarction in a fetus at approximately 21 weeks' gestation. In contrast to previous case reports, the hemorrhagic infarcts seen in our case were hypoechoic.

Intrauterine growth and ultrasound findings in fetuses with Beckwith-Wiedemann syndrome.

OBJECTIVE: To assess intrauterine growth in a series of nine fetuses diagnosed with Beckwith-Wiedemann syndrome. METHODS: Infants confirmed postnatally to have Beckwith-Wiedemann syndrome were identified from records maintained in the Division of Clinical Genetics. Antenatal ultrasound and birth records were evaluated. Head circumference (HC), abdominal circumference (AC), and estimated fetal weight (EFW) were assigned percentiles based on gestational age. Newborn HC and birth weight were also assigned percentiles. Polyhydramnios was diagnosed using either amniotic fluid index or documented subjective assessment. RESULTS: Nine infants with Beckwith-Wiedemann syndrome had antenatal ultrasound examinations. Seven of these had more than one examination. Two infants were suspected to have Beckwith-Wiedemann syndrome in utero. Important ultrasound findings included omphalocele (four), enlarged liver and kidneys (one), and enlarged liver (one). Fetal tongue protrusion on ultrasound was not identified in any fetus. Six of nine fetuses (66%) with ultrasound examinations after 25 weeks' gestation had polyhydramnios. Evaluation of the fetal HC, AC, and EFW percentiles demonstrated that fetuses with Beckwith-Wiedemann syndrome may exhibit accelerated growth as early as 25-30 weeks' gestation, but may exceed the 90th percentile only after 36 weeks' gestation. CONCLUSIONS: Fetuses with omphalocele, polyhydramnios, and an AC less than the 90th percentile may have Beckwith-Wiedemann syndrome. Polyhydramnios and accelerated growth beginning between 25 and 36 weeks' gestation, even without omphalocele, should alert the physician to the possibility of Beckwith-Wiedemann syndrome.

Color and duplex Doppler sonographic investigation of in utero spontaneous regression of pulmonary sequestration.

Bronchopulmonary sequestration is a congenital abnormality of nonfunctional pulmonary tissue that lacks normal connections with the bronchial tree. The sequestered tissue typically receives the majority of its blood supply from systemic vessels, most often the distal thoracic or upper abdominal aorta. These lesions often are associated with fetal hydrops, polyhydramnios, and persistent masses postnatally. Bronchopulmonary sequestrations are thought to require resection owing to their predisposition for chronic pulmonary infections later in life. However, spontaneous in utero resolution of these lesions can occur. This report describes the real time, color Doppler, and duplex Doppler ultrasonographic investigation of an intrathoracic bronchopulmonary sequestration that resolved spontaneously. Our investigation of this case provides new insight into a possible mechanism for spontaneous regression of bronchopulmonary sequestration.

Prenatal sonographic diagnosis of mid shaft hypospadias.

We report the prenatal diagnosis of mid shaft hypospadias and describe the sonographic features of fetal hypospadias including an abnormal urethral canal, ventral curvature of the distal penis, extension of the penile glans beyond the prepuce, and fetal micturation in a plane perpendicular to the penile shaft. An accurate family history is an essential part of the evaluation of the milder degrees of fetal hypospadias.

Puerperal psychosis mimicking eclampsia.

Puerperal psychosis occurs after delivery in 1-2/1,000 births. It usually presents after delivery, however, it also may present in the antepartum period. We report the third case which presented prior to delivery without a preceding history of maternal puerperal psychosis and the first which presented with catatonia and symptoms of eclampsia. Although uncommon, the first presentation of psychosis during pregnancy should be considered part of the differential diagnosis in pregnant patients presenting with altered mental status after organic causes are excluded.

Ultrasonographically guided intrauterine contraceptive device removal before chorionic villus sampling.

OBJECTIVE: Management of a retained intrauterine contraceptive device with no visible string during early pregnancy presents a dilemma. Because these devices are frequently used by multiparous women, it is not unusual that many women with retained devices are also of advanced maternal age. We describe our experience with ultrasonographically guided first-trimester retrieval of an intrauterine contraceptive device in conjunction with chorionic villus sampling. STUDY DESIGN: Patients with a first-trimester pregnancy and a retained intrauterine contraceptive device where no string was visible were offered ultrasonographically guided retrieval of the device. If the patient had genetic risks and desired prenatal diagnosis, chorionic villus sampling was offered at the same office visit. RESULTS: Six patients underwent intrauterine contraceptive device retrieval, under continuous ultrasonographic guidance, by use of an intrauterine contraceptive device hook. All patients had a posterior or fundal device. One patient had two in situ: a Lippes Loop (Ortho Pharmaceutical Corp., Raritan, N.J.) removed by its string and a Cu-7 (G.D. Searle & Co., Chicago) removed under ultrasonographic guidance. The remaining five patients had a Cu-7. Four of six patients had chorionic villus sampling performed immediately after the intrauterine contraceptive device removal and one patient had chorionic villus sampling 3 weeks later. There were two losses in our series: one after a lengthy procedure and one before documented viability. All infants were structurally normal and born at term. CONCLUSION: First-trimester ultrasonographically guided retrieval of a retained intrauterine contraceptive device may be safely performed in conjunction with chorionic villus sampling.

Use of amphotericin B during pregnancy: case report and review.

Unlike the situation with many antimicrobial agents, there is limited experience with the use of amphotericin B during pregnancy. Although reports of fungal infections during pregnancy have been published, few describe fungemia with either Candida or Torulopsis species. We present a case of fungemia due to Torulopsis glabrata that occurred during pregnancy and that was treated with amphotericin B. Drug concentrations were measured in placental tissue, cord serum, and infant serum at delivery. Although the last dose of amphotericin B was administered 4 weeks before delivery, the concentrations in all three specimens were still within the MIC ranges for most strains of Candida albicans and T. glabrata as measured by broth dilution. We speculate that persistent tissue concentrations of amphotericin B most likely contributed to the sustained hypokalemia in the mother and the increased creatinine level in the infant. In the latter case, placental tissue may have served as the reservoir from which amphotericin B was slowly released into fetal circulation.

Müllerian remnants in complete androgen insensitivity syndrome.

Patients with complete androgen insensitivity syndrome rarely have Müllerian remnants. A patient with this syndrome found to have a microscopic fallopian tube at the time of gonadectomy is described and possible etiologies for the finding are discussed.

Ribosomal RNA methylation in Staphylococcus aureus and Escherichia coli: effect of the "MLS" (erythromycin resistance) methylase.

Classical acquired resistance to erythromycin in Staphylococcus aureus ("MLS," or macrolide-lincosamide-streptogramin, resistance) was shown by Weisblum and colleagues to be a direct consequence of the conversion of one or more adenosine residues of 23S rRNA, within the subsequence(s) GA3G, to N6-dimethyladenosine (m62A). The methylation reaction is effected by a class of methylase, whose genes are typically plasmid- or transposon-associated, and whose synthesis is inducible by erythromycin. Using a recently obtained clinical MLS isolate of S. aureus, we have further defined the methylation locus as YGG X m62A X AAGAC; and have shown that this subsequence occurs once in the 23S RNA and that it is essentially completely methylated in all copies of 23S RNA that accumulate in induced cultures. Similar findings were obtained with laboratory S. aureus strains containing two well-characterized evolutionary variants (ermB, ermC) of MLS methylase genes. Analyses of a strain of E. coli containing the ermC gene indicated that the specificity of the methylase gene was unchanged, but that its expression was muted. Even after prolonged periods of induction, the strain manifested only partial resistance to erythromycin, and only about one-third of the copies of the MLS subsequence were methylated in such "induced" cultures. Since the E. coli 23S RNA sequence is known in its entirety, localization of the MLS subsequence is in this case unambiguous; as inferred by homology arguments applied earlier to the S. aureus data, the subsequence is in a highly conserved region of 23S RNA considered to contribute to the peptidyl transferase center of the ribosome.

The "erythromycin-resistance" methylated sequence of Staphylococcus aureus ribosomal RNA.

We have determined the sequence of an oligonucleotide from the large ribosomal subunit RNA of Staphylococcus aureus whose methylation renders the organism resistant to erythromycin and other antibiotics (the "MLS" phenotype). Analysis of RNase A digests of [3H]methyl-, 32P-labeled RNA yielded the sequence GG . m6(2)A . AAGACp, where m6(2)A is an N6-dimethylated adenosine residue that in sensitive cells is unmethylated. Comparison with homologous sequences recently reported for Saccharomyces cerevesiae mitochondria indicates that an A to G mutation in this latter system mimics dimethylation in St. aureus with regard to functional consequences.