Prenatal diagnosis of tracheo-oesophageal fistula and oesophageal atresia.

OBJECTIVES: To assess the accuracy of the prenatal ultrasound finding of subjectively small/absent stomach bubble in the prenatal diagnosis of tracheo-oesophageal fistula and oesophageal atresia (TOF/OA). METHODS: A retrospective study of prenatal ultrasound scans showing small/absent stomach bubble was carried out between 1st January 1994 and 31st December 2003. RESULTS: There were 62 cases with prenatally suspected (n = 40) and/or post-natally diagnosed (n = 22) TOF/OA. Among the 40 cases of prenatally suspected TOF/OA 15 were thought to be isolated and 25 non-isolated. Of the 15 suspected isolated cases, 7 were normal and 8 had TOF/OA (5 isolated + 3 TOF/OA with another anomaly) at delivery. Among the 25 cases of prenatally suspected non-isolated TOF/OA, there was confirmation in only two cases, in the remaining 23 cases other anomalies were confirmed but TOF/OA was not present.Twenty-two babies with TOF/OA were identified in whom there had been no prenatal ultrasound suspicion on ultrasound scanning. Six had isolated TOF/OA and 16 had non-isolated TOF/OA. CONCLUSION: Of the 32 cases of confirmed TOF/OA,10 (31%) were suspected prenatally. If the TOF/OA was an isolated anomaly (11 cases), the prenatal detection rate was 45%. Interpretation of ultrasound findings suspicious of TOF/OA requires caution, particularly, when there are associated multiple anomalies on scan.

Autopsy after termination of pregnancy for fetal anomaly: retrospective cohort study.

OBJECTIVE: To study trends in termination of pregnancy for fetal anomaly over 10 years and to assess the contribution of autopsy to the final diagnosis and counselling after termination. DESIGN: Retrospective study with cases from a congenital anomaly register and a defined unselected population. DATA SOURCES: Pregnancies resulting in termination for fetal anomaly identified from the Oxford congenital anomaly register. Details about the prenatal diagnosis and autopsy findings were retrieved from case notes. RESULTS: Of the 57 258 deliveries, 309 (0.5%) were terminated because of prenatally diagnosed abnormality. There were 129/29 086 (0.4%) terminations for fetal anomaly carried out in 1991-5 and 180/28 172 (0.6%) in 1996-2000. The percentage of fetuses that underwent autopsy fell from 84% to 67%. Autopsy was performed in 132 cases identified by ultrasound scan, with no evidence for abnormal karyotype. In 95 (72%) the autopsy confirmed the suspected diagnosis and did not add important further information, two cases were not classified, and in 35 (27%) the autopsy added information that led to a refinement of the risk of recurrence (reduced in 17, increased in 18); in 11 of these 18 cases it was increased to a one in four risk. CONCLUSIONS: Though there has been an increase in the rate of terminations of pregnancy for fetal anomaly, there has been a decline in the autopsy rate. When a prenatal diagnosis was based on the results of a scan only, the addition of information from an autopsy by a specialist paediatric pathologist provided important information that changed the estimated risk of recurrence in 27% of cases and in 8% this was to a higher (one in four) risk.

Clostridium welchii infection following amniocentesis: a case report and review of the literature.

We report a case of severe Clostridium welchii infection following amniocentesis with septicaemia, haemolysis, DIC, pulmonary oedema and renal failure. Full recovery occurred following aggressive conservative management using antibiotics, endometrial curettage and intensive monitoring. The patient retained her uterus and had a successful pregnancy two years later although caesarean section for uterine rupture was required. Conservative management with conservation of the uterus and ovaries may be a safe and effective option in the management of severe Clostridium infections, using antibiotics, endometrial curettage and multidisciplinary team input.

Prenatal diagnosis of fetal RhD status by molecular analysis of maternal plasma.

BACKGROUND: The ability to determine fetal RhD Status noninvasively is useful in the treatment of RhD-sensitized pregnant women whose partners are heterozygous for the RhD gene. The recent demonstration of fetal DNA in maternal plasma raises the possibility that fetal RhD genotyping may be possible with the use of maternal plasma. METHODS: We studied 57 RhD-negative pregnant women and their singleton fetuses. DNA extracted from maternal plasma was analyzed for the RhD gene with a fluorescence-based polymerase-chain-reaction (PCR) test sensitive enough to detect the RhD gene in a single cell. Fetal RhD status was determined directly by serologic analysis of cord blood or PCR analysis of amniotic fluid. RESULTS: Among the 57 RhD-negative women, 12 were in their first trimester of pregnancy, 30 were in their second trimester, and 15 were in their third trimester. Thirty-nine fetuses were RhD-positive, and 18 were RhD-negative. In the samples obtained from women in their second or third trimester of pregnancy, the results of RhD PCR analysis of maternal plasma DNA were completely concordant with the results of serologic analysis. Among the maternal plasma samples collected in the first trimester, 2 contained no RhD DNA, but the fetuses were RhD-positive; the results in the other 10 samples were concordant (7 were RhD-positive, and 3 RhD-negative). CONCLUSIONS: Noninvasive fetal RhD genotyping can be performed rapidly and reliably with the use of maternal plasma beginning in the second trimester of pregnancy.

Antenatal diagnosis of complete facial duplication--a case report of a rare craniofacial defect.

We report a case of the prenatal sonographic detection of facial duplication, the diprosopus abnormality, in a twin pregnancy. The characteristic sonographic features of the condition include duplication of eyes, mouth, nose and both mid- and anterior intracranial structures. A heart-shaped abnormality of the cranial vault should prompt more detailed examination for other supportive features of this rare condition.

Presence of fetal DNA in maternal plasma and serum.

BACKGROUND: The potential use of plasma and serum for molecular diagnosis has generated interest. Tumour DNA has been found in 'the plasma and serum of cancer patients, and molecular analysis has been done on this material. We investigated the equivalent condition in pregnancy-that is, whether fetal DNA is present in maternal plasma and serum. METHODS: We used a rapid-boiling method to extract DNA from plasma and serum. DNA from plasma, serum, and nucleated blood cells from 43 pregnant women underwent a sensitive Y-PCR assay to detect circulating male fetal DNA from women bearing male fetuses. FINDINGS: Fetus-derived Y sequences were detected in 24 (80%) of the 30 maternal plasma samples, and in 21 (70%) of the 30 maternal serum samples, from women bearing male fetuses. These results were obtained with only 10 microL of the samples. When DNA from nucleated blood cells extracted from a similar volume of blood was used, only five (17%) of the 30 samples gave a positive Y signal. None of the 13 women bearing female fetuses, and none of the ten non-pregnant control women, had positive results for plasma, serum or nucleated blood cells. INTERPRETATION: Our finding of circulating fetal DNA in maternal plasma may have implications for non-invasive prenatal diagnosis, and for improving our understanding of the fetomaternal relationship.

Analysis of limb reduction defects in babies exposed to chorionic villus sampling.

In 1991 we reported a cluster of babies with limb abnormalities and suggested that chorionic villus sampling (CVS) was aetiologically associated with these defects. To address the issue more objectively, we have assessed reported limb reduction defects in 75 babies exposed to CVS in utero. 13 babies had an absent limb or a defect through the humerus or femur; 9 had defects through the radius or tibia; 22 defects of the carpus, tarsus, metacarpus, or metatarsus; 25 defects of the digits; and 6 defects of the terminal phalanx or nail only. There was a strong correlation between the severity of the defects and the duration of gestation when CVS was done. The median gestational age at CVS ranged from 56 (range 49-65) postmenstrual days for the most severe category to 72 (51-98) days for the least severe. The relation was seen for both isolated limb defects and for cases with oromandibular-limb hypogenesis syndromes. This relation is further evidence that CVS has an aetiological role in some limb reduction anomalies.

Prenatally diagnosed testicular torsion.

A case is reported of absent testis in a boy of 7 months who was noted to have a cystic intra-abdominal mass at 18-19-week prenatal ultrasound scan. This is the second report of prenatally detected testicular torsion, the previous case being noted much later in pregnancy. On both occasions, the diagnosis was only established after birth.

Uterine-peritoneal amniotic fluid leakage: an unusual complication of intrauterine shunting.

Bilateral pleuroamniotic shunting was performed at 33 weeks' gestation in a fetus with bilateral hydrothorax, hydrops, and gross polyhydramnios. The procedure was successful, but acute amniotic fluid leakage into the maternal peritoneal cavity occurred soon after. This produced marked maternal discomfort and transient oligohydramnios, with consequent fetal distress. Expectant management was adopted in view of fetal lung immaturity. Resolution of maternal ascites occurred within 24 hours and the fetal heart rate normalized as amniotic fluid reaccumulated. The pregnancy progressed uneventfully thereafter.

Fetal biophysical profile scoring: selective use of the nonstress test.

The fetal biophysical profile score was modified by selective use of the nonstress test. In 2712 study patients (7851 tests) the incidence of nonstress test was reduced to 2.7% with no measurable effect or test accuracy. The nonstress test was most useful in evaluation of abnormal ultrasound monitored variables.

Identification of the small for gestational age fetus with the use of gestational age-independent indices of fetal growth.

This study reviews the roles of sonographic assessment of the rate of growth of the fetal abdominal circumference, the femur length/abdominal circumference ratio, and qualitative determination of amniotic fluid volume as gestational age-independent indices for identification of the small for gestational age fetus. The sensitivity and specificity for single and combinations of test results were evaluated in 50 appropriate for gestational age and 40 small for gestational age fetuses. Positive and negative predictive values were derived for the general population. Our results indicate that either a rate of growth of the fetal abdominal circumference less than or equal to 10 mm/14 days or a femur length/abdominal circumference ratio greater than or equal to 23.5 correctly identifies most small for gestational age fetuses. When the general population is screened, only 15% of small for gestational age fetuses will be missed by this combination of criteria. The presence of a pocket of amniotic fluid less than or equal to 2.0 cm is highly suggestive of a small for gestational age fetus. However, the presence of a pocket of amniotic fluid greater than 2.0 cm does not guarantee an appropriate for gestational age fetus. We conclude that these gestational age-independent indices of fetal growth offer useful tools for differentiating between the small for gestational age and appropriate for gestational age fetus.

Cord prolapse: is antenatal diagnosis possible?

Cord presentation was diagnosed antenatally in nine patients at term referred for fetal ultrasound assessment (incidence of 0.61%). Seven patients were delivered by cesarean section; cord position was confirmed in four and suspected in three patients. There were two vaginal deliveries, one following spontaneous version and the other a stillbirth associated with cord prolapse.

Ovine fetal urine production following maternal intravenous furosemide administration.

The response of the ovine fetus to maternal furosemide administration was studied in six chronically catheterized fetal lamb preparations. These studies indicate that in the chronic sheep model maternally administered diuretics do not augment fetal urine production. Additionally, passage of the drug from the maternal intravascular compartment to the fetal intravascular compartment could not be demonstrated. It is suggested that on the basis of these data, the results of the "Lasix challenge test" should be interpreted with caution when they are used to evaluate human fetal renal function.