Prenatal diagnosis of a lean umbilical cord: a simple marker for the fetus at risk of being small for gestational age at birth.
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OBJECTIVE: The purpose of this study was to investigate whether the prenatal diagnosis of a 'lean' umbilical cord in otherwise normal fetuses identifies fetuses at risk of being small for gestational age (SGA) at birth and of having distress in labor. The umbilical cord was defined as lean when its cross-sectional area on ultrasound examination was below the 10th centile for gestational age. METHOD: Pregnant women undergoing routine sonographic examination were included in the study. Inclusion criteria were gestational age greater than 20 weeks, intact membranes, and singleton gestation. The sonographic cross-sectional area of the umbilical cord was measured in a plane adjacent to the insertion into the fetal abdomen. Umbilical artery Doppler waveforms were recorded during fetal apnea and fetal anthropometric parameters were measured. RESULTS: During the study period, 860 patients met the inclusion criteria, of whom 3.6% delivered a SGA infant. The proportion of SGA infants was higher among fetuses who had a lean umbilical cord on ultrasound examination than among those with a normal umbilical cord (11.5% vs. 2.6%, p < 0.05). Fetuses with a lean cord had a risk 4.4-fold higher of being SGA at birth than those with a normal umbilical cord. After 25 weeks of gestation, this risk was 12.4 times higher when the umbilical cord was lean than when it was of normal size. The proportion of fetuses with meconium-stained amniotic fluid at delivery was higher among fetuses with a lean cord than among those with a normal umbilical cord (14.6% vs. 3.1%, p < 0.001). The proportion of infants who had a 5-min Apgar score < 7 was higher among those who had a lean cord than among those with normal umbilical cord (5.2% vs. 1.3%, p < 0.05). Considering only patients admitted in labor with intact membranes and who delivered an appropriate-for-gestational-age infant, the proportion of fetuses who had oligohydramnios at the time of delivery was higher among those who had a lean cord than among those with a normal umbilical cord (17.6% versus 1.3%, p < 0.01). CONCLUSION: We conclude that fetuses with a lean umbilical cord have an increased risk of being small for gestational age at birth and of having signs of distress at the time of delivery. (+info)
Sirenomelia. Pathological features, antenatal ultrasonographic clues, and a review of current embryogenic theories.
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We aimed to discuss the prenatal diagnosis and pathological features of sirenomelia, and to review current embryogenic theories. We observed two sirenomelic fetuses that were at the 19th and 16th gestational week respectively. In the former, transvaginal ultrasound revealed severe oligohydramnios and internal abortion, whereas bilateral renal agenesis, absence of a normally tapered lumbosacral spine, and a single, dysmorphic lower limb were detected in the latter. In both cases, X-rays and autoptic examination allowed categorization on the basis of the skeletal deformity. Subtotal sacrococcygeal agenesis was present in both cases. Agenesis of the urinary apparatus and external genitalia and anorectal atresia were also found. Classification of sirenomelia separately from caudal regression syndrome is still debated. Recent advances in the understanding of axial mesoderm patterning during early embryonic development suggest that sirenomelia represents the most severe end of the caudal regression spectrum. Third-trimester ultrasonographic diagnosis is usually impaired by severe oligohydramnios related to bilateral renal agenesis, whereas during the early second trimester the amount of amniotic fluid may be sufficient to allow diagnosis. Early antenatal sonographic diagnosis is important in view of the dismal prognosis, and allows for earlier, less traumatic termination of pregnancy. (+info)
Intrauterine sling: a complication of the stuck twin syndrome.
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Stuck twin syndrome usually presents with polyhydramnios in the recipient sac and severe oligohydramnios in the donor sac. The donor is displaced against the uterine wall and remains adherent in that position. We present a case in which the diagnosis was more complicated, owing to the suspension of the stuck twin by a sling within the sac of the recipient. A monochorionic diamnionic twin gestation was complicated by twin-twin transfusion syndrome at 18 weeks of gestation. In our example, the stuck twin was suspended by a sling from the placenta. The sling band represented the intertwin membrane that was folded upon itself. Amniotic fluid from the recipient twin was present in three dimensions around the stuck twin, except for the sling band. The suspension of the stuck twin by a sling within the amniotic fluid of the recipient is an unusual manifestation of the stuck twin syndrome. (+info)
Studies of the mechanism of amniotic sac puncture-induced limb abnormalities in mice.
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The principal advantage of chorionic villus sampling (cvs) over amniocentesis for the determination of the genetic constitution of the embryo is that it may be undertaken earlier in pregnancy. If carried out too early in pregnancy, it has the risk of inducing craniofacial and limb abnormalities, a condition termed the oromandibulofacial limb hypogenesis (OMFL) syndrome in genetically normal infants. It is believed that the defects observed have a vascular origin, possibly due to anoxia of tissues due to fetal blood loss or thrombus formation at the site of biopsy with distal embolization. We believe that this does not adequately explain the findings from the experimental animal literature involving amniotic sac puncture (ASP). Based on these experimental findings, we have hypothesised that (i) the defects observed following cvs may result from the consequences of oligohydramnios following the inadvertent puncturing of the amniotic sac during this procedure, and (ii) that cleft palate and the postural limb defects observed (e.g., clubfoot and clubhand) are secondary to embryonic/fetal compression. Our experimental studies shed new light on the mechanism of induction of the limb defects seen, but particularly syndactyly. Evidence of hypoperfusion of the peripheral part of the developing limb bud is observed, which interferes with apoptosis that occurs in the digital interzones, or induces an abnormal degree of cellular proliferation and/or tissue regeneration in these sites, possibly because of over-expression of critical genes involved in limb pattern specification. Cleft palate, tail abnormalities and abnormalities of sternal ossification are also observed in our model. (+info)
Early prenatal ultrasound diagnosis of cleidocranial dysplasia.
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A woman was referred in the first trimester of her third pregnancy because of a family history of cleidocranial dysplasia. An ultrasound examination at 14 weeks 4 days revealed a fetus with appropriate biometric measurements. However, the clavicles were noted to be hypoplastic and the cranium appeared less well ossified than expected for gestational age, suggesting the diagnosis of cleidocranial dysplasia. On subsequent examination at 21 weeks, the findings were essentially unchanged. Induced vaginal delivery owing to decreased amniotic fluid volume occurred at 37 weeks, and a female weighing 3200 g was delivered. The infant had clinical and X-ray signs of cleidocranial dysplasia. (+info)
Fetal arterial and venous Doppler parameters in the interpretation of oligohydramnios in postterm pregnancies.
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OBJECTIVE: The objective of the current study was to evaluate fetal arterial and venous Doppler parameters in postterm pregnancies with oligohydramnios and those with normal amniotic fluid. STUDY DESIGN: A cross-sectional study was performed in 38 pregnancies beyond 41 weeks' gestation. Pulsed Doppler imaging was used to determine the pulsatility index (PI) for the fetal middle cerebral artery (MCA), renal artery, umbilical artery, inferior vena cava (IVC) and ductus venosus. The amniotic fluid index (AFI) was used for semiquantitive assessment of amniotic fluid volume. Oligohydramnios was defined as an AFI < 5 cm. RESULTS: Oligohydramnios was detected in 10 cases, and a normal AFI was present in 28 cases. In the presence of oligohydramnios the PI of the MCA was decreased, while the renal artery PI and the MCA PI/UA PI ratio were found to be elevated. In cases of oligohydramnios the PI in the IVC was increased but was unchanged in the ductus venosus. CONCLUSION: Oligohydramnios in post-term pregnancies is associated with arterial redistribution of fetal blood flow typifying the brain sparing effect and with decreased resistance in the MCA and increased resistance in the fetal IVC. (+info)
An autopsy case of Adams-Oliver syndrome.
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We report an autopsy case of a male fetus with Adams-Oliver syndrome. His mother was a healthy, 31-year-old woman and her family and past histories were unremarkable. Therapeutic termination was done at 28(+6) weeks gestational age due to oligohydramnios detected by antenatal ultrasonography. Chromosomal study revealed normal karyotype. On autopsy, characteristic transverse terminal defect of four extremities was found. Both feet were short and broad. All toes were rudimentary with no nails and fingers were irregularly short. On infantogram, all toe-bones were stubby and rudimentary. The middle and terminal phalanges of 2nd, 3rd & 5th fingers and the terminal phalange of 4th finger on the right hand were absent. The middle and terminal phalanges of 2nd & 5th fingers and terminal phalange of 3rd finger were defected on the left hand. His abnormalities were consistent with features of Adams-Oliver syndrome, which has not been reported in Korea. (+info)
Non-reassuring fetal status in the prolonged pregnancy: the impact of fetal weight.
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OBJECTIVE: To evaluate the incidence of abnormal fetal findings and Cesarean delivery for non-reassuring fetal status as a function of birth weight in the uncomplicated prolonged pregnancy. METHODS: Seven hundred and ninety-two patients at or beyond 41 weeks' gestation were managed expectantly. Population-specific birth-weight percentiles were calculated. Fetuses were retrospectively categorized as small (birth weight < 10th percentile), average (10th percentile < or = birth weight < or = 90th percentile) or large (birth weight > 90th percentile). The incidences of abnormal antepartum fetal testing results (i.e. oligohydramnios and/or abnormal non-stress testing) and Cesarean delivery for intrapartum non-reassuring fetal status were calculated for these three birth-weight categories. RESULTS: There was a significant inverse relationship between the incidence of abnormal fetal testing and birth-weight category (36%, 14% and 9% for small, average and large fetuses, respectively, P < 0.001). Small fetuses were more likely to require a Cesarean delivery for non-reassuring fetal status during labor than were all other fetuses (12.3% vs. 5.3%, P = 0.024). CONCLUSIONS: The frequency of oligohydramnios and abnormal non-stress testing is inversely related to birth weight in the expectantly managed prolonged pregnancy. In addition, small fetuses born at or beyond 41 weeks' gestation have an increased rate of Cesarean delivery for intrapartum non-reassuring fetal status. (+info)