1/6. An unstable dicentric Robertsonian translocation in a markedly discordant twin.Karyotypes from independent amniocenteses reflected a rare, unstable, functionally dicentric Robertsonian translocation chromosome in most cells in male Twin B who grew more slowly than the chromosomally normal female sib (Twin A). Twin B's balanced de novo Robertsonian translocation dic(13;14)(p11.1;p11.1), present in 81% of cells, underwent recurrent centromeric fission in 6 out of 30 independent colonies that explains a balanced 46,XY,-13, fis(13)(p11.1),-14, fis(14)(p11.1) karyotype. aneuploidy for chromosomes 13q or 14q was present in 5% of cells. Instability of the Robertsonian translocation was evident because nine of the 30 colonies (30%) grown from single amniocytes had metaphase cells with more than one chromosome complement. Although uniparental disomy was excluded and a targeted ultrasound was normal, the couple was advised of the uncertain but real risk of abnormalities in Twin B and the risk to Twin A of terminating Twin B. The pregnancy proceeded and at 31 weeks gestation Twin A was in the 33rd percentile for size and Twin B in the 1st percentile. At 32 weeks, chromosome analysis revealed a balanced 45,XY,dic(13;14)(p11.1;p11.1) karyotype in all of Twin B's newborn cord blood cells with no evidence of fission or aneuploidy. Selection against unbalanced mitotic products of the unstable, functionally dicentric chromosome in early fetal development is proposed to result in Twin B's highly discordant small birth size.- - - - - - - - - - ranking = 1keywords = fetal development (Clic here for more details about this article) |
2/6. A normal 46,XX infant with a 46,XX/69,XXY placenta: a major contribution to the placenta is from a resorbed twin.A predominantly triploid 69,XXY placenta was found associated with a normal 46,XX infant. Therefore, a triploid placenta is apparently capable of supporting normal fetal development. The chromosome and pathological results support the conclusion that the triploid placenta originates from a 'vanishing twin' pregnancy. This case is unusual in that persistence of the placenta from the vanished twin has virtually replaced most of the normal placenta.- - - - - - - - - - ranking = 1keywords = fetal development (Clic here for more details about this article) |
3/6. Obstructive sleep apnea during pregnancy. Therapy and implications for fetal health.A 32 yr-old woman in her last trimester of pregnancy was found to have severe obstructive sleep apnea (OSA). The overnight polysomnogram demonstrated an apnea plus hypopnea index of 159 events per hour. Apneas were associated with severe oxygen desaturation to 40% during rapid eye movement sleep, maternal bradycardia, and second degree heart block. External cardiotocography showed normal fetal heart rate reactivity to fetal movements, even during the apneas and episodes of oxygen desaturation. Nasal continuous positive airway pressure at a level of 15 cm H2O effectively treated the apneas and desaturation and had no effect on the fetal heart rate. The patient was induced electively during the 39th wk of pregnancy and gave birth to a newborn with growth retardation. Early recognition and treatment of OSA in pregnancy might prevent problems with fetal development.- - - - - - - - - - ranking = 1keywords = fetal development (Clic here for more details about this article) |
4/6. Maternal phenylketonuria-chronology of the detrimental effects on embryogenesis and fetal development: pathological report, survey, clinical application.Maternal phenylketonuria (PKU) is likely to have detrimental effects on embryogenesis and fetal development. Manifestations in the offspring include spontaneous abortion, various congenital malformations, intrauterine growth retardation, and microcephaly. The time at which the metabolic abnormalities induce pathologic embryogenesis can be documented by knowing the time of the development of specifically damaged organ systems. This review reveals that, while the most recognized congenital malformations occur in the heart, the most common abnormality is growth inhibition occurring throughout pregnancy. The organ system most commonly affected by this growth inhibition is the brain, resulting in a high incidence of micrencephaly. It appears that maternal phenylketonuria interferes with appropriate fetal growth and that this effect occurs during the entire course of pregnancy and has no tissue specificity. This information can be both informative to pathologists and useful to clinicians.- - - - - - - - - - ranking = 5keywords = fetal development (Clic here for more details about this article) |
5/6. Human maternal uniparental disomy for chromosome 16 and fetal development.Two severely growth-retarded fetuses found to have maternal uniparental disomy (UPD) for chromosome 16 and trisomy 16 placental mosaicism both had an unfavourable outcome. Antenatally, the first case was complicated by an unexplained raised maternal serum alpha-fetoprotein concentration, preterm premature rupture of the membranes, and growth retardation detectable at 21 weeks' gestation, whilst the other had an unexplained raised maternal serum human chorionic gonadotrophin level, a two-vessel cord on ultrasound, and cessation of growth at 25 weeks. At post-mortem, both babies had an imperforate anus. Fetal maternal UPD may explain the poor outcome that occurs in some cases of confined placental mosaicism for chromosome 16 and is also associated with specific fetal abnormalities.- - - - - - - - - - ranking = 4keywords = fetal development (Clic here for more details about this article) |
6/6. Sonographically detected fetal and placental abnormalities associated with trisomy 16 confined to the placenta. A case report and review of the literature.trisomy 16 is the most frequent autosomal anomaly seen in early spontaneous abortions, accounting for 15 per cent of all chromosomally abnormal early spontaneous abortions. This trisomy is thought to be lethal in the non-mosaic state and incompatible with full fetal development. We report a case of placental trisomy 16 mosaicism detected after chorionic villus sampling (CVS). The patient was referred at 18 weeks of gestation on account of moderate intra-uterine growth restriction (IUGR). Detailed sonography showed a thickened and enlarged placenta with multiple 'cysts', polyhydramnios, a single umbilical artery and a small ventricular septal defect (VSD). CVS, amniocentesis (AC) and fetal blood sampling (FBS) were performed. After direct preparation of chorionic villi only 47,XX, 16 cells were seen. However, chromosomal analysis of cultivated amniotic fluid cells and fetal lymphocytes only showed a normal karyotype 46,XX. After direct preparation of a second CVS at 19 4 weeks of gestation the karyotype 47,XX 16 was confirmed in the contralateral part of the placenta and near the insertion of the umbilical cord. A normal female karyotype 46,XX was demonstrated by extensive karyotyping of various sites of the placenta, the neonatal skin fibroblasts and lymphocytes postnatally. In accordance with this observation the multiple 'cysts' of the placenta disappeared in the third trimester. We speculate that the sonographic findings of multiple round placental 'cysts' without a hyperreflective border may be caused by the trisomic cell lineages and therefore may be a sonographic marker of trisomy 16.- - - - - - - - - - ranking = 1keywords = fetal development (Clic here for more details about this article) |