Antenatal Human Parvovirus B19 Infection and Nonimmune Hydrops Fetalis Presenting as Severe Preeclampsia

EDITORIAL COMMENT: We accepted this paper for publication since the authors believe it is the first report of hydrops fetalis due to parvovirus infection apparently causing severe preeclampsia. This is similar to the 'maternal preeclampsia syndrome' classically described with fetal and placental hydrops due to maternal rhesus isoimmunization (A), and which also can occur with fetal and placental hydrops due to fetal alpha thalassaemia major. The authors indicate that treatment of fetal anaemia could possibly result in resolution of the signs of preeclampsia in such cases. Indeed the members of the editorial subcommittee have already heard, on the Australian academic grapevine, of surviving infants treated in utero for anaemia caused by parvovirus and erythroblastosis due to maternal rheus isoimmunization respectively, in 2 mothers with signs of severe preeclampsia.
(A) Scott JS. Pregnancy toxaemia associated with Hydrops foetalis, Hydatidiform mole and Hydramnios. J Obstet Gynaecol Br Emp 1958; 65:689–701. William Blair-Bell Memorial Lecture delivered at the Royal College of Obstetricians and Gynaecologists on May 30, 1958.     

Antecedents to and Outcomes of Rh(D) Isoimmunization: Mater Mothers Hospital, Brisbane, 1988–1995

Summary: We analyzed the antecedents and outcomes of Rh(D) isoimmunization in a local population. Forty-two Rh(D) isoimmunized women attending Mater Mothers Hospital for antenatal care were identified through the Mater Hospital Blood Bank database; their records were reviewed for variables including sensitizing events, obstetric interventions and pregnancy outcomes. In this group, 74% of women became sensitized despite receiving anti-D immune globulin, 17% did not receive anti-D appropriately and the others failed to attend for treatment of bleeding in pregnancy. Antenatal sensitization was implicated in 6 women (14%) and potentially responsible for isoimmunization in another 18. Over half of the 80 viable pregnancies in this study group required some form of obstetric intervention. Thirty pregnancies required amniocentesis and 1 in 3 babies underwent either intrauterine or exchange transfusion. Three fetal deaths occurred as a result of severe disease. This study offers information highlighting circumstances in which immunoprophylaxis guidelines have failed to impart protection against Rh(D) sensitization and the consequences of such failures.     

Amniocentesis in the Management of Preterm Premature Rupture of the Membranes

A retrospective analysis has been performed of perinatal outcome in 81 pregnancies in which preterm premature rupture of membranes (PPROM) was managed using amniocentesis to diagnose intrauterine infection and lung maturity. Ten patients (13%) had a positive Gram stain on microscopy whilst 29 (37%) had a positive culture. Forty-one patients (58%) had a mature lecithin:sphingomyelin ratio. There was evidence of sepsis in 13 neonates (16%), with a further 16 (20%) being colonized. Both Gram stain and amniotic fluid culture were relatively poor predictors of neonatal sepsis. For Gram stain the sensitivity was low at only 15%. Although the sensitivity for culture was higher (69%), the specificity (71%) was too low to be clinically useful. It is recommended that a randomized controlled trial of amniocentesis in PPROM is needed to define the role of this diagnostic test.     

Transabdominal Chorion Villus Sampling: A Safe and Reliable Procedure

A complete follow-up of the first 578 patients undergoing transabdominal chorion villus sampling (TACVS) in our combined practices was undertaken to determine the pregnancy loss rate. Factors contributing to losses and the problems incurred in achieving a clinically relevant result were also examined. It was found that increasing experience led to fewer procedural difficulties but that there persisted a higher problem rate in those women with a retroverted uterus. In 98.1% of patients an adequate volume of tissue was obtained and in 95.5% a clinically relevant result was achieved. This second figure rose to 96.3% in the latter part of the study. There was a total fetal loss rate of 2%, with only 0.5% (3 patients) having a missed abortion within 4 weeks of the procedure. It is concluded that TACVS is a reliable procedure with a high level of safety.     

Antepartum and Postpartum Complications of Twin-Twin Transfusion

Summary: Twin-twin transfusion is a condition that was previously associated with close to a 100% perinatal mortality. Recent reports suggest that a survival rate of about 60% can be achieved with serial amniocentesis and modern neonatal care. However, it is now apparent that the survivors of this condition have multisystem complications that can result in neonatal mortality and long-term morbidity. Fourteen cases of twin-twin transfusion were examined to determine the antenatal findings that may predict the postnatal outcomes of these infants. The overall survival was 61% (17 of 28). The mean gestation at diagnosis was 23.0 weeks (range 18–34 weeks) and the mean gestation at delivery was 29.0 weeks (range 23–37 weeks). The mean number of amniocenteses was 2.9 and the average total volume of amniotic fluid removed was 6,114 mL. Different patterns of complications were seen in the donor and recipient twins. Hypertrophic cardiomyopathy affected 9 of the recipient twins. Anuria/oliguria was found in 4 of the donor twins and none of the recipients. Periventricular leukomalacia was found in 8 twins and 7 also had mild ventriculomegaly; of the surviving 17 twins, 5 had either periventricular leukomalacia, mild ventriculomegaly or both. Amniotic fluid leakage and perforation of the intervening membrane subsequent to serial amniocentesis were seen in 5 cases. Severe intrauterine growth retardation and abnormal cardiotocographs were a common feature. These complications directly resulted in neonatal mortality and long-term morbidity in the survivors. Not all complications were detected antenatally and the severity was not able to be anticipated.     

First Trimester Aneuploidy Screening Using Nuchal Iranslucency, Free Beta Human Chorionic Gonadotrophin and Maternal Age

Summary: Screening for aneuploidy using maternal age has a low detection rate and high false positive rate. Second trimester maternal serum screening increases trisomy 21 detection and decreases die false positive rate. First trimester screening would enable definitive diagnosis with chorionic villus sampling, and simple surgical termination of affected pregnancies would still be an option. Nuchal translucency (NT), free beta human chorionic gonadotrophin (fβHCG) and maternal age were assessed in 302 patients before chorionic villus sampling. NT positively and fβHCG negatively correlated with gestation, but neither correlated with maternal age nor with each other. Both NT and fβHCG were increased in trisomy 21. NT was increased and fβHCG was decreased in trisomy 18. Multivariate discriminant analysis enabled 87.5% detection of trisomy 21 in this high-risk population, for a 14% false positive rate. In a simulated normal population, using a risk cut-off of 1 in 250, 71% detection was achieved for a 7% false positive rate. The combination of NT, fβHCG and maternal age is a simple, readily available and viable first trimester screening strategy.     

Placenta Praevia — A Review with Emphasis on the Role of Ultrasound

Considerable confusion exists in the literature as a result of the wide range of classification systems for placenta praevia (PP) and low-lying placenta. The discrepancy between frequency of low-lying placentas in the second trimester and PP at term reflects to a certain extent the lack of understanding of the anatomy and physiology of the pregnant uterus. It seems that 'placental conversion' is a real phenomenon and is probably due to the differential growth rates of the placenta and uterus. Maternal bladder overdistension and myometrial contractions account for only a small part of the discrepancy. Diagnostic ultrasound obviously has an important role in placental localization. The role of Magnetic Resonance Imaging remains to be determined. The management of patients with low-lying placenta diagnosed in the second trimester, and the frequency of repeat scans is determined largely by the management protocol of the attending obstetrician.