Circulating cell-free fetal DNA for the detection of RHD status and sex using reflex fetal identifiers.

OBJECTIVE: To determine the sensitivity and specificity of circulating cell-free fetal DNA in determining the fetal RHD status and fetal sex. METHODS: Maternal blood was collected in each trimester of pregnancy from RhD negative nonalloimmunized women. Whole blood was centrifuged, separated into plasma and buffy coat, and frozen at -80°C. DNA analysis was conducted via allele-specific primer extensions for exons 4, 5, and 7 of the RHD gene and for a 37-base pair insertion in exon 4 (RHD pseudogene; psi) three Y-chromosome sequences (SRY, DBY, and TTY2), and an extraction control (TGIFL-like X/Y). RhD serotyping on cord blood and gender assessment of the newborns were entered into a Web-based database. RESULTS: One hundred twenty women were enrolled. The median gestational age at the first venipuncture was 12.4 (range: 10.6-13.9) weeks with 120 samples drawn; 118 samples were drawn at 17.6 (16-20.9) weeks; and 113 samples at 28.7 (27.9-33.9) weeks. Overall accuracy for RHD was 99.1%, 99.1%, and 98.1% for each trimester and was 99.1%, 99.1%, and 100% for fetal sex determination. CONCLUSIONS: Fetal RHD genotyping and sex can be very accurately determined in all three trimesters using circulating cell-free fetal DNA in the maternal circulation.

Chorionic villus sampling before multifetal pregnancy reduction.

OBJECTIVE: This study was undertaken to determine the technical feasibility and accuracy of chorionic villus sampling before multifetal pregnancy reduction and to determine whether sampling increases the pregnancy loss rate after the reduction procedure. STUDY DESIGN: Between January 22, 1986, and January 20, 2000, a total of 1183 patients underwent first-trimester multifetal pregnancy reduction at Mount Sinai Medical Center. Chorionic villus sampling was attempted in 86 patients before the reduction procedure. Information on the technical success and accuracy of chorionic villus sampling, as well as pregnancy outcome, was collected on all patients. Pregnancy loss rates before 24 weeks' gestation in patients undergoing chorionic villus sampling before multifetal pregnancy reduction were compared with rates in patients not undergoing sampling. RESULTS: Chorionic villus sampling was successfully completed in 85 (98.8%) of 86 patients in whom sampling was attempted. Of 166 fetuses, 165 (99.4%) were successfully sampled. Of 165 fetuses, 3 (1.8%) had karyotypic abnormalities. Sampling errors were probably made in 2 (1.2%) of 165 fetuses. Of the 73 patients who have been delivered or are beyond 24 weeks' gestation, only 1 patient (1.4%) had a pregnancy loss after the multifetal pregnancy reduction. CONCLUSIONS: Chorionic villus sampling before multifetal pregnancy reduction is technically feasible and accurate, with an acceptably low sampling error rate. Chorionic villus sampling before multifetal pregnancy reduction appears to be safe and does not increase the risk of loss after the reduction procedure.

Gastrointestinal disorders of the fetus.

The approach to developing a differential diagnosis to an abnormal gastrointestinal ultrasound finding should include consideration of the lesion's location, size, shape, and echogenicity; fetal gender; relationship to and understanding of adjacent structures; and the presence of associated anomalies. Once a differential diagnosis has been established, ancillary testing, such as amniocentesis, maternal serology, or fetal echocardiography should be undertaken to refine further the diagnosis. A multidisciplinary team approach should be taken in the prenatal management of a suspected fetal anomaly. This may include collaboration with specialists in the fields of perinatology, prenatal ultrasound, genetic counseling, neonatology, pediatric surgery, and patient support groups.

One hundred consecutive cases of selective termination of an abnormal fetus in a multifetal gestation.

OBJECTIVE: To determine whether transabdominal selective termination of one or more abnormal fetuses in a multifetal pregnancy with dichorionic placentation is a safe and effective procedure. METHODS: One hundred consecutive selective termination procedures were performed by transabdominal injection of potassium chloride into the heart or umbilical vein of an anomalous fetus in a multifetal pregnancy. All of the abnormal fetuses were presumed to have dichorionic diamniotic placentas, based on an ultrasound evaluation before the procedure. Follow-up data were obtained for each patient regarding the development of postprocedural complications, laboratory or clinical evidence of a coagulopathy, maternal or neonatal morbidity, gestational age at delivery, and birth weight of the infants. RESULTS: Ninety-one sets of twins were reduced to singletons, six sets of triplets were reduced to twins, two sets of triplets were reduced to singletons, and one set of quadruplets was reduced to triplets. The anomalous fetus or fetuses were identified correctly and terminated in each case. Three patients spontaneously aborted, and one women electively terminated her pregnancy 2 weeks after the procedure. The mean gestational age at delivery of the 96 patients who delivered surviving infants was 36.8 weeks, and 85.4% delivered at 32 weeks or later. Three women developed laboratory evidence of a coagulopathy, but there were no cases of clinically evident disseminated intravascular coagulation. CONCLUSION: This procedure, performed at a single institution by a small number of operators using a common protocol, accomplished its objective in all cases, was accompanied by a low spontaneous loss rate, and resulted in the birth of healthy infants at or near term in the vast majority of cases. This series suggests that selective termination is a reasonable option to consider when one abnormal fetus is found in a multifetal pregnancy with dichorionic placentation.

Circulating hematopoietic stem cell populations in human fetuses: implications for fetal gene therapy and alterations with in utero red cell transfusion.

Circulating progenitor cell populations in normal human fetuses and fetuses with various hematological problems were evaluated. Thirty blood samples from 21 human fetuses (17-36 weeks of gestation) were assayed for erythroid, myeloid, and mixed-cell progenitor cells. The mean number of progenitor cells/10(4) blood mononuclear cells in the normal fetal population was 103 +/- 47. Granulomonocytic and mixed progenitor cells (capable of giving rise to both erythroid and myeloid progeny) were the predominant progenitor types in these samples, with pure erythroid progenitors barely detectable. The frequency of progenitor cells in the samples from fetuses with hematological disorders was within the range of normal in all but 1 fetus infected with parvovirus in whom very few progenitor cells were detected. The frequency of progenitor cells in the blood did not change after intravascular red cell transfusion for alloimmunization despite the large volumes transfused, indicating that transfusion may have triggered a release of progenitor cells into the circulation. Progenitor cells in human fetal blood are present in distributions similar to those commonly detected in cord blood. Their total number in the circulating blood is in the same order used for pediatric and adult bone marrow transplantation. These results can be used to calculate the number of colony-forming cells which could be obtained from a fetus by in utero apheresis and which could be made available for autologous fetal gene therapy.

Conflicts between physicians and patients in non-elective cesarean delivery: incidence and the adequacy of informed consent.

A study was undertaken in 372 consecutive patients undergoing non-elective cesarean delivery to explore the incidence and nature of conflicts between physician and patient surrounding the decision to undergo non-elective cesarean delivery; to examine the adequacy of informed consent at the time of non-elective cesarean delivery; and to describe the importance of a preventive ethics approach to non-elective cesarean delivery. During a 6-month interval, all patients who underwent non-elective cesarean delivery and their physicians were asked to take part in a survey in the early postpartum period concerning their response to recommendations for cesarean delivery. The survey included demographics as well as questions pertaining to informed consent and the presence and nature of patient-physician conflict. Of the 326 patients who were interviewed, 319 (98%) agreed to the recommendation for non-elective cesarean delivery and 7 patients (2%) initially disagreed. Reasons for disagreeing included: feared surgery (4 of 7), needed husband's approval (1 of 7), and questioned the medical necessity of surgery (2 of 7). In all 7 cases of initial disagreement, cesarean delivery was eventually performed with the patient's consent. The mean age of patients who initially disagreed was younger (24.7 +/- 6) than that of those who agreed (31.0 +/- 4 [p < 0.05]). Conflicts were present in 7 of 113 clinic patients and 0 of 213 private patients (p < 0.05). Of those surveyed, 26 (8.7%) indicated that they did not have adequate input in the decision for non-elective cesarean delivery. Patients with inadequate input expressed significantly more concerns with regard to the effect of surgery on their own health (p < 0.05) as well as its effect on the baby (p < 0.05). Our findings suggest that even though the incidence of physician-patient conflict about non-elective cesarean delivery was quite low, a significant number of patients (1 in 12) may have reservations concerning the informed consent process at the time of non-elective cesarean delivery. Patients with reservations are more likely to have greater concerns with regard to maternal and fetal risks, suggesting that a more detailed risk disclosure prior to the procedure is warranted for all pregnant patients. Perhaps by incorporating the preventive strategies discussed, the adequacy of informed consent and therefore the patient's autonomy could be enhanced, thus diminishing patient reservations and preventing physician-patient conflict in the intrapartum period.

Antiplatelet antibody testing in thrombocytopenic pregnant women.

OBJECTIVE: The purpose of the study was to attempt to distinguish pregnant women with gestational thrombocytopenia from those with idiopathic immune thrombocytopenia by eight different platelet antibody assays. STUDY DESIGN: Sera from pregnant women with presumed gestational thrombocytopenia (n = 160) and idiopathic immune thrombocytopenia (n=90) were prospectively tested for indirect and platelet-associated immunoglobulins G and M and complement C3, as well as for serotonin release. After the results were analyzed, a subset of patients were subsequently analyzed for circulating antiplatelet antibody directed against platelet membrane glycoprotein GPIIb/IIIa. RESULTS: Indirect immunoglobulin G was significantly greater in the 85 women with idiopathic immune thrombocytopenia than in the 129 women with gestational thrombocytopenia (p<0.001). Platelet-associated immunoglobulin G was elevated in the majority of women, both those with gestational thrombocytopenia and those with idiopathic immune thrombocytopenia. There were also no statistically significant difference in the values for platelet-associated C3 or indirect immunoglobulin M and C3. Levels of platelet-associated immunoglobulin M showed a tendency to be higher in women with gestational thrombocytopenia (p=0.04), as did the values in the serotonin release assay (p=0.06). CONCLUSION: Our data demonstrate that patients with gestational thrombocytopenia had surprisingly high levels of platelet-associated immunoglobulin despite mild thrombocytopenia. Comparison of a relatively large number of patients with idiopathic immune thrombocytopenia and gestational thrombocytopenia indicates that women with idiopathic immune thrombocytopenia cannot be distinguished from those with gestational thrombocytopenia by means of one or more of the prototypic platelet antiglobulin tests currently in use. Our preliminary data with glycoprotein-specific assays indicate that they may be more useful.

Rapid exclusion of chromosomal aneuploidies by fluorescence in situ hybridization prior to fetal surgery for obstructive uropathy--a case report.

Ultrasound of a fetus at 17 weeks gestation revealed posterior urethral valve syndrome with anhydramnios. Fluorescence in situ hybridization (FISH) to detect aneuploidies of chromosomes 13, 18, 21, X and Y was performed on transitional cells from the fetal bladder obtained at percutaneous vesicocentesis, followed by conventional cytogenetics. Fetal urine was chosen due to unavailability of amniotic fluid for karyotypic analysis. A nonlethal (disomic) karyotype was suggested by FISH, and thus placement of a vesicoamniotic shunt was performed. The ability to prognosticate in cases of obstructive uropathy is not absolute, and fetal surgery for relief of urinary obstruction is best performed at the earliest possible gestational age. Thus, all available means for rapidly ruling out lethal congenital anomalies should be undertaken in cases of obstructive uropathy prior to any decision regarding fetal surgery.

Prenatal diagnosis of structural anomalies.

The ultrasound diagnoses of fetal anomalies affecting obstetric management were initially made in the early 1970s. Since this breakthrough, ultrasound diagnosis and prenatal management of structural fetal abnormalities have become essential and evolving components of prenatal diagnosis and therapy. In this overview, we review recent contributions in the peer review literature on four controversial topics: choroid plexus cysts, cystic hygroma, ventral wall defects, and hydronephrosis.

Clinical significance and sonographic diagnosis of velamentous umbilical cord insertion.

In order to evaluate the clinical significance of velamentous cord insertion (VCI) and the role of ultrasound in its diagnosis, all 82 cases of VCI during January 1985 to January 1989 at the Mount Sinai Medical Center were reviewed. The overall rate of VCI in our study (0.5%) was similar to that of previous reports. Pregnancy outcomes in VCI patients with 77 singleton gestations were compared with a control group of 15,865 patients. In contrast to the existing literature, multiparity and prior cesarean section deliveries were not increased in pregnancies with VCI. The VCI group had more intrapartum complications and a lower birthweight than the controls. Routine nontargeted obstetric ultrasound failed to detect any cases of VCI, including three cases of vasa previa. Since VCI was not identified prenatally and many of its sequelae are readily identifiable only during the intrapartum period, the potential for preemptive obstetric intervention appears to be limited. In addition, failure to diagnose apparent VCI during a routine ultrasound does not appear to be a departure from the standard of care.

Reliability of pleural fluid lymphocyte counts in the antenatal diagnosis of congenital chylothorax.

Two cases are presented in which fetal thoracentesis was performed to evaluate pleural effusions. In the first, a fetus with nonimmune hydrops had pleural effusions with lymphocyte counts consistent with congenital chylothorax. However, amniotic fluid cultures grew cytomegalovirus and the diagnosis of congenital cytomegalovirus infection was confirmed at autopsy. In the second, the pleural fluid lymphocyte count was lower than that considered to be diagnostic of congenital chylothorax. Nevertheless, the clinical course in this case and the patient's history of two previous infants who were presumed to have that disease suggest that this was the most likely diagnosis. These cases emphasize that pleural fluid lymphocyte counts alone are not reliable in establishing the cause of hydrothorax before birth.