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Biomedical subjects

R J Wapner

Publications and source records attributed to R J Wapner.

At least 19 recordsLinked to original sources
PubMed1992

Chorionic mosaicism: association with fetal loss but not with adverse perinatal outcome.

Cytogenetic data from the United States NICHD collaborative study of chorionic villus sampling (CVS) were used to evaluate the clinical significance of chorionic mosaicism. The 10,754 patients with normal cytogenetic results were compared with 108 patients (1.0 per cent) with placental mosaicism and 181 patients (1.6 per cent) with pseudo-mosaicism. Of the pregnancies intended to continue, the pregnancy loss rate was significantly greater in patients with placental mosaicism than in the cytogenetically normal cohort (8.6 vs. 3.4 per cent, p less than 0.05). However, there was no difference in the frequencies of abruptio placenta, preterm labour or delivery, small-for-gestational-age newborns, pregnancy-induced hypertension, or neonates with Apgar scores less than 7.

Abortion, Spontaneous↗
PubMed1992

An intravaginal controlled-release prostaglandin E2 pessary for cervical ripening and initiation of labor at term.

The purpose of this randomized, double-blind study was to evaluate the efficacy and safety of a new controlled-release hydrogel pessary for ripening the cervix and initiating labor. Subjects had an entry Bishop score of 4 or less and gestational age of 37 or more weeks. One hundred fourteen women received a placebo pessary and 101 received the hydrogel pessary, containing 10 mg of prostaglandin (PG) E2. Compared with the placebo group, those given the PGE2 pessary were more likely to have an increase in Bishop score of 3 or more (60 or 59% versus 21 or 18%; P less than .0001), change to a Bishop score of 6 or higher (59 or 58% versus 18 or 16%; P less than .0001), and active labor (68 or 67% versus 15 or 13%; P less than .0001). Including the crossover study, uterine hyperstimulation (28 of 182, 15%) and fetal heart rate abnormalities (18 of 182, 10%) in PGE2-treated subjects were reversed on removal of the pessary with no apparent harm to the mother or fetus. These temporary adverse effects appeared while the pessary was in place and after the onset of active labor. Oxytocin was unnecessary in 89 of 182 (49%) of the PGE2-treated cases and was used more often to augment than to induce labor. We conclude that the described controlled-release PGE2 vaginal pessary induces appreciable cervical ripening and frequently initiates active labor with little or no need for oxytocin. The pessary may cause uterine hyperstimulation or fetal heart rate abnormalities, but these would be expected to reverse on removal of the pessary.

Delayed-Action Preparations↗
PubMed1992

Twin pregnancies: accuracy of first-trimester abdominal US in predicting chorionicity and amnionicity.

A first-trimester transabdominal ultrasound (US) study was performed on twin pregnancies to determine the utility of US in predicting chorionicity and amnionicity. Among 85 dichorionic-diamniotic (DC-DA) twin pairs, a thick membrane was present in 78 (92%). Four of the DC-DA cases without a thick membrane had two distinct placental sites, allowing 82 DC-DA pregnancies (96%) to be predicted. Among 16 monochorionic-diamniotic (MC-DA) twin pairs, a thin membrane was present in 14 (88%). None of the four monochorionic-monoamniotic (MC-MA) cases had an identifiable membrane. The lambda sign had no value in this evaluation and was actually misleading, while a thick membrane or the identification of two separate placentas was always predictive of DC-DA twinning. However, a thin membrane, while usually predictive of an MC-DA pregnancy, did not exclude a DC-DA gestation. When no membrane is present, an MC-MA gestation is probable; however, a diamniotic pregnancy may still be present, and further evaluation is suggested.

Amnion↗
PubMed1991

Hepatitis B prevalence in an unregistered prenatal population. Implications for neonatal therapy.

STUDY OBJECTIVE: To evaluate the risk and associated cofactors for hepatitis B infection in inner-city pregnant women not registered for prenatal care. DESIGN: Fifteen-month survey of 208 patients not registered for prenatal care, compared with 1555 women registered for prenatal care during the same period. SETTING: An urban university hospital prenatal clinic and labor unit. RESULTS: Unregistered patients had a significantly higher rate of hepatitis B surface antigen positivity than patients who had registered with the clinic (6.7% vs 0.8%; P less than .0001). Unregistered patients with positive results of urine drug screening (46%) had a relative risk for seropositivity of 29.2%, compared with registered patients who did not have histories of illicit drug use (95% confidence interval, 25.9% to 32.4%), while registered patients with past histories of drug use had a relative risk of 6.7%, compared with the reference group that did not have histories of drug use (95% confidence interval, 1.8% to 24.0%). CONCLUSIONS: Among inner-city pregnant women not registered for prenatal care, a positive result of urine drug screening is a rapidly available marker for increased risk of hepatitis B surface antigen positivity. Infants born to unregistered women with positive results of urine drug screening before maternal hepatitis B surface antigen results are available may warrant empiric initiation of hepatitis B virus-specific prophylaxis.

Female↗
PubMed1991

Detection of retained products of conception following spontaneous abortion in the first trimester.

A retrospective analysis was performed to determine whether ultrasound could reliably rule in or out retained products of conception (POC) in women after first-trimester spontaneous abortions (miscarriages). Ninety-seven first-trimester pregnancies with pathologically proven results from dilatation and curettage (D&C) were studied within 7 days of ultrasound examination (60% within 2 days), either by the abdominal or a combination of abdominal and vaginal approaches. Cases were eliminated if there was clinical evidence of a spontaneous evacuation of POC during the interval between the ultrasound and the D&C. POC were diagnosed only if chorionic villi were evident pathologically. The pertinent ultrasound findings were related to the endometrium (thickness, echogenicity, a gestational saclike structure or a space-occupying collection). The results indicated that ultrasound could correctly diagnose POC in all of the cases by detecting a gestational sac or collection (77 cases), or a thickened endometrium of greater than 5 mm (6 cases). Ultrasound was less reliable in ruling out retained POC. When only a thin endometrial stripe of less than 2 mm was present, there was little likelihood of having POC (1 of 7 cases) with a moderately thick endometrium of 2 to 5 mm not diagnostic. Vaginal ultrasound added little new information and failed to change the ultrasound interpretation.

Abortion, Incomplete↗
PubMed1991

Doppler evaluation of umbilical and uterine-arcuate arteries in the postdates pregnancy.

To assess the correlation between Doppler velocimetry and perinatal outcome in the postdates pregnancy, 75 women who were at least 41 weeks' gestation were evaluated twice weekly until delivery. Evaluation included Doppler velocimetry of the umbilical and uterine-arcuate arteries, as well as nonstress testing and amniotic fluid volume estimation. The mean umbilical artery systolic-diastolic ratio (S/D) was significantly higher in the pregnancies with subsequent abnormal perinatal outcomes than in those with normal outcomes (2.42 versus 2.19; P = .03). Using a receiver operating characteristic curve, an abnormal umbilical artery S/D was defined as 2.40 or greater. Using this value, sensitivity was 57.1% and specificity was 77.8%. Our study suggests that an umbilical artery S/D of 2.40, rather than the more traditionally accepted cutoff of 3.0, may be a useful threshold to identify those postdates pregnancies at high risk for abnormal perinatal outcome.

Adult↗
PubMed1990

Selective reduction of multifetal pregnancies.

Selective reduction was carried out in 46 multifetal pregnancies by means of potassium chloride injection into the pericardial region of the fetus. There were three indications for the procedure: to improve perinatal outcome and to increase the likelihood that a term infant would be born in a multifetal pregnancy (34 women); to allow the birth of a healthy infant without the birth of a congenitally abnormal coexisting fetus (8 women); and to preserve a singleton pregnancy when the woman would otherwise have the whole pregnancy terminated (4 women). Of the 80 fetuses left after reduction 75 (94%) have survived. In 3 cases ultrasound scanning showed cardiac activity in the injected fetus 20-30 min after the initial injection despite 2 min of asystole immediately after the injection; repeated injection, carried out the same day, led to fetal death in all 3 cases. Selective reduction of multifetal pregnancies for the three indications described is an ethically justifiable option for the management of multifetal pregnancy, to which there are no public policy obstacles.

Congenital Abnormalities↗
PubMed1990

Usefulness of a short femur in the in utero detection of skeletal dysplasias.

In 28 fetuses studied during a 4 1/2-year period, the initial femur was below 2 standard deviations (SDs) of the mean when compared with the biparietal diameter. These fetuses were considered at risk for skeletal dysplasias and were followed up. Studies were performed at a mean gestational age of 26.7 weeks (range, 15.3-41.0 weeks). Group 1 had a femur length 1-4 mm below the 2-SDs line (range, -2.0 to -4.0 SDs); no other abnormalities were detected. Interval examination of 12 femurs showed that 10 either remained shortened to the same degree or had a growth spurt. At birth, all subjects were healthy except one with mild growth retardation and one with a chromosomal abnormality. Of the two subjects that failed to continue normal growth, one was healthy and the other was a heterozygous achondroplastic dwarf. Group 2 had greater femoral shortness; all measurements were more than 5 mm below the 2-SD line (range, -4.3 to -31.0 SDs). All had fetal abnormalities and significant skeletal dysplasias. The authors conclude that the number of millimeters below the 2-SDs line is an accurate, easy criterion for evaluation of femoral length.

Bone Diseases, Developmental↗
PubMed1990

The biophysical profile. A literature review and reassessments of its usefulness in the evaluation of fetal well-being.

Antenatal monitoring studies to assess fetal well-being and to identify the compromised fetus are in widespread use. This literature review analyzes the theoretical basis for fetal monitoring and the clinical research that has defined its utility, and it discusses the variations in protocols and scoring systems for the biophysical profile. While recognizing that there, is as yet, no consensus on the optimal monitoring protocol, the authors espouse one approach in which the cardiac nonstress test and the amniotic fluid volume are the initial tests, with full biophysical profile reserved for abnormal test outcomes. This approach to monitoring should be expeditious without diminishing its predictive value.

Embryonic and Fetal Development↗
PubMed1990

Mosaicism in chorionic villus sampling: an association with poor perinatal outcome.

Prenatal diagnosis by first-trimester chorionic villus sampling was successful in 4319 pregnancies involving 4395 fetuses. Cytogenetic information was obtained by both rapid cytotrophoblastic preparation and monolayer mesenchymal tissue culture. Chromosomal mosaicism was present in 55 of 4319 (1.3%). The abnormal cell line involved the cytotrophoblast in 79.6% of the mosaic specimens. None of the abnormalities found in the cytotrophoblast were confirmed in the fetus when the tissue culture was normal, supporting the belief that the cells of the mesenchymal core more truly reflect the chromosomal constitution of the fetus. However, a significant increase in the perinatal loss rate in the placental mosaic group was noted when compared with the nonmosaics: 16.7 versus 2.7% (P = .0001). These findings suggest that placental mosaicism may be a cause of perinatal loss.

Abortion, Spontaneous↗
PubMed1989

Absence of end-diastolic umbilical artery blood flow predicts poor fetal outcome despite normal blood gases.

A case is reported in which the fetal acid-base status was assessed by means of cordocentesis in a fetus without end-diastolic umbilical artery blood flow. The absence of end-diastolic flow was not associated with acidosis or hypoxia. However, the fetal condition deteriorated 3 days later, which suggests that even with a normal fetal acid-base status, an extended margin of safety cannot be assumed with the absence of end-diastolic umbilical flow.

Acid-Base Equilibrium↗
PubMed1989

Intravascular exchange and bolus transfusion in the severely isoimmunized fetus.

Eight Rh-sensitized fetuses, between 21 weeks 2 days and 35 weeks of gestation, received 31 intravascular transfusions (13 exchange and 18 bolus) and one intraperitoneal transfusion under ultrasonographic guidance. The interval between transfusions was 13.4 +/- 4.7 days. Posttransfusion hematocrit dropped at a rate of 1.0% +/- 0.6% per day. Procedure time for the bolus transfusion was shorter than for the exchange transfusion (t test, p less than 0.001). Bleeding from the puncture site complicated 10 of the 31 intravascular transfusions, without apparent maternal or fetal consequences. Fetuses were delivered between 33 and 36 weeks of gestation, after lung maturity was achieved.

Adult↗
PubMed1989

Successful treatment in two women with antiphospholipid antibodies and refractory pregnancy losses with intravenous immunoglobulin infusions.

In two women with antiphospholipid antibodies and recurrent fetal losses refractory to usual treatments, therapy consisting of aspirin, heparin, and intravenous gamma-globulin infusions was successful. Production of antiphospholipid antibodies was not suppressed. The transient decrease in anticoagulant activity noted in one case was not reproduced in vitro and was probably not physiologically important.

Abortion, Habitual↗