Fetal syphilis: clinical and laboratory characteristics.

OBJECTIVE: To examine the pathophysiology of fetal syphilis and correlate hematologic, immunologic, and sonographic findings. METHODS: Twenty-four women with untreated syphilis during pregnancy were prospectively identified. Sonography with amniocentesis and percutaneous umbilical blood sampling were performed. Darkfield examination, rabbit infectivity testing, and polymerase chain reaction for detection of Treponema pallidum were performed on amniotic fluid. Hematologic and chemical testing of fetal blood was performed using standard techniques. Fetal antitreponemal IgM was detected by Western blot assay. Maternal syphilis was treated with 2.4 to 4.8 million units of benzathine penicillin G intramuscularly. Neonatal outcomes and signs of congenital syphilis were recorded. RESULTS: Six women had primary, 12 had secondary, and six had early latent syphilis. Sixty-six percent of fetuses (95% confidence interval [CI] 47%, 82%) had either congenital syphilis or detection of Treponema pallidum in amniotic fluid. Sixty-six percent had hepatomegaly, including three fetuses (12.5%, 95% CI 4%, 31%) with ascites. Fetal antitreponemal IgM was detected in three cases. Abnormal liver transaminases were found in 88% (CI 69%, 96%), anemia in 26% (CI 13%, 47%), and thrombocytopenia in 35% (CI 19%, 55%). Maternal treatment was successful in 83% (CI 64%, 93%). Risk of treatment failure was significantly increased when hepatomegaly and ascites were present (P =.01). CONCLUSION: Findings with fetal syphilis are similar to those of neonatal syphilis. We hypothesize that fetal transaminase elevation occurs early in the course of infection; hematologic abnormalities and hydrops occur later. Severity of disease may be associated with risk of treatment failure.

Fetoscopic laser ablation of placental vessels in severe previable twin-twin transfusion syndrome.

OBJECTIVE: We undertook a pilot study to determine the feasibility and efficacy of fetoscopic laser occlusion of chorioangiopagous vessels in severe previable twin-twin transfusion syndrome. STUDY DESIGN: A total of 35 patients were referred to the investigators with ultrasonographic findings consistent with twin-twin transfusion syndrome, posterior placental implantation, gestational age < 25 weeks, and clinical hydramnios. Placental vessel occlusion was performed with a rigid 2.9 x 3.85 mm dual-channel fetoscope and neodymium:yttrium-aluminum-garnet laser light. RESULTS: Of the original 35 patients, 5 were eliminated preoperatively and 4 intraoperatively for various factors. The 26 treated patients had a mean gestational age of 20.8 weeks (range 18 to 24) and a mean fundal height of 36.1 cm (range 29 to 44). One patient has surviving triplets, 8 have surviving twins, 9 have a single survivor (2 neonatal and 7 fetal deaths occurred in this group), and 8 have no survivors (all had pregnancy loss within 3 weeks of treatment). The cases with survivors were delivered for obstetric indications at a mean of 32.2 weeks (range 26 to 37), having gained a mean of 11.7 weeks (range 6 to 17) in utero. Fifty-three percent (28/53) of the fetuses survived with 96% (27/28) developing normally at a mean age of 35.8 months (range 1 to 68). Thirty-three of 35 placentas were monochorionic with chorioangiopagous vessels on gross and microscopic evaluation. CONCLUSIONS: Fetoscopic laser occlusion of chorioangiopagous vessels is technically feasible and improves the course and outcome of severe twin-twin transfusion syndrome in previable fetuses.

Ultrasound anthropometric reliability.

Method errors and reliabilities were estimated for seven sonographic measurements in pregnancies of 106 women examined between January and July 1989. Teams of two experienced sonographers replicated the following measurements: biparietal diameter (BPD), occipital-frontal diameter (OFD), anterior-posterior diameter (APD), transabdominal distance (TAD), and femur diaphysis length (FDL). Multilevel modeling procedures were used to estimate the variance components. Significant (p < 0.01) covariates in the fixed part of the model included an increase in error with greater parity, estimated menstrual age (EMA), and maternal abdominal wall thickness (taken at the umbilicus). Intraobserver reliability ranged from 85.2% (AC) to 99.3% (FDL); interobserver reliability ranged from 80.8% (TAD) to 92.4% (FDL). Method errors, describing the expected error for 68% of the measurements taken, ranged from 0.8 mm to 7.7 mm (intraobserver) and from 1.2 mm to 7.8 mm (interobserver). These results suggest that large error components should be considered in the interpretation of the reliability of ultrasonographically obtained measurements.

Antepartum prediction of pulmonary hypoplasia: an elusive goal?

Diagnosis of fetal pulmonary hypoplasia could be of great benefit to the obstetrician in the management of those pregnancies complicated by prolonged preterm ruptured membranes. Ultrasonography and magnetic resonance imaging were employed for fetal diagnosis of pulmonary hypoplasia and we were unable to predict accurately those fetuses with pulmonary hypoplasia using two different published ultrasound formulas. Moreover, magnetic resonance imaging appears not to offer any advantages over sonographic evaluation in the diagnosis of fetal pulmonary hypoplasia.

Serum erythropoietin quantitation in pregnancy using an enzyme-linked immunoassay.

During normal pregnancy there is a decrease in the hematocrit due to a disproportionate increase in the blood volume compared with the red cell mass. Using a new enzyme-linked immunoassay (Amgen Diagnostics), serum erythropoietin was quantified in normal nonanemic pregnancies throughout gestation and in third trimester anemic patients. We found that the mean hematocrit in normal pregnancy reached a nadir late in the second trimester and the serum erythropoietin plateaued at a 50% increase. Those pregnancies complicated by anemia defined by a hematocrit less than 30 vol% demonstrated a statistically significant increase in serum erythropoietin above those not anemic.

Identification of Treponema pallidum in amniotic fluid and fetal blood from pregnancies complicated by congenital syphilis.

Two pregnant women with secondary syphilis underwent amniocentesis and evaluation for fetal syphilis. In both cases, motile spirochetes, typical of Treponema pallidum, were observed during dark-field microscopic examination of the amniotic fluid. The presence of T pallidum was confirmed by antitreponemal monoclonal antibody immunofluorescence assays and by rabbit infectivity tests using the amniotic fluid. In the first case, an infant at 35 weeks' gestation delivered within 24 hours of amniocentesis had hepatosplenomegaly, osteochondritis, and neurosyphilis. In the second case, a fetus at 24 weeks' gestation was hydropic and a fetal blood sample showed anemia, thrombocytopenia, and elevated liver enzymes. Fetal syphilis was confirmed by rabbit infectivity testing using fetal blood obtained by funipuncture. This is the first report of the diagnosis of fetal syphilis by funipuncture and confirmation of the presence of virulent T pallidum in the blood of a human fetus. The mother was treated for secondary syphilis, but the infant had residual signs of congenital infection at birth 14 weeks later. Neonatal serum from the first case and fetal serum from the second case showed specific immunoglobulin M reactivity with the 47-kd antigen of T pallidum by Western blot assays. A new wild-type strain of T pallidum, designated DAL-1, was isolated from the amniotic fluid of the first case and is available for future studies. We conclude that the presence of T pallidum in amniotic fluid or fetal blood indicates fetal-placental infection. Further investigation is necessary to determine the pathogenesis of amniotic fluid infection and its role in the prenatal diagnosis of congenital syphilis.

Embryofetal effects of pentamidine isethionate administered to pregnant Sprague-Dawley rats.

The effects of pentamidine isethionate on the developing embryo and fetus have not been previously published. Pregnant Sprague-Dawley rats were given various doses of pentamidine during the period of embryogenesis. Animals were killed on days 18 to 20 of pregnancy and their fetuses were removed by hysterectomy. Autopsies were performed on all fetuses. There were significant differences among groups with regard to maternal weight gain and pregnancy resorption. More pregnancy resorptions were noted in the group that received normal human doses (4 mg/kg/day) of pentamidine than in the control group (p less than 0.05). One structural anomaly consisting of unilateral renal agenesis was noted in the 711 fetuses examined. Skeletal survey of fetal rats was unremarkable. Pentamidine was without teratogenic effects in rats when administered in doses similar to those recommended for adult humans; however, it appears to have an embryocidal effect when given in those same doses during embryogenesis.

Chronic renal disease and pregnancy outcome.

During the 18-year period from 1971 through 1988, 37 women whose pregnancies were complicated by moderate or severe renal insufficiency were managed at Parkland Memorial Hospital. Common maternal complications included anemia, chronic hypertension, and preeclampsia. Perinatal complications included midpregnancy losses and low birth weight from preterm delivery, fetal growth retardation, or both. Despite the high incidence of maternal morbidity, 85% of pregnancies in the 26 women with moderate renal insufficiency resulted in a live-born infant; there was one stillbirth and no neonatal deaths. Of the 11 women with severe disease, seven were delivered of live-born infants after greater than or equal to 26 weeks' gestation. Although six of these 37 women had worsening renal function during pregnancy, it seems unlikely that pregnancy per se caused this. More importantly, in four of these six women and in four others who had stable function throughout pregnancy, end-stage renal disease developed within a mean of 4 years after delivery. In 14 women blood volume was determined during pregnancy, and whereas those with moderate disease had normal volume expansion, women with severe disease had significantly attenuated expansion. Finally, serial creatinine clearances did not increase during pregnancy in half the women with moderate insufficiency and none with severe dysfunction.