Polymicrogyria in a fetus with human parvovirus B19 infection: a case with radiologic-pathologic correlation.

We report the prenatal magnetic resonance imaging (MRI) appearance of polymicrogyria with pathologic correlation in a fetus with congenital parvovirus B19 infection. Prenatal ultrasound revealed non-immune hydrops, but detected no fetal brain abnormalities. A subsequent fetal MRI scan performed at 23 weeks' gestation demonstrated bilateral polymicrogyria, which was confirmed at autopsy. To our knowledge, prenatal diagnosis of polymicrogyria in association with congenital parvovirus B19 infection has not been previously described. This case provides further evidence for brain abnormalities resulting from congenital parvovirus B19 infection, and suggests that fetal neuroimaging with MRI would be of value in suspected cases of congenital parvovirus infection.

Mode of delivery in pregnancies complicated by preeclampsia with very low birth weight infants.

The aims of this study were to examine data from an institution at which the goal has been to pursue vaginal delivery in patients with a preterm gestation and preeclampsia and to test the hypothesis that labor does not increase the risk of poor outcome for the preterm infant of a mother with preeclampsia. An analysis of all singleton infants born live who weighed 1500 gm or less and who were born to mothers with preeclampsia or eclampsia from 1975 to 1990 was undertaken. The infants who were delivered by cesarean section without labor and with a reassuring fetal assessment were compared with the infants who went through labor. Of 116 women with singleton pregnancies with preeclampsia and an infant who weighed 1500 gm or less, 54.3% were delivered by cesarean section without labor, 31.0% because of nonreassuring fetal assessment and 23.3% (group 1) because of other indications. Of the patients allowed to labor (group 2), 47.2% had cesarean sections because of fetal intolerance of labor and 32.1% were delivered vaginally. Of the patients who were delivered vaginally, 75% had an unfavorable Bishop's score at the outset of the induction. There was no significant difference between groups 1 and 2 for a number of immediate and long-term outcome variables except for a lower incidence of respiratory distress syndrome in the infants who went through labor. On the basis of these limited data a trial of labor should be considered in carefully selected women with preeclampsia who have very-low-birth-weight infants.

Nitric oxide synthase activity in pregnant rabbit uterus decreases on the last day of pregnancy.

OBJECTIVE: Our purpose was to test a potential role for the endogenous smooth muscle relaxant nitric oxide in the control of gestational uterine activity by quantifying and characterizing its synthetic enzyme, nitric oxide synthase, in uterine tissue at the end of pregnancy. STUDY DESIGN: We measured nitric oxide synthase activity through the conversion of tritiated L-arginine to tritiated L-citrulline in subcellular preparations of decidua and myometrium from pregnant rabbits at 27, 30, and 31 days' (term)gestation. Nitric oxide synthase was characterized by measuring its relative inhibition by arginine analogs and its calcium-calmodulin requirement. Nitric oxide synthase activities were compared by one-way analysis of variance with Fisher's post hoc test. RESULTS: Nitric oxide synthase activity in decidua was high at 27 days' gestation (6.32 +/- 1.10 pmol/mg protein per minute, n = 6), less with the approach of labor (30 days = 3.16 +/- 1.25 pmol/mg per minute, n = 4), and lowest at 31 days (1.07 +/- 0.29 pmol/mg per minute, n = 4, p < 0.05). Decidual nitric oxide synthase was calcium insensitive, and arginine analogs reduced activity with potencies consistent with their effect on the induced form of nitric oxide synthase. CONCLUSION: Decidual nitric oxide synthase activity, which has the characteristics of the inducible isoform of the enzyme, is significantly lower on the last day of gestation. This suggests a role for nitric oxide in the control of uterine contractility during pregnancy.

Terbutaline tocolysis and glucose intolerance.

OBJECTIVE: To determine whether there is an increased incidence of glucose intolerance in association with chronic terbutaline therapy, administered either orally or as a continuous subcutaneous infusion. METHODS: Sixty-nine women received terbutaline, orally (38 subjects) or as a continuous subcutaneous infusion (31 subjects). Their gestational diabetes screening results were compared to the results in 82 women not receiving beta-mimetic therapy. RESULTS: Subjects receiving terbutaline had significantly higher mean glucose concentrations after the 1-hour 50-g glucose tolerance test (GTT) than did controls (P < .05, one-way analysis of variance with multiple comparisons). Among subjects receiving a continuous subcutaneous infusion of terbutaline, the incidence of abnormal 3-hour 100-g GTT results was higher than among controls (20 versus 4%; P = .023 by chi 2). CONCLUSIONS: The incidence of GTT abnormalities is increased among women receiving terbutaline. We recommend surveillance of glucose tolerance among patients receiving terbutaline chronically, regardless of the route of administration.

Antenatal care of the patient with previous preterm premature rupture of membranes.

Although there is a 21% recurrence risk for PPROM, little research has been directed to the obstetric management of women with prior PPROM. This article reviews indirect information regarding risk assessment, diet, lifestyle factors, and infections. A management plan is suggested.

Discordance of müllerian agenesis in monozygotic twins. A case report.

With the case described here there have been six reported cases of discordance of müllerian development in monozygotic twins. The etiology of the disorder remains obscure. Although a genetic basis may exist in some cases, it could not be demonstrated in any of the six cases.

Effects of in vivo amphetamine administration on dopamine synthesis regulation in rat brain striatal synaptosomes.

The stimulation of dopamine synthesis in rat brain striatal synaptosomes produced by the depolarizing agent veratridine was markedly reduced by prior in vivo amphetamine administration. This effect did not appear to be due to an interference with the depolarization process, per se, since veratridine-induced inhibition of tyrosine uptake, a biochemical correlate of depolarization, was unaffected by amphetamine. Antagonism of veratridine-induced synthesis stimulation was not duplicated by in vivo treatment with pargyline, apomorphine, gamma-butyrolactone or haloperidol, suggesting that this effect may be due to a direct cellular action of amphetamine. In contrast to the inhibition of veratridine-induced synthesis stimulation produced by in vivo amphetamine administration, the synthesis stimulation produced by in vitro amphetamine treatment was not reduced. However, this stimulation was altered in character and was no longer calcium-dependent. A similar loss of calcium-dependency for amphetamine-induced synthesis stimulation was also observed after in vivo reserpine treatment. These results suggest that in vivo amphetamine administration can markedly alter the interactions between tyrosine hydroxylase and synaptosomal dopamine pools that may be involved in the regulation of catecholamine formation.