Human parvovirus B19 (B19) infection during pregnancy has been associated with fetal deaths. We conducted several studies to develop data needed to make recommendations for preventing fetal death associated with infection. In the first study, after an outbreak of B19 infection, specimens of cord blood from 47 infants with congenital anomalies, 10 with suspected intrauterine infection, and gestational age-matched controls were tested for IgG and IgM antibodies to B19. None had evidence of recent infection. Next, 192 women with unknown exposure to B19 who had stillbirths or spontaneous abortions were studied. Two patients and two controls had evidence of recent B19 infection. In a second case-control study of women who had stillbirths after outbreaks of erythema infectiosum in area schools, none of the 20 patients or 26 controls were IgM positive at the time of delivery. The rate of infection, as demonstrated by IgM positivity, among 267 pregnant control subjects was approximately 1%. These studies suggest that among pregnant women unselected for exposure to B19, neither infection nor stillbirths are common.

Glucose given to the newborn human may result in hyperglycemia, suggesting that its utilization is impaired at this developmental stage. Galactose is thought to be a more appropriate carbohydrate source for the newborn. The enzymes involved in hexose phosphorylation may, in part, be responsible for these observations. A key regulatory enzyme of hepatic glucose assimilation, glucokinase, is diminished in newborns compared to adults, whereas galactokinase activity is increased. When newborn dogs were fasted and then fed either glucose or galactose, their plasma insulin responses to glucose were similar, but the pups fed galactose demonstrated an attenuated systemic appearance rate of glucose. Hexose incorporation into hepatic glycogen and net glycogen synthesis was augmented in the galactose-fed dogs. In vitro, liver from neonatal dogs showed enhanced galactokinase activity relative to that for hexokinase or glucokinase. Neonatal hexose assimilation may be independent of insulin action and, instead, be related to the developmental presence of hexose phosphorylating enzymes.

Summary(14, 16), but did have significant effects on fetal weight and the pup's postnatal metabolic adaptation to birth. Three days of The effects of maternal canine starvation (MCS) for 5 days on maternal canine resulted in fasting neonatal hypoglyhepatic intermediates in fetus and fasted neonates were studied at cemia and attenuated plasma free fatty acids, Hepatic glycolytic 0, 3, 6, 9, and 24 h of age. Maternal starvation reduced the birth and gluconeogenic intermediate concentrations among these newweights of the pups by 23% (232 * ' versus 300 * lo g). In the born dogs suggested that glycolysis was enhanced whereas gluco-MCS fetuses, hepatic glycogen concentration was significantly neogenesis was attenuated. The latter was hypothesized to be due decreased (416 versus 526 pmole/g) whereas uridine diphosphate to decreased hepatic free fatty acid oxidation resulting in diminglucose concentration was significantly increased (0.196 versus ished cytoplasmic NADH (16). 0.135 ~m"le/g), suggesting diminished gl~coge" 'ynthetase act''-order to study the effects of a more significant nutritional ity. After birth, hepatic glucose levels were significantly decreased deficit on the fetus and its postnatal fasting metabolic adaptation, at 3 (2.90 versus 5-95 ~mole/g) and 24 (3.09 versus 5-29) h in the we have extended the period of maternal canine to 5 MCS pups. ~luco~e-6-phosphate (G6P) and fructose-6-~hos~hate days, hi^ study analyzes the of extended maternal star-(F6P) levels were low in MCS pups throughout the study, G6P vation on hepatic glycolytic and gluconeogenic intermediates and being significantly decreased at 9 and 24 h, and F6P at 0,6,9, and energy and oxidation reduction states in the fetus and fasted 24 in the MCS group.1,6-di~hos~hate did not show newborn pup, during the first day of life, The potential determiany changes among groups. Of greater importance, hepatic ATP nation of regulatory rate limiting steps may help interpret the concentrations were significantly reduced in the MCS pups changes in circulatory fuels observed in these pups (17). B~ throughout the first day of life.examining the possible alterations of hepatic metabolic intermefasting in attenuated glycogen diates, an of these altered biochemical events may synthesis and an altered transition from fetal to neonatal life. be assessed employing the standard cross-over plot theory, Diminished G6P and F6P levels suggest that hepatic glycolytic activity may he enhanced at the level of phosphofructokinase. In the presence of lactate carbon incorporation into glucose that MATERIALS AND METHODS approaches control rates of gluconeogenesis, the diminished G6P Materials, ~1 1 enzymes used were purchased from Sigma, St. and F6P levels also suggest significant recycling of lactate carbon ~~~i~, MO. hetween glucose and lactate. Furthermore, despite the apparent Animals. Beagle dogs and their pups used in this study were the predominance of glycolysis, diminished hepatic ATP levels suggest same as those used in Part I (17). that MCS plus neonatal fastin...

Pediatr. Res. 15: 859-865 (1981) pmoles/g) hr, whereas UDP-glucose concentrations were significantly elevated in these pups during fetal, 3, 9, and 24 hr of age. Phosphoenolpyruvate was higher after maternal starvation in the fetus and at 6 and 9 hr, whereas cerebral pyruvate concentrations were elevated at 3, 6, and 9 hr of age. The elevation of pyruvate with no alteration of lactate concentration resulted in an elevated cytoplasmic NAD/NADH ratio at 3 hr of age (1381 f 194 versus 792 2 198). Cerebral a-ketoglutarate and calculated oxaloacetate concentrations were elevated throughout the day after maternal starvation whereas malate concentrations were depressed at 3 and 9 hr of age. Cerebral energy charge was unaffected, whereas the calculated energy reserve was lower a t 3.6, and 24 hours. Cerebral amino acids demonstrated elevated aspartate concentrations at 3 and 6 hr. Cerebral glutamine concentrations were lower during fetal stage (7.86 2 0.52 versus 10.01 0.41 pmoles/g) and 3, 6, and 9 hr of life. SpeculationThese data suggest that cerebral glycogen synthesis was diminished and that the oxidation of cerebral amino acids, in particular glutamine, may contribute to maintain cerebral energy production during the relative fasting neonatal hypoglycemia which develops in pups after maternal starvations.