Correlation of neonatal nucleated red blood cell counts in preterm infants with histologic chorioamnionitis

OBJECTIVE

The aim of this study was to compare the neonatal nucleated red blood cell counts in preterm infants in the presence and absence of clinical and histologic chorioamnionitis while controlling for gestational age and birth weight percentile.

STUDY DESIGN

Nucleated red blood cell counts were obtained from preterm infants delivered after preterm labor or preterm premature rupture of membranes. Patients were divided on the basis of clinical and histologic chorioamnionitis. Nucleated red blood cell counts between groups were compared, and regression analysis controlling for gestational age and birth weight percentile was performed.

RESULTS

Of 359 patients, both measures of infection status were significantly associated with increased nucleated red blood cell counts. In the regression analysis histologic chorioamnionitis retained significance, whereas clinical chorioamnionitis did not.

CONCLUSIONS

Histologic chorioamnionitis produces an erythropoietic response in the fetus. Whether fetal erythropoiesis is a direct response to mediators of inflammation or whether it is the result of a rise in erythropoietin is unknown.

Intrapartum assessment of fetal well-being: a comparison of scalp stimulation with scalp blood pH sampling

OBJECTIVE

To determine whether the need for fetal scalp pH sampling is decreased by the scalp stimulation test and whether redefinition of reactivity and presence of variability further decrease the need for scalp pH sampling.

METHODS

One hundred eight women with fetal heart rate (FHR) patterns suggestive of acidosis underwent fetal scalp blood pH evaluations. Digital scalp stimulation was performed for 15 seconds 1-2 minutes before pH sampling. The study group was subdivided based on reactivity to scalp stimulation and scalp puncture and was correlated with pH values. Reactivity was defined as an acceleration of 15 beats per minute or more lasting at least 15 seconds and redefined as an acceleration of 10 beats per minute or more lasting at least 10 seconds. Nonreactive responses were subdivided based on FHR variability preceding the scalp stimulation and were correlated with pH values. Fisher exact test was used for analysis.

RESULTS

All 51 instances of acceleration of 15 beats per minute or more lasting at least 15 seconds following scalp stimulation had a scalp pH of 7.20 or more. Using an acceleration of 10 beats per minute or more lasting at least 10 seconds, seven more reactive responses were obtained after scalp stimulation, all with pH of 7.20 or more. The 15 instances in which the pH was less than 7.20 were nonreactive irrespective of the definition of reactivity (P < .001). Twenty-one of the 50 instances of nonreactive responses (reactive response: acceleration of 10 beats per minute or more lasting at least 10 seconds) had positive variability. Only two of these 21 (9.5%) instances compared to 13 of the 29 (45%) instances with negative variability had pH less than 7.20 (P < .007).

CONCLUSIONS

The scalp stimulation test could decrease the need for fetal scalp blood sampling by 47%. Redefinition of reactivity could decrease the need for scalp sampling by 54%. In addition, assessment of FHR variability before scalp stimulation could decrease further the need for scalp blood sampling by 73%.

Obstetric antecedents of intraventricular hemorrhage and periventricular leukomalacia in the low-birth-weight neonate

OBJECTIVE

Neonatal intraventricular hemorrhage and periventricular leukomalacia have a strong correlation with eventual neurologic deficit. Our objective was to correlate obstetric factors with the development of these lesions.

STUDY DESIGN

Seven hundred forty-five consecutive inborn neonates with birth weights from 500 to 1750 gm were divided into three clinical groups: premature rupture of membranes, refractory preterm labor with intact membranes, and delivery initiated by the physician for maternal or fetal indications. Neonatal neurosonography was performed on days 3 and 7 of life and results were described as normal or abnormal. Abnormal scans included intraventricular hemorrhage seen within 3 days and echodense or echolucent periventricular leukomalacia seen within 7 days of life. Major abnormalities included intraventricular hemorrhage grades 3 and 4, intraventricular hemorrhage with periventricular leukomalacia, and echolucent periventricular leukomalacia. Abnormal scans were correlated with groups of origin and clinical and histologic chorioamnionitis.

RESULTS

Abnormal scans occurred in 33% of cases of premature rupture of membranes and in 38.9% of cases of preterm labor compared with 17.7% of physician-initiated cases (p < 0.000001). Major lesions occurred in 17.6% of cases of premature rupture of membranes, 21.4% of cases of preterm labor, and 1.1% of physician-initiated cases (p < 0.0000001). Clinical chorioamnionitis occurred in 19.7% of cases of premature rupture of membranes, 11.9% of cases of preterm labor, and 1.1% of physician-initiated cases (p < 0.001) and was associated with a significant increase in the incidence (p < or = 0.005) and severity (p < or = 0.007) of these lesions. Histologic chorioamnionitis occurred in 59.9% of cases of premature rupture of membranes, 43.2% of cases of preterm labor, and 8% of physician-initiated cases and did not correlate significantly with the incidence or severity of abnormal scans. These findings were independent of gestational age.

CONCLUSIONS

The incidence and severity of intraventricular hemorrhage and periventricular leukomalacia were significantly increased in premature rupture of membranes and preterm labor compared with the physician-initiated cases. Clinical chorioamnionitis increased the incidence and severity of these lesions.

A comparison of rapid amniotic fluid markers in the prediction of microbial invasion of the uterine cavity and preterm delivery

OBJECTIVE

The purpose of this study was to evaluate amniotic fluid lactate dehydrogenase level in comparison with other rapid markers in prediction of microbial invasion of the uterine cavity and preterm delivery < or = 36 hours after amniocentesis.

STUDY DESIGN

One hundred thirty-one women in preterm labor with intact membranes underwent transabdominal amniocentesis. Amniotic fluid was analyzed for leukocyte count, glucose level, lactate dehydrogenase level, and Gram stain. Cultures for aerobes, anaerobes, and Mycoplasma sp. were performed. Amniocentesis-to-delivery interval was calculated. The study group was divided and the findings compared according to amniotic fluid culture results and according to amniocentesis-to-delivery interval. Sensitivity, specificity, and positive and negative predictive value were calculated for lactate dehydrogenase, leukocyte count, glucose, and Gram stain in the prediction of positive amniotic fluid culture and preterm delivery < or = 36 hours after amniocentesis. Receiver-operator characteristic curve analysis, logistic regression analysis, t tests, and nonparametric tests were used.

RESULTS

The prevalence of positive amniotic fluid cultures was 12% (16 of 131). The median lactate dehydrogenase level (1084 U/L) was significantly greater for women with a positive amniotic fluid culture than for those with a negative culture (median lactate dehydrogenase level 194 U/L; p < 0.0002). The critical values calculated for optimal performance in prediction of a positive amniotic fluid culture were a lactate dehydrogenase level > or = 419 U/L, leukocyte count > or = 50 cells/mm3 (50 x 10(6)/L) and glucose < or = 17 mg/dl (0.94 mmol/L). Lactate dehydrogenase, leukocyte count, glucose, and Gram stain were equally sensitive and specific in prediction of a positive amniotic fluid culture. Thirty-nine women (29.8%) gave birth < or = 36 hours after amniocentesis. The median lactate dehydrogenase level (414 U/L) was significantly greater among women giving birth < or = 36 hours after amniocentesis than among women giving birth > 36 hours after amniocentesis (median lactate dehydrogenase, 173 U/L; p < 0.001). Critical values of lactate dehydrogenase > or = 225 U/L, leukocyte count > or = 10 cells/mm3 (10 x 10(6)/L) and glucose < or = 34 mg/dl (1.9 mmol/L) were selected for optimal performance in prediction of amniocentesis-to-delivery interval < or = 36 hours. Lactate dehydrogenase level had the best sensitivity (74%) in prediction of delivery < or = 36 hours after amniocentesis in contrast to leukocyte count (49%), glucose (62%), and positive Gram stain (26%). Amniotic fluid lactate dehydrogenase values > or = 225 U/L were associated with a fivefold greater risk for delivery < or = 36 hours after amniocentesis (odds ratio 5.46, 95% confidence interval 2.00 to 14.87; p = 0.0006).

CONCLUSION

Amniotic fluid lactate dehydrogenase level has diagnostic value in prediction of a positive amniotic fluid culture and delivery < or = 36 hours after amniocentesis. Lactate dehydrogenase is a readily available, inexpensive, rapid amniotic fluid marker that can be measured in any hospital laboratory.

Intrauterine transmission of hepatitis A virus

BACKGROUND

Hepatitis A is a common, self-limited disease transmitted by fecal-oral contamination.

CASE

A 23-year-old woman, para 2-0-0-2, developed hepatitis A at 20 weeks' gestation. At 27 weeks, ultrasound revealed polyhydramnios and fetal ascites. Hepatitis A immunoglobulin M antibody in fetal blood obtained by funipuncture confirmed acute hepatitis A infection in the fetus. Polyhydramnios and ascites persisted until 35 weeks, when the fetus developed ultrasound signs of meconium peritonitis, and delivery was accomplished uneventfully. Meconium peritonitis was diagnosed in the neonatal period and treated surgically.

CONCLUSION

To our knowledge, this is the first report of intrauterine transmission of hepatitis A. The disease presented with fetal ascites and was confirmed by positive fetal blood serology.

Acute myocardial infarction in pregnancy with subsequent medical and surgical management

BACKGROUND

Myocardial infarction is a rare event in pregnancy that requires medical stabilization with possible surgical interventions.

CASE

A 37-year-old woman developed an anterior wall myocardial infarction secondary to severe coronary artery disease during the early third trimester of pregnancy. The patient was managed with multiple modalities to stabilize her condition and prolong the gestation. The salient point in the management included: defibrillation and pharmacologic agents, intra-aortic balloon pump, coronary artery bypass graft surgery using a cardiopulmonary bypass pump while maintaining continuous fetal heart rate monitoring, and delivery of the neonate at term.

CONCLUSION

Aggressive management of this patient allowed continuation of pregnancy with good outcome for mother and neonate.

Relationship between neonatal nucleated red blood cell counts and hypoxic-ischemic injury

OBJECTIVE

To determine if nucleated red blood cell counts(RBC) are different in infants who develop intraventricular hemorrhage and periventricular leukomalacia in the first week of life and in those who do not.

METHODS

Nucleated RBCs were obtained from 441 infants weighing more than 499 g and less than 1751 g. Neonatal cranial fontanel sonography was performed on days 3 and 7 of life, and neonates were divided into those with normal and abnormal sonographic findings. The nucleated RBCs were compared between these groups and between normal and abnormal groups matched for birth weight and gestational age.

RESULTS

Mean gestational age, birth weight, birth weight percentile, Apgar score, respiratory distress syndrome and mortality were different between the infants with normal and abnormal ultrasound findings. The nucleated RBCs (per 100 white blood cells) were not different (40.5 +/- 126.8 versus 41.8 +/- 71.7, t = 0.09, P = .9). When we controlled for gestational age and birth weight, there was no significant difference between nucleated RBCs in those with normal and abnormal sonography (54.3 +/- 206.5 versus 41.4 +/- 72.0,t = 0.56, P = .6). In growth-restricted neonates, there was a significant increase in nucleated RBCs regardless of whether growth restriction was defined as tenth percentile or less, 25th percentile or less, or 50th percentile or less, even when we controlled for gestational age.

CONCLUSION

Nucleated RBCs are not different in preterm infants with or without intraventricular hemorrhage and periventricular leukomalacia, even when one controls for gestational age and birth weight. There are significant elevations in nucleated RBCs in growth-restricted fetuses. Birth weight percentile must be considered when using nucleated RBCs as a marker of intrauterine hypoxia.

Absence of relaxation to lactate in human placental vessels of pregnancies with severe preeclampsia

OBJECTIVE

Our objective was to determine whether the observed relaxation to lactate and other agents in placental vessels of normal pregnancies is altered in severe preeclampsia.

STUDY DESIGN

Isolated placental arteries and veins from women with severe preeclampsia and uncomplicated term pregnancies were precontracted with prostaglandin F2 alpha under 5% oxygen and 5% carbon dioxide with the balance nitrogen (Po2 35 to 38 torr) and then exposed to lactate (1 to 10 mmol/L, pH 7.4, n = 8 to 15), arachidonic acid (0.01 to 10 mumol/L, n = 6 to 13), nitroglycerin (1 nmol to 1 mumol/L, n = 4 to 12), or forskolin (0.01 to 10 mumol/L, n = 6 to 9). The response to lactate was also examined in placental vessels from appropriate-for-gestational-age preterm deliveries (n = 8) for comparison with a similar group with severe preeclampsia (n = 8). The t test and analysis of variance statistics were used.

RESULTS

Relaxation to lactate was markedly inhibited in both placental arteries and veins of women with severe preeclampsia compared with vessels from uncomplicated term or preterm pregnancies. Responses to the other relaxing agents were not altered in the severely preeclamptic vessels.

CONCLUSIONS

In severe preeclampsia absence of lactate-induced dilatation of placental vessels may contribute to the fetal complications associated with impaired blood flow and vasospasm.

Acute appendicitis in pregnancy and the occurrence of major intraventricular hemorrhage and periventricular leukomalacia

BACKGROUND

Infection and endotoxemia have been associated with neurologic injury in the newborn. In addition, recent reports have noted an increased incidence of fetal neurologic injury in the presence of intrauterine infection.

CASES

Three pregnancies complicated by acute appendicitis and refractory preterm labor resulting in the delivery of neonates who developed early major intraventricular hemorrhage and/or periventricular leukomalacia are described.

CONCLUSION

We hypothesize that extrauterine infections like acute appendicitis may play a role in the occurrence of neonatal neurologic injury.

Recurrent chorioamnionitis and second-trimester abortion because of an enterouterine fistula

BACKGROUND

Chorioamnionitis, a common cause of second-trimester abortion, is usually secondary to an ascending infection. Recurrent chorioamnionitis with second-trimester abortion secondary to an occult enterouterine fistula has not been reported previously.

CASE

A 26-year-old Indian woman, para 0-0-2-0, presented with two spontaneous second-trimester losses. Her third pregnancy carried to 24 weeks, but she delivered after the development of pneumonia, bacteremia, preterm labor, and chorioamnionitis. The patient passed melena containing blood clots after the delivery. After the last pregnancy, laparoscopy and laparotomy revealed an ileal-uterine fistula and a foreign body (necrotic cartilage). The blind loop of bowel was resected and the fistulous tract excised.

CONCLUSION

Our patient's recurrent pregnancy wastage was caused by chorioamnionitis secondary to an enterouterine fistula resulting from foreign body ingestion. A complete reversal of this problem is anticipated.

Epidemiologic predictors of hepatitis C virus infection in pregnant women

OBJECTIVE

To identify sensitive epidemiologic predictors of a positive hepatitis C virus antibody test in asymptomatic persons, and to compare the cost of testing only persons with an epidemiologic predictor to that of universal screening.

METHODS

Seventeen hundred consecutive pregnant women were tested by enzyme-linked immunosorbent assay for antibody to hepatitis C virus. Seventy-five subjects tested positive and were compared with 257 pregnant women who tested negative. Cohort and control patients were interviewed and their medical records were reviewed to identify those with chosen predictors of a positive hepatitis C virus antibody test.

RESULTS

Seventy-four of 75 cohort patients and 108 of 257 controls had one or more predictors of a positive antibody test. Cohort patients were significantly more likely (P < .001) to have the following: human immunodeficiency virus infection, a sex partner with a risk factor for hepatitis, age greater than 30 years, and a history of drug use, blood transfusion, sexually transmitted disease, hepatitis, or incarceration. The sensitivity and specificity of a single predictor in identifying a person with a positive test were 99 and 58%, respectively. The cost of finding a single individual with a positive antibody test by universal screening was $674, compared to $303 by selectively screening persons with one or more predictors of a positive antibody test.

CONCLUSIONS

Most individuals with positive hepatitis C virus antibody tests can be identified on the basis of epidemiologic predictors, reducing the cost of testing by 55%. These patients may receive appropriate medical therapy, and their children may be evaluated for possible infection by vertical transmission of hepatitis C virus.

Properties of a lactate-induced relaxation in human placental arteries and veins

OBJECTIVE

Our purpose was to determine the vasoactive effects and mechanism of action of lactate in human placental vessels by means of isometric muscle bath studies.

STUDY DESIGN

Isolated 1 to 2 mm human placental arteries and veins from normal term pregnancies, precontracted with prostaglandin F2 alpha and incubated under a PO2 of approximately 35 torr were exposed to lactate, 1 to 10 mmol/L, (pH 7.4), pyruvate, hydrogen peroxide, nitroglycerin, or forskolin. The effects of endothelium removal or inhibitors of cyclooxygenase (indomethacin 10 mumol/L) and L-arginine metabolism (nitro-L-arginine 30 mumol/L) on the response to lactate and the effects of an antagonist of guanylate cyclase activation (methylene blue 10 mumol/L), cyanide (1 mmol/L), and hypoxia (PO2 8-10 torr) on responses to all agents were determined by analysis of variance and t test statistics.

RESULTS

Lactate-elicited dose-dependent relaxation was not inhibited by endothelium removal, indomethacin, or nitro-L-arginine but was attenuated by methylene blue, cyanide, and hypoxia. Relaxation to hydrogen peroxide was inhibited by methylene blue and cyanide but not hypoxia. Relaxation to nitroglycerin was inhibited only by methylene blue, and relaxation to forskolin was not inhibited by these probes. Pyruvate did not produce a significant relaxation.

CONCLUSIONS

These findings suggest that lactate causes relaxation in the human placental vessels by an oxygen and cyclic guanosine-3':5'-monophosphate-dependent mechanism, which may involve the generation of hydrogen peroxide but not the metabolism of arginine. Lactate-induced dilatation may be of importance during labor and in situations of acute and chronic fetal hypoxia.

Gestational diabetes alters human placental vascular responses to changes in oxygen tension

OBJECTIVE

Our objective was to study tone responses caused by hypoxia, reoxygenation, and hydrogen peroxide in human placental vessels from gestational diabetic and normal term pregnancies.

STUDY DESIGN

Isolated placental arteries and veins from women with well-controlled gestational diabetic and uncomplicated term pregnancies were precontracted with U46619 under 5% oxygen/5% carbon dioxide/balance nitrogen (PO2 35 to 38 torr) and then exposed to hypoxia (95% nitrogen/5% carbon dioxide) atmosphere (PO2 8 to 10 torr) for 5 to 7 minutes followed by rapid reoxygenation. Cumulative doses of hydrogen peroxide (1 to 100 mumol/L) were added at 2-minute intervals. The studies were conducted in both the presence and the absence of endothelium. Prostaglandin involvement was examined by treatment with indomethacin. Analysis of variance and t test statistics were used.

RESULTS

After incubation under 5% oxygen, hypoxia caused a larger prostaglandin-independent relaxation in arteries and veins of women with gestational diabetes than in normal vessels. Placental vessels of women with gestational diabetes were found to undergo a significantly larger contraction than normal vessels when exposed to posthypoxic reoxygenation or micromolar concentrations of hydrogen peroxide. Both responses were eliminated and reversed to a relaxation by pretreatment with 10 mumol/L indomethacin in both gestational diabetic and normal vessels, consistent with mediation through the formation of prostaglandins. Removal of the endothelium did not appear to alter any of the observed responses.

CONCLUSIONS

Gestational diabetes produces an enhancement of the observed relaxation caused by hypoxia and the contraction produced by reoxygenation or hydrogen peroxide.

Didanosine (ddI) and zidovudine (ZDV) susceptibilities of human immunodeficiency virus (HIV) isolates from long-term recipients of ddI

Thirty HIV isolates, obtained from 15 patients before and after receiving single drug therapy with didanosine (ddI), were examined for sensitivity to ddI and zidovudine (ZDV) using a peripheral blood mononuclear leukocyte (PBML)-based assay. Fourteen of the patients had ARC, one had AIDS and 12 had received previous therapy with ZDV. After a median of 1 year of ddI therapy, isolates were significantly less sensitive to ddI than were isolates obtained prior to therapy (P = 0.03). A decrease in ddI sensitivity was observed in ten of the 15 isolate pairs. In contrast to ddI susceptibilities, sensitivity to ZDV increased over the same period of time (P = 0.03). Additional isolates were obtained from four patients who received ddI monotherapy for 2 years. Three of these isolates demonstrated no change in ddI sensitivity compared to baseline. No correlation could be made in this study between development of decreased ddI sensitivity and serum p24 levels, CD4 counts, or clinical outcome. Decreased ddI sensitivity occurs frequently among HIV isolates obtained from long-term recipients of ddI. This decreased sensitivity is modest in degree and is of unknown clinical significance.

Hydrogen peroxide and reoxygenation cause prostaglandin-mediated contraction of human placental arteries and veins

OBJECTIVE

Because our previous studies in several vascular preparations suggest that posthypoxic reoxygenation elicits tone responses by generation of hydrogen peroxide we compared the actions of reoxygenation and hydrogen peroxide on isolated human placental arteries and veins.

STUDY DESIGN

Endothelium-intact and denuded arteries and veins (1 to 2 mm diameter, from normal term deliveries), incubated under 95% oxygen/5% carbon dioxide or 5% oxygen/5% carbon dioxide (balance nitrogen) and precontracted with 1 to 10 nmol/L U46619, were exposed to hypoxia (95% nitrogen/5% carbon dioxide, PO2 8 to 10 torr) followed by reoxygenation and to 1 to 100 mumol/L hydrogen peroxide in the presence and absence of the inhibitor of prostaglandin biosynthesis, 10 mumol/L indomethacin.

RESULTS

In both arteries and veins posthypoxic reoxygenation or exposure to hydrogen peroxide produced vascular contraction that was eliminated or reversed to a modest relaxation by indomethacin, consistent with mediation by prostaglandins. Hypoxia after incubation with 5% oxygen, but not 95% oxygen, caused a modest prostaglandin-independent relaxation. Removal of the endothelium did not alter any of these responses.

CONCLUSION

Placental arteries and veins show a similar prostaglandin-mediated contraction to hydrogen peroxide and posthypoxic reoxygenation, consistent with a possible involvement of hydrogen peroxide in the response to reoxygenation.