Amniotic fluid analysis. Its role in maternal neonatal infection.

Indirect evidence suggests that amnionitis, in the absence of maternal symptoms, contributes to neonatal morbidity. The incidence is unknown because diagnostic techniques are not available. A quantitative amniotic fluid analysis of bacteria, white blood cells, and lactic dehydrogenase levels was performed during labor among 28 patients considered to be a risk for infection. Thirteen of 16 patients with bacterial colony counts greater than 10(3)/ml subsequently developed maternal infection had a premature delivery, neonatal sepsis, or a combination of these factors. Maternal fever was a late sign in clinical infection and was frequently absent in cases of premature delivery associated with microbiologic evidence of amnionitis. Amniotic fluid analysis may be of value in diagnosing unrecognized amnionitis among patients delivering prematurely and those requiring nonelective cesarean section.

Obstetric observations in eleven cases of neonatal sepsis due to the group B beta hemolytic streptococcus.

Neonatal sepsis due to Group B streptococcus is reported to be increasing, but the reasons are unclear. Eleven cases from a single hospital were reviewed for common obstetric factors. Frequent observations associated with 8 surviving infants were maternal infection, early evaluation and treatment of the newborn, and 4+ or 5+ growth on maternal cultures. In contrast, mothers of the 3 infants who died had no clinical signs of infection, and cultures were not obtained. All 11 infants had direct monitoring during labor but the frequency of infection, 1/1600 live births, was lower than usually reported. Three surviving infants and 3 nonsurvivors were premature. Semiquantitative culture technics suggest that the predominance of Group B streptococcus in the vagina may be a more important etiologic factor than the frequency of its presence.

Listeriosis and borreliosis as causes of antepartum fever.

Fever of unknown origin in the pregnant woman presents special diagnostic, therapeutic, and obstetric problems. Two such clinically ill, febrile third-trimester patients, one presenting with maternal septicemia and transplacental fetal listeriosis and the other with borreliosis, are discussed. Although the neonatal outcome in such infections historically is poor, the infants of these mothers survived. It is suggested that special diagnostic procedures, timely administration of parenteral antibiotics, and vigilant antepartum testing be considered in all similar pregnant patients.

Group B streptococcal neonatal infection: clinical review of plans for prevention and preliminary report of quantitative antepartum cultures.

The neonatal and obstetric approaches to preventing group B streptococcal neonatal infections are reviewed. Although recent reports recommend prophylactic antibiotic treatment of antepartum and intrapartum group B streptococcal carriers and low-birth-weight infants, acceptance of these schemes is not widespread. A preliminary study to evaluate the value of semiquantitative vaginal and cervical cultures of antepartum women for group B streptococcus in predicting maternal and neonatal infectious morbidity revealed: 1) 11% of the study population were carriers (group B streptococcus isolated from broth only) but only 2.8% had heavy colonization (growth in broth and on streaked plates), and 2) morbidity associated with 8 heavily colonized mothers during the current pregnancy included group B streptococcal endometritis (1 patient), neonatal sepsis (1), and readmission of a newborn for transient cyanosis (1). Two of the heavily colonized mothers were known carriers in their last pregnancy; 1 had group B streptococcal endometritis and the infant of the second developed clinical sepsis at 2 weeks of age. The clinical value of semiquantitative culture techniques requires additional investigation.

Unrecognized amnionitis and prematurity: a preliminary report.

Quantitative amniotic fluid cultures were performed on 12 patients delivered of premature infants (10-premature labor, 2-premature rupture of membranes). Specimens from patients in premature labor were obtained at the time of amniotomy via transcervical needle aspiration or intrauterine catheter. Of the seven patients with colony counts greater than 1,000 per ml, two mothers and four neonates had clinical evidence of infection. Blood cultures from two infants and one mother and cerebrospinal fluid cultures from one newborn infant were positive for the same organism isolated from amniotic fluid. Anearobic bacteria were the predominant isolates in four specimens and included Bacteriodes species in two. In contrast, the five mothers and infants associated with counts of less than 1,000 per ml exhibited no infectious morbidity. Three had no bacterial growth from amniotic fluid, and factors commonly associated with prematurity were recognized in four. These clinical and microbiologic observations suggest that current methods of evaluating patients with premature labor and delivery are incomplete, and the role of unrecognized amnionitis should be reevaluated.

Effect of MgSO4 on heart rate monitoring in the preterm fetus.

OBJECTIVE: To evaluate in a controlled, blind fashion, using both subjective and objective criteria, whether MgSO4 is associated with clinically significant changes in fetal heart rate monitoring. STUDY DESIGN: Fetal heart rate tracings were prospectively collected before and after MgSO4 loading in 50 preterm labor patients. Three obstetricians, blind to treatment status, graded the tracings using both subjective and objective criteria. RESULTS: The baseline fetal heart rate declined slightly after therapy. Subjective, but not objective, evaluation demonstrated a greater likelihood of decreased variability after MgSO4 loading. There was no difference in periodic changes after MgSO4 loading. Multiple regression analysis showed a greater likelihood of decreased variability at earlier gestational ages but no relationship to the serum magnesium level. CONCLUSION: Magnesium sulfate tocolysis is associated with a subjective decrease in fetal heart rate variability in the preterm fetus.

Abnormal antepartum fetal heart rate tracings, failure to intervene, and fetal death: review of five cases reveals potential pitfalls of antepartum monitoring programs.

The goal of antepartum fetal heart rate monitoring is to identify which infants among high-risk obstetric patients are at risk for intrauterine death and which are not. Effective programs, by appropriately selecting cases for intervention and nonintervention, should contribute to lowering of perinatal morbidity and mortality rates. A review of five fetal deaths preceded by abnormal antepartum FHR tracings suggests effective programs require strict control. Individuals performing the testing should be experienced and knowledgeable in regard to instrumentation characteristics and recognition of normal and abnormal fetal heart rates. Dual responsibility of antepartum testing and providing primary patient care to labor and delivery patients is undesirable. Test interpretation should be based on strict criteria.

Amniotic fluid infection as determined by transabdominal amniocentesis in patients with intact membranes in premature labor.

The rate of microbial infection of amniotic fluid among patients in premature labor with intact membranes and the effect of this condition on perinatal morbidity and mortality are not known. Two study this question, specimens of amniotic fluid were collected by transabdominal amniocentesis from 31 patients in premature labor with intact membranes. Microorganisms were isolated from 25% (8/31) of the specimens; 87% (7/8) of these mothers underwent delivery within 48 hours of amniocentesis, and 75% (6/8) of positive culture were from mothers who were never febrile. Perinatal morbidity was significantly greater among mothers with positive amniotic fluid cultures, as evidenced by earlier gestational age at delivery (31 vs. 36 weeks), lower newborn weight (1,740 vs. 2,613 grams), and longer hospitalization (39 vs. 9 days). A few simple, commonly available laboratory tests (amniotic fluid Gram stain, lactic dehydrogenase levels, and white blood cell count) appear to be useful in making a rapid diagnosis. The data suggest that the presence of microorganisms in the amniotic fluid of afebrile patients in premature labor with intact membranes represents an infectious process rather than an innocuous condition and raises questions with regard to current obstetric trends in the management of premature labor. The routine evaluation of similar patients by transabdominal amniocentesis is not recommended unless prospective studies can demonstrate a decrease in perinatal morbidity and mortality with this approach.

Perinatal complications in group B streptococcal carriers: a longitudinal study of prenatal patients.

Although prenatal group B streptococcal detection and eradication have been proposed to prevent morbidity, the risk of perinatal complications in prenatal carriers of group B streptococci has not been defined. We evaluated 718 prenatal patients with serial cultures to compare morbidity in carriers and noncarriers. Complications occurring more frequently (p less than or equal to 0.05) in prenatal carriers were: collective morbidity, low birth weight, and premature rupture of membranes associated with low birth weight. Maternal pelvic infection and neonatal sepsis were increased in colonized women at delivery but not in prenatal carriers. Ninety-two percent of colonized women were not delivered of low birth weight infants. No carriers delivered vaginally or by repeat cesarean section became infected. Neither inoculum size nor chronic carriage was related to morbidity. The predictive value of a positive prenatal culture did not exceed 8% for any of the complications. We concluded that overall morbidity in carriers of group B streptococci is greater than in noncarriers; however, the risk for specific complications is too low to justify routine testing for detection of group B streptococci until prospective study demonstrates the value of such programs.

Comparison of clindamycin and chloramphenicol in treatment of serious infections of the female genital tract.

A study was performed of 102 obstetric-gynecologic patients who were thought to have sepsis or a pelvic abscess. Fifty-three of these women received chloramphenicol and 49 received clindamycin. In addition, all patients received penicillin or a similar antibiotic and an aminoglycoside. Similar clinical results were observed with the two treatment regimens. In eight of the 49 patients who received clindamycin and in three of 52 patients who received chloramphenicol, use of the drug was discontinued because of side effects. These combinations of antibiotics did not eliminate the necessity for major operative drainage, which was required in 40 patients. Resistant organisms were recovered from only two patients. Although sepsis and shock were most frequently associated with gram-negative aerobic bacteremia, they occurred in two patients in whom only anaerobes were recovered from blood cultures. Because the clinical results with the two regimens were equivalent, a decision to use either clindamycin or chloramphenicol should be based on the individual physician's assessment of the toxicity of these agents.