Oxytocin for labor induction.

Induction of labor has increased from 9% to 18% of all U.S. deliveries in recent years. Several useful oxytocin induction protocols are available, both from the ACOG Practice Bulletin #10 and institutional sources. Higher-dose protocols tend to result in fewer cesarean deliveries for dystocia but more "fetal distress." There is no consensus as to which protocol is best, and the clinician is advised to understand the trade-offs involved and how those trade-offs could relate to the clinician's local situation. Given the availability now of prostaglandin agents for induction with an unfavorable cervix, the advantage of less hyperstimulation in low-dose oxytocin protocols may become increasingly important. The most important risks include hyperstimulation (frequent but usually brief and well-tolerated), failed induction (occasional and important), and uterine rupture in some studies (rare but dangerous). Pain was not a sensitive indicator of uterine rupture in a large 1989 study. Fetal heart rate changes were much more likely to herald uterine rupture in that study. Oxytocin's greatest weakness is that some patients will not respond well to it, especially with marked cervical unfavorability. However, given an individual patient whose uterus will respond adequately to this drug, oxytocin has the advantage of short half-life and the option for prompt cessation if desired. Intrauterine pressure catheters with oxytocin usage are usually well-worth their minor risks. Current ACOG literature lists induction of labor in the setting of one or more previous low-transverse cesarean deliveries as necessitating "special attention" and "close patient monitoring." The well-informed clinician will be familiar with the issues involved.

Lowering the threshold for the diagnosis of gestational diabetes.

OBJECTIVE: Our purpose was to determine whether lowering the diagnostic threshold for gestational diabetes mellitus on 3-hour 100 gm oral glucose tolerance testing will select a population at risk for adverse perinatal outcome. STUDY DESIGN: In this retrospective study 434 patients with an abnormal 50 gm glucose screen result (> or = 140 mg/dl) underwent a standardized 3-hour oral glucose tolerance test. The results were stratified according to maternal weight and the criteria recommended by Sacks or Carpenter. Birth weight and rate of macrosomia were the primary perinatal outcome variables analyzed. RESULTS: Analysis of the data set stratified according to the Sacks criteria revealed results very similar to the Carpenter criteria data set. Patients who would have been newly diagnosed with gestational diabetes mellitus only if the lowered criteria were used (group 2) were older and heavier. No other variable comparisons achieved statistical significance. When the same patients were stratified according to prepregnancy weight, overweight patients were older, gained less weight during the third trimester, underwent cesarean section more often, and had higher cumulative maternal morbidity. Regression analysis showed that the degree of hyperglycemia did not predict macrosomia or influence birth weight, but prepregnant maternal body mass index was associated with macrosomia. CONCLUSIONS: Fetal macrosomia is influenced by maternal prepregnant body mass index. Lowering the glucose tolerance test threshold would result in overdiagnosis of gestational diabetes mellitus without improving perinatal outcome.

Use of the TDx-FLM assay in evaluating fetal lung maturity in an insulin-dependent diabetic population. The Diabetes and Fetal Maturity Study Group.

OBJECTIVE: To assess the usefulness of the recently introduced TDx-FLM assay in managing pregnant women with diabetes. METHODS: Participating institutions were recruited from the 1993 and 1994 Society of Perinatal Obstetricians Diabetes Special Interest Group meetings. Study patients consisted of insulin-dependent diabetic women who had undergone transabdominal amniocentesis with assay of the fluid by the TDx-FLM method. Pertinent data were requested concerning pregnancy and respiratory outcomes of the corresponding neonates. RESULTS: Data from 261 pregnancies at 13 institutions were collected. Eight of the 182 infants born within 4 days of amniocentesis developed respiratory distress syndrome (RDS); five of the eight infants with RDS required intubation, and all five had TDx-FLM values less than 70 mg of surfactant per gram of albumin. Three of the eight infants with RDS required hood oxygen only; two of these infants had TDx-FLM values at least 70 mg/g. Thirteen of 144 (9%) subjects who delivered within 4 days of amniocentesis and for whom a TDx-FLM assay and phosphatidylglycerol level were both reported had a TDx-FLM level of at least 70 mg/g and a negative phosphatidylglycerol result. No infant with this combination of results developed RDS. Fifteen of the 40 patients who delivered more than 4 days after amniocentesis, with both tests available, had TDx-FLM values at least 70 mg/g and were phosphatidylglycerol negative. CONCLUSION: In infants of diabetic mothers, TDx-FLM values at least 70 mg/g were not associated with RDS requiring intubation. The TDx-FLM assay may be useful in determining the best time of delivery for pregnant patients with diabetes, especially in a situation in which the TDx-FLM assay is mature and the phosphatidylglycerol result is immature.

Antenatal vitamin K therapy of the low-birth-weight infant.

OBJECTIVE: The purpose of our study was to determine whether maternal vitamin K1 administered antenatally improved global coagulation parameters and the levels of specific vitamin K-dependent proteins in low-birth-weight infants. STUDY DESIGN: Thirty-three preterm mothers admitted in labor were assigned in a prospective, blinded fashion to receive either intramuscular vitamin K1 (17) or placebo (16). At delivery cord blood samples were tested for prothrombin time, activated partial thromboplastin time, factor II and protein C activity, and antigen levels. Statistical analysis was by Student t test. RESULTS: No statistically significant differences could be demonstrated with regard to group mean values for global tests (prothrombin time, activated partial thromboplastin time) or specific vitamin K-dependent protein levels (factor II, protein C) in newborns whose mothers received antenatal vitamin K compared with those who did not. CONCLUSION: These results would suggest that antenatal vitamin K1 therapy to mothers < 32 weeks' gestation has no significant effect on the level of vitamin K-dependent factors in the fetus.

Pre-preparation of the sterile instrument table for emergency cesarean section.

Cesarean section instrument tables are often not prepared in advance because of concern of contamination risk. The Association of Operating Room Nurses Standards decries the use of pre-preparation of surgical instrument tables because of this risk, although there are no scientific data to support this claim. We evaluated the contamination risk of pre-preparation of surgical instrument tables, prolonged table coverage and table uncovering using a specific technique referred to as the "sardine can roll." Colony counts were positive in only seven of 180 cultures (< or = 15 colonies per plate in each instance) from six tables evaluated after prolonged coverage or uncovering, or both. These data suggest that contamination risk is slight for the uncovering technique described herein and advance table preparation (24 hours or less, never recovered) is a reasonable clinical option in units in which table preparation reduces response time in emergent clinical situations, such as cesarean section for acute fetal distress.

A prospective randomized clinical trial comparing two oxytocin induction protocols.

OBJECTIVE: Our objective was to compare the safety and efficacy of two accepted oxytocin induction protocols that differ in oxytocin dose increments. STUDY DESIGN: At the Carolinas Medical Center in Charlotte, North Carolina, 151 women with indications for induction of labor were prospectively randomized into one of two oxytocin induction protocols. Safety and efficacy of the two protocols were analyzed with two-tailed t tests and chi 2. RESULTS: Time from induction to establishment of a regular labor pattern was significantly shorter in the experimental group compared with the traditional group (p = 0.03). However, no significant difference was seen from onset of induction to time of delivery. Incidences of hyperstimulation were not significantly different between the two protocols, but there was a trend toward a higher incidence of fetal heart rate changes in the experimental group (p = 0.08). CONCLUSION: These data suggest that induction with larger dose increments will shorten time to adequate labor without an associated increase in uterine hyperstimulation or poor neonatal outcome. The differences in heart rate changes are concerning and merit further investigation. If confirmed by further studies, an increased risk of cord compression could outweigh the benefit of a faster onset of contractions.

Fatal maternal laryngeal papillomatosis in pregnancy: a case report [corrected].

Although genital condylomata worsen with pregnancy, we are unaware of any reports of fatal maternal laryngeal papillomatosis. A maternal death at 20 weeks' gestation of a patient with chronic laryngeal papillomatosis is described. Pregnant patients with a history of this disorder who have symptoms should be considered candidates for immediate evaluation.

Schistocytosis, aminotransferase elevation and thrombocytopenia in preeclampsia/eclampsia.

Some preeclamptic patients have schistocytosis, abnormal liver function tests and thrombocytopenia. To determine how strongly these three abnormalities cluster with each other, a sequential series of 49 preeclamptic or eclamptic patients was analyzed for the presence of schistocytosis, serum aminotransferase elevation and thrombocytopenia. These three abnormalities were found less often together (the HELLP syndrome) than singly or in pairs. These data do not clearly separate HELLP patients from other preeclamptic patients.

Altered villus vessel fibronectin in preeclampsia.

Fibronectin is a high molecular-weight glycoprotein found in most tissues and body fluids. Maternal plasma fibronectin levels have been shown to be elevated in preeclampsia, but little is known about placental fibronectin in preeclampsia. Fibronectin tissue distribution in placental villi was "blindly" graded by two examiners using placentas from eight nonpreeclamptic and six preeclamptic pregnancies. Selected frozen sections of normal-appearing areas from each placenta were incubated with rabbit antihuman fibronectin antiserum and then stained with fluorescein isothiocyanate-conjugated goat antirabbit immunoglobulin G and examined by fluorescent microscopy. We found less intensity of fetal vessel fibronectin staining in villi from placentas from preeclamptic pregnancies than in those of normal pregnancies (p less than 0.02, Mann-Whitney U test). It is unclear why fetal villous vessels in preeclampsia have decreased tissue fibronectin, but this may reflect an additional vascular abnormality associated with the preeclampsia syndrome.

The preterm cervix and preterm labor: relative risks, predictive values, and change over time.

The accurate prediction and diagnosis of preterm labor continue to frustrate the clinician. This is partly due to a scarcity of cervical data from the early third trimester. A total of 760 prospective, serial, paired, and blinded pelvic examinations were done at 28 to 34 weeks of gestation for 191 patients without a history of preterm labor. If the cervix was dilated greater than or equal to 1 cm (internal os) or effaced greater than 30%, the relative risk of preterm labor was increased to 1.8 to 4.2. Negative predictive values for cervical status were greater than 92%, but positive predictive values were less than or equal to 18%. Change over time was unusual (dilatation increase greater than or equal to 1 cm or effacement increase greater than or equal to 40%), suggesting that a baseline late second-trimester examination could assist in the early but accurate diagnosis of preterm labor should it be suspected later in gestation. These data suggest that even in the low-risk patient, an early cervical examination could be beneficial.

Factor VIII procoagulant antigen levels in normal pregnancy and preeclampsia.

It has been suggested that the basis for the marked discordance in factor VIII parameters in preeclampsia is the result of proteolysis of the factor VIII procoagulant component (VIII:C) owing to activation of the coagulation system. To investigate this further, levels were compared of factor VIII:C and VIII:C (Ag), the immunologic equivalent of the procoagulant activity, in a series of preeclamptic patients and patients with uncomplicated pregnancies. No significant difference in the mean (+/- SD) level of factor VIII:C or VIII:C (Ag) could be detected between these groups. Our results do not support proteolysis of factor VIII:C as a mechanism to account for the discordant levels of the factor VIII parameters in preeclampsia.

Evidence of accelerated platelet production and consumption in nonthrombocytopenic preeclampsia.

Platelet size and the distribution of platelet sizes are both increased in preeclamptic patients with normal platelet counts. These changes suggest that accelerated platelet production and consumption are both widespread in preeclampsia.

Predictive value of fibronectin levels in normotensive gravid women destined to become preeclamptic.

The plasma fibronectin concentration was abnormally elevated (greater than 400 micrograms/ml) in 16 of 17 normotensive gravid women who subsequently developed preeclampsia. Of this group, 13 had elevated levels detectable greater than or equal to 4 weeks before the onset of hypertension. Our results indicate that plasma fibronectin levels can be abnormally increased long before the onset of clinical symptoms and that abnormalities of this glycoprotein may be an early indication of this pathologic process.

Plasma fibronectin levels in preeclampsia: a possible biochemical marker for vascular endothelial damage.

Fibronectin is a plasma glycoprotein which is involved in coagulation, platelet function, tissue repair, and the vascular endothelial basement membrane. We have found plasma fibronectin concentrations to be elevated in a group of preeclamptic patients. This finding is consistent with other evidence for a role of the vascular endothelium in preeclampsia.