Robert A. Knuppel

Comparison of intrapartum electronic fetal heart rate monitoring versus intermittent auscultation in detecting fetal acidemia at birth

OBJECTIVE Our purpose was to compare continuous intrapartum electronic fetal heart rate monitoring with intermittent auscultation for detecting fetal acidemia at birth. STUDY DESIGN Data from a previously published randomized trial of electronic fetal heart rate monitoring versus intermittent auscultation were analyzed to identify any differences between the two methods in detecting fetal acidemia at birth. Fetal acidemia at birth was defined as the presence of cord blood arterial pH < 7.15. RESULTS A total of 1419 patients with umbilical cord blood acid-base measurements were identified, 739 in the electronic FHR monitoring group and 680 in the auscultation group. Electronic FHR monitoring had significantly better sensitivity (97% vs 34%, p < 0.001), lower specificity (84% vs 91%, p < 0.001), higher positive predictive value (37% vs 22%, p < 0.05), and higher negative predictive value (99.5% vs 95%, p < 0.001) in detecting fetal acidemia at birth. In addition, electronic FHR monitoring was significantly better in detecting all types of acidemia: metabolic (95.5% vs 26.5%, p < 0.001), mixed (95% vs 37.5%, p < 0.001), and respiratory (100% vs 41.5%, p < 0.001). CONCLUSION These data suggest that electronic FHR monitoring is superior to intermittent auscultation in detecting fetal acidemia at birth.

Cost-Benefit Analysis of Prenatal Diagnosis for Down Syndrome Using the British or the American Approach

Objective To compare the cost and benefits of prenatal diagnosis for Down syndrome using the British and American approaches. Methods This cost-benefit analysis was based on a decision-analytic approach. The British strategy included screening by a first-trimester ultrasound at 10–14 weeks for nuchal translucency thickness, and the American strategy included only second-trimester screening by using maternal age and maternal serum screening. The key probabilities of the decision-tree analysis and all cost estimates were based on American standards. The best scenario of the British strategy assumed ultrasound nuchal translucency thickness sensitivity (for detecting Down syndrome) of 80% and a false-positive rate of 5% and the worst scenario assumed a sensitivity of 50% and a false-positive rate of 10%. The results were expressed in annual costs based on approximately 4 million births per year in the United States. Results As compared with do-nothing, the American strategy was found to allow savings of approximately

Effect of Vacuum Extraction on Umbilical Cord Blood Acid-Base Measurements

96 million per year and the best scenario for the British strategy was savings of approximately

Irregular bleeding, body mass index and coital frequency in Norplant@ contraceptive users

5 million per year. The financial costs of the British and American strategies would be comparable only if the first-trimester ultrasound had a sensitivity of 80% and a false-positive rate of 5% in detecting Down syndrome. Conclusion The British strategy does not appear to be economically beneficial in the United States even under the most ideal scenarios of ultrasound accuracy.

The use of second-trimester genetic sonogram in guiding clinical management of patients at increased risk for fetal trisomy 21

The objective of this study was to determine whether vacuum extraction is associated with umbilical cord blood acid-base changes when used electively or in the presence of suspected fetal distress. Data from 1,428 patients from a previously published randomized trial of intrapartum electronic fetal heart rate monitoring versus intermittent auscultation were analyzed to identify differences in umbilical cord blood acid-base measurements associated with the elective use of vacuum extraction (patients with duration of second stage of labor 60 min or less) and also in the presence of suspected fetal distress during the second stage of labor. When used electively, vacuum extraction was associated with lower pH (in both umbilical cord artery and vein), lower venous base excess, and higher venous carbon dioxide tension (PCO2), as compared to normal spontaneous vaginal delivery. After correcting for duration of second stage of labor, elective vacuum delivery was significantly associated only with a decrease in cord venous pH and increase in venous PCO2. However, these cord blood acid-base changes were not accompanied by any differences in perinatal morbidity and mortality or in the number of neonates born with acidemia (cord arterial pH < 7.15 or < 7.10). In cases of suspected fetal distress, the use of vacuum extraction was not associated with any detectable cord blood acid-base changes as compared to normal spontaneous vaginal delivery. These data support the continued use of vacuum extraction, especially in cases of suspected fetal distress during the second stage of labor.

The impact of prenatal care in the United States on preterm births in the presence and absence of antenatal high-risk conditions.

Seventy-five women with a mean age of 27.5 years who requested Norplant implants for contraception were studied over a five-year period. The patients kept daily diaries of their vaginal bleeding and coital frequency, and were seen at least every six months at which time their weight was measured. This study examines the impact of Norplant implants use on menstrual regularity, body mass index and coital frequency. Irregular bleeding was most prevalent during the first two years of Norplant implants use and accounted for the primary reason for discontinuation of this method. No increase in Body Mass Index (BMI) was noted in Norplant implants users over the five-year study period. Women with irregular bleeding did not have a higher or lower BMI compared to women with regular bleeding and irregular bleeding patterns did not impact on coital frequency. Over five years, four pregnancies occurred during Norplant implant use. Norplant implants are a highly effective contraceptive method and women using this method should not expect an increase in body weight. Irregular bleeding is most frequent during the first two years of use and menstrual cyclicity resumes in the majority of women by the third year of use and continues to the fifth year of use.