A new method to assess fetal head descent in labor with transperineal ultrasound.

OBJECTIVES: To assess the feasibility and reproducibility of measuring fetal head station and descent during labor using transperineal ultrasound (TPU) imaging, to compare the evaluation of fetal station through digital examinations with concurrent TPU assessments, and to assess its utility in distinguishing patients whose pregnancy will result in spontaneous vaginal delivery from those who will require operative vaginal delivery or Cesarean section for failure to progress. METHODS: TPU and digital examinations were performed in 88 term laboring patients with a singleton fetus in cephalic presentation. Using TPU imaging, head descent was quantified by measuring the angle between the long axis of the pubic symphysis and a line extending from its most inferior portion tangentially to the fetal skull. Intraobserver and interobserver variability were calculated using variance component analysis. TPU imaging was used to measure the angle of head descent during the second stage of labor in 23 of the women. RESULTS: Analysis of replicated measurements on 75 subjects, by the same observer at approximately the same time, yielded an average SD (intraobserver variability) of approximately 2.9 degrees for the measurement of angle of head descent on TPU examination. A separate variance component analysis on a subset of 15 assessments for which measurements were repeated by a second observer, with two to four replicate measurements obtained by each, yielded an interobserver error estimate of 1.24 degrees. A significant linear association was found between clinical digital assessments and measurement of angle of head descent by TPU examination (P < 0.001). An angle of at least 120 degrees measured during the second stage of labor was always associated with subsequent spontaneous vaginal delivery. In six pregnancies ending in Cesarean section the mean angle of descent measured at last TPU examination was only 108 degrees. CONCLUSIONS: The angle of head descent measured by TPU imaging provides an objective, accurate and reproducible means for assessing descent of the fetal head during labor.

A comparison between acoustic output indices in 2D and 3D/4D ultrasound in obstetrics.

OBJECTIVE: Three-dimensional (3D) ultrasound is gaining popularity in prenatal diagnosis. While there are no studies regarding the safety of 3D ultrasound, it is now widely performed in non-medical facilities, for non-diagnostic purposes. The present study was aimed at comparing the acoustic output, as expressed by thermal index (TI) and mechanical index (MI), of conventional two-dimensional (2D) and 3D/4D ultrasound during pregnancy. METHODS: A prospective, observational study was conducted, using three different commercially available machines (iU22, Philips Medical Systems; Prosound Alfa-10, Aloka; and Voluson 730 Expert, General Electric). Patients undergoing additional 3D/4D ultrasound examinations were recruited from those scheduled for fetal anatomy and follow-up exams. Fetuses with anomalies were excluded from the analysis. Data were collected regarding duration of the exam, and each MI and TI during 2D and 3D/4D ultrasound exams. RESULTS: A total of 40 ultrasound examinations were evaluated. Mean gestational age was 31.1 +/- 5.8 weeks, and mean duration of the exam was 20.1 +/- 9.9 min. Mean TIs during the 3D (0.27 +/- 0.1) and 4D examinations (0.24 +/- 0.1) were comparable with the TI during B-mode scanning (0.28 +/- 0.1, P = 0.343). The MIs during the 3D volume acquisitions were significantly lower than those in the 2D B-mode ultrasound studies (0.89 +/- 0.2 vs. 1.12 +/- 0.1, P = 0.018). The 3D volume acquisitions added 2.0 +/- 1.8 min of actual ultrasound scanning time (i.e. not including data processing and manipulation, or 3D displays, which are all post-processing steps). The 4D added 2.2 +/- 1.2 min. CONCLUSIONS: Acoustic exposure levels during 3D/4D ultrasound examination, as expressed by TI, are comparable with those of 2D B-mode ultrasound. However, it is very difficult to evaluate the additional scanning time needed to choose an adequate scanning plane and to acquire a diagnostic 3D volume.

Evaluating rapid diagnostic tests of intra-amniotic infection: Gram stain, amniotic fluid glucose level, and amniotic fluid to serum glucose level ratio.

OBJECTIVE: The aim of the study was to compare the diagnostic utility of the Gram stain, the amniotic fluid glucose level, and the ratio of amniotic fluid glucose level to serum glucose level in detecting intra-amniotic infection. STUDY DESIGN: We conducted a prospective study of 127 patients with preterm labor and 26 patients with preterm premature rupture of the membranes (153 total). All patients underwent amniocentesis to diagnose intra-amniotic infection. The diagnostic criterion for intra-amniotic infection was a positive amniotic fluid culture result. RESULTS: The Gram stain is 80% sensitive and 91% specific when a positive is considered the presence of white blood cells or bacteria. Amniotic fluid glucose level and the ratio of amniotic fluid glucose level to serum glucose level are significantly lower when amniotic fluid culture results are positive, but as diagnostic tests they are inferior to the Gram stain. Logistic regression models that combine predictors yield superior accuracy with respect to individual tests. The most accurate combination was amniotic fluid glucose level and Gram stain with white blood cells or bacteria. Although the number of patients with preterm premature rupture of the membranes was small in this study (n = 26), analysis of our data suggests that the diagnostic performance levels of these tests were similar when used in patients with preterm labor and intact membranes and in patients with premature rupture of the membranes. CONCLUSIONS: The amniotic fluid glucose level and the ratio of amniotic fluid to serum glucose level have equivalent diagnostic utility and are inferior to the Gram stain. The combination of Gram stain with amniotic fluid glucose level is superior to any individual test.

Obstetric care for renal allograft recipients or for women treated with hemodialysis or peritoneal dialysis during pregnancy.

Pregnancies in women on dialysis and in women who have had renal transplant are no longer uncommon. Optimal obstetric outcomes require a multidisciplinary team approach, patient counseling, and clinicians who are knowledgeable and experienced in taking care of these patients. Counseling should begin before pregnancy, and all reproductive age women on dialysis and who have undergone renal transplant should receive family planning counseling. Preconceptional counseling should be provided to those patients who desire pregnancy. If the patient presents in early pregnancy, she should be informed about the maternal and fetal risks associated with her pregnancy. Prenatal care must include intensive surveillance for hypertension, preeclampsia, preterm labor, intrauterine growth restriction, anemia, infection, and renal allograft rejection. Aggressive treatment of complications is mandatory. There are limitations to our current knowledge about pregnancies in these patients. It is important for clinicians who provide care for these patients to be aware of these limitations when making obstetric management decisions. Cesarean section should be reserved for usual obstetric indications. Breast-feeding is not advised in patients taking cyclosporin or azathioprine. Transplant patients have unique gynecologic needs, so they should be encouraged to pursue follow-up gynecologic care after the pregnancy.

Pregnancy in a woman with class H diabetes mellitus and previous coronary artery bypass graft: a case report and review of the literature.

BACKGROUND: Maternal and fetal mortality have been reported to be high in pregnant women with diabetes mellitus and ischemic heart disease. Review of the literature identified only two cases of pregnancy after coronary artery bypass surgery in diabetic patients. Because of limited case experience, there are no clear recommendations for counseling and managing such patients. CASE: We managed a pregnancy complicated by class H diabetes mellitus in which the patient had an earlier need for four-vessel coronary artery bypass surgery. The application of contemporary techniques for diabetic and cardiac management led to successful maternal and perinatal outcomes at 36 weeks' gestation. CONCLUSION: Preconception coronary artery bypass surgery, along with contemporary medical and obstetric management, may lead to improvement in the outcome of pregnancies complicated by class H diabetes.