Structural-tridimensional study of yolk sac in pregnancies complicated by diabetes.

OBJECTIVES: To assess by two- and three-dimensional ultrasound the diameter and volume of the yolk sac in pregnant women affected by type 1 diabetes during the first trimester of pregnancy. METHODS: 18 women affected by insulin-dependent diabetes mellitus (IDDM) and 52 normoglycemic pregnant women (controls) were enrolled in this study. The women were evaluated once a week (5-12 weeks of pregnancy). Ultrasound examination in all pregnant women was initially performed in a bidimensional fashion with a transvaginal 6.5-MHz probe and subsequently using a three-dimensional technique. RESULTS: In the pregnant diabetic women the diameter of the yolk sac was significantly higher than that of controls in the first weeks of pregnancy, reaching a maximum diameter at 9 weeks, and decreasing thereafter, earlier than controls. The volume of the yolk sac increased in both groups from 5 weeks of pregnancy and reached maximum values at 10 weeks in both groups. The volumetric increase and decrease after reaching highest values were greater in IDDM patients. CONCLUSION: The clinical and diagnostic implications of the results of this study are still to be defined. Such a diagnostic technique may prove to be an additional element in monitoring diabetic women during early pregnancy.

Amniotic fluid lamellar body counts for the determination of fetal lung maturity: an update.

AIM: To reassess the cut-off value for lamellar body counts (LBs) for fetal lung maturity (FLM) over a 10-year study period. PATIENTS AND METHODS: 178 pregnancies were selected under strict inclusion criteria and delivered within 48 h from amniocentesis. FLM was determined by amniotic fluid LBs in centrifuged samples (300 x g for 10 min) in a commercially available Coulter Counter. Cases beyond 37 weeks were excluded. RESULTS: Mean gestational age was 33.5+/-3.0 weeks at amniocentesis and 33.7+/-3.0 weeks at birth. After reassessing the best compromise between sensitivity and specificity for all cases using the receiver operating characteristic (ROC) procedure, an FLM cut-off value of < or = 22,000/microL was obtained. Diagnostic accuracy (and confidence interval, CI) was: sensitivity, 73% (60.0-83.6%); specificity, 81.7% (CI 73.6-88.1%); positive predictive value, 66.2%; and negative predictive value, 86.0%. CONCLUSION: No significant change in FLM cut-off for LBs was found when comparing the value from this study and the results of our earlier report presented in 1996 (< or = 22,000 vs. < or = 20,000/microL), although the new value may be more accurate, since it is based on neonatal outcome with the exclusion of cases in which the diagnosis of FLM is seldom warranted, i.e., > 37 weeks' gestational age.

Computerized cardiotocography parameters in pregnant women affected by pregestational diabetes mellitus.

AIM: To evaluate whether computerized CTG (cCTG) is a reliable method of predicting neonatal outcome in pregnancies complicated by pregestational diabetes at term. PATIENTS AND METHODS: We considered 27 pregnant women affected by pregestational diabetes and 46 normal pregnancies as controls that fulfilled the following criteria: singleton, Caucasian, euglycemic pregnancies at term (>37 weeks gestational age). All women delivered by cesarean section (CS), with an antepartum cCTG performed within one hour before the CS and an UBGA available at birth. No patient was in labor during FHR monitoring. RESULTS: Among cCTG parameters, accelerations 15 bpm, HV min, HV ms and STV were significantly lower in comparison to controls. We observed that in the diabetic pregnant women the parameter STV was not able to predict or to linearly regress with the most important UBGA parameters: pH and pCO2. Contrarily, in normal pregnancies, the STV linearly regressed with both the pH (p < 0.03) and pCO2 (p<0.04). CONCLUSIONS: Computerized FHR criteria may not be applicable to fetuses in pregestational diabetic pregnancies at term. Therefore some criteria should perhaps be modified for a correct interpretation of cCTG in these pregnancies.

Preliminary report on a new and noninvasive method for the assessment of fetal lung maturity.

OBJECT: Several patterns of fetal breathing movements (FBMs), i.e. abdominal wall movements (AWm), thoracic wall movements (TWm) and nasal fluid flow velocity waveforms (NFFVW), were investigated by ultrasound (US) technology and related to fetal pulmonary maturity and immaturity, i.e. fetal lung maturity (FLM) tests, in order to validate the hypothesis that they may indicate whether the fetal lung is mature or immature, regardless of gender, weight and gestational age. MATERIAL AND METHODS: We prospectively enrolled 143 high-risk pregnancies in which a complete US study of FBMs and FLM tests was performed. Among them 43 women satisfied the inclusion criteria. US-FLM was defined as the presence of regular NFFVW detected by pulsed Doppler and spectral analysis, or irregular NF-FVW synchronous with TWm detected by M-mode. An US guided amniocentesis was performed in order to collect amniotic fluid (AF) and FLM was evaluated by L/S (lecithin/sphingomyelin) determination, presence of phosphatidylglycerol (PG) and lamellar bodies (LBs) count. At the end of the study the diagnostic accuracy of US-FLM was compared to that of FLM tests. RESULTS: Diagnostic accuracy for US evaluation of FLM was as follows: sensitivity: 89.6%; specificity: 85.7%; PPV: 92.8%; NPV: 80%. Diagnostic accuracy of FLM tests was as follows: sensitivity: 100%; specificity: 51.7%; PPV: 100%; NPV: 50%. L/S determination predicted lung maturity with a sensitivity of 100%; specificity of 93.1%; PPV of 100%; NPV of 87.5%. CONCLUSION: Presence of regular NFFVW or irregular NFFVW and TWm correlate accurately with conventional FLM tests. We suggest that this noninvasive procedure may be helpful for assessing FLM, particularly under certain circumstances, e.g., oligo-anhydramnios, laboratory logistic equipment difficulties or heavily stained AF samples, amniocentesis refusal, religious concerns.

Validity of short term variation (STV) in detection of fetal acidemia.

AIMS: We aimed to establish a cut-off for short term variation (STV) in msec in electronic FHR tracings as a single parameter for the prediction of neonatal acidemia and hypercarbia at birth. METHODS: 195 consecutive cases of singleton pregnancies between 26 to 42 weeks' gestation delivered by cesarean section, with an antepartum tracing performed within 4 hours from birth and umbilical artery gas analysis (UBGA) available at birth. RESULTS: A positive correlation (r = 0.27, p < 0.0001) was found when STV was regressed against gestational age. We also found significant correlations between STV and UBGA parameters (pH [r = 0.12, p < 0.05] and pCO2 [r = -0.17, p < 0.01]). In order to evaluate the influence of gestational age on STV values, we subdivided patients into three subgroups (< 34 weeks: n = 31; 35-37 weeks: n = 37, and > 37 wks: n = 127). Only in the subgroup < 34 wks, STV < 5.1 msec was a significant predictor of acidemia (pH < 7.0), (sensitivity: 100%, specificity: 61%, p < 0.05); in the same subgroup STV < 4.9 msec predicted pCO2 > 60 mmHg with a sensitivity: 71.4% and a specificity: 62.5% (p < 0.02). CONCLUSION: In cases < 34 weeks' gestation, STV values below 4.9 msec and 5.1 msec are able to predict umbilical artery pH < 7.0 and PCO2 > 60 mmHg, respectively.

Association between maternal-fetal Doppler velocimetry and fetal lung maturity.

AIMS: To correlate maternal-fetal Doppler velocimetry parameters to indices of fetal lung maturity (FLM). METHODS: Fifty-five consecutive third trimester pregnancies in which a pulsed-wave Doppler study, including uterine resistance index (Ut RI), umbilical artery pulsatility index (UA PI), middle cerebral artery pulsatility index (MCA PI) and the UA/MCA ratio was performed within 24 hours before amniocentesis and within a week from birth. FLM was determined by amniotic fluid lamellar bodies count (LBs). RESULTS: A positive correlation between MCA PI and LBs (p < 0.007, r = 0.44) was found. MCA PI showed a trend to lower values in fetuses that developed RDS at birth (1.3 +/- 0.5 vs. 1.7 +/- 0.4, NS). LBs significantly decreased as Ut RI increased (O.R.: 0.98, C.I. 0.97-0.99, p < 0.05). A mean Ut RI > 0.64 was correlated to delayed FLM (LBs < 20,000/microl; sensitivity: 90.9%, specificity: 90.3%; positive predictive value: 76.9%, negative predictive value: 96.6%). COMMENT: In third trimester pregnancies abnormal uterine artery waveforms may be associated to a delayed FLM, as expressed by decreased amniotic fluid LBs.