Does the availability of maternal HbA1c results improve the accuracy of sonographic diagnosis of macrosomia?

OBJECTIVE: To determine whether measuring maternal glycosylated hemoglobin (HbA1c) can improve the accuracy of sonographic estimation of fetal macrosomia. METHODS: Sonographic estimation of fetal weight (EFW) and maternal HbA1c were obtained in term, non-diabetic patients within 1 week before delivery. Neonatal birth weights were recorded at delivery and compared with both sonographic estimations and HbA1c. Macrosomia was defined as birth weight of >or=4000 g. The absolute error of the sonographic EFW was calculated. Receiver-operating characteristics (ROC) curve analysis was used to evaluate sonographic EFW and HbA1c as predictors of birth weight >or=4000 g. Variables were tested using regression analysis and student's t-test. RESULTS: One hundred and sixty two patients were evaluated between July and December 2002. Twenty-eight patients (17.3%) delivered macrosomic infants. Sonographic EFW >or=4000 g predicted macrosomia with sensitivity, specificity and positive and negative predictive values of 66.6%, 88.8%, 54.5% and 93.0%, respectively. Its overall accuracy was 85.5%. The area under the ROC curve of sonographic EFW in the prediction of macrosomia was 0.9 (P < 0.001). HbA1c levels in women delivering macrosomic and non-macrosomic neonates were 5.3 +/- 0.7% and 5.2 +/- 0.5%, respectively (P = 0.27). The area under the ROC curve of HbA1c in the prediction of macrosomia was 0.53 (P = 0.27). CONCLUSIONS: Maternal HbA1c is not a useful test in the prediction of birth weight. It therefore cannot be used to improve the accuracy of sonographic EFW.

Inferior vena cava thrombosis presenting as non-immune hydrops in the fetus of a woman with diabetes.

We present a rare case of non-immune hydrops fetalis (NIHF) caused by a thrombus in the inferior vena cava in a neonate with low levels of anti-thrombin III. The diagnosis of (NIHF) was made in utero in a 43-year-old woman with poorly controlled gestational diabetes who subsequently developed pre-eclampsia. Cesarean section was performed due to fetal compromise and worsening pre-eclampsia. The thrombus resolved after neonatal treatment with heparin.

Maternal pain and anxiety in genetic amniocentesis: expectation versus reality.

OBJECTIVE: To investigate maternal perceptions of both pain and anxiety before and after genetic amniocentesis. STUDY DESIGN: This prospective study of midtrimester, singleton pregnancies was conducted between March 2000 and July 2000. Study variables included patient demographics, medical and obstetric histories, indication for amniocentesis and a description of the source of information used by the patient regarding the procedure and technical degree of difficulty. Maternal pain and anxiety associated with performing amniocentesis were subjectively quantified with the use of the visual analog scale (VAS). Statistical analysis included Wilcoxon signed rank test, anova, and simple and stepwise regression analyses. RESULTS: One hundred and eighty-three women participated in the study. Perception of pain before amniocentesis was significantly higher compared to that expressed immediately after the procedure, with a mean VAS score of 3.7 +/- 2.5 vs. 2.1 +/- 2.0 (P < 0.0001). Similarly, perception of anxiety was significantly greater prior to the procedure, with a mean VAS score of 4.6 +/- 2.8 vs. 2.8 +/- 2.4 after the amniocentesis (P < 0.0001). Perceptions of pain and anxiety were significantly and positively correlated to each other both before and after the procedure (P < 0.0001). History of a prior amniocentesis was the only variable associated with reducing expected pain and anxiety (negative correlation, P < 0.001), whereas the technical degree of difficulty was the only significant variable impacting on the actual pain and anxiety (positive correlation, P < 0.005). CONCLUSIONS: Preamniocentesis counseling should emphasize the fact that, for most women, the actual pain and anxiety experienced during the procedure are significantly lower than expected. In fact, on a scale of 0-10, the mean level of pain was only 2.1, with a slightly higher mean level of anxiety.

A comparison of sonographic cervical parameters in predicting spontaneous preterm birth in high-risk singleton gestations.

OBJECTIVES: To assess the role of cervical sonography and to compare various sonographic cervical parameters in their ability to predict spontaneous preterm birth in high-risk singleton gestations. DESIGN: A prospective cohort of 469 high-risk gestations were longitudinally evaluated between 15 and 24 weeks' gestation on 1265 occasions with transvaginal cervical sonography and transfundal pressure. The cervical parameters obtained were funnel width and length, cervical length, percent funneling and cervical index. The information obtained was used for patient management. Restriction of physical activities was initiated at cervical lengths of < or = 2.5 cm with cerclage as an option for cervical lengths of < or = 2.0 cm. RESULTS: Receiver operating characteristic curve analyses showed that a cervical length of < or = 2.5 cm between 15 and 24 weeks' gestation was equal to the other sonographic cervical parameters in its ability to predict spontaneous preterm birth. The sensitivities for delivery at < 28, < 30, < 32 and < 34 weeks' gestation were 94%, 91%, 83% and 76%, respectively, while the negative predictive values were 99%, 99%, 98% and 96%, respectively. The placement of a cerclage did not influence the positive and negative predictive values. In comparison to women with other risk factors, cervical length was best in the prediction of preterm birth in women with a prior mid-trimester loss; an optimal cut-off of < or = 1.5 cm had sensitivities for delivery at < 28, < 30, < 32 and < 34 weeks' gestation of 100%, 100% 92% and 81%, respectively. The rate of preterm delivery at < 34 weeks' gestation increased dramatically when the cervical length was < or = 1.5 cm. Cervical length was the only independent variable that entered the logistic regression model for the prediction of preterm delivery at < 34 weeks' gestation. CONCLUSIONS: In high-risk singleton gestations a cervical length of < or = 2.5 cm was equal to other sonographic cervical parameters in its ability to predict spontaneous preterm birth and was better for the prediction of earlier forms of prematurity (at < 28 and < 30 weeks) than later forms (at < 32 and < 34 weeks). The optimal cervical lengths and their performance for predicting prematurity may be influenced by obstetric risk factors.

Use of cervical ultrasonography in prediction of spontaneous preterm birth in twin gestations.

OBJECTIVE: This study was undertaken to compare various ultrasonographic cervical parameters with respect to ability to predict spontaneous preterm birth in twin gestations. STUDY DESIGN: This prospective study involved 131 women carrying twins who were longitudinally evaluated on 524 occasions between 15 and 28 weeks' gestation with transvaginal cervical ultrasonography and transfundal pressure. The following cervical parameters were obtained: funnel width and length, cervical length, percentage of funneling, and cervical index. Receiver operating characteristic curve analysis was used to determine the ultrasonographic cervical parameter evaluated at 15 to 20 weeks' gestation, 21 to 24 weeks' gestation, and 25 to 28 weeks' gestation that were best for prediction of spontaneous preterm birth at <28 weeks' gestation, <30 weeks' gestation, <32 weeks' gestation, and <34 weeks' gestation. RESULTS: The median gestational age at delivery was 36 weeks' gestation (range, 21-41 weeks' gestation). Receiver operating characteristic curve analysis indicted that a cervical length of < or =2.0 cm, regardless of gestational age category at cervical measurement, was at least as good as other ultrasonographic cervical parameters at predicting spontaneous preterm birth. Between 15 and 20 weeks' gestation a cervical length cutoff value of < or =2.0 cm had specificities of 97%, 98%, 99%, and 100% and negative predictive values of 99%, 98%, 95%, and 89% for delivery at <28, <30, <32, and <34 weeks' gestation, respectively. The positive predictive values for delivery at <32 and <34 weeks' gestation were 80% and 100%, respectively. Between 21 and 24 weeks' gestation a cervical length of < or =2.0 cm had specificities of 84%, 84%, 85%, and 86% and negative predictive values of 99%, 99%, 94%, and 87% for delivery at <28, <30, <32, and <34 weeks' gestation, respectively. Between 25 and 28 weeks' gestation cervical length had excellent negative predictive values of 99%, 98%, 95%, and 93% for delivery at <28, <30, <32, and <34 weeks' gestation, respectively. CONCLUSIONS: In twin gestations a cervical length of < or =2.0 cm measured between 15 and 28 weeks' gestation was at least as good as other ultrasonographic cervical parameters at predicting spontaneous preterm birth. The high specificities indicate that cervical length was better at predicting the absence than the presence of various degrees of spontaneous prematurity.

Use of cervical ultrasonography in prediction of spontaneous preterm birth in triplet gestations.

OBJECTIVE: The aim of this study was to assess the role of cervical ultrasonography in the prediction of spontaneous preterm birth in triplet gestations and to compare various ultrasonographic cervical parameters with respect to predictive ability. STUDY DESIGN: This prospective cohort study included 51 triplet gestations longitudinally evaluated between 15 and 28 weeks' gestation on 274 occasions with transvaginal cervical ultrasonography and transfundal pressure. The cervical parameters obtained were funnel width and length, cervical length, percentage of funneling, and cervical index. RESULTS: Receiver operating characteristic curve analyses showed that cervical lengths of < or =2.5 cm and < or =2.0 cm between 15 and 24 weeks' gestation and between 25 and 28 weeks' gestation, respectively, were at least as good as other ultrasonographic cervical parameters for the prediction of spontaneous preterm birth. A cervical length of < or =2.5 cm between 15 and 20 weeks' gestation had both a specificity and a positive predictive value of 100% for delivery at <28 weeks' gestation, and the sensitivities and negative predictive values ranged from 25% to 50% and from 72% to 91%, respectively, for deliveries at <28, <30, and <32 weeks' gestation. A cervical length of < or =2.5 cm between 21 and 24 weeks' gestation had an 86% sensitivity for prediction of spontaneous delivery at <28 weeks' gestation. A cervical length of < or =2.0 cm between 25 and 28 weeks' gestation had both a sensitivity and a negative predictive value of 100% for delivery at both <28 and <30 weeks' gestation. CONCLUSIONS: In triplet gestations cervical lengths of < or =2.5 cm between 15 and 24 weeks' gestation and < or =2.0 cm between 25 and 28 weeks' gestation were at least as good as other ultrasonographic cervical parameters for the prediction of spontaneous preterm birth.

Sonographic and clinical methods in the diagnosis of macrosomia.

Receiver operator characteristic curves for both clinical and sonographic predictions of macrosomia subsume areas between 0.81 and 0.95, significantly larger than the area of 0.5 that indicates a useless test. Thus, these tests are defined as useful from a statistical point of view. Prediction of macrosomia by clinical or imaging techniques, however, is limited by the substantial false-positive and false-negative rates inherent in these tests. We recommend that physicians continue to use clinical methods to estimate fetal weight, including asking women with parity to provide their own estimates. We recognize that the relative error associated with clinical or sonographic estimates of fetal weight limits their use in clinical practice. Sonographic laboratories may improve their results by performing ROC curve analysis on their own data and by selecting cutoff values that best predict macrosomia in their setting. Serial sonographic measurements that are above the limits chosen to define macrosomia increase the likelihood that a birth weight will be macrosomic. Separate ROC curves must be generated for twins and breech presentations and for patients with diabetes to answer weight-related clinical questions such as mode and timing of delivery. Three-dimensional ultrasound and magnetic resonance imaging are expected to generate ROC curves for estimates of fetal weight that are better than those for two-dimensional ultrasound or clinical estimates. Such analyses have yet to be published.

Receiver operating characteristic curves of ultrasonographic estimates of fetal weight for prediction of fetal growth restriction in prolonged pregnancies.

OBJECTIVE: Recent studies have documented increased perinatal morbidity and mortality rates in the growth-restricted postterm fetus. Our purpose was to evaluate the receiver operating characteristic curve of ultrasonographically estimated fetal weight as a predictor of fetal growth restriction in prolonged pregnancies. STUDY DESIGN: Fetal weight was estimated ultrasonographically within 9 days of delivery (mode 1 day) in members of a cohort of 410 patients with prolonged pregnancies (>41 weeks). Estimated fetal weights were compared with birth weights in receiver operating characteristic curve analysis. RESULTS: The areas under the receiver operating characteristic curves for predicting birth weights <10th percentile (3125 g in this population) and <5th percentile (2930 g in this population) were 0.89 and 0.96, respectively. Both areas were significantly different from an area indicating a useless test. The estimated fetal weight values corresponding to the inflection points for the receiver operating characteristic curves predicting birth weights <10th percentile and <5th percentile were 3370 and 3200 g, respectively. With estimated fetal weight at less than these test cutoff values, the relative risks for a fetus to have a birth weight <10th percentile or <5th percentile were 14.6 (95% confidence interval, 6.25-33.8) and 89.8 (95% confidence interval, 12.1-665), respectively. Analysis of the receiver operating characteristic curves resulted in improved test characteristics relative to using the actual 10th and 5th birth weight percentiles as cutoff values for estimated fetal weight (relative risk of 14.6 vs 9.5 and 89.8 vs 26.0, respectively). CONCLUSIONS: Ultrasonographic estimation of fetal weight is a useful test for predicting fetal growth restriction in prolonged pregnancies. Future studies should evaluate whether intervention on the basis of this identification results in improved perinatal outcome.

Receiver operating characteristic curves of sonographic estimated fetal weight for prediction of macrosomia in prolonged pregnancies.

We evaluated areas under receiver operating characteristic curves for sonographic estimated fetal weight (EFW) as a predictor of macrosomia in prolonged pregnancies. These areas were 0.85 for birth weights of > or = 4000 g and 0.95 for birth weights of > or = 4500 g. Both were significantly greater than 0.5, the area under curves for useless tests. Areas under curves before and after adjustment for time elapsed between measurement and delivery did not differ significantly. At the inflexion point cut-off level of 3711 g, sensitivity, specificity and positive and negative predictive values of EFW for birth weight of > or = 4000 g were 85, 72, 49 and 94%, respectively. At the inflexion point cut-off level of 4192 g for birth weight of > or = 4500 g, these values were 83, 92, 30 and 99%. The relative risk for birth weight of > or = 4000 g was 7.99, and for birth weight of > or = 4500 g, 39.50, both significant. In conclusion, sonographic EFW is a useful test for predicting macrosomia. Adjustment for time elapsed did not significantly improve either test, probably because of slow rates of fetal growth at this gestational age. Cut-off values derived from this analysis result in high sensitivity but low positive predictive value. A randomized controlled trial of mode and timing of delivery for predicted macrosomia is needed.

Predictive value of amniotic fluid index for oligohydramnios in patients with prolonged pregnancies.

The objective of this study was to evaluate the predictive values of the amniotic fluid index for measures of perinatal morbidity and for clinical observations consistent with oligohydramnios. We evaluated positive and negative predictive value of the amniotic fluid index for measures of perinatal morbidity and for clinical observations consistent with oligohydramnios at various cutoff values for amniotic fluid index in a cohort of 449 consecutive postdates patients who had a clinician's observation of amniotic fluid quantity and quality recorded at the time of rupture of membranes. Newborn morbidity was a rare event. Clinical observations consistent with oligohydramnios had significant positive and negative predictive values for some measures of newborn morbidity. The last amniotic fluid index performed during antepartum testing had 95% confidence intervals for relative risks for these measures of newborn morbidity that included unity and therefore were not significant. At a cutoff value of 5.0 cm, the positive predictive value of the amniotic fluid index for clinical observations consistent with oligohydramnios was 50%; the negative predictive value was 85%, with a prevalence of clinical observations consistent with oligohydramnios of 19%. The presence of fetal heart rate decelerations did not significantly improve the positive predictive value of the amniotic fluid index. Higher positive predictive values were obtained at cutoff values of 4 cm and 3 cm with minimal loss in negative predictive value. The amniotic fluid index did not possess significant predictive value for measures of newborn morbidity. Clinical observations consistent with oligohydramnios at the time of rupture of membranes did have predictive value for some of these measures and thus probably are a reflection of the actual amount of fluid present inside the uterus prior to rupture of membranes. The amniotic fluid index is only a fair predictor of clinical observations consistent with oligohydramnios. Thus, a positive test correctly predicted these observations 50% of the time, with 50% false-positive results. Undertaking delivery in the 50% of patients without clinical observations consistent with oligohydramnios may lead to a higher cesarean section rate since these patients do not require induction and are subject to the risk of a failed induction of labor. A negative test correctly predicted observations consistent with normal fluid 85% of the time, with a false-negative rate of 15%. Thus, a negative test was no guarantee that observations consistent with oligohydramnios, and thus newborn morbidity, would not subsequently appear. Frequent testing with multiple modalities and induction of labor when the Bishop score is favorable remain sensible options. Induction of labor in postdates patients with a low amniotic fluid index needs to be evaluated in a yet-to-be-performed prospective randomized control trial before a low amniotic fluid index is assumed to be the sole indicator for induction of labor. More stringent cutoff values for amniotic fluid index may be justified.

Pregnancy in women aged 40 and older.

Counseling patients about pregnancy at advanced maternal age is a difficult process. This is true both because our knowledge of the attendant risks is incomplete and still evolving, and because of the difficulties of assigning risks and addressing counterbalancing benefits for individual patients. There are a number of social and personal considerations involved in a decision to become a parent after the age of 40. Generally, older parents tend to be more mature, to be in stable and healthy marriages, and to have more financial and family resources to assist with the process of child rearing. Parents in their fifth decade, however, may complain of having less energy to devote to young children or may be at a stage in their careers in which they have less time for family participation than when they were younger. Also, grandparents, who can play a critical role in early childhood development, often have become too old to participate in that role or have died. All of these issues must be considered by parents contemplating late childbearing. A great deal has been written, much of it positive, even enthusiastic, about the quality of pregnancy and childbirth among older women. Nevertheless, much of the literature is difficult to interpret because of problems in controlling for confounding variables. In addition, much of the focus on so-called older women has been on those older than 35 years. In fact, the great majority of the medical literature concerning late childbearing relates to women between the ages of 35 and 40. The data that directly concern women in their fifth decade suggest that risks that began to accelerate after the age of 35 become considerably greater and increase more rapidly after the age of 40. Obviously, couples must decide what risks they are willing to accept and how these potential risks might be countervailed by the presumed advantages of parenthood relatively late in the reproductive years. There is convincing evidence to show that fecundity is decreased with advancing maternal age, and various forms of early pregnancy loss are increased. Thus, to delay childbearing results in a significant decrease in the likelihood of becoming pregnant or carrying a pregnancy to term. The possibility of genetic disorders is, as has been discussed previously, relatively easy to quantitate, and most age-related anomalies are amenable to prenatal diagnosis. It seems clear that women with underlying medical diseases, particularly hypertension and diabetes mellitus, contribute heavily to the excess morbidity and mortality associated with late childbearing.(ABSTRACT TRUNCATED AT 400 WORDS)