Vaginal electrohysterography: the design and preliminary evaluation of a novel device for uterine contraction monitoring in an ovine model (.).

OBJECTIVE: Tocodynamometry is the most common method of labor evaluation but most clinicians would agree it has limited utility before 26 weeks of gestation. The obesity epidemic has further reduced our ability to accurately detect uterine contractions using the tocodynamometer at any gestational age. We sought to design and test a novel contraction monitor that bypasses the maternal abdomen. METHODS: An optimized version of an intravaginal electrohysterographic ring device was tested in an ovine model. The device and its methodology as well as the tocodynamometer were validated against the current gold standard uterine activity monitor, the intrauterine pressure catheter in six sheep at varying gestational ages. RESULTS: Both the intravaginal ring device and the tocodynamometer correlated well with IUPC, r = 0.69 and 0.73, respectively (p < 0.001). The number of contractions detected by each monitor remained similar even after accounting for confounders. CONCLUSIONS: These results suggest that uterine activity can be monitored from the vaginal interface in an ovine model and offers an alternative clinical tool for the detection of contractions in situations, in which tocodynamometry would be ineffective or intrauterine monitoring inappropriate.

Fetal death resulting from an isolated congenital partial pericardial defect.

BACKGROUND: Congenital pericardial defects occur from a defect in the formation of the pleuropericardial membrane during embryonic development. This defect may be asymptomatic but can be fatal if complicated by herniation of any portion of the heart. CASES: We report two cases in which herniation of a portion of the heart occurred through a partial left pericardial defect and resulted in fetal death. In case one, there were no fetal symptoms, and in case two, an irregular heartbeat was detected prompting a fetal echocardiogram that was negative for heart abnormalities. CONCLUSION: Although isolated congenital pericardial defects are rare, they can result in fetal death. Awareness may help to refine ultrasonography or other diagnostic modalities to evaluate possible congenital pericardial defects in utero.

Performance of estimated glomerular filtration rate prediction equations in preeclamptic patients.

Accurate estimation of the glomerular filtration rate (GFR) in patients with preeclampsia requires the collection of a 24-hour urine and can have important therapeutic and diagnostic implications. This procedure is often difficult or impossible to accomplish in this patient group. In this study, the Cockcroft-Gault, the Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formulas were evaluated for their accuracy in determining GFR in the setting of preeclampsia. The estimated GFRs calculated from the above formulas were compared with the creatinine clearance values obtained from a 24-hour urine collections in 543 preeclamptic patients recruited from several large hospitals. Additionally, a set of new equations, preeclampsia GFR (PGFR), based on ethnicity, was created. The Cockcroft-Gault, MDRD, and CKD-EPI formulas were inaccurate in predicting GFR and both were significantly less accurate than PGFR. The latter formula provided an estimated GFR that was much closer to the creatinine clearance. Current GFR estimation equations based on serum creatinine values in nonpregnant patients are not reliable measures of renal function in patients with preeclampsia. The use of a new formula (PGFR) is recommended.

Clinical consequences of an increasing trend of preferential use of cultured villi for molecular diagnosis by CVS.

OBJECTIVE: To compare the use of uncultured versus cultured villus cells for DNA-based prenatal diagnosis. METHODS: A retrospective review of molecular testing of chorionic villus sampling (CVS) cases from 1988-2007. Method of analysis, gestational age (GA) at CVS and at diagnosis, time from procedure to results, results of maternal contamination studies, and the laboratory employed were abstracted from patient charts. Trends in laboratory practices over time were analyzed. RESULTS: Time from CVS to diagnosis was longer when cultured cells were used. Average GA at diagnosis was 14-6/7 weeks with cultured cells vs 13-0/7 weeks with uncultured villi (p < 0.001). Recently, laboratories are more frequently requiring cultured cells, resulting in significantly greater delays in time to diagnosis and GA at results. CONCLUSIONS: 'Direct' DNA extraction saves 2 weeks from CVS to results. More women are afforded the option of an earlier, safer pregnancy termination if uncultured villi are used for molecular diagnosis. Implementation of standardized DNA extraction protocols and sample-size requirements can optimize the use of uncultured villi for molecular prenatal diagnosis. Increased awareness of the importance of rapid results and the advantages of 'direct' DNA extraction from uncultured villi can lead to improvements that are of clinical significance for patients undergoing early prenatal diagnosis.

The association of hypotonia and depression in the term and near-term neonate with metabolic acidemia.

AIMS: To determine the association of hypotonia and depression in neonates at or near term with metabolic acidemia at birth (umbilical arterial pH<7.0 and base excess <-12 mM). METHODS: This case-control study identified 87 infants without chromosomal or congenital abnormalities born at a single university hospital between 7/91 and 10/04 with hypotonia at birth requiring resuscitation and admission to the neonatal intensive care unit that had a cord gas at delivery. Controls were the subsequent delivery with a cord gas matched by gestational age. RESULTS: Cases and controls did not differ in gestational age (38.7+/-1.9, 38.6+/-1.9 weeks) or birth weight (3,066+/-664, 3,171+/-655 g, P=0.20). Cases were more likely to have a cord pH<7.0 [17 (20%) vs. 1 (1.1%), P=0.0001] and cord pH 7.0-7.1 [13 (14.9%) vs. 2 (2.3%), P=0.003]. Among the hypotonic infants, 31 (35.6%) also were depressed at birth with a 5-min Apgar <7. In the depressed subset of hypotonic neonates 14/31 (45%) had a pH<7.0. Of the 12 hypotonic neonates with seizures, 3 (25%) had pH<7.0. Multivariate analysis showed a significant association between neonatal hypotonia and hypoglycemia, umbilical arterial pH, and nucleated red blood cell count. CONCLUSIONS: Although metabolic acidemia is significantly associated with hypotonia at the time of birth, the majority of neonates with hypotonia and depression or seizures do not have objective evidence of asphyxia as measured by a cord gas at the time of delivery.

Intrahepatic vein for fetal blood sampling: one center's experience.

OBJECTIVE: The objective of the study was to examine 1 center's experience with fetal blood sampling via the fetal intrahepatic vein (IHV) and cordocentesis. STUDY DESIGN: Consecutive IHV and cordocentesis procedures between July 1987 and February 2006 were compared with respect to success rates, streaming at the sampling site, nonreassuring fetal heart rate (NRFHR), or need for urgent delivery post procedure. A subanalysis of cases with fetal thrombocytopenia was performed. Data were analyzed using Fisher's exact and Student t tests. RESULTS: Two hundred ten procedures (130 IHV samplings and 110 cordocenteses) were identified. Success rates were significantly higher with IHV sampling than with cordocentesis (84.6% vs 69.1%, P = .004). Streaming from the sampling site occurred after 0.79% of IHV procedures vs 30.8% of cordocenteses (P < .0001). There was no difference between IHV and cordocentesis in the incidence of NRFHR or need for immediate delivery. Twenty-five cases of fetal thrombocytopenia (20 sampled via IHV, 5 by cordocentesis) were identified. Streaming from the sampling site occurred in 0 of 20 IHV cases vs 2 of 5 cordocentesis cases (40%) (P = .03). CONCLUSION: IHV has a significantly lower rate of streaming from the sampling site, compared with cordocentesis. Our data suggest that IHV sampling conveys a particular advantage when fetal thrombocytopenia is suspected.

Intrapartum electronic fetal monitoring and the identification of systemic fetal inflammation.

OBJECTIVE: To determine if intrapartum electronic fetal heart rate monitoring (EFM) can identify the fetal in utero systemic inflammatory response or neonatal sepsis, risk factors for the development of brain injury. STUDY DESIGN: This case-control study matched cases with both histologic chorioamnionitis and funisitis (75 preterm and 63 term) to the next delivery without placental or cord inflammation by gestational age and mode of L delivery. The last 2 hours of EFM prior to delivery were reviewed by 3 perinatologists blinded to placental pathology. RESULTS: Preterm and term cases had significantly increased baseline heart rates. Term cases had significant increases in tachycardia, total and late decelerations, and nonreactivity and also had fewer accelerations. EFM parameters had sensitivity of 29-65%, specificity of 46-93%, positive predictive value of 53-80% and negative predictive value of 54-58% in identifying fetal systemic inflammation in this matched, case-control sample. Of the preterm neonates, 9 with sepsis were compared to 141 with negative cultures and were found to have a significant increase in baseline fetal heart rate and tachycardia of longer duration. CONCLUSION: Although significant associations were found, EFM lacks precision in identifying the fetal in utero systemic inflammatory response and neonatal sepsis, predisposing conditions for the development of neonatal encephalopathy.

Phenotypic characteristics shared by preeclamptic patients and an animal model of the syndrome: report of a pilot study.

BACKGROUND: Preeclampsia is a disorder that affects between 3% and 10% of all pregnancies. Progress in the understanding of the etiology (or etiologies) of this disorder has been impeded by the lack of suitable animal models of its early pathogenesis. Etiologic possibilities abound, and there are a number of considerations that suggest that preeclampsia is not one disease but rather a group of diseases with similar phenotypic characteristics. A rat model of this syndrome has been developed by inducing excessive volume expansion using desoxycorticosterone acetate and by replacing the drinking water with 0.9% saline. These animals develop hypertension, proteinuria, and intrauterine growth restriction (IUGR). However, they do not develop glomerular endotheliosis or a reduced glomerular filtration rate (GFR). We therefore surveyed the charts of patients with a discharge diagnosis of preeclampsia. We addressed the question of whether there was a group of such patients with the characteristics of our rat model. These include hypertension, proteinuria, IUGR, and either normal or only mildly abnormal GFR. METHODS: We performed a retrospective chart review of 630 consecutive patients discharged with a diagnosis of preeclampsia. Of the patients, 1290 had all data available to allow appropriate analysis. RESULTS: A total of 29 patients demonstrated hypertension (>140/90 mm Hg), proteinuria (>300 mg/ 24 h), and IUGR and did not have any confounding comorbid conditions. Of these 29 patients, 18 had GFR that were within the range expected for gestational age or only slightly reduced. CONCLUSIONS: There is a group of patients that mirror the characteristics of our animal model. Accordingly, at least one etiology of preeclampsia is related to excessive expansion of the extracellular fluid volume.

Cord gas analysis, decision-to-delivery interval, and the 30-minute rule for emergency cesareans.

OBJECTIVE: Our primary objective was to examine the relationship between umbilical arterial gas analysis and decision-to-delivery interval for emergency cesareans performed for nonreassuring fetal status to determine if this would validate the 30-minute rule. STUDY DESIGN: For this retrospective cohort study, all cesarean deliveries performed for nonreassuring fetal status from September 2001 to January 2003 were reviewed. A synopsis of clinical information that would have been available to the clinician at the time of delivery and the last hour of the electronic fetal heart rate tracing prior to delivery were reviewed by three different maternal-fetal medicine specialists masked to outcome, who classified each delivery as either emergent (delivery as soon as possible) or urgent (willing to wait up to 30 minutes for delivery) since immediacy of the fetal condition is the key factor affecting the type of anesthesia used. RESULTS: Of 145 cesareans performed for nonreassuring fetal status during this period, 117 patients met criteria for entry, of which 34 were classified as emergent and 83 as urgent. Kappa correlation was 0.35, showing only fair/moderate agreement between reviewers. In the emergent group, general anesthesia was more common (35.3%, 10.8%, p=0.003), and the decision-to-delivery interval was 14 minutes shorter (23.0+/-15.3, 36.7+/-14.9 minutes, p<0.001). Linear regression showed a statistically significant relationship between increasing decision-to-delivery interval and umbilical arterial pH (r=0.22, p=0.02) and base excess (r=0.33, p<0.001) showing that delivery proceeded sooner for most of those with the worst cord gases, with a gradual improvement over time. For the 13 (11%) neonates with cord gases placing them at increased risk for long-term neurologic sequelae, the decision-to-delivery interval was 24.7+/-14.6 minutes (range 6 to 50 minutes), and 3/13 (23%) were classified as urgent rather than emergent. CONCLUSION: Electronic fetal monitoring shows considerable variation in interpretation among maternal-fetal medicine specialists and is not a sensitive predictor of the fetus developing metabolic acidosis. There is no deterioration in cord gas results after 30 minutes, and most neonates delivered emergently or urgently for nonreassuring fetal status even when born after 30 minutes have normal cord gases. The 30-minute rule is a compromise that reflects the time it takes the fetus to develop severe metabolic acidosis, our imprecision in its identification, and its rarity in the presence of nonreassuring fetal monitoring.

Nulliparity and duration of pregnancy in multiple gestation.

OBJECTIVE: We sought to test the hypothesis that nulliparous women with multiple gestations would be more likely to have shorter gestational durations, a higher frequency of previable deliveries, and fewer pregnancy complications when compared with parous women. METHODS: We reviewed the medical records of women who delivered a multiple gestation at 15 or more weeks at 2 institutions between January 1, 1990 and June 30, 2002 (n = 1,035). We recorded demographic data, medical complications, and pregnancy outcomes and analyzed these using paired t tests for continuous variables, chi(2) for categorical variables, and linear regression analysis for the effect of multiple variables on the primary outcome variable, gestational age at delivery. RESULTS: There was a statistically significant difference in mean gestational age at delivery (34 versus 34.9 weeks, P =.006) between the nulliparous and multiparous groups after excluding women with a history of previous preterm birth and/or midtrimester loss. There were no differences between groups in the likelihood of delivering before 20, 24, or 28 weeks. In linear regression analysis, ongoing fetal number (P <.001), premature rupture of membranes (PROM; P <.001), cerclage (P =.002), and death of 1 or more fetuses (P <.001) were associated with shorter gestation. Cesarean delivery was associated with longer gestation (P <.001). Nulliparous women were significantly more likely to have a pregnancy complicated by hypertension (20.8% versus 9.2%, P <.001), diabetes (7% versus 4%, P =.03), or PROM (24.4% versus 17.3%, P =.006). CONCLUSION: Nulliparous women with a multiple gestation deliver their pregnancies, on average, 0.9 weeks earlier than parous women and more frequently experience hypertension, diabetes, and PROM. They are not, however, more likely to deliver before 24 weeks of gestation.

A dilated fetal stomach predicts a complicated postnatal course in cases of prenatally diagnosed gastroschisis.

OBJECTIVE: The purpose of this study was to determine whether dilation of the fetal stomach is associated with increased perinatal complications in infants with prenatally diagnosed gastroschisis. STUDY DESIGN: From 34 newborn infants with gastroschisis who were delivered at our institution over a 10-year period, 2 groups were analyzed on the basis of the presence or absence of a dilated fetal stomach. Reactive versus nonreactive nonstress test results were recorded, when performed. Neonatal outcomes were compared. RESULTS: Twenty-one fetuses had no evidence of gastric dilation. Thirteen fetuses had a dilated fetal stomach that was identified by ultrasound scanning. Within this group there was a higher incidence of nonreactive nonstress tests (P=.01). Infants with a prenatally dilated stomach had a higher incidence of volvulus and neonatal death, a significantly delayed time to full oral feeds, and a longer hospitalization than those infants who did not have a prenatally dilated stomach (P