Monocyte chemotactic protein-1 expression is increased in human gestational tissues during term and preterm labor.

OBJECTIVE: Microarray analysis was used to characterize the labor-selective transcriptome of the human myometrium during labor. One highly up-regulated transcript, monocyte chemotactic protein-1 (MCP-1), was further characterized. METHODS: Expression of MCP-1 was evaluated in the myometrium, the placenta, the gestational membranes (GM) and the amniotic fluid (AF) by real time RT-PCR, Northern blot analysis and ELISA. The level of immunoreactive (IR) MCP-1 content of primary myometrial cultures treated with inflammatory cytokines was quantified by ELISA. RESULTS: Up-regulation of the myometrial MCP-1 transcript in term laboring patients was demonstrated by microarray and confirmed by real time (RT)-PCR and Northern blot analysis. Increased MCP-1 transcripts were demonstrated in GM during term labor. The IR content of myometrial MCP-1 was increased during term labor and in the AF from patients experiencing preterm delivery. Levels of IR MCP-1 increased in myometrial cultures in response to interleukin 1-beta. CONCLUSION: The expression of myometrial MCP-1 was significantly increased during term labor and was similarly increased in vitro in response to interleukin 1-beta, a pro-inflammatory substance known to play a role in preterm birth. The increased IR content of MCP-1 within the AF preceding preterm delivery may render this protein a useful predictor of preterm birth.

Mid-trimester endovaginal sonography in women at high risk for spontaneous preterm birth.

CONTEXT: Although shortened cervical length has been consistently associated with spontaneous preterm birth, it is not known when in gestation this risk factor becomes apparent. OBJECTIVE: To determine whether sonographic cervical findings between 16 weeks' and 18 weeks 6 days' gestation predict spontaneous preterm birth and whether serial evaluations up to 23 weeks 6 days' gestation improve prediction in high-risk women. DESIGN, SETTING, AND PARTICIPANTS: Blinded observational study performed between March 1997 and November 1999 at 9 university-affiliated medical centers in the United States in 183 women with singleton gestations who previously had experienced a spontaneous birth before 32 weeks' gestation. OBSERVATION: Certified sonologists performed 590 endovaginal sonographic examinations at 2-week intervals. Cervical length was measured from the external os to the functional internal os along a closed endocervical canal. Funneling and dynamic cervical shortening were also recorded. MAIN OUTCOME MEASURE: Spontaneous preterm birth before 35 weeks' gestation, analyzed by selected cutoff values of cervical length. RESULTS: Forty-eight women (26%) experienced spontaneous preterm birth before 35 weeks' gestation. A cervical length of less than 25 mm at the initial sonographic examination was associated with a relative risk (RR) for spontaneous preterm birth of 3.3 (95% confidence interval [CI], 2.1-5.0; sensitivity = 19%; specificity = 98%; positive predictive value = 75%). After controlling for cervical length, neither funneling (P =.24) nor dynamic shortening (P =.054) were significant independent predictors of spontaneous preterm birth. However, using the shortest ever observed cervical length on serial evaluations, after any dynamic shortening, the RR of a cervical length of less than 25 mm for spontaneous preterm birth increased to 4.5 (95% CI, 2.7-7.6; sensitivity = 69%; specificity = 80%; positive predictive value = 55%). Compared with a single cervical measurement at 16 weeks' to 18 weeks 6 days' gestation, serial measurements at up to 23 weeks 6 days significantly improved the prediction of spontaneous preterm birth in a receiver operating characteristic curve analysis (P =.03). CONCLUSIONS: Cervical length assessed by endovaginal sonography between 16 weeks' and 18 weeks 6 days' gestation, augmented by serial evaluations, predicts spontaneous preterm birth before 35 weeks' gestation in high-risk women.

The future of intrapartum fetal pulse oximetry.

Fetal pulse oximetry has undergone a remarkable evolution since its conception over 10 years ago. A number of important observations, including the recent publication of a large randomized clinical trial, have provided further insight into our understanding of intrapartum fetal physiology and intrapartum fetal assessment. The purpose of this paper is to review significant developments in this technology over the past 2 years and to propose paths for future clinical research.

Changes in flow velocity, resistance indices, and cerebral perfusion pressure in the maternal middle cerebral artery distribution during normal pregnancy.

BACKGROUND: There are few longitudinal data currently available detailing the normal changes in maternal cerebral hemodynamics during human pregnancy. This lack of information limits the study of pregnancy-associated cerebrovascular adjustments and, in particular, preeclampsia, where the brain appears to be especially susceptible to ischemic and encephalopathic injury. Our objective was to define the hemodynamic changes, specifically velocity, resistance indices, and cerebral perfusion pressure, in the middle cerebral artery (MCA) distribution of the brain during normal pregnancy. METHODS AND MATERIALS: Transcranial Doppler ultrasound was used to determine the systolic, diastolic and mean blood velocities in the middle cerebral arteries in non-laboring women studied longitudinally during normal gestation. The resistance index (RI), pulsatility index (PI), and cerebral perfusion pressure (CPP) were calculated using the velocity and blood pressure data. Data were analyzed using a longitudinal statistical model incorporating random patient effects and a homoscedastic (compound symmetric) variance-covariance structure over time (gestational age). The predicted mean value (Least Squares Mean), and the 5th and 95th percentiles, were defined for normal pregnancy. RESULTS: MCA systolic velocity decreased (24%) as did the mean velocity (17%). The diastolic velocity did not change significantly. The MCA RI decreased by 19% and the PI decreased by 25%. The MCA CPP increased by 52% between 12 and 40 weeks of gestation. CONCLUSIONS: The normative ranges for MCA velocity, RI, and CPP have been defined in normal human pregnancy using longitudinally collected data. By having a defined normal range, identification of abnormalities in cerebral hemodynamics during pregnancy is now possible, and this may help researchers and clinicians to elucidate etiologies and treatments for pregnancy-related pathophysiologic states such as preeclampsia

A multicenter controlled trial of fetal pulse oximetry in the intrapartum management of nonreassuring fetal heart rate patterns.

OBJECTIVE: Recent developments permit the use of pulse oximetry to evaluate fetal oxygenation in labor. We tested the hypothesis that the addition of fetal pulse oximetry in the evaluation of abnormal fetal heart rate patterns in labor improves the accuracy of fetal assessment and allows safe reduction of cesarean deliveries performed because of nonreassuring fetal status. STUDY DESIGN: A randomized, controlled trial was conducted concurrently in 9 centers. The patients had term pregnancies and were in active labor when abnormal fetal heart rate patterns developed. The patients were randomized to electronic fetal heart rate monitoring alone (control group) or to the combination of electronic fetal monitoring and continuous fetal pulse oximetry (study group). The primary outcome was a reduction in cesarean deliveries for nonreassuring fetal status as a measure of improved accuracy of assessment of fetal oxygenation. RESULTS: A total of 1010 patients were randomized, 502 to the control group and 508 to the study group. There was a reduction of >50% in the number of cesarean deliveries performed because of nonreassuring fetal status in the study group (study, 4. 5%; vs. control, 10.2%; P =.007). However, there was no net difference in overall cesarean delivery rates (study, n = 147 [29%]; vs. control, 130 [26%]; P = .49) because of an increase in cesarean deliveries performed because of dystocia in the study group. In a blinded partogram analysis 89% of the study patients and 91% of the control patients who had a cesarean delivery because of dystocia met defined criteria for actual dystocia. There was no difference between the 2 groups in adverse maternal or neonatal outcomes. In terms of the operative intervention for nonreassuring fetal status, there was an improvement in both the sensitivity and the specificity for the study group compared with the control group for the end points of metabolic acidosis and need for resuscitation. CONCLUSION: The study confirmed its primary hypothesis of a safe reduction in cesarean deliveries performed because of nonreassuring fetal status. However, the addition of fetal pulse oximetry did not result in an overall reduction in cesarean deliveries. The increase in cesarean deliveries because of dystocia in the study group did appear to result from a well-documented arrest of labor. Fetal pulse oximetry improved the obstetrician's ability to more appropriately intervene by cesarean or operative vaginal delivery for fetuses who were actually depressed and acidotic. The unexpected increase in operative delivery for dystocia in the study group is of concern and remains to be explained.

The effect of fetal neck position on nuchal fold thickness.

OBJECTIVE: Our purpose was to determine whether ultrasonographic measurements of nuchal fold thickness are affected by the position of the fetal neck. STUDY DESIGN: Fetal nuchal fold thickness was prospectively measured in 258 women undergoing routine ultrasonography at 15 to 21 completed weeks of gestation. Patients with fetal structural or chromosomal anomalies were excluded. At the time of examination the position of the fetal head was noted as being extended or flexed on the basis of the angle between the spine and the base of the skull. Gestational age was based on menstrual dates or ultrasonographic biometric parameters. Data were tested for normality. Mann-Whitney U test and analysis of covariance were used (significance was considered to be P <.05). Data are presented as median and range. RESULTS: A total of 258 fetuses were examined with 167 (65%) in the flexed and 91 (35%) in the extended neck position. Gestational age was not significantly different between the flexed and extended groups (median, 19.1 weeks; range, 15.5-21.6 weeks; vs median, 19.1 weeks; range, 15.6-22 weeks; P =.23). Nuchal fold thickness was significantly lower in the flexed group than in the extended group (median, 3.5 mm; range, 1.3-6.2 mm; vs median, 3.9 mm; range, 2.2-4.9 mm; P =.0097). Nuchal fold thickness increased significantly with gestational age in both groups. The difference in nuchal fold thickness between the 2 groups persisted even after the increase in nuchal fold thickness was adjusted for with gestational age (P =.002, analysis of covariance). The difference between the 2 groups was higher at earlier gestations. CONCLUSION: Nuchal fold thickness is affected by gestational age and fetal neck position. Correction for these variables may improve the accuracy of nuchal fold thickness measurements in screening for fetal chromosomal anomalies.

Continuous intrapartum pH, pO2, pCO2, and SpO2 monitoring.

The goal of intrapartum surveillance and its further development is better patient care for both the fetus and the gravida. A normal FHR pattern is usually associated with the delivery of a normal well-oxygenated infant; however, a nonreassuring FHR is not always associated with the delivery of a compromised infant. This situation has led to an increase in unnecessary obstetric interventions in the form of a rising cesarean section rate. Fetal scalp sampling was developed in an attempt to improve the predictive value of electronic FHR monitoring, but because this technique is not widely used, management decisions are frequently made using FHR patterns alone. Much research has been performed in the search for a continuous biochemical measurement of fetal status, including continuous pH, pO2, or pCO2 and various combinations of these methodologies. None of these measurements are used in current clinical practice, mainly owing to technical problems and difficulties associated with the continuous direct measurement of these parameters in fetal blood throughout labor. The promising new field of fetal pulse oximetry has the potential to provide reliable, meaningful, and reproducible data as shown in early cross-sectional studies and more recent longitudinal studies. By identifying developing hypoxia, this technology may reduce the uncertainty associated with electronic FHR monitoring. Fetal pulse oximetry may also provide critical information relating to the detection and management of the hypoxic fetus. Any new method of intrapartum fetal monitoring requires careful evaluation to assess its potential value before its introduction into clinical practice. The use of fetal SpO2 monitoring in the presence of a nonreassuring FHR pattern is being examined in a multicenter randomized controlled trial. This study will address the question of whether supplementary monitoring of fetal SpO2 levels can lead to a reduction in the cesarean section rate for fetal distress. The available data on fetal noninvasive pulse oximetry have been obtained from a combination of well-designed cohort studies (level II-2 evidence) or from earlier multiple time series (level II-3 evidence). The results from the US Multicenter Trial (level I evidence) should provide a significant addition to current evidence. A continuous fetal noninvasive monitor measuring fetal oxygenation directly could lead to an improvement in the sensitivity and specificity of fetal surveillance. This improvement could ultimately result in a reduction in unnecessary interventions by differentiating hypoxic fetuses from nonhypoxic fetuses and, more importantly, may lead to earlier intervention for fetuses in danger of serious compromise.

Fetal pulse oximetry and other monitoring modalities. Future directions.

Although in the beginning phase of its use, the application of fetal oximetry in high-risk obstetrics is predicted to increase. Even at its early clinical application, patient data have shown that fetal oximetry has the excellent potential to be used with other fetal monitoring modalities to further characterize the metabolic state of the fetus, especially during labor. Similar to other monitoring modalities, the clinicians also need to be aware of its limitations.

Association of cerebral perfusion pressure with headache in women with pre-eclampsia.

OBJECTIVE: To study estimated cerebral perfusion pressure and its relation to headache and scotomata in women with pre-eclampsia. DESIGN: Prospective, observational study. SETTING: University teaching hospitals. POPULATION: Seventy-nine pre-eclamptic women with (n = 42) and without (n = 37) headache. Patients with scotomata were also studied separately. METHODS: Transcranial Doppler ultrasound was used to estimate the resistance index, pulsatility index, and estimated cerebral perfusion pressure in the middle cerebral artery. eCPP data were plotted on the same axes as the mean (and 5th and 95th% prediction limits) eCPP data from 63 normal pregnant women followed longitudinally through pregnancy. Data outside of the 95% prediction limits were regarded as abnormal. Data from the pre-eclamptic women were also expressed in terms of the number of standard deviations from the mean value established for normal pregnancy (multiples of the standard deviation: MOS). All studies were prior to labour, under similar conditions, and before volume expansion or treatment. Analysis of data was performed using Student's t test, Mann-Whitney U test, ANOVA, and Fisher's exact test with two-tailed P < 0.05, and receiver operating characteristic curve analysis with a one-tailed P < 0.05. MAIN OUTCOME MEASURES: Resistance index, pulsatility index, and eCPP. RESULTS: Pre-eclamptic women with headache were much more likely to have abnormal eCPP (34/42; 88%) than those without headache (18/37; 49%), P = 0.004, OR 4.5 (95% CI 1.5 to 13.9). There were no differences in terms of MOS in the resistance index or pulsatility index between the two groups, but estimated perfusion pressure, expressed as multiples of the standard deviation in the group with headache, was significantly higher than in the women without. Headache was noted in both over-perfusion and under-perfusion states. Only women with headache had scotomata, and their presence was not related to the severity of the headache or any difference in resistance indices or eCPP. CONCLUSIONS: Headache in women with pre-eclampsia is strongly associated with the presence of abnormal cerebral perfusion pressure. This information may be of use in clinical management.

The physiologic and medical rationale for intrapartum fetal monitoring.

In the United States and most industrialized countries, intrapartum fetal surveillance is performed primarily by electronic fetal heart rate monitoring. Following implementation of this technology into clinical practice, a reduction in perinatal mortality has been accompanied by a concomitant increase in the cesarean section rate to concerning levels. Although these trends are not solely due to one factor such as electronic fetal heart rate monitoring, it is well-recognized that this method of surveillance is hampered by subjectivity in interpretation and by a high false-positive (falsely nonreassuring) rate. The purpose of this review is to assess the physiologic rationale for intrapartum assessment, the significant limitations of current primary and ancillary monitoring methods, and the development of new technologies such as fetal oxygen saturation monitoring (pulse oximetry) that potentially hold great promise for the future.

Effects of blood pressure on orbital and middle cerebral artery resistances in healthy pregnant women and women with preeclampsia.

OBJECTIVE: The object of the study was to test the hypothesis that preeclampsia leads to an abnormal vascular response to increasing blood pressure in cerebral vessels by analyzing the relationship between mean arterial pressure and resistance index in the central retinal, ophthalmic, and middle cerebral arteries in women with normal pregnancies and women with preeclampsia. STUDY DESIGN: Transcranial and color flow Doppler ultrasonographic studies were used to determine systolic, diastolic, and mean velocities and the resistance indexes in the central retinal, ophthalmic, and middle cerebral arteries in 24 women with normal pregnancies and 18 women with preeclampsia. In each group the relationship between the mean arterial pressure and the resistance index was determined for each artery by means of linear regression analysis. The Pearson correlation coefficients for each mean arterial pressure versus resistance index relationship were compared between the groups. In a separate analysis middle cerebral artery data obtained from 79 women with preeclampsia (with and without headache) were compared with data from the normal pregnancy group and analyzed in terms of the relationship between mean arterial pressure and resistance index. RESULTS: The resistance index in women with normal pregnancies decreased with increasing mean arterial pressure in all 3 vessels studied (ophthalmic artery r = -0.33, central retinal artery r = -0. 43, middle cerebral artery r = -0.30). In the women with preeclampsia, however, as mean arterial pressure increased the resistance index increased in the orbital vessels and decreased in the middle cerebral artery (ophthalmic artery r = 0.54, central retinal artery r = 0.65, middle cerebral artery r = -0.25). The correlation coefficients in the women with preeclampsia were significantly different from those in the women with normal pregnancies for the ophthalmic and central retinal arteries (P =. 001) but not for the middle cerebral artery (P =.8). Within-group analysis in the patients with normal pregnancies showed no differences between the correlation coefficients of the studied vessels. In the women with preeclampsia the ophthalmic artery (P =. 02) and the central retinal artery (P =.005) were significantly different from the middle cerebral artery but not from each other. Women with preeclampsia who had headache had a different correlation coefficient for the middle cerebral artery than did those without headache (r = -0.34 versus r = 0.23; P <.001). The correlation coefficient for the middle cerebral artery for women with preeclampsia without headache was not significantly different from the central retinal artery and ophthalmic artery correlation coefficients in the general preeclampsia group. CONCLUSIONS: Women with preeclampsia demonstrate a different relationship between blood pressure and resistance index in the ophthalmic and central retinal arteries than do women with normal pregnancies. In the middle cerebral artery, however, preeclampsia does not appear to affect the resistance index response to increasing mean arterial pressure in women with headache. In women with preeclampsia without headache the relationship seen in the ophthalmic artery and central retinal artery is preserved in the middle cerebral artery. This may indicate a failure in the autoregulatory capacity of the middle cerebral artery in the presence of headache. Alternatively, the resistance index response in the ophthalmic artery and central retinal artery may represent small-caliber vessel vasospasm that is not present in the middle cerebral artery in women with preeclampsia who have headache.

Elevated second-trimester maternal serum hCG: a marker of inadequate angiogenesis.

OBJECTIVE: To measure angiogenin, a potent inducer of neovascularization and interleukin-6, as an indicator of acute inflammation, in second-trimester amniotic fluid of patients with elevated maternal serum hCG. METHODS: In this case-control study, 20 patients with elevated maternal serum hCG (at least 2.0 multiples of median) at triple screen were matched 2:1 with controls on the basis of year of amniocentesis, parity, and race. Inclusion criteria were 1) singleton gestation, 2) no evidence of anomalies, and 3) genetic amniocentesis. Amniotic fluid was immunoassayed for angiogenin and interleukin-6. The immunoassay sensitivity for angiogenin was 0.026 ng/mL, interassay coefficient of variation 4.6%, and intra-assay coefficient of variation 2.9%. For interleukin-6, the immunoassay sensitivity was 2.37 pg/mL, interassay coefficient of variation 2.7%, and intra-assay coefficient of variation 1.9%. Angiogenin and interleukin-6 values were normalized by using natural log transformation for statistical analysis. Statistical analysis included analysis of variance and stepwise regression, with P < .05 significant. RESULTS: After correcting (by multivariate regression) for gestational age at sampling and nulliparity, amniotic fluid angiogenin levels were significantly lower in the study subjects than in controls (26%+/-11% lower, P=.004), whereas the interleukin-6 levels did not change significantly (34%+/-40% lower, P=.3). CONCLUSION: Amniotic fluid angiogenin levels are significantly lower in patients with elevated maternal serum hCG at triple screen, suggesting inadequate angiogenesis, but interleukin-6 values do not differ significantly.

A prospective evaluation of fetal pericardial fluid in 506 second-trimester low-risk pregnancies.

OBJECTIVE: To measure fetal pericardial fluid in low-risk second-trimester pregnancies and to evaluate outcome for those with measurements greater than 2 mm. METHODS: Five hundred and six women were referred for sonography between 16 and 25 weeks' gestation for common obstetric indications (dating, fetal survey, and placental location) unrelated to an increased risk of anomalies. All cases were evaluated with two-dimensional and M-mode real-time ultrasonography with the use of a mechanical sector transducer. The maximum distance of the fetal hypoechoic cardiac rim was recorded. We reviewed maternal and infant charts for those with measurements greater than 2 mm. RESULTS: Median (range) maternal age was 25 (15-42) years. Median gravidity and parity were two (1-14) and one (0-11), respectively. Median estimated gestational age was 20.4 (16.3-24.9) weeks. Fetal pericardial fluid was seen in 360 of 506 (71%) fetuses. Of these 360 fetuses, the mean distance (+/- 2 standard deviation) of the fetal hypoechoic cardiac rim was 1.20 mm +/- 0.91 mm (95% confidence interval 1.15, 1.25). Among the 506 cases, the maximum measurement was 3 mm. Ten of the 506 (2%) cases had measurements greater than 2 mm. None of these ten fetuses had a cardiac structural abnormality or arrhythmia, and perinatal outcome was unremarkable. CONCLUSION: During second-trimester fetal ultrasonographic examination, visualization of pericardial fluid up to 2 mm in the fetus with current high-resolution technology is common and should not be regarded as pathologic.

Current status of the multicenter randomized clinical trial on fetal oxygen saturation monitoring in the United States.

Current clinical methods of intrapartum fetal assessment are sensitive but poorly specific in detecting fetal compromise during labor. These limitations have substantially contributed to the escalating cesarean section rate which occurred in the US during the last several decades. Experimental and clinical research efforts directed towards application of the oxygen saturation monitor (pulse oximeter) to intrapartum fetal assessment have produced encouraging results. If this new method of fetal assessment is to enter the clinical arena, safety and efficacy issues must first be properly evaluated via randomized clinical trials. The purpose of this report is to describe the design of a multicenter randomized clinical trial of intrapartum fetal oxygen saturation monitoring recently begun in the US. Specific aspects of the trial, including purpose, study design, sample size estimates, control and test groups, inclusion and exclusion criteria, fetal heart rate classification, definition of normal fetal arterial oxygen saturation (SpO2), clinical management protocol, and assessment of maternal-fetal outcomes will be addressed.

The efficacy of intrapartum fetal surveillance when fetal pulse oximetry is added to cardiotocography.

OBJECTIVE: To determine if oxygen saturation measurement with pulse oximetry (SpO2) in combination with cardiotocograghy (CTG), improves the assessment of the intrapartum fetal condition. STUDY DESIGN: Four expert obstetricians individually evaluated 119 cases that were monitored during labor: during the first session the CTG data were available, and in the second session CTG and SpO2 data were evaluated. They were instructed to indicate the need for intervention and to estimate the umbilical artery pH. RESULTS: In the non-acidotic group (umbilical artery pH > or = 7.15, n = 112) the average(+/-S.D.) number of interventions decreased from 27(+/-17) to 16(+/-9) when SpO2 was available. This reduction in number of interventions resulted in an significantly increased specificity for two referees. In the acidotic group (n = 7) the average number of interventions also decreased, from 6(+/-2) to 4(+/-2), and as a consequence the sensitivity decreased. The pH estimate based on CTG + SpO2 was higher in both acidotic and non-acidotic fetuses than the estimated pH based on CTG alone. CONCLUSION: In this study all referees intervened less frequently when SpO2 was used as an adjunct to CTG. This resulted in fewer unnecessary operative interventions, but may also lead to unidentified fetal acidosis. The number of acidotic newborns (n = 7) was too small, however, to draw definite conclusions. Larger studies should address the efficacy of SpO2 in detecting fetal compromise before clinical use can be advocated.

Prospective evaluation of the antenatal incidence and postnatal significance of the fetal echogenic cardiac focus: a case-control study.

OBJECTIVE: We evaluated the antenatal incidence and postnatal significance of echogenic cardiac foci observed during antenatal ultrasonography. STUDY DESIGN: During a 4-month period, all women undergoing dating ultrasonography between 16.0 and 24.9 weeks' gestation at one referral center were prospectively evaluated for an echogenic cardiac focus during an apical four-chamber view of the heart. Referrals for maternal or fetal complications were excluded. Postnatal echocardiography was performed for those identified with positive findings. Controls were selected from among normal subjects in the general group for comparison with the study group. RESULTS: Five hundred six consecutive fetuses were evaluated at a mean +/- SD gestational age of 20.6 +/- 1.6 weeks. There were 25 (4.9%) fetuses found to have echogenic cardiac focus (left ventricle = 19, right ventricle = 6). Echocardiography was performed between 0.3 and 20.1 weeks postdelivery. After birth, 12 echogenic left ventricle papillary muscles and three echogenic left ventricle chordae were identified; there were no postnatal right ventricle findings. There were no cases of intracardiac tumor or myocardial dysfunction; one neonate had minor structural malformations. There were no significant differences in maternal age, gravidity, parity, gestational age at ultrasonography, gestational age at delivery, or 5-minute Apgar scores. A significant difference was observed in birth weight between the control (n = 50) and study (n = 25) groups (3465 +/- 501 gm vs 3124 +/- 589 gm; p = 0.002). This difference persisted after correcting for gestational age, although all infants in both groups born after 37.0 weeks weighed > 2500 gm. CONCLUSIONS: The incidence of echogenic cardiac foci during routine midtrimester ultrasonography is 4.9%. As an isolated finding, the echogenic cardiac focus may be associated with a statistically significant but clinically insignificant decrease in birth weight. Because of these findings, we consider an isolated echogenic cardiac focus in a patient at low risk for cardiac abnormalities a variant of normal, which does not warrant follow-up clinical evaluation.

Umbilical cord blood gas analysis at delivery.

Fetal acid-base status is the end point that all antepartum and intrapartum surveillance tools are designed to assess, either directly or indirectly. Umbilical arterial blood pH is normal in 80% of depressed newborns, thereby proving the absence of birth asphyxia both in the delivery room and in the courtroom. The technique, normal ranges, and risks, benefits and cost analysis of routine versus selected umbilical blood sampling are considered. The American College of Obstetricians and Gynecologists recommends performing umbilical blood sampling for acid-base analysis in selected deliveries. However, in our opinion routine umbilical blood sampling at all deliveries has merit.