Three-dimensional ultrasound detection of abnormally located intrauterine contraceptive devices which are a source of pelvic pain and abnormal bleeding

OBJECTIVE

To determine whether intrauterine contraceptive devices (IUDs) that are located abnormally within the myometrium or cervix cause a higher incidence of pelvic pain and abnormal bleeding compared with normally positioned devices.

METHODS

Over a period of 9 months, all patients with an IUD presenting at our unit for two-dimensional pelvic ultrasound underwent a three-dimensional (3D) volume reconstruction of the coronal view, to visualize the entire IUD within the cavity. The IUD was deemed malpositioned if any part extended past the cavity, into the myometrium or cervix. The indications for ultrasound were recorded at presentation for the exam. The presenting symptoms of patients with an abnormally located IUD were compared with those with normally positioned ones.

RESULTS

Among 167 consecutive patients with an IUD evaluated using the 3D reconstructed coronal view, 28 (16.8%) had an IUD with side arms abnormally located within the myometrium. The abnormal positioning of the IUD arms was only detected using the 3D coronal view. A higher proportion of patients with an abnormally located IUD presented with bleeding (35.7%) or pain (39.3%) compared with those with normally positioned IUDs (15.1% with bleeding and 19.4% with pain) (P = 0.02 and 0.03, respectively). Seventy-five percent of patients with an abnormally located IUD presented with bleeding or pain compared with 34.5% of those whose IUD was normally placed (P = 0.0001). Twenty of 21 patients with an abnormally located IUD presenting with pelvic pain or bleeding reported improvement in their symptoms after IUD removal.

CONCLUSION

A 3D coronal view of the uterus is useful in the visualization of IUDs. The coronal view showing the entire device and its position within the uterus may help in identifying the cause of pelvic pain and bleeding in patients with an embedded IUD.

Three-dimensional prenatal diagnosis of frontonasal malformation and unilateral cleft lip/palate

Frontonasal malformation includes a spectrum of anomalies involving the eyes, nose, lips, forehead and brain. We present a case in which a fetal labial cleft was initially identified using traditional two-dimensional sonography. Three-dimensional sonography with multiplanar reconstruction and surface-rendering were essential to establish the diagnosis of frontonasal malformation with severe nasal hypoplasia and unilateral complete cleft lip/palate.

Outcomes of trial of labor following previous cesarean delivery among women with fetuses weighing >4000 g

OBJECTIVE

To compare outcomes at term of a trial of labor in women with previous cesarean delivery who delivered neonates weighing > 4000 g versus women with those weighing < or = 4000 g.

STUDY DESIGN

We reviewed medical records for all women undergoing a trial of labor after prior cesarean delivery during a 12-year period. The current analysis was limited to women at term with one prior cesarean and no other deliveries. The rates of cesarean delivery and symptomatic uterine rupture for women with infants weighing > 4000 g were compared to the rates for women with infants weighing < or = 4000 g. Logistic regression was used to control for the potential confounding by use of epidural, maternal age, labor induction, labor augmentation, indication for previous cesarean, type of uterine hysterotomy, year of delivery, receiving public assistance, and maternal race. Adjusted odds ratios and 95% confidence intervals were calculated.

RESULTS

Of 2749 women, 13% (365) had infants with birth weights > 4000 g. Cesarean delivery rate associated with birth weights < or = 4000 g was 29% versus 40% for those with birth weights > 4000 g (P = .001). With use of logistic regression, we found that birth weight > 4000 g was associated with a 1.7-fold increase in risk of cesarean delivery (95% CI, 1.3-2.2). The rate of uterine rupture for women with infants weighing < or = 4000 g was 1.0% versus a 1.6% rate for those with infants weighing > 4000 g (P = .24). Although the logistic regression analysis revealed a somewhat higher rate of uterine rupture associated with birth weights of > 4000 g (adjusted OR, 1.6; 95% CI, 0.7-4.1), this difference was not statistically significant. The rate of uterine rupture was 2.4% for women with infants weighing > 4250 g, but this rate did not differ significantly from the rate of uterine rupture associated with birth weights < or = 4250 g (P = .1).

CONCLUSION

A trial of labor after previous cesarean delivery may be a reasonable clinical option for pregnant women with suspected birth weights of > 4000 g, given that the rate of uterine rupture associated with these weights does not appear to be substantially increased when compared to lower birth weights. However, some caution may apply when considering a trial of labor in women with infants weighing > 4250 g. In these women with infants weighing > 4000 g, the likelihood of successful vaginal delivery, although lower than for neonates weighing < or = 4000 g, is still 60%.

The use of helical computed tomography in pregnancy for the diagnosis of acute appendicitis

OBJECTIVE

Accurate diagnosis of acute appendicitis in pregnancy by clinical evaluation is difficult. A safe, reliable test was sought to decrease a delay in diagnosis and to avoid unnecessary invasive procedures. A helical or spiral computed tomographic technique has proven to be a very accurate test in the nonobstetric population for the identification of acute appendicitis. We report its use in pregnant patients with suspected acute appendicitis.

STUDY DESIGN

All pregnant patients who were undergoing helical computed tomography at our institution from April 1997 to February 1998 for the suspected clinical diagnosis of acute appendicitis were retrospectively reviewed. Helical computed tomography was performed by standard departmental protocol. A positive study was reported if an enlarged appendix, which did not fill with contrast material, was present with periappendiceal inflammatory changes. Outcomes were determined by the results of surgery and pathologic examination or clinical follow-up.

RESULTS

Seven patients were identified in the study period. Two patients had positive findings on helical computed tomography, and acute appendicitis was confirmed at laparotomy and by pathologic inspection. There were no further prenatal complications and both patients delivered at term. Five patients had a normal-appearing appendix on helical computed tomography, and all of these patients had resolution of their pain and symptoms.

CONCLUSION

Helical computed tomography appears to be a useful, noninvasive test to accurately diagnose acute appendicitis in pregnancy.

Trial of labor after 40 weeks' gestation in women with prior cesarean

OBJECTIVE

To compare outcomes in women with prior cesareans delivering at or before 40 weeks' gestation with those delivering after 40 weeks.

METHODS

We reviewed labor outcomes over 12 years at one institution for women with one prior cesarean and no other deliveries who had a trial of labor at term. We analyzed the rates of symptomatic uterine rupture and cesarean for term deliveries before or after 40 weeks and stratified for spontaneous and induced labor. Potential confounding by birth weight was controlled using logistic regression. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated.

RESULTS

Of 2775 women with one prior scar and no other deliveries, 1504 delivered at or before 40 weeks and 1271 delivered after 40 weeks. For spontaneous labor, rupture rate at or before 40 weeks was 0.5% compared with 1.0% after 40 weeks (P =.2, adjusted OR 2.1, CI 0.7, 5.7). For induced labor, uterine rupture rates were 2.1% at or before 40 weeks and 2.6% after 40 weeks (P =.7, adjusted OR 1.1, CI 0.4, 3.4). For spontaneous labor, rate of cesareans during subsequent trials of labor at or before 40 weeks was 25% compared with 33.5% after 40 weeks (P =.001, adjusted OR 1.5, CI 1.2, 1.8). For induced labor, rate of cesareans during subsequent trials of labor at or before 40 weeks was 33.8% compared with 43% after 40 weeks (P =.03, adjusted OR 1.5, CI 1.1, 2.2).

CONCLUSION

The risk of uterine rupture does not increase substantially after 40 weeks but is increased with induction of labor regardless of gestational age. Because spontaneous labor after 40 weeks is associated with a cesarean rate similar to that following induced labor before 40 weeks, awaiting spontaneous labor after 40 weeks does not decrease the likelihood of successful vaginal delivery.

Oxytocin dose and the risk of uterine rupture in trial of labor after cesarean

OBJECTIVE

To examine the association between uterine rupture and oxytocin use in trial of labor after cesarean.

METHODS

A case-control study was performed. Cases were all women with uterine ruptures who received oxytocin during a trial of labor after a single cesarean delivery within a 12-year period (n = 24). Four controls undergoing trial of labor after a single cesarean delivery were matched to each case by 500 g birth weight category, year of birth, and by induction or augmentation (n = 96). The study had an 80% power to detect a 40% increase in oxytocin duration or a 65% increase in total oxytocin dose.

RESULTS

No significant differences were seen in initial oxytocin dose, maximum dose, or time to maximum dose. Although women with uterine ruptures had higher exposure to oxytocin as measured by mean total oxytocin dose (544 mU higher) and oxytocin duration (54 minutes longer), these differences were not statistically significant. Women with uterine rupture who received oxytocin were more likely to have experienced an episode of uterine hyperstimulation (37.5% compared with 20.8%, P =.05). However, the positive predictive value of hyperstimulation for uterine rupture was only 2.8%.

CONCLUSION

Although no significant differences in exposure to oxytocin were detected between cases of uterine rupture and controls, the rarity of uterine rupture limited our power to detect small differences in exposure. In women receiving oxytocin, uterine rupture is associated with an increase in uterine hyperstimulation, but the clinical value of hyperstimulation for predicting uterine rupture is limited.

Variation in fetal femur length with respect to maternal race

We sought to evaluate whether the expected fetal femur length, based on biparietal diameter, varies in second-trimester fetuses with respect to maternal race. The study population was composed of all fetuses scanned from 15 to 20 completed weeks' gestation during a 2-month period (June to August 1998). Maternal race was documented at the time of the ultrasonographic examination. Biparietal diameter and femur length were prospectively documented. The variance from the expected femur length, given the biparietal diameter, was calculated, and the mean variations were compared according to maternal race. The study subgroups were composed of the fetuses of 39 Asian mothers, 31 black mothers, and the first 100 white mothers. The mean values of the variance from the expected fetal femur length by biparietal diameter +/- 1 SD for the various racial groups were as follows: fetuses of Asian mothers, -0.66 +/- 1.64 mm; fetuses of black mothers, 0.88 +/- 1.57 mm; and fetuses of white mothers, 0.13 +/- 1.66 mm (P = .0007). To isolate the differences among the 3 racial groups, the mean values of the variance from the expected femur length by biparietal diameter for the fetuses of Asian and black mothers were compared with the mean value for the fetuses of white mothers (Asian versus white mothers, P = .014; black versus white mothers, P = .026). A significant difference in the mean variance from the expected femur length by biparietal diameter was identified among the fetuses of women in the second trimester with respect to racial group. Less-than-expected femur lengths were noted among the fetuses of Asian mothers, and greater-than-expected femur lengths were noted among the fetuses of black mothers, compared with the femurs of fetuses of white mothers. The implications for the use of fetal femur length as a component of the genetic sonogram in patients of various races require further study.

Interdelivery interval and risk of symptomatic uterine rupture

OBJECTIVE

To relate interdelivery interval to risk of uterine rupture during a trial of labor after prior cesarean delivery.

METHODS

We reviewed the medical records of all women who had a trial of labor after cesarean delivery over 12 years (July 1984 to June 1996). Analysis was limited to women with only one prior cesarean delivery and no prior vaginal deliveries who delivered term singletons and whose medical records included the month and year of the prior delivery. The time in months between the prior cesarean delivery and the index trial of labor was calculated, and the women were divided accordingly to permit comparison with respect to symptomatic uterine rupture.

RESULTS

Two thousand four hundred nine women had trials of labor after one prior cesarean delivery and had complete data from the medical records. There were 29 uterine ruptures (1.2%) in the population. For interdelivery intervals up to 18 months, the uterine rupture rate was 2.25% (seven of 311) compared with 1.05% (22 of 2098) with intervals of 19 months or longer (P =.07). Multiple logistic regression was used to assess the risk of uterine rupture according to interdelivery interval while controlling for maternal age, public assistance, length of labor, gestational age at least 41 weeks, and oxytocin use. Women with interdelivery intervals of up to 18 months were three times as likely (95% confidence interval, 1.2, 7.2) to have symptomatic uterine rupture.

CONCLUSION

Interdelivery intervals of up to 18 months were associated with increased risk of symptomatic uterine rupture during a trial of labor after cesarean delivery compared with that for longer interdelivery intervals.

Effect of previous vaginal delivery on the risk of uterine rupture during a subsequent trial of labor

OBJECTIVE

We examined the effect of prior vaginal delivery on the risk of uterine rupture in pregnant women undergoing a trial of labor after prior cesarean delivery.

STUDY DESIGN

The medical records of all pregnant women with a history of cesarean delivery who attempted a trial of labor during a 12-year period at a single center were reviewed. For the current analysis, the study population was limited to term pregnancies. The effect of previous vaginal delivery on the risk of uterine rupture during a subsequent trial of labor was evaluated. Separate analyses were performed for women with a single previous cesarean delivery and for those with >1 prior cesarean delivery. For each of these subgroups, the rate of uterine rupture among women who had > or =1 prior vaginal delivery was compared with the rate among women with no prior vaginal delivery. Logistic regression analysis was used to examine the associations with control for confounding factors.

RESULTS

Of 3783 women with 1 prior scar, 1021 (27.0%) also had > or =1 prior vaginal delivery. During a subsequent trial of labor, the rate of uterine rupture was 1.1% among pregnant women without prior vaginal delivery and 0.2% among pregnant women with prior vaginal delivery (P =.01). Logistic regression analysis controlling for duration of labor, induction, birth weight, maternal age, year of birth, epidural analgesia, and oxytocin augmentation indicated that, among women with a single scar, those with a prior vaginal delivery had a risk of uterine rupture that was one fifth that of women without a previous vaginal delivery (odds ratio, 0.2; 95% confidence interval, 0.04-0.8). In the group of 143 pregnant women with >1 previous cesarean delivery, women with a prior vaginal delivery had a somewhat lower risk of uterine rupture (3.9% vs 2.5%; adjusted odds ratio, 0.6; 95% confidence interval, 0.01-6.7). This difference was not statistically significant.

CONCLUSION

Among women with 1 prior cesarean delivery undergoing a subsequent trial of labor, those with a prior vaginal delivery were at substantially lower risk of uterine rupture than women without a previous vaginal delivery.

Isolated polydactyly: prenatal diagnosis and perinatal outcome

Our objective was to determine the clinical significance of isolated polydactyly identified on prenatal sonogram. All patients with sonographically detected isolated polydactyly scanned over an 11-year period were identified from our database. All patients underwent detailed surveys, and follow-up was obtained by review of the medical records and telephone conversations with parents and referring physicians. Thirteen patients with isolated polydactyly were identified. Follow-up was available in 12 patients. Indications for referral included advanced maternal age (2), second-opinion polydactyly (4), family history of polydactyly (1), uncertain dates (5), and growth (1). The gestational ages at the times of sonographic diagnosis ranged from 17.5 to 34 weeks with all but one case being identified before 23 weeks. Prenatal identification included polydactyly of the upper limb (8), lower limb (4), and both upper and lower limbs (1). Postaxial polydactyly was seen in 12 patients and preaxial in one. Polydactyly was confirmed in all 12 cases in which follow-up was available. Karyotypes were normal in all five fetuses in which amniocentesis was performed. Ten of 12 fetuses were born alive, one died in utero at 34 weeks as a complication of severe pre-eclampsia and one died at term as a result of a cord accident. No surviving neonate had any other identifiable malformation or suspected karyotypic abnormality. In conclusion isolated polydactyly identified by prenatal sonography is associated with good perinatal outcome.

Adenomyosis: sonographic findings and diagnostic accuracy

The purposes of this study were to evaluate the accuracy of pelvic sonography in identification of adenomyosis and to characterize the most commonly seen sonographic features. We identified all patients over a 10 year period in whom a prospective diagnosis of adenomyosis was suspected on the basis of sonographic findings and who had undergone hysterectomy at a single hospital. Patients were referred for sonography based on standard indications. Sonographic features used in the diagnosis of adenomyosis consisted of two or more of the following: a mottled inhomogeneous myometrial texture, globular appearing uterus, small cystic spaces within the myometrium, and a "shaggy" indistinct endometrial stripe. Correlation was made with the pathology report on the hysterectomy specimen. Fifty-one women met the study criteria. Forty-three of 51 (84.3%) patients sonographically suspected of having adenomyosis were confirmed as having adenomyosis by pathologic examination. All patients with adenomyosis had a mottled heterogeneous appearing uterus, 95% had a globular uterus, 82% had small myometrial lucent areas, and 82% had an indistinct endometrial stripe. Eight patients (15.6%) who had been suspected of having adenomyosis by pelvic sonography did not have adenomyosis reported in the pathology specimen. Six of these eight (75%) patients had multiple small fibroids, one had stage IV endometriosis, and one had a normal uterine specimen with no evidence of pathology. Pelvic sonography provides an accurate diagnosis of adenomyosis in the majority of cases.

The frequency of the detection of fetal echogenic intracardiac foci with respect to maternal race

OBJECTIVE

To determine if there is a racial difference in the frequency of identification of echogenic intracardiac foci (EIF) seen sonographically in the hearts of second-trimester fetuses.

METHODS

Over a 2-month period (June 1998-August 1998), all fetuses scanned between 15 and 20 completed weeks' gestation were evaluated prospectively for the presence or absence of EIF. Pregnancies specifically referred for the presence of EIF were excluded. The sonographer performing the scan indicated maternal race as Asian, black, white, or (if maternal race was not clear) unknown. Maternal race, gestational age, and the presence or absence of EIF were prospectively documented. Follow-up of those fetuses with EIF was obtained from the referring physicians' offices. The groups were compared with respect to maternal race and presence or absence of EIF.

RESULTS

There were 46, 34, 400, and nine fetuses of the Asian, black, white, and unknown mothers, respectively. The mean gestational age +/- 1 SD at examination was 18.2 +/- 1.6, 17.5 +/- 1.4, 17.7 +/- 1.5, and 17.8 +/- 1.1 weeks, for the Asian, black, white, and unknown mothers, respectively. The incidence of sonographically detected EIF was 30.4, 5.9, 10.5 and 11.1% for the Asian, black, white, and unknown mothers, respectively, P = 0.001. In a multivariate logistic regression model, Asian mothers had an odds ratio of 3.8 (95% CI, 1.8, 7.6) for having a fetus identified as having EIF, as compared with white mothers.

CONCLUSIONS

The Asian patient is more likely than patients of other races to have a fetus with identified EIF. The counseling implications for Asian mothers undergoing midtrimester sonography when EIF is identified should be tempered, due to the increased frequency of EIF as a normal finding in the Asian population.

Labor after previous cesarean: influence of prior indication and parity

OBJECTIVE

To determine whether the risk of cesarean for women who had trials of labor after one prior cesarean differs from that of nulliparas overall and by indications for those cesareans.

METHODS

We reviewed medical records of women who had trials of labor after cesareans between July 1984 and June 1996, and of nulliparas who delivered between December 1994 and August 1995. Cesarean rates for women with prior cesareans were compared with the rates for nulliparas overall and by prior cesarean indication (breech, failure to progress, nonreassuring fetal testing, or other). Lengths of labor for women who had repeat cesareans for failure to progress in index pregnancies were compared by prior cesarean indication.

RESULTS

The cesarean rate was 28.7% (634 of 2207) for the prior cesarean group and 13.5% (219 of 1617) for nulliparas (P =.001), and varied according to the prior cesarean indication (13.9%, 37.3%, 25. 4%, and 24.8% for breech, failure to progress, nonreassuring fetal testing, and other, respectively). Mean durations of labor in the index pregnancies for women who had cesareans for failure to progress were 13.9, 11.5, 13.4, and 15.1 hours for breech, failure to progress, nonreassuring fetal testing, and other, respectively.

CONCLUSION

Overall rates of cesareans were higher for women with one prior cesarean than for nulliparas. Rates of cesareans after trials of labor were related to the prior cesarean indications. Rates were highest for women whose prior cesareans were for failure to progress and lowest for women whose prior cesareans were for breech. The latter group had a rate that was essentially identical to that of nulliparas. Among women with cesareans for failure to progress in index pregnancies, lengths of labor were shorter for those whose prior cesareans were for failure to progress than for those whose prior cesareans were for other indications, suggesting that physicians may intervene earlier in these cases.

The prognostic significance of hyperextension of the fetal head detected antenatally with ultrasound

OBJECTIVES

The purpose of this study was to evaluate the clinical significance of hyperextension of the fetal head detected by ultrasound prior to the onset of labour.

METHODS

Over a 10-year period, we retrospectively identified all fetuses who had hyperextension of the fetal head reported on antenatal ultrasound. Hyperextension referred to persistence of the cervical spine in extreme extension, with an extension angle of at least 150 degrees persisting for the duration of the scan. Follow-up information was obtained from Hospital medical records and obstetrical care providers.

RESULTS

Follow-up was obtained on 57 of the 65 fetuses (87.7%) identified over the study period. Ten of the 57 fetuses had normal structural fetal surveys and had sonographically identified resolution prior to delivery. All 10 patients delivered at term and had newborns with normal neonatal courses. Twenty-six of 57 fetuses had no sonographic findings other than persistent hyperextension, and 19 of these 26 fetuses (73%) had normal neonatal courses. Twenty-one of 57 fetuses (37%) had structural anomalies sonographically identified in addition to hyperextension of the fetal head. All 21 of these pregnancies ended in either termination or fetal or neonatal demize.

CONCLUSIONS

Although resolution of isolated hyperextension of the fetal head is associated with a normal neonatal outcome, persistent isolated hyperextension of the fetal head can be associated with either a normal or an abnormal neonatal outcome. Fetuses with hyperextended heads and antenatally diagnosed structural anomalies have dismal outcomes. The identification of a fetus with hyperextension of the fetal head should prompt a detailed search for structural abnormalities.

Is a full bladder still necessary for pelvic sonography?

The objective was to determine whether a full bladder is routinely necessary for a complete sonographic evaluation of the female pelvis. Over the course of 1 month, all women having a gynecologic sonogram were scanned initially transabdominally through a full bladder by the sonographer (standard images taken). A physician then joined the sonographer and scanned the patient transvaginally without prior knowledge of the findings seen transvesically. The physician finished the examination transabdominally, with the bladder empty. The physician and sonographer then determined (1) whether the scan was sufficient transvaginally only, (2) whether the scan was sufficient transvaginally and transabdominally with an empty bladder, or (3) or whether a full bladder was necessary. Two hundred and six consecutive patients were scanned prospectively. The transvaginal scan alone was sufficient to demonstrate all findings for 172 (83.5%) patients. The transvaginal and transabdominal scans through an empty bladder were needed for 31 (15.1%) patients. Three patients (1.5%) required a full bladder in addition to the other two techniques to visualize one normal ovary each. In conclusion, transvaginal scanning with an adjunctive transabdominal empty bladder approach can replace the full bladder technique for routine pelvic sonography. The transabdominal scan with an empty bladder is necessary, particularly for patients with enlarged uteri. It is no longer reasonable, however, to subject all patients undergoing pelvic sonography to bladder distention.

The sonographic diagnosis of Dandy-Walker and Dandy-Walker variant: associated findings and outcomes

Outcomes of pregnancies with sonographically diagnosed Dandy-Walker (DW) or Dandy-Walker variant (DWV) syndromes vary widely. We examined our own experience with these diagnoses in an effort to identify those sonographic features that best predicted neonatal outcome. We identified 50 fetuses with DW and 49 with DWV diagnosed sonographically. Eighty-six per cent of fetuses with DW and 85% of fetuses with DWV had other sonographically identifiable anomalies, the most common being ventriculomegaly (DW: 32%; DWV: 27%) and cardiac defects (DW:38%; DWV: 41%). Forty-six per cent and 36% of available karyotypes in cases of DW and DWV, respectively, were abnormal. 50 out of 99 women in our series elected pregnancy termination. Only three pregnancies with DW resulted in a living infant, and only one of these had a normal paediatric examination at six-week follow-up. Thirteen out of 49 infants with DWV survived the neonatal period and 7 of 13 were reported initially as normal infants, including six with an isolated finding of DWV. We conclude that overall, the prognosis for these posterior fossa defects is grim but not uniformly fatal. The presence of other anomalies is associated with the worst prognosis. Isolated Dandy-Walker variant has the highest chance of leading to a normal neonate.

Amnion-chorion separation after 17 weeks' gestation

OBJECTIVE

To evaluate the cause of and perinatal outcomes of amnion-chorion separation that is apparent sonographically after 17 weeks' gestation.

METHODS

We searched our ultrasound database over 7 years for information on pregnant women who had live fetuses and complete separation between amnion and chorion that persisted beyond 17 weeks' gestation. For inclusion in the study, the women had to have amnion separated from chorion on at least three sides of the gestational sac. Medical records were reviewed for whether women had amniocenteses, results of the amniocenteses, and outcomes of the pregnancies.

RESULTS

Of 15 pregnant women with live fetuses, ten had amniocenteses before identification of amnion-chorion separation and five did not. Three had fetuses with Down syndrome, two of whom had amnion-chorion separation evident before amniocentesis, and all three had other sonographic findings suggestive of aneuploidy. Three fetuses died. The other pregnancies were complicated by one or more adverse events, including two fetuses with growth restriction, five preterm deliveries, two with oligohydramnios, and one with abruptio placentae. Five infants were delivered at term and are alive and well. Overall, ten of 15 pregnancies resulted in live newborns, one of whom had Down syndrome.

CONCLUSION

Complete amnion-chorion separation that persisted after 17 weeks' gestation is associated with a variety of adverse perinatal outcomes, including aneuploidy.

Intrapartum uterine rupture and dehiscence in patients with prior lower uterine segment vertical and transverse incisions

OBJECTIVE

To determine whether gravidas with prior low vertical uterine incision(s) are at a higher risk for uterine rupture during a trial of labor after cesarean delivery than women with prior low transverse uterine incision(s).

METHODS

The medical records of women undergoing a trial of labor after prior cesarean delivery over a 12-year period (July 1984-June 1996) at a tertiary-care hospital were reviewed. Maternal and perinatal outcomes for women with prior low transverse and low vertical incision were compared. Women whose low vertical incision was noted to extend into the corpus of the uterus were excluded. All uterine scar disruptions, which included both symptomatic ruptures and detected asymptomatic dehiscences, were analyzed together, and ruptures were examined separately.

RESULTS

The outcomes of 2912 patients undergoing trial of labor for the low transverse group and 377 patients undergoing trial of labor for the low vertical group were compared. Overall, there were 38 (1.3%) scar disruptions in the low transverse group and six (1.6%) in the low vertical group, P = .6. There were 28 (1.0%) symptomatic ruptures in the low transverse group and 3 (0.8%) in the low vertical group, P > .999. The study had a power of 80% to detect an increase in the low vertical rupture rate from 1% (as noted for low transverse incisions) to 3%.

CONCLUSION

Gravidas with a prior low vertical uterine incision are not at increased risk for uterine rupture during a trial of labor compared with women with a prior low transverse uterine incision.

Uterine rupture during induced or augmented labor in gravid women with one prior cesarean delivery

OBJECTIVE

Our purpose was to examine the risk of uterine rupture during induction or augmentation of labor in gravid women with 1 prior cesarean delivery.

STUDY DESIGN

The medical records of all gravid women with history of cesarean delivery who attempted a trial of labor during a 12-year period at a single center were reviewed. The current analysis was limited to women at term with 1 prior cesarean delivery and no other deliveries. The rate of uterine rupture in gravid women within that group undergoing induction was compared with that in spontaneously laboring women. The association of oxytocin induction, oxytocin augmentation, and use of prostaglandin E(2) gel with uterine rupture was determined. Logistic regression analysis was used to examine these associations, with control for confounding factors.

RESULTS

Of 2774 women in the analysis, 2214 had spontaneous onset of labor and 560 women had labor induced with oxytocin or prostaglandin E(2) gel. The overall rate of rupture among all patients with induction of labor was 2.3%, in comparison with 0.7% among women with spontaneous labor (P =.001). Among 1072 patients receiving oxytocin augmentation, the rate of uterine rupture was 1.0%, in comparison with 0.4% in nonaugmented, spontaneously laboring patients (P =.1). In a logistic regression model with control for birth weight, use of epidural, duration of labor, maternal age, year of delivery, and years since last birth, induction with oxytocin was associated with a 4.6-fold increased risk of uterine rupture compared with no oxytocin use (95% confidence interval, 1.5-14.1). In that model, augmentation with oxytocin was associated with an odds ratio of 2.3 (95% confidence interval, 0.8-7.0), and use of prostaglandin E(2) gel was associated with an odds ratio of 3.2 (95% confidence interval, 0.9-10.9). These differences were not statistically significant.

CONCLUSION

Induction of labor with oxytocin is associated with an increased rate of uterine rupture in gravid women with 1 prior uterine scar in comparison with the rate in spontaneously laboring women. Although the rate of uterine rupture was not statistically increased during oxytocin augmentation, use of oxytocin in such cases should proceed with caution.

Rate of uterine rupture during a trial of labor in women with one or two prior cesarean deliveries

OBJECTIVE

We sought to determine whether there is a difference in the rate of symptomatic uterine rupture after a trial of labor in women who have had 1 versus 2 prior cesarean deliveries.

STUDY DESIGN

The medical records of all women with a history of either 1 or 2 prior cesarean deliveries who elected to undergo a trial of labor during a 12-year period (July 1984-June 1996) at the Brigham and Women's Hospital were reviewed. Rates of uterine rupture were compared for these 2 groups. Potential confounding variables were controlled by using logistic regression analyses.

RESULTS

Women with 1 prior cesarean delivery (n = 3757) had a rate of uterine rupture of 0.8%, whereas women with 2 prior cesarean deliveries (n = 134) had a rate of uterine rupture of 3.7% (P =.001). In a logistic regression analysis that was controlled for maternal age, use of epidural analgesia, oxytocin induction, oxytocin augmentation, the use of prostaglandin E(2) gel, birth weight, gestational age, type of prior hysterotomy, year of trial of labor, and prior vaginal delivery, the odds ratio for uterine rupture in those patients with 2 prior cesarean deliveries was 4.8 (95% confidence interval, 1.8-13. 2)

CONCLUSIONS

Women with a history of 2 prior cesarean deliveries have an almost 5-fold greater risk of uterine rupture than those with only 1 prior cesarean delivery.

Does the 10-MHz transvaginal transducer improve the diagnostic certainty that an intrauterine fluid collection is a true gestational sac?

PURPOSE

We studied whether a 10-MHz transvaginal transducer improves the diagnostic certainty that a small intrauterine fluid collection is a true gestational sac.

METHODS

Over a 6-week period, women who presented with a positive pregnancy test and a fluid collection (devoid of any characteristics such as yolk sac or fetal pole) in the uterus seen with a standard 6-7-MHz transvaginal transducer were entered in the study. The patients were immediately rescanned with a 10-MHz transvaginal probe, and characteristics of the fluid collection using this probe were noted. Specifically, the visualization of a yolk sac or the intradecidual or double decidual sign was considered an objective improvement in the certainty that the fluid collection was a gestational sac.

RESULTS

Twelve patients presented with a positive pregnancy test and a fluid collection in the uterus seen with a 6-7-MHz probe. Eight of these fluid collections were smaller than 1 cm in mean diameter, and all 8 of these patients had an objective improvement in the diagnosis of an intrauterine pregnancy using the 10-MHz probe. The other 4 patients had fluid collection 1-2 cm in mean diameter seen at 6-7 MHz. The 10-MHz probe improved the diagnostic confidence in 2 of these 4 patients.

CONCLUSIONS

In patients with early pregnancies who have questionable gestational sacs on sonography with standard 6-7-MHz transducers, the 10-MHz probe improves the diagnostic confidence of the presence of an intrauterine gestational sac.

Trial of labor after cesarean delivery: the effect of previous vaginal delivery

OBJECTIVE

This study examined the effects of order of previous modes of delivery on the rate of cesarean delivery and duration of a trial of labor among women with a history of 1 previous cesarean delivery and 1 previous vaginal delivery.

STUDY DESIGN

The medical records of 4393 women at our institution who were seen June 1984-July 1996 for a trial of labor after a previous cesarean delivery were abstracted. The 800 women with a history of 1 previous cesarean and 1 previous vaginal delivery were included in this analysis. They were split into 2 groups by obstetric history: (1) 1 cesarean delivery followed by 1 vaginal delivery (vaginal last) and (2) 1 vaginal delivery followed by 1 cesarean delivery (cesarean last). Patient characteristics, durations of labor, and rates of cesarean delivery were compared with chi2 analysis, the Student t test, and the Wilcoxon rank sum test. Possible confounding variables were controlled for with multivariate logistic regression.

RESULTS

The rates of cesarean delivery for the vaginal last and cesarean last groups were 7.2% and 14.7%, respectively (P = .002). The median durations of labor for the vaginal last and cesarean last groups were 5.6 and 7.0 hours, respectively (P = .01). The differences in cesarean rates and durations of labor were seen regardless of the indication for the previous cesarean delivery.

CONCLUSIONS

Among women with 1 previous cesarean and 1 previous vaginal delivery, those whose most recent delivery was vaginal had a lower rate of cesarean delivery and shorter duration of labor than did those whose most recent delivery was cesarean.

The second-trimester fetal iliac angle as a sign of Down's syndrome

OBJECTIVE

To determine whether the iliac angle of second-trimester fetuses is a useful sonographic marker for the detection of fetuses with Down's syndrome.

METHODS

We prospectively measured the iliac angle for all fetuses karyotyped over a 17-month period. A transverse view of the upper fetal pelvis was obtained at the time of amniocentesis and, by means of a protractor, the angle between the two iliac bones was measured. The angles of all those fetuses with Down's syndrome and the first 500 fetuses with normal karyotypes were compared, as was gestational age and maternal age.

RESULTS

Nineteen fetuses with Down's syndrome and 1167 fetuses with normal karyotypes underwent genetic amniocentesis over the study period. The mean gestational age of the fetuses with Down's syndrome was 16.6 weeks (+/- 1.9 weeks), and for the controls, 16.1 weeks (+/- 1.4 weeks) (p = 0.3). The mean maternal ages were 34.7 years (+/- 4.8 years) and 35.4 years (+/- 4.1 years) for those pregnancies with Down's syndrome and with normal karyotypes, respectively (p = 0.5). The mean iliac angle was 80.1 degrees (+/- 19.7 degrees) for those fetuses with Down's syndrome, and 63.1 degrees (+/- 20.3 degrees) for those fetuses with normal karyotypes (p = 0.0004). The iliac angle was at least 90 degrees in 36.8% (seven of 19 fetuses) with Down's syndrome and in 12.8% (64 of 500 fetuses) with normal karyotypes (p = 0.003).

CONCLUSION

Fetuses with Down's syndrome have a significantly larger iliac angle than fetuses with normal karyotypes. Use of an iliac angle cut-off point of 90 degrees would identify over one-third of second-trimester fetuses with Down's syndrome. However, because of the high false-positive rate (12.8%), the iliac angle is not useful in a high-risk population as a screening test when used in isolation.

The significance of prenatally identified isolated clubfoot: is amniocentesis indicated?

OBJECTIVE

Our purpose was to determine the significance of finding an isolated clubfoot on a prenatal sonogram.

STUDY DESIGN

All fetuses found to have an isolated congenital clubfoot over a 9-year period were retrospectively identified. Fetuses with associated anomalies were excluded. Review of medical records for obstetric and neonatal outcome and pathologic and cytogenic results were tabulated.

RESULTS

Eighty-seven fetuses were identified from our database as having isolated clubfoot on prenatal ultrasonography, with complete follow-up available for 68 fetuses. Sixty of the 68 fetuses were confirmed as having clubfoot after delivery (false-positive rate = 11.8%). The male/female ratio was 2:1. Four fetuses (5.9%) had abnormal karyotypes: 47,XXY, 47,XXX, trisomy 18, and trisomy 21. Nine fetuses had hip or other limb abnormalities noted after birth. Other anomalies not detected until delivery included a unilateral undescended testis, ventriculoseptal defects (n = 2), hypospadias (n = 2), early renal dysplasia, mild posterior urethral valves, and a two-vessel cord. Five of the 68 patients (including those with aneuploidy) had pregnancy terminations. Eleven patients were delivered preterm.

CONCLUSION

Karyotypic evaluation is recommended when isolated clubfoot is identified on prenatal sonogram because other subtle associated malformations may not be detected ultrasonographically in the early second trimester.

Significance of an echogenic intracardiac focus in fetuses at high and low risk for aneuploidy

Our objective was to evaluate the significance of an echogenic intracardiac focus in a mixed population of fetuses at high and low risk for aneuploidy. Over a 1 year period, we prospectively identified all fetuses with an echogenic intracardiac focus seen during prenatal sonography. A detailed structural evaluation was performed on each fetus as permitted by gestational age. The location and number of foci were tabulated prospectively, as were associated abnormalities. Follow-up was obtained by review of the medical record. Of the 290 fetuses who had an echogenic intracardiac focus, 14 of them were aneuploid (4.8%). Of the 290 mothers, 125 women were aged 35 years or older and 165 women were younger than 35 years old. Among the 125 fetuses born to women 35 years or older, eight were aneuploid fetuses (6.4%), while among the 165 fetuses of younger mothers, six were aneuploid fetuses (3.6%) (rate ratio = 1.8; 95% confidence interval [extremes] = 0.6, 4.9). Only one of the 14 aneuploid fetuses had an echogenic intracardiac focus as the only sonographic finding, and this occurred in a woman aged 41 years. The majority of the echogenic intracardiac foci (87.6%) were located in the left ventricle, while 4.8% of the foci were right-sided and 7.6% were bilateral. Among the 14 aneuploid fetuses, 14% had bilateral echogenic intracardiac foci and 7% had right-sided foci. Among the euploid fetuses, 7.3% had bilateral echogenic intracardiac foci and 4.7% had right-sided foci. In conclusion, we have shown that the presence of an echogenic intracardiac focus does raise the risk that the fetus has a chromosomal abnormality, most commonly Down syndrome, although all but one aneuploid fetus in our study had other sonographic findings.

The association of early-onset fetal growth restriction, elevated maternal serum alpha-fetoprotein, and the development of severe pre-eclampsia

From Antenatal Diagnostic Center referrals over 22 months, consultations for early-onset fetal growth restriction versus skeletal dysplasia were retrospectively identified. Those with elevated maternal serum alpha-fetoprotein (MSAFP) levels are the focus of this report. All had an early ultrasound confirming menstrual dates and subsequent sonography at < 28 weeks with at least two fetal biometric measures delayed by > or = 2 standard deviations from mean values. Of the five patients identified, the mean gestational age at the time of diagnosis of fetal growth restriction was 23.3 +/- 2.9 weeks. All had normal karyotypes and normal amniotic fluid AFP. None of the patients had evidence of hypertension or pre-eclampsia at diagnosis of fetal growth restriction. All five gravidas subsequently developed severe pre-eclampsia from 5.5 to 12.5 weeks after documentation of fetal growth delay. Three developed HELLP syndrome. Pregnancies were continued a mean duration of 10-2 weeks, with all five delivering at preterm gestations (mean = 33.5 +/- 1.7 weeks) for maternal indications of severe pre-eclampsia. Unexplained early-onset fetal growth restriction in conjunction with unexplained elevations of MSAFP together consistently heralded the subsequent development of severe pre-eclampsia.

The iliac angle as a sonographic marker for Down syndrome in second-trimester fetuses

OBJECTIVE

To determine whether measurements of the iliac wing angle on sonograms of the second-trimester fetus can be used to detect fetuses at increased risk for Down syndrome.

METHODS

All second-trimester Down syndrome fetuses karyotyped by amniocentesis over 5 years for whom adequate views of the iliac bones were available were reviewed retrospectively. The control group consisted of consecutive, normal second-trimester fetuses undergoing karyotyping during the same period. The angles between the iliac bones of the fetal pelves were measured on transverse sonograms, and the two groups were compared. A separate prospective evaluation of the ideal level for measurement of the iliac angle was made in two fetuses, one with and one without Down syndrome.

RESULTS

We evaluated 38 Down syndrome and 46 control fetuses. The mean iliac-angle measurements differed significantly for the Down syndrome fetuses as compared with normal control fetuses: 78.8 degrees +/- standard deviation (SD) 18.5 and 66.9 degrees +/- SD 13.9, respectively. An iliac angle of at least 90 degrees was measured in 14 (36.8%) Down syndrome fetuses and in two (4.3%) control fetuses, also a significant difference. In a prospective pilot evaluation of two fetuses, we measured the largest iliac angle at the most cephalad level of the iliac bones, and the smallest angle was measured at the most caudad level. The iliac angle measurements for the fetus with Down syndrome ranged from 55 degrees to 100 degrees; for the normal fetus, the range was 52 degrees to 80 degrees.

CONCLUSION

Although there is considerable overlap, the average iliac angle for fetuses with Down syndrome is significantly larger than that of normal fetuses. The angle measurement varies widely in any given fetus and is dependent on the level of the image. A prospective study is needed to evaluate the best level of angle measurement for the detection of fetuses with Down syndrome.

Fetal origin of amniotic fluid polymorphonuclear leukocytes

OBJECTIVE

Although polymorphonuclear leukocytes are the inflammatory cells most frequently recovered from the amniotic cavity in cases of suspected intrauterine infection, the source of these cells has not been definitively determined. We took advantage of the gender difference between the mother and her male fetus, and we report four cases in which amniotic fluid polymorphonuclear leukocytes were identified as fetal by fluorescence in situ hybridization with probes specific for X and Y chromosomes. Fetal membranes were intact at the time amniotic fluid was obtained in all cases.

STUDY DESIGN

Amniotic fluid was obtained from women with male fetuses in premature labor with clinical or laboratory evidence of infection. Cytospin preparations of amniotic fluid samples with polymorphonuclear leukocytes were prepared and sequentially stained with fluorescent reagents. To determine which cells were polymorphonuclear leukocytes, all replicate samples were stained with the fluorescent nuclear stain 4'-6-diamidino-2-phenyl-indole. This allowed definition of the characteristic multilobed polymorphonuclear leukocytes nuclear morphologic features. The sample was then probed with a rhodamine-labeled probe specific for the X chromosome and a fluorescein-labeled probe specific for the Y chromosome to assess whether the polymorphonuclear leukocytes were male or female.

RESULTS

Ninety percent to 99% of polymorphonuclear leukocytes identified by normal multiple lobed nuclear morphologic study on 4'-6-diamidino-2-phenyl-indole staining had an X and Y chromosome and were therefore fetal cells.

CONCLUSIONS

These data demonstrate a fetal response during intraamniotic infection. Further investigation of the roles for maternal and fetal polymorphonuclear leukocytes in chorioamnionitis may provide valuable information about the critical interaction of the two immune responses in this setting.

Outcome of singleton pregnancies with severe oligohydramnios in the second and third trimesters

We evaluated the significance of severe oligohydramnios, or anhydramnios, in the second and third trimesters, by determining the range of etiologies as well as the differences in fetal and neonatal outcome. All prenatal ultrasound results on pregnancies found to have severe oligohydramnios over a 7.5-year period at 13-42 weeks' gestation were retrospectively collected. Follow-up results were obtained from review of medical records, autopsies and pathology reports. A total of 250 singleton pregnancies met the criteria of having severe oligohydramnios. A bimodal distribution in gestational age at diagnosis was seen, with more cases diagnosed at 13-21 weeks and at 34-42 weeks. Fetal abnormalities were present in 50.7% of those diagnosed with severe oligohydramnios in the second trimester and in 22.1% of those in the third trimester. There were 10.2% and 85.3% survivors when severe oligohydramnios was diagnosed in the second and third trimesters, respectively. The rate of aneuploidy was at least 4.4% for the entire singleton population. A bimodal distribution of pregnancies presenting with severe oligohydramnios represents two different naturally occurring populations in terms of both etiology and prognosis.

The ultrasonographic appearance and outcome for fetuses with masses distorting the fetal face

Our objective was to determine the appearance, cause, and outcome of fetal face masses diagnosed antenatally by ultrasonography. Over a 6 year period, 10 consecutive fetuses with facial masses were identified. Ultrasonographic findings, neonatal pathologic findings, and outcome data were correlated. Four (40%) of the 10 fetuses died, including one with a palatal teratoma associated with a Dandy-Walker malformation and three with intracranial teratomas--one of which was associated with hydrops fetalis. Among the survivors, one fetus had a dacryocystocele that was managed conservatively and one had drainage of a salivary gland cyst. The remaining four neonates had successful excision of their tumors in the neonatal period and survived; these infants had a nasal teratoma, a thyroid teratoma, a gingival granular cell tumor, and a scalp hemangioma. Four of the 10 pregnancies had associated polyhydramnios, three of which ended in stillbirth or neonatal death. In conclusion, 40% of the fetuses with antenatal diagnosis of fetal facial masses did not survive. If those with intracranial teratomas are removed from this group, one of seven (14%) fetuses with extracranial masses died. The intracranial teratomas were uniformly fatal. Polyhydramnios was associated with poor outcome.

Sonographically detected abnormalities of the umbilical cord

OBJECTIVES

This study was undertaken as a retrospective chart review to evaluate the range of umbilical cord abnormalities detected by prenatal sonography, as well as the outcome and pathologic correlation.

METHODS

We identified 13 cases of umbilical cord abnormalities detected sonographically over a 46-month period. We evaluated the ultrasound appearance, size, location, and color Doppler characteristic in each case.

RESULTS

There were 4 instances of clear cysts on the umbilical cord, 8 with complex masses, and 1 with complete, cystic encasement of the cord throughout its length. The pathology included vascular abnormalities (hemangioma, hematoma, varicosity), edema of the umbilical cord with pseudocysts, and syncytial knots. There was 1 known karyotypic abnormality (trisomy 13). Twelve of the 13 newborns survived; the neonatal death occurred in the fetus with trisomy 13.

CONCLUSION

The presence of umbilical cord abnormalities may represent a variety of pathologic entities. Clinical outcome is usually favorable.

Levorotation of the fetal cardiac axis: a clue for the presence of congenital heart disease

OBJECTIVE

To evaluate the use of the cardiac axis within the chest for the prenatal detection of congenital heart defects.

METHODS

We reviewed retrospectively the sonographic findings of all fetuses scanned between 17 and 40 weeks' gestation and diagnosed prenatally as having heart defects. The cardiac diagnoses were confirmed postnatally. The control group consisted of 75 consecutive fetuses with normal fetal surveys and newborn follow-up examinations. The cardiac axes were measured retrospectively using an image of the four-chamber view of the heart and measuring the angle between the interventricular septum and a line bisecting the chest. Mean and standard deviations (SDs) of the axis measurements in normal and abnormal fetuses were compared by Student t test.

RESULTS

The 75 fetuses with heart defects diagnosed by prenatal sonogram had a mean cardiac axis of 56 +/- 13 degrees, compared with 43 +/- 7 degrees in normal fetuses (P < .001). Using 57 degrees (two SDs above the mean for normal fetuses) as the upper limit of normal, 33 of 75 (44%) abnormal fetuses versus none of 75 normal fetuses were identified. The frequency of cardiac rotation was greater in fetuses with truncus arteriosus, Ebstein's anomaly, pulmonic stenosis, coarctation of the aorta, and tetralogy of Fallot.

CONCLUSION

The presence of a cardiac axis exceeding 57 degrees in the fetal chest is associated with a substantial risk of congenital heart defects. The finding of an abnormal axis should prompt further evaluation of the fetal heart.