Edwin R. Guzman

Transumbilical placement of the vaginal probe in obese pregnant women.

Transabdominal ultrasonography in obese pregnant women is often unsatisfactory because of the poor transmission of ultrasound through a thickened abdominal wall. We report our experience with the placement of a transvaginal probe in the umbilicus to improve resolution in obese pregnant patients. The technique, which involves filling the umbilicus with ultrasound transmission gel and inserting the transvaginal probe into the umbilicus, was applied in 25 consecutive obese patients who had unsatisfactory fetal imaging by the standard transabdominal approach. The most frequent reason for incomplete fetal survey by the standard transabdominal approach was unsatisfactory imaging of the fetal heart (19 of 25 cases, 76%). The transumbilical approach resulted in improved resolution and satisfactory cardiac examination in 18 of these 19 cases (95%). In two cases, color and pulsed Doppler interrogation of intrafetal vessels become possible. A complete fetal survey was accomplished in 96% of the cases.

Relationship Between Endocervical Canal Length Between 15-24 Weeks Gestation and Obstetric History

The object was to determine whether there is a correlation between the obstetric history and the ultrasonographically determined endocervical canal length between 15 and 24 weeks gestation. A retrospective cohort study was performed in singleton pregnancies of multigravidas with normal and abnormal obstetric histories. They underwent sonographic evaluation for the determination of the endocervical canal length between 15 and 24 weeks gestation. The shortest endocervical canal length measurements between 15 and 20 weeks and also between 21 and 24 weeks of gestation were recorded. An ultrasound diagnosis of cervical incompetence was defined as progressive shortening of the endocervical canal length to <2 cm or a single endocervical canal length measurement <2 cm. A multivariable general linear regression model was used to correlate the relationship between endocervical canal lengths at 15-20 weeks and 21-24 weeks gestation in the current pregnancy with the earliest gestational age at delivery of prior pregnancies. Chi-square test was used to determine the relationship between the development of an ultrasound diagnosis of cervical incompetence and the earliest gestational age at delivery of prior pregnancies. A total of 155 pregnancies were studied. The number of women according to the obstetric history categories were: 57 had delivered <24 weeks, 12 between 24 and 26 weeks, 16 between 27 and 32 weeks, 16 between 33 and 36 weeks, and 54 delivered > or =37 weeks. There was a significant correlation between the endocervical canal length measurements between 15-20 (P < 0.0001) weeks and 21-24 weeks (P < 0.0001) in the studied pregnancy and the earliest gestational age at delivery of prior pregnancies. A significant relationship between the ultrasound diagnosis of cervical incompetence and the obstetric history category (P = 0.0026) was observed. There were 36 cases of ultrasound diagnosed cervical incompetence with 91.7% (33/36) occurring in women who had a prior <27 weeks gestation delivery. These data provide further evidence that cervical incompetence is a relative condition and not an all or none phenomenon. In addition, women with a prior delivery <30 weeks gestation should be followed with second trimester serial cervical sonography to rule out cervical incompetence.

Second-trimester genetic sonography in patients with advanced maternal age and normal triple screen

OBJECTIVE To estimate the value of second‐trimester genetic sonography in detecting fetal Down syndrome in patients with advanced maternal age (at least 35 years) and normal triple screen. METHODS Since July 1999, a prospective collection and recording of all individual triple screen risks for fetal Down syndrome was initiated for all patients with advanced maternal age presenting in our ultrasound unit for second‐trimester genetic sonography. Genetic sonography evaluated the presence or absence of multiple aneuploidy markers. Outcome information included the results of genetic amniocentesis, if performed, and the results of pediatric assessment and follow‐up after birth. RESULTS By June 2001, 959 patients with advanced maternal age and normal triple screen were identified. Outcome information was obtained in 768 patients. The median risk for fetal Down syndrome based on maternal age was 1:213 (range 1:37–1:274). The median risk for fetal Down syndrome based on triple screen results was 1:1069 (range 1:275–1:40,000). A total of 673 patients had normal genetic sonography, and none (0%) had Down syndrome; 95 had one or more aneuploidy markers present, and four (4.2%) had fetuses with Down syndrome. The triple screen risks for these four fetuses ranged from 1:319 to 1:833. CONCLUSION This study suggests that patients with advanced maternal age and normal genetic sonography carried very little risk for Down syndrome. The use of genetic sonography may increase the detection rate of fetal Down syndrome in this group of pregnant women.

Effects of Narcotic and Non-Narcotic Continuous Epidural Anesthesia on Intrapartum Fetal Heart Rate Tracings as Measured by Computer Analysis

OBJECTIVEnTo evaluate the effect of narcotic and non-narcotic continuous epidural anesthesia on intrapartum fetal heart rate (FHR) tracings as measured by computer analysis.nnnMETHODSnWe studied 37 women with uncomplicated pregnancies at term with reactive FHR tracings. The women were randomized to receive epidural anesthesia with either bupivicaine with fentanyl or bupivicaine alone. One-hour FHR tracings were obtained before epidural anesthesia. Thirty minutes after the initial bolus of the epidural a repeat computer analysis of 60-minute FHR tracing was obtained. Median values are reported for FHR parameters with statistical analysis performed by the Mann-Whitney U and Wilcoxon signed rank tests where appropriate. A power calculation was performed using a power of 90% to determine a required sample size of 28 patients. Statistical significance was set at P < .05.nnnRESULTSnIn early first stage of labor, there was no significant difference in pre- and postepidural anesthesia FHR baseline, accelerations of 10 and 15 beats per minute, episodes of high and low variation, and short- and long-term variation when using either narcotic or non-narcotic anesthetic agents.nnnCONCLUSIONSnThus, the clinician can consider the use of narcotic as well as non-narcotic continuous epidural anesthesia in the dosages used in our study with its attendant advantages without fear of obscuring the fetal heart rate tracing.

Antenatal Prediction of Fetal pH in Growth Restricted Fetuses Using Computer Analysis of the Fetal Heart Rate

We tested the accuracy of a mathematical model based on computer analysis of the fetal heart rate tracing in predicting umbilical artery pH at birth. In a previous report based on data on 38 growth-restricted fetuses, the second-order polynomial regression equation, umbilical artery pH = 7.28 + 0.002 (duration of episodes of low variation in minutes) + 0.00009 (duration of episodes of low variation in minutes), was retrospectively found to be the best model for the prediction of umbilical artery pH at birth. In the present study, this formula was prospectively tested in 29 growth restricted fetuses between 26 and 37 weeks of gestation from pregnancies with abnormal uterine and/or umbilical artery Doppler velocimetry. Computer analysis of the fetal heart rate tracing of 1 hour duration was performed within 1.5-6 hours of cesarean birth prior to the onset of labor. Umbilical artery cord blood was collected at birth with pH determined within 5 minutes of collection. Acidemia was defined as umbilical artery pH < 7.20, preacidemia pH 7.20-7.25 and nonacidemia pH > 7.25. Then, the data on all 67 growth-restricted fetuses were pooled to generate a new formula that was retrospectively assessed against the entire group. Values are reported as median (range). In the 29 prospectively evaluated cases, there was no statistical difference between the predicted and actual umbilical artery pH at birth [7.28 (7.1-7.29) vs. 7.28 (7.18-7.37), P = 0.57]. The median difference between the paired predicted and actual umbilical artery pH values was -0.001 (-0.10-0.08). The difference between the predicted and actual umbilical artery pH was zero and within +/- 0.04 in 17% (5/29) and 76% (22/29) of the cases, respectively. When the data on the 67 growth-restricted fetuses were pooled together the formula did not change. There was no difference between the predicted and actual umbilical artery pH at birth when the formula was applied to all 67 growth-restricted fetuses [7.28 (7.08-7.29) vs. 7.27 (6.97-7.37), P = 0.41]. The median difference between the paired predicted and actual pH values was -0.001 (-0.12-0.12). The difference between the predicted and actual umbilical artery pH was zero and within +/- 0.04 in 15% (10/67) and 74% (49/67) of the cases, respectively. The accuracy of the formula in correctly categorizing the umbilical artery pH at birth was: acidemia 67% (8/12), preacidemia 28% (8/29) and nonacidemia 80% (37/46), P < 0.0001. A mathematical formula using the computer analysis index of duration of episodes of low variation reliably predicted umbilical artery pH at birth. This type of noninvasive monitoring may allow for the antepartum estimation and continuous tracking of fetal pH.

Effects of therapeutic amniocentesis on uterine and umbilical artery velocimetry in cases of severe symptomatic polyhydramnios

The objective of this study was to determine the effects of removal of amniotic fluid in cases of symptomatic severe polyhydramnios on Doppler waveform indices of the uterine and umbilical arteries and flow velocities of the uterine arteries. Nine women underwent therapeutic amniocentesis during ten pregnancies for symptomatic polyhydramnios due to Beckwith-Wiedemann Syndrome (n = 1), esophageal atresia (n = 2), chorioangioma (n = 1), twin-twin transfusion syndrome (n = 3), a presumed autosomal recessive syndrome (n = 2), and an unbalanced double translocation (n = 1; partial dup 3q and partial del 9p syndrome). An average of 2.78 +/- 0.9 (range 1-4) 1 of fluid were removed at each procedure between the gestational ages of 18 and 34 weeks (mean of 28 weeks). The systolic/diastolic (S/D) ratio, pulsitility index (PI), and resistance index (RI) of the uterine and umbilical arteries were obtained before and after the procedure using color and pulsed Doppler. After angle correction, the peak systolic velocity (PSV) and mean velocity (MV) in centimeters/second (cm/s) of the uterine arteries were also determined. The presence or absence of a uterine artery waveform notch was determined. Dominant uterine arteries were defined as those with lower impedance indices or higher flow velocities. Statistical analysis was performed with the Wilcoxon signed-rank test. Significance was set at P < 0.05. There was a significant increase in the median value of the uterine artery MV (43.8 vs. 81.1 cm/s, P = 0.005) and PSV (74.2 vs. 125.5 cm/s, P = 0.007) after amniocentesis. The uterine S/D (3.0 vs. 1.84, P = 0.007), PI (1.12 vs. 0.68, P = 0.008), and RI (0.60 vs. 0.45, P = 0.005) impedance indices significantly decreased following amniocentesis. When uterine arteries were categorized as dominant vs. nondominant, there were greater improvements in impedance indices and flow velocities in the nondominant uterine arteries. There were three cases of unilateral and one case of bilateral early diastolic notches of the uterine artery waveforms which either resolved (n = 4) or improved (n = 1). There was no effect on the umbilical artery impedance indices. Therapeutic amniocentesis significantly improved uterine artery impedance indices and resulted in improved flow velocities, while there was no effect on umbilical artery waveform indices. The procedure resulted in the disappearance or improvement of the uterine waveform notch. Our findings suggest that in cases of severe polyhydramnios abnormal uterine artery velocimetry may not be due to lack of trophoblastic invasion of the spiral arteries but to increased intrauterine pressure secondary to polyhydramnios.

The clinical significance of absence of end-diastolic velocities of the umbilical artery detected in the severely preterm fetus

Objective: To determine whether there is a gestational age cutoff at the time of diagnosis of AEDV of the umbilical artery Doppler waveform that is associated with nearly zero perinatal survival. n nMethods: Over an 8-year period we identified and compared the outcomes of pregnancies in which AEDV of the umbilical artery Doppler waveform was detected between 19–24 and 25–28 weeks of gestation. All fetuses had normal structure and karyotypes. Small for gestational age (SGA) was defined as less than the 10th percentile for gestational age based on Brenner’s curve. Values are reported in median (range). n nResults: There were no survivors among the 27 cases identified at 19–24 weeks of gestation: 5 terminations for severe-SGA fetus (birth weight 336 [130–430] grams), 3 terminations for severe preeclampsia and SGA fetus, 12 fetal deaths, 7 neonatal deaths, and 10 cases (46%) of pregnancy-induced hypertension/preeclampsia (PIH/PE). All 8 cases detected at 25–28 weeks of gestation resulted in neonatal survival at discharge (P <0.0001), and there were 2 cases (25%) of PIH/PE (P = 0.54). n nConclusion: In this study, AEDV of the umbilical artery Doppler waveform identified at less than 25 weeks of gestation is associated with a 100% perinatal mortality rate and a high rate of PIH/PE. This information should be incorporated into the counseling and management of women in this clinical setting.

Elective cerclage versus cervical sonography in the management of women with prior midtrimester loss

Abstract Objective: To compare the outcome of women with a history of midtrimester loss (MTL) when managed with elective cerclage (EC) versus serial cervical sonography (CS). Methods: Over a 7-year period, we identified 199 women with a prior MTL carrying singleton gestations. We compared pregnancy outcomes between 114 women managed with serial CS between 15 and 24 weeks of gestation and 85 women who received EC. In the group who were followed with serial CS, a rescue cerclage or restricted physical activity as the only treatment was considered when the cervical length shortened to 2.0 cm or less. Values were reported as median (range). Results: Results are reported in the following table. Elective cerclage (N = 85) Cervical sonography (N = 114) Cerclage rate 100% 35% Gestational age (GA) at delivery (weeks) 37 (23–41) 38 (18–42) GA less than 37 weeks 44.1% 25.4% ( P = 0.009) GA less than 33 weeks 21.0% 17.5% Preoperative cervical length — 0.88 (0.0–2.0) Conclusion: Women with prior midtrimester loss managed with serial cervical sonography have equal or better perinatal outcomes with lower utilization of cerclage than those treated with elective cerclage.