In utero progression of mild fetal ventriculomegaly

OBJECTIVE

To evaluate the progression in utero of mild isolated fetal ventriculomegaly (defined as a transverse diameter of the atrium of the lateral ventricle measuring between 10 and 15 mm), and to estimate the proportion of fetuses that normalize (diameter decreasing to less than 10mm), stabilize (remaining between 10 and 15 mm), or progress to more severe ventriculomegaly (becoming greater than 15 mm).

METHODS

The obstetric databases of 3 institutions were queried for any studies mentioning ventriculomegaly or hydrocephalus. Reports and original images were reviewed to verify cases of isolated mild ventriculomegaly, with no other anomalies on comprehensive ultrasonographic examination. Fetuses that had 2 or more evaluations more than 3 weeks apart were included.

RESULTS

A total of 63 fetuses met the criteria for isolated mild ventriculomegaly. The mean gestational age and ventricular measurements were 24.7+/-3.7 weeks and 11.8+/-1.1mm, respectively, at the initial scan and 34+/-2.9 weeks and 12.1 +/-3.8mm, respectively, at the final scan. The mean number of scans was 3.75 per fetus (range, 2-6). Amniocentesis revealed the deletion of 5p, which causes the cri du chat, in 1 of 21 fetuses; 26 fetuses (41%) showed normalization of the lateral ventricles; 10 fetuses (16%) showed progression; and 27 (43%) appeared stable. shows the statistics of the individual groups. Three of the fetuses that "stabilized" improved from 15 mm to 11, 11.5, and 11.7 mm, respectively. Two worsened from 10.2 to 14 mm and from 11.4 to 13 mm.

CONCLUSIONS

More than 40% of the cases of mild isolated fetal ventriculomegaly resolved in utero. The significant overlap in measurements for the different groups precludes prediction in individual cases. However, of the 13 cases where the transverse diameter measured 13 mm or more, only 1 normalized, while 9 of the remaining 12 cases stabilized and 3 progressed.

The prevalence and timing of cervical cerclage placement in multiple gestations

OBJECTIVES

To investigate the prevalence and timing of cervical cerclage placement in multiple gestations.

METHODS

Our perinatal database was queried for all multiple gestations delivered at Evanston Hospital from 12/95 through 12/00. This list was then cross-matched with billing and medical records for 'incompetent cervix' and 'cerclage.' The medical records of all deliveries </=26 weeks were reviewed in order to ascertain if cervical incompetence was responsible for the preterm delivery.

RESULTS

There were 802 deliveries of multiple gestations >/=14 weeks over a 5-year period. The number of patients that underwent cerclage placement was 29 or 3.6%. The mean gestational age at cerclage placement was 18.6+/-4.5 weeks (range 11-24.6). Twelve were elective or prophylactic while 17 were 'urgent' or 'emergent.' The mean gestational age for the 17 emergent cerclages was 21.4+/-2.2 weeks (range 16.6-24.6). When compared with those patients who did not undergo cerclage placement, there was no difference in maternal demographics including age, parity, or previous full-term delivery. There was a significant difference in the gestational age at delivery for the cerclage vs. no cerclage group; 29.3+/-5.6 vs. 34.4+/-4.6 weeks, respectively, and in the frequency of losses at </=26 weeks; 8/23 (38%) vs. 48/707 (6.8%), P<0.001. Ten of the losses in the no cerclage group appeared consistent with incompetent cervix for a total of 39/802 or 4.9% rate of cervical incompetence in our multiple gestation population.

CONCLUSIONS

The relatively low prevalence of cervical incompetence in our multiple gestations does not justify prophylactic cervical cerclage placement. Expectant management with serial cervical examinations starting at 16-18 weeks appears more prudent.

Single vs weekly courses of antenatal corticosteroids for women at risk of preterm delivery: A randomized controlled trial

CONTEXT

The practice of administering weekly courses of antenatal corticosteroids to pregnant women at risk of preterm delivery is widespread, but no randomized trial has established the efficacy or safety of this practice.

OBJECTIVES

To evaluate the efficacy of weekly administration of antenatal corticosteroids compared with a single course in reducing the incidence of neonatal morbidity and to evaluate potential complications of weekly treatment.

DESIGN AND SETTING

Randomized, double-blind, placebo-controlled intention-to-treat trial conducted in 13 academic centers in the United States from February 1996 through April 2000.

PARTICIPANTS

A total of 502 pregnant women between 24 and 32 completed weeks' gestation who were at high risk of preterm delivery.

INTERVENTION

All patients received a complete single course of antenatal corticosteroids (either betamethasone, 12 mg intramuscularly repeated once in 24 hours for 2 doses, or dexamethasone, 6 mg intramuscularly repeated every 12 hours for 4 doses). Participants who had not delivered 1 week after receipt of the single course were randomly assigned to receive either betamethasone, 12 mg intramuscularly repeated once in 24 hours for 2 doses every week until 34 weeks' gestation or delivery, whichever came first (n = 256), or a similarly administered placebo (n = 246).

MAIN OUTCOME MEASURE

Composite neonatal morbidity (including severe respiratory distress syndrome, bronchopulmonary dysplasia, severe intraventricular hemorrhage, periventricular leukomalacia, proven sepsis, necrotizing enterocolitis, or perinatal death).

RESULTS

Composite morbidity occurred in 22.5% of the weekly-course group vs 28.0% of the single-course group (unadjusted relative risk, 0.80; 95% confidence interval, 0.59-1.10). Neither group assignment nor the number of treatment courses was associated with a reduction in composite morbidity.

CONCLUSIONS

Weekly courses of antenatal corticosteroids did not reduce composite neonatal morbidity compared with a single course of treatment. Weekly courses of antenatal corticosteroids should not be routinely prescribed for women at risk of preterm delivery.

Indomethacin tocolysis and intraventricular hemorrhage

OBJECTIVE

To determine the association between indomethacin tocolysis and neonatal intraventricular hemorrhage.

METHODS

Fifty-six preterm neonates with intraventricular hemorrhage were matched by gestational age with neonates (n = 224) without this morbidity. Maternal and neonatal charts were reviewed to ascertain the type of tocolytic exposure experienced by the neonate. Other maternal and neonatal demographic and outcome data were also abstracted. Results were analyzed using the Student t test, chi(2) analysis, and multivariable logistic regression. The number of studied subjects provided 80% power to determine if antenatal exposure to indomethacin was twice as likely among infants with intraventricular hemorrhage.

RESULTS

Univariate analysis revealed that there were no significant differences between the study and control groups with respect to maternal age, parity, or betamethasone exposure. Infants with intraventricular hemorrhage were significantly more likely to be born at an earlier gestational age, a lower birth weight, after maternal chorioamnionitis, after vaginal delivery, and after exposure to either indomethacin alone or a combination of indomethacin and magnesium. Additionally, their neonatal course was significantly more likely to be complicated by sepsis and respiratory distress syndrome. In a multivariable logistic model, only gestational age, chorioamnionitis, vaginal delivery, and respiratory distress syndrome continued to be significantly associated with intraventricular hemorrhage. Indomethacin exposure, either as single-agent (adjusted odds ratio 1.3, 95% confidence interval 0.5, 3.3) or combination tocolytic therapy (adjusted odds ratio 2.0, 95% confidence interval 0.8, 4.8), was not significantly associated with intraventricular hemorrhage.

CONCLUSION

Indomethacin tocolysis is not associated with an increased risk of intraventricular hemorrhage.

Indomethacin tocolysis and risk of necrotizing enterocolitis

OBJECTIVE

To investigate the possible association of indomethacin tocolysis with neonatal necrotizing enterocolitis.

METHODS

A case-control study was performed for the period November 1, 1997, through May 1, 1999. All cases of proven necrotizing enterocolitis were ascertained, and four controls for each case were randomly identified from all Special Care Nursery admissions before 37 weeks' gestation without necrotizing enterocolitis during that same period.

RESULTS

During the 18-month period there were 24 cases of necrotizing enterocolitis out of 10,200 deliveries. Infants with necrotizing enterocolitis were more preterm (29.7 +/- 3.9 compared with 32.7 +/- 6.0 weeks; P =.03) and had lower birth weights (1453 +/- 777 compared with 1820 +/- 678 g; P =.02) compared with controls (n = 96). Respiratory distress syndrome (RDS) and sepsis were both significantly associated with an increased risk of necrotizing enterocolitis: 16 of 24 cases compared with 40 of 96 controls had RDS (odds ratio [OR] 2.8, 95% confidence interval [CI] 1.0, 8.3) and 14 of 24 cases compared with 11 of 96 controls were septic (OR 10.8, 3.4, 95% CI 34.2). Indomethacin as a single agent was not associated with necrotizing enterocolitis (OR 1.0, 95% CI 0.2, 4.8). Using a logistic regression model, necrotizing enterocolitis was strongly associated with sepsis (adjusted OR 8.5, 95% CI 2.2, 32.5). When sepsis was removed from the model, double-agent tocolytic therapy was significantly associated with necrotizing enterocolitis (adjusted OR 6.9, 95% CI 1.1, 43.6).

CONCLUSION

Tocolysis with indomethacin as a single agent was not associated with necrotizing enterocolitis in this case-control study. Combination tocolytic therapy may be a marker for subclinical infection and not causally related to necrotizing enterocolitis.

Positive predictive value of suspected growth aberration in twin gestations

OBJECTIVE

Our purpose was to determine the positive predictive value of ultrasonographic surveillance for growth abnormalities in twin gestations as a function of gestational age.

STUDY DESIGN

Women with twin gestations and delivery between January 1992 and March 1998 who had a 20- to 24-week sonogram with normal fetal anatomic findings and who had at least 1 sonogram showing abnormal growth were identified. Abnormal growth on ultrasonography was defined as an estimated fetal weight <10th percentile, abdominal circumference <5th percentile, or twin discordance (>20% difference in twin weights as a function of the heavier twin). Birth weights were then assessed for evidence of twin discordance or growth restriction.

RESULTS

The positive predictive value for the occurrence of a growth abnormality at birth, after an abnormal growth finding on ultrasonography at any time during gestation, was 47.7%. The positive predictive value was greatest (85%) when suspected growth restriction was first documented at 20 to 24 weeks of gestation and decreased with increasing gestational age. Even though sonograms were obtained at a mean interval of 4.4 +/- 2.0 weeks, those gestations with normal growth at 20 to 24 weeks had an elapsed time of 10.3 +/- 3.9 weeks until a growth abnormality was subsequently detected.

CONCLUSION

In twin gestations the positive predictive value of a sonogram for a growth abnormality at birth is significantly decreased after normal findings on a 20- to 24-week sonogram. This finding suggests that a routine 2- to 4-week interval between sonograms for all twin gestations may be unwarranted.

Prophylactic amnioinfusion in preganancies complicated by chorioamnionitis: a prospective randomized trial

The objective of this article is to prospectively investigate the efficacy of amnioinfusion as a means to reduce febrile morbidity in pregnancies complicated by chorioamnionitis. All laboring patients with a temperature > or =100.1 degrees F were approached for study participation. Exclusion criteria included amnionitis diagnosed at greater than 8 cm dilation, multiple gestation, placental abruption, or a nonreassuring fetal heart rate tracing. Consenting patients were randomized to receive antibiotics (ampicillin or penicillin with gentamicin) and acetaminophen with or without amnioinfusion. All patients received intrauterine pressure catheter placement. For study patients, normal saline at room temperature was infused at 10 mL/min for 60 min, then 3 mL/min until delivery. Postpartum endometritis was defined as a temperature = 100.4 degrees F accompanied by uterine tenderness more than 12 hr after delivery. Statistical analysis was performed using the Student's t-test for continuous data and Chi-square for discrete variables. Thirty-six patients were enrolled, and complete data were available for 34 patients (17 in each group). There were no differences between groups with respect to maternal age, gravidity, race, or gestational age. There were also no differences between groups in duration of rupture of membranes, temperature at randomization, interval from randomization to delivery, cesarean section rate, or umbilical cord arterial pH. The mean temperature at the time of delivery was 99.8+/-0.9 degrees F for the amnioinfusion group versus 100.5+/-1.0 degrees F for the control group (p=0.046). Three of 17 amnioinfusion patients and 3 of 17 control patients had postpartum endometritis. There was 1 neonatal infection in the treatment group and no neonatal infections among the control patients. Prophylactic amnioinfusion was associated with a decline in temperature at the time of delivery. No untoward effects from the amnioinfusion were identified.

Association of parvovirus infection with isolated fetal effusions

The association of parvovirus B19 infection and hydrops fetalis is well known. However, the association of parvovirus and fetal pleural or pericardial effusions has not been reported. We present five cases of isolated pleural or pericardial effusion with documented maternal parvovirus infection in four of these pregnancies. In the absence of structural or karyotypic abnormalities, spontaneous resolution of the effusion portends for a successful pregnancy outcome.

Lack of effect of antenatal indomethacin on fetal cerebral blood flow

OBJECTIVE

Our purpose was to investigate fetal cerebral blood flow and the incidence of intraventricular hemorrhage in patients undergoing tocolysis with either indomethacin or magnesium sulfate at < 30 weeks' gestation.

STUDY DESIGN

Consenting patients at < 30 weeks' gestation with preterm labor were randomized to receive indomethacin or magnesium sulfate tocolysis. Magnesium sulfate was administered intravenously with an 8 gm loading dose given over the first hour, 4 gm over the second hour, and then a maintenance infusion of 2.5 gm per hour. The infusion was continued for approximately 12 hours after the cessation of uterine contractions. Patients randomized to receive indomethacin were given an initial dose of 50 to 100 mg orally or per rectum, followed by 25 to 50 mg orally every 4 to 6 hours for 24 to 48 hours. Oral tocolytic agents were not used after successful tocolysis. Betamethasone was administered to all patients. Patients underwent fetal cerebral Doppler studies during tocolytic therapy and at least 24 hours after completion of the treatment.

RESULTS

Twelve patients were randomized to receive indomethacin and twelve patients were randomized to receive magnesium sulfate. Twenty-one fetuses underwent cerebral Doppler studies in triplicate during and after therapy. The mean gestational age at tocolysis was 27.5 +/- 1.9 weeks for the indomethacin group and 26.4 +/- 1.6 weeks for the magnesium sulfate group (p = 0.14). The middle cerebral artery resistance index for fetuses during indomethacin treatment was 0.73 +/- 0.09, whereas the resistance index after therapy was 0.75 +/- 0.05 (p = 0.49). The resistance index during magnesium sulfate tocolysis was 0.79 +/- 0.04 and after therapy it was 0.76 +/- 0.04 (p = 0.18). There was no significant difference in the resistance index between the groups on or off therapy. In addition, the incidence of intraventricular hemorrhage was similar in both groups.

CONCLUSION

These results suggest that indomethacin does not significantly affect fetal cerebral blood flow. If antenatal indomethacin in the preterm fetus increases the risk of intraventricular hemorrhage, it would appear to be by another mechanism.

Fetal supraventricular tachycardia complicated by hydrops fetalis: a role for direct fetal intramuscular therapy

Maternally administered digoxin for the treatment of fetal supraventricular tachycardia (SVT) complicated by hydrops fetalis may be ineffective secondary to poor transplacental drug transfer. We present our experience with eight pregnancies treated with transplacental therapy or combined maternal and direct fetal intramuscular therapy. Response to treatment following maternal intravenous administration (MIV) of digoxin or a combination of fetal intramuscular (FIM) digoxin and MIV is described for eight hydropic fetuses during nine successful pharmacologic conversions. The MIV digoxin was administered using standard loading and maintenance protocols. FIM was administered at a dose of 88 micrograms/kg q 12-24 hours, to a maximum of three injections in the fetal buttock. Time to onset of the first two hours of sinus rhythm (TO2 degrees), time to onset > 90% sinus rhythm (TO > 90%), and time to resolution of hydrops fetalis (HF) were noted. The mean heart rate was 257 +/- 36 beats/minute and the mean gestational age was 29 +/- 4.8 weeks. Fetal SVT was due to a reentrant mechanism in all cases. For the three fetuses that underwent successful cardioversion following MIV digoxin (all required additional maternal antiarrhythmic drugs), TO2 degrees was 145 +/- 114 hours, TO > 90% was 176 +/- 55 hours, and HF resolved in 41 +/- 37 days. Initial combined FIM and MIV therapy in four fetuses resulted in a TO2 degrees of 5.5 +/- 4 hours, TO > 90% of 22 +/- 14 hours, and resolution of HF in 25 +/- 21 days. For the two failed cardioversions with transplacental treatment alone (one fetus had recurrent SVT with hydrops after initial successful cardioversion with MIV), TO2 degrees was 203 +/- 180 hours and TO > 90% was 313 +/- 270 hours. Once FIM was begun in these fetuses, TO2 degrees was 17 +/- 7 hours and TO > 90% was 60 +/- 13 hours; HF resolved in 45 days in one fetus, whereas the other fetus never had resolution of hydrops despite 100 days of antiarrhythmic therapy. Direct fetal intramuscular injection of digoxin combined with transplacental therapy appears to shorten the time to initial conversion of SVT and to sustain sinus rhythm in the fetus with SVT complicated by hydrops fetalis.

A prospective study of the association between isolated fetal pyelectasis and chromosomal abnormality

OBJECTIVE

To determine the incidence of chromosomal abnormalities among fetuses with isolated pyelectasis.

METHODS

Between March 1991 and March 1994, 121 cases of isolated fetal pyelectasis were identified at our institution. Pyelectasis was defined as a renal pelvis anteroposterior diameter of at least 4 mm before 33 weeks' gestation, and at least 7 mm at 33 weeks or thereafter. Once identified, women were offered antenatal genetic testing; if they declined, consent was sought for umbilical cord blood studies at delivery.

RESULTS

Chromosomal evaluation was available in 99 women. Two chromosomal abnormalities were identified: one trisomy 21 and one mosaic 46, XY/47, XYY. The ages of the women were 32 and 28 years, respectively. Calculation of adjusted risks for Down syndrome and all chromosomal abnormalities indicated a 3.9-fold increase in Down syndrome risk and a 3.3-fold increase in risk for all chromosomal abnormalities in the presence of isolated fetal pyelectasis.

CONCLUSION

Isolated fetal pyelectasis is associated with increased risk, over that related to age, for both Down syndrome and all chromosomal abnormalities. These factors may be valuable in counseling individual patients regarding the appropriateness of amniocentesis.

Digitate intravascular appendages and aneurysm of the vein of Galen

Peculiar intravascular appendages were found in a case of aneurysm of the vein of Galen. Such appendages consisted of finger-like polypoid growths which protruded within the lumen of ectatic cerebral veins and arteries. They were solid, relatively large, and non-branching. Histologically, their structure was comparable to that of a vessel wall, but was concentrically laminated around the longitudinal axis. Some appendages were associated with thrombi. It is suggested that appendages of this kind probably represent secondary vascular malformations, that they are likely to develop in reaction to abnormal hemodynamic strains upon the vessel walls, and that they might be thrombogenic and, therefore, potentially beneficial for patients with arteriovenous shunts.

The clinical significance of a single umbilical artery as an isolated finding on prenatal ultrasound

OBJECTIVE

To evaluate the perinatal outcome in fetuses with single umbilical artery detected on targeted prenatal ultrasound without other anomalies.

METHODS

During a 3.5-year period, an isolated single umbilical artery was suspected on prenatal ultrasound examination in 57 fetuses evaluated at two referral centers. Targeted imaging to rule out concurrent fetal anomalies was normal in all cases. Pregnancy and perinatal outcome data were retrieved by review of the medical records or from conversations with referring physicians. Complete follow-up was available in 50 cases.

RESULTS

A two-vessel umbilical cord was confirmed at birth in 50 neonates. The mean gestational age at delivery was 38.6 +/- 2.8 weeks; the mean birth weight was 3202.8 +/- 835.8 g. Seventeen patients (34%) underwent genetic amniocentesis, and all fetuses had a normal karyotype. The only neonate ascertained to have a congenital anomaly after birth was diagnosed with total anomalous pulmonary venous return. This neonate underwent a corrective surgical procedure and is thriving with no apparent problems at 3.5 years of age. There were no perinatal deaths.

CONCLUSION

In the absence of additional sonographically detectable anomalies, an isolated single umbilical artery does not seem to affect clinical outcome and therefore should not alter routine obstetric management.

Isolated choroid plexus cyst(s): an indication for amniocentesis

OBJECTIVE

Our purpose was to prospectively evaluate the risk of chromosomal abnormalities associated with isolated choroid plexus cyst(s) in gravid women undergoing second-trimester ultrasonographic examination.

STUDY DESIGN

During a 24-month period 9100 pregnant women underwent midtrimester ultrasonographic evaluation. Women with a fetal diagnosis of choroid plexus cyst(s) were offered amniocentesis and a repeat examination in 4 to 6 weeks.

RESULTS

A diagnosis of choroid plexus cyst(s) was made in 102 fetuses (1.1%). In four of these fetuses multiple congenital anomalies were noted. Three of the four fetuses had a chromosomal abnormality, two trisomy 18 and one unbalanced translocation, t(3;13). In the remaining 98 fetuses the choroid plexus cysts were isolated findings, that is, there were no other ultrasonographically detected anomalies. Seventy-five of these 98 fetuses underwent amniocentesis. An abnormal karyotype was identified in four fetuses: three had Down syndrome (two trisomy 21 and one unbalanced translocation, t[14;21]), and one trisomy 18. The offspring of the 23 patients in which amniocentesis was declined were phenotypically normal.

CONCLUSIONS

In our prospective study the risk of chromosomal abnormality with isolated choroid plexus cyst(s) was 1:25, a risk that exceeds the 1:200 risk of pregnancy loss after amniocentesis and the 1:126 and 1:260 risk for aneuploidy and Down syndrome, respectively, in a 35-year-old pregnant women during the midtrimester. These findings indicate that amniocentesis should be offered to pregnant women in the presence of isolated fetal choroid plexus cyst(s).

The efficacy of oral terbutaline after intravenous tocolysis

OBJECTIVE

Our purpose was to investigate in a prospective, randomized study the efficacy of oral terbutaline after successful intravenous tocolysis in reducing preterm birth.

STUDY DESIGN

Patients between 28 and 35 weeks' gestation with uterine contractions and change in cervical examination were treated with intravenous magnesium sulfate for 12 to 24 hours. After successful tocolysis patients were approached for study participation and randomized to receive either oral terbutaline or no therapy. The dose of terbutaline was individualized to achieve a maternal pulse > 100 beats/min, and terbutaline was continued until 36 completed weeks of gestation. Recurrent preterm labor (contractions with change in cervical examination) for either group was treated with intravenous magnesium sulfate, and subsequent treatment was based on the previous randomization.

RESULTS

Fifty-five patients were enrolled (28 terbutaline, 27 no oral tocolytic). No difference was found between groups with respect to time gained (4.0 +/- 2.7 vs 4.6 +/- 3.1 weeks, p = 0.412), gestational age at delivery (35.6 +/- 2.7 vs 36.1 +/- 2.4 weeks, p = 0.562), > or = 37 weeks at delivery (nine vs 13, p = 0.291), recurrent preterm labor (10 vs four, p = 0.104), recurrent uterine contractions alone (five vs eight, p = 0.527), birth weight (2616 +/- 633 gm vs 2645 +/- 599 gm, p = 0.785), special care nursery admissions (eight vs six, p = 0.759), or neonatal respiratory distress syndrome (three vs two, p = 0.965).

CONCLUSION

The use of oral terbutaline after successful parenteral tocolysis failed to reduce the rate of preterm birth.

Iatrogenic respiratory distress syndrome following elective repeat cesarean delivery

OBJECTIVE

To determine the incidence of iatrogenic respiratory distress syndrome (RDS) following elective repeat cesarean delivery and to identify whether it was associated with departures from accepted management guidelines.

METHODS

Between January 1986 and March 1991, there were 23,125 deliveries at Northwestern Memorial Hospital, of which 1207 were repeat cesarean births without labor. During this period, 18 neonates of 37 weeks' gestation or greater or 2500 g or greater who were delivered by elective repeat cesarean were admitted to the neonatal intensive care unit (NICU) for respiratory difficulties.

RESULTS

Five of the 18 neonates admitted to the NICU with respiratory difficulty following elective repeat cesarean delivery met the criteria for RDS. This represents an incidence of 0.41% (five of 1207), or one case of RDS for every 241 repeat cesarean deliveries without labor. Four of the five neonates required mechanical ventilation for an average of 6.8 days. The average NICU stay was 11.2 days. Complications included pneumothorax (one) and pulmonary hemorrhage (one). Departures from accepted management guidelines included a discrepancy between ultrasound and menstrual dates (two), no confirmation of menstrual dates (one), and delivery before 39 weeks' gestation (two).

CONCLUSION

Iatrogenic RDS continues to occur in the setting of elective repeat cesarean delivery and is associated with a failure to adhere to clinical protocols.