Circulating cell-free fetal DNA for the detection of RHD status and sex using reflex fetal identifiers.

OBJECTIVE: To determine the sensitivity and specificity of circulating cell-free fetal DNA in determining the fetal RHD status and fetal sex. METHODS: Maternal blood was collected in each trimester of pregnancy from RhD negative nonalloimmunized women. Whole blood was centrifuged, separated into plasma and buffy coat, and frozen at -80°C. DNA analysis was conducted via allele-specific primer extensions for exons 4, 5, and 7 of the RHD gene and for a 37-base pair insertion in exon 4 (RHD pseudogene; psi) three Y-chromosome sequences (SRY, DBY, and TTY2), and an extraction control (TGIFL-like X/Y). RhD serotyping on cord blood and gender assessment of the newborns were entered into a Web-based database. RESULTS: One hundred twenty women were enrolled. The median gestational age at the first venipuncture was 12.4 (range: 10.6-13.9) weeks with 120 samples drawn; 118 samples were drawn at 17.6 (16-20.9) weeks; and 113 samples at 28.7 (27.9-33.9) weeks. Overall accuracy for RHD was 99.1%, 99.1%, and 98.1% for each trimester and was 99.1%, 99.1%, and 100% for fetal sex determination. CONCLUSIONS: Fetal RHD genotyping and sex can be very accurately determined in all three trimesters using circulating cell-free fetal DNA in the maternal circulation.

Maintaining quality assurance for sonographic nuchal translucency measurement: lessons from the FASTER Trial.

OBJECTIVE: To evaluate nuchal translucency measurement quality assurance techniques in a large-scale study. METHODS: From 1999 to 2001, unselected patients with singleton gestations between 10 + 3 weeks and 13 + 6 weeks were recruited from 15 centers. Sonographic nuchal translucency measurement was performed by trained technicians. Four levels of quality assurance were employed: (1) a standardized protocol utilized by each sonographer; (2) local-image review by a second sonographer; (3) central-image scoring by a single physician; and (4) epidemiological monitoring of all accepted nuchal translucency measurements cross-sectionally and over time. RESULTS: Detailed quality assessment was available for 37 018 patients. Nuchal translucency measurement was successful in 96.3% of women. Local reviewers rejected 0.8% of images, and the single central physician reviewer rejected a further 2.9%. Multivariate analysis indicated that higher body mass index, earlier gestational age and transvaginal probe use were predictors of failure of nuchal translucency measurement and central image rejection (P = 0.001). Epidemiological monitoring identified a drift in measurements over time. CONCLUSION: Despite initial training and continuous image review, changes in nuchal translucency measurements occur over time. To maintain screening accuracy, ongoing quality assessment is needed.

First- and second-trimester Down syndrome screening markers in pregnancies achieved through assisted reproductive technologies (ART): a FASTER trial study.

OBJECTIVE: To determine whether first- and second-trimester Down syndrome screening markers and screen-positive rates are altered in pregnancies conceived using assisted reproductive technologies (ARTs). METHODS: ART pregnancies in the multicenter FASTER trial were identified. Marker levels were evaluated for five types of ART: in vitro fertilization with ovulation induction (IVF-OI), IVF with OI and egg donation (IVF-OI-ED), IVF with ED (IVF-ED), and intrauterine insemination with OI (IUI-OI) or without OI (IUI). Each group was compared to non-ART controls using Mann-Whitney U analysis. RESULTS: First-trimester marker levels were not significantly different between ART and control pregnancies, with the exception of reduced PAPP-A levels in the IUI-OI group. In contrast, second-trimester inhibin A levels were increased in all ART pregnancies, estriol was reduced and human chorionic gonadotropin (hCG) was increased in IVF and IUI pregnancies without ED, and alpha-fetoprotein (AFP) was increased in ED pregnancies. Second-trimester screen-positive rates were significantly higher than expected for ART pregnancies, except when ED was used. CONCLUSIONS: These data show that ART significantly impacts second-, but not first-, trimester markers and screen-positive rates. The type of adjustment needed in second-trimester screening depends on the particular type of ART used.

The impact of maternal obesity on midtrimester sonographic visualization of fetal cardiac and craniospinal structures.

OBJECTIVE: To examine the impact of maternal obesity on the rate of suboptimal ultrasound visualization (SUV) of fetal anatomy and determine the optimal timing of prenatal ultrasound examination for the obese gravida. METHODS: A computerized ultrasound database was used to identify ultrasound examinations for singleton gestations performed between 14(0/7) and 23(6/7) weeks at a tertiary care, university-based hospital. Patients were divided into four groups and categorized based on body mass index (BMI): nonobese (BMI <30 kg/m2), class I obesity (30< or =BMI<35 kg/m2), class II obesity (35< or =BMI<40 kg/m2), and extreme obesity (BMI > or =40 kg/m2). The rates of SUV for fetal cardiac and craniospinal structures were calculated for each group and compared. RESULTS: A total of 11,019 pregnancies were studied, of which 38.6% of the patients were obese. Overall, the rate of SUV of the fetal structures was higher for obese compared to nonobese women for both cardiac (37.3 [1723/4200] vs 18.7% [1275/6819]; P<0.0001) and craniospinal structures (42.8 [1798/4200] vs 29.5% [2012/6819]; P<0.0001). Increased severity of maternal obesity was associated with SUV rate for both the cardiac (nonobese 18.7% [1275/6819], class I 29.6% [599/2022], class II 39.0% [472/1123], and extreme obesity 49.3% [580/1055]; P<0.0001) and for the craniospinal structures: (nonobese 29.5% [2012/6819], class I 36.8% [744/2022], class II 43.3% [486/1123], and extreme obesity 53.4% [563/1055]; P<0.0001). With increasing gestational age at examination, the rate of SUV decreased for both obese and nonobese women. However, for obese women there was minimal improvement in visualization after 18-20 weeks. Even after adjustment for gestational age and the type of ultrasound machine, obese women (class I, class II, and extreme obesity) were still associated with increased odds for SUV of the fetal cardiac and craniospinal structures compared to nonobese women. CONCLUSION: Maternal obesity increases the rate of SUV for the fetal cardiac structures by 49.8% and for the craniospinal structures by 31%. The optimal gestational age for visualization of fetal cardiac and craniospinal anatomy in obese patients may be after 18-20 weeks.

Relationship between fetal pulmonary maturity assessment and neonatal outcome in premature rupture of the membranes at 32-34 weeks' gestation.

The absence of fetal pulmonary maturity in patients with preterm premature rupture of the membranes (PPROM) is often considered an indication for conservative management. The purpose of this study was to examine the value of biochemical pulmonary maturity assessment for the prediction of neonatal outcome in patients with PPROM between 32 and 34 weeks' gestation. Pregnancies complicated by PPROM at 32 to 34 weeks' gestation that delivered from January 1995 to May 2000 and had biochemical pulmonary maturity assessment were reviewed. Patients with medical disorders, multiple gestations, fetal growth restriction or structural anomalies, or evidence of intra-amniotic infection were excluded. Neonatal outcome measures were compared between patients with mature and immature pulmonary indices. During this time period, 244 patients with PPROM at 32-34 weeks' gestation were delivered; 78 patients met inclusion criteria (n = 41 patients with mature indices and n = 37 patients with immature indices). There were no cases of perinatal death or sepsis. There was no difference in major neonatal morbidities including need for mechanical ventilation, grade 2 or 3 necrotizing enterocolitis, grade 3 or 4 intraventricular hemorrhage, or seizures. After controlling for confounding factors including gestational age at PPROM and delivery, latency period, group B streptococcus (GBS) vaginal colonization, corticosteroid therapy, neonatal sex, mode of delivery, fetal indications for delivery, and umbilical cord pH, biochemical pulmonary maturity was not predictive of major neonatal morbidity. In our population, biochemical pulmonary maturity status does not appear to be predictive of neonatal morbidity in pregnancies complicated by PPROM at 32-34 weeks' gestation.

Meconium staining and meconium aspiration syndrome. Is there seasonal variation?

OBJECTIVE: To determine whether the incidence of pregnancies complicated by meconium-stained amniotic fluid (MSAF) or meconium aspiration syndrome (MAS) differs with seasonal changes. METHODS: An established perinatal database was used to identify all term (> or = 37 weeks) singleton gestations resulting in a live birth from January 1, 1997 to December 31, 1999. Patients were divided into groups based on the season of delivery: winter (December-February), spring (March-May), summer (June-August), and fall (September-November). Rates of MSAF (%MSAF/total deliveries) and MAS (%MAS/total deliveries) were calculated and compared among seasons. Local climatic data (average monthly temperature and monthly precipitation) were obtained from the National Weather Service. Multiple logistic regression analysis was performed to control for the effects of confounding variables and odds ratio (OR) with 95% confidence intervals (CI) were calculated. p < 0.05 was considered significant. RESULTS: Over the 3-year study period there were a total of 14,888 deliveries meeting the criteria. MSAF occurred in 3,206 (21.5%) deliveries and MAS developed in 92 (0.6% of total, 2.9% of MSAF). There were no differences in the rate of MSAF (p = 0.2) or MAS (p = 0.6) between seasons. By logistic regression neither season, temperature, nor precipitation were associated with MSAF or MAS. CONCLUSIONS: Our findings suggest that over the period examined there were no significant seasonal variations in the incidence of MSAF or MAS.

Nucleated red blood cell counts in term neonates with umbilical artery pH < or = 7.00.

The purpose of this study was to determine whether nucleated red blood cell (NRBC) counts are elevated in term neonates who have severe fetal acidemia at birth. The neonatal NRBC counts of term (gestational age > or = 37 weeks) neonates with pathological acidemia were compared with those from control neonates who met the following criteria: gestational age > or = 37 weeks, birth weight > or = 2800 g, umbilical artery pH > or = 7.25, and a 5-minute APGAR > 7. Pathological acidemia was defined as an umbilical artery pH < or = 7.0 and a base excess > -12 mEq/L. Twenty-six neonates met all inclusion criteria and were compared to 78 controls. The mean NRBC/100 WBC was 11.9 +/- 13.5 (range 0 to 45) for acidemic neonates compared to 3.9 +/- 2.9 NRBC/100 WBC (range 0 to 11) for control neonates [p <0.001]. Our findings suggest that the onset of hypoxia-ischemia in pregnancies complicated by severe fetal acidemia often begins prior to the intrapartum period.

Relationship between the sonographic pattern of intrauterine growth restriction and acid-base status at the time of cordocentensis.

OBJECTIVE: To determine whether there is a difference in acid-base status at the time of cordocentesis between fetuses with symmetric and asymmetric intrauterine growth restriction (IUGR). STUDY DESIGN: Non-anomalous singleton fetuses with IUGR who underwent fetal blood sampling for rapid karyotype analysis from 1992-1995 were retrospectively identified. Cases with gestational age <24 weeks, abnormal karyotype, or evidence of congenital infection were excluded. Fetuses were divided into two groups based on Head Circumference/ Abdominal Circumference Ratio (HC/AC). The asymmetric-IUGR group had HC/AC > or = 95% tile for GA, and the symmetric-IUGR group had HC/AC <95% tile. GA adjusted values of umbilical venous pH, pCO2, pO2, HCO3, hemoglobin and reticulocyte count were calculated by subtracting the mean values for GA from the observed and compared between groups. RESULTS: Both symmetric-IUGR (n = 7) and asymmetric-IUGR (n = 9) had umbilical venous pH and pO2, levels lower than GA normative values. However, there were no differences between groups for any of the parameters studied. CONCLUSIONS: Fetuses with symmetric and asymmetric IUGR due to UPI display a similar degree of acid-base impairment.

Influence of maternal-fetal medicine subspecialization on the frequency of trial of labor in term pregnancies with breech presentation.

OBJECTIVE: To investigate the role of subspecialization in maternal-fetal medicine (MFM) on the frequency of a trial of labor in term pregnancies with breech presentation. METHODS: We conducted a retrospective study of 332 singleton pregnancies > or =37 weeks with nonfootling breech presentation that delivered over a 6-year period (1994-1998) at a university-based, tertiary care hospital. Patients were divided into two groups based on whether the delivery was attended by an MFM or non-MFM obstetrician-gynecologist. Demographic and clinical data were compared between groups and outcome variables included whether the patient had an attempt at vaginal delivery, cesarean delivery after a labor attempt, or vaginal breech delivery. RESULTS: The frequency of labor attempt (OR 1.4, 95% CI 0.9-2.3), vaginal breech success rate (OR 0.6, 95% CI 0.3-1.5), and overall cesarean rates (OR 0.9, 95% CI 0.5-1.7) were similar between groups. Using discriminant function analysis, only nulliparity (R2 = 1.6%, F = 6.0, P = 0.005) and birthweight (R2 = 2.0% F = 6.4, P = 0.01) were associated with trial of vaginal delivery. CONCLUSIONS: Subspecialization in MFM had no impact on the frequency of trial of labor in the term pregnancy with a breech presentation.

Patients with an ultrasonographic cervical length < or =15 mm have nearly a 50% risk of early spontaneous preterm delivery.

OBJECTIVE: The aim of this study was to determine the value in the prediction of spontaneous preterm delivery of ultrasonographically measured cervical length measured between 14 and 24 weeks' gestation. STUDY DESIGN: A retrospective cohort study examined cervical length by means of a two-stage procedure, transabdominal ultrasonography followed by transvaginal ultrasonography if cervical length was <30 mm. RESULTS: A total of 6877 patients met inclusion criteria. Mean cervical length was 37.5 mm. Odds ratios for early preterm delivery (< or =32 weeks' gestation) for patients with cervical lengths < or =10, < or =15, < or = 20, < or =25, and < or =30 mm were, respectively, 29.3 (95% confidence interval, 11.3-75.8), 24.3 (95% confidence interval, 12. 9-45.9), 18.3 (95% confidence interval, 10.8-31.0), 13.4 (95% confidence interval, 8.8-20.6), and 3.2 (95% confidence interval, 2. 4-4.4). For early preterm delivery a cervical length of < or =15 mm had a positive predictive value of 47.6%, a negative predictive value of 96.7%, a sensitivity of 8.2%, and a specificity of 99.7%. CONCLUSIONS: A short cervix seen on a second-trimester sonogram was a powerful predictor of early spontaneous preterm delivery (< or =32 weeks' gestation). Nearly 50% of patients with a cervical length < or =15 mm had an early spontaneous preterm delivery, which suggests that clinical trials of interventions (eg, cerclage) in this population are urgently needed.

The relationship between nucleated red blood cell counts and early-onset neonatal seizures.

OBJECTIVE: This study was undertaken to better define the timing of neurologic insult in neonates with early-onset seizures through evaluation of neonatal nucleated red blood cell levels. STUDY DESIGN: Medical records and the International Classification of Diseases, Ninth Revision codes were used to identify all term neonates with neonatal convulsions who were delivered at our institution (January 1, 1990-December 31, 1995). Each neonate with early-onset seizures was matched to the next 3 neonates who met the following criteria: gestational age > or =37 weeks, no early-onset seizures, birth weight > or =800 g, umbilical artery pH > or =7.25, and a 5-minute Apgar score >7. Demographic characteristics, clinical factors, and mean initial nucleated red blood cell counts were compared between groups. RESULTS: During the 6-year study period, there were a total of 36, 490 singleton term deliveries of infants who were alive at birth. Forty-five (0.1%) of these neonates had early-onset seizures. Thirty neonates with early-onset seizures met the inclusion criteria. Mean nucleated red blood cell counts (number of nucleated red blood cells per 100 white blood cells) for neonates with early-onset seizures were significantly increased compared with those of control neonates (18.4 +/- 22.0 vs 4.6 +/- 4.5; P <.0008). CONCLUSIONS: Our findings are suggestive of the hypothesis that neurologic injury leading to early-onset seizures often occurs before the intrapartum period.

Benefits associated with harmonic tissue imaging in the obstetric patient.

OBJECTIVE: We sought to determine the impact of harmonic tissue imaging on image resolution and visualization of fetal structures during obstetric ultrasonography. STUDY DESIGN: Patients with singleton second- or third-trimester fetuses were recruited. Prospective comparisons of conventional fundamental imaging and harmonic tissue imaging were made. Visualization rates and frequencies of improvement in resolution were calculated. Discriminate function analysis evaluated determinants of improved visualization. RESULTS: Harmonic tissue imaging improved resolution of at least one fetal structure in 51.4% of patients studied. Differences were most marked for 4-chamber views of the heart with improvement in resolution in 30.5% of patients and change in ability to visualize in 9.5%. Maternal weight and gestational age had a significant influence on whether improvements were noted with harmonic tissue imaging, accounting for 27% of the variance. CONCLUSIONS: Harmonic tissue imaging offers significant improvements over fundamental imaging in image resolution and structure visualization in obese patients during the second trimester of pregnancy.

Vaginal birth after cesarean in the diabetic gravida.

OBJECTIVE: To compare the delivery outcomes in term diabetic patients without a prior cesarean delivery to those attempting vaginal birth after cesarean (VBAC). STUDY DESIGN: A retrospective chart review study was performed of singleton pregnancies complicated by class A-2-R diabetes who delivered at > or = 37 weeks from 1991 to 1997. Exclusion criteria were prior classical or low vertical cesarean, more than one prior cesarean delivery, fetal structural defects or any contraindications to labor. Outcome measures were compared for patients without prior cesarean (group 1) to those with a VBAC attempt (group 2). RESULTS: One hundred fifty-nine patients, 127 patients without a prior cesarean delivery and 32 patients with a VBAC attempt, met all the study criteria. The cesarean delivery rate was 26.3% (34/127) in group 1 and 56.3% (18/32) in group 2 (VBAC success rate, 43.7%). There were no cases of uterine rupture. There were no differences in the frequency of endometritis rates or neonatal intensive care unit admission, whether vaginal or cesarean delivery occurred. CONCLUSION: VBAC success rates appeared to be lower for diabetic gravidas as compared to those for nondiabetic women reported in the literature. Although maternal and neonatal complication rates were low, further studies are necessary to determine the safety of VBAC in this population.

Delivery of the marginally preterm infant: what are the minor morbidities?

OBJECTIVE: We sought to determine frequencies of minor morbidities associated with delivery between 32 and 36 weeks' gestation. STUDY DESIGN: The study population consisted of all infants delivered between 32 and 36 weeks' gestation at a tertiary care hospital during 1997. Maternal and neonatal charts were abstracted for maternal history, pregnancy complications, and neonatal demographics comparing complications present at each gestational week. The Student t test, chi(2) analysis, and stepwise regression analysis were used to assess statistical significance. Odds ratios were calculated. RESULTS: There were 553 patients eligible for study. There was increased risk of neonatal intensive care unit admission with delivery before 34 weeks' gestation (P <.04). An increased incidence of feeding difficulties was present before 35 weeks' gestation (P <.001). Hypothermia remained more frequent until 35 weeks' gestation (P <.05). Delivery at 35 weeks' gestation did not increase the mean number of neonatal hospital days. CONCLUSION: Although the incidences of major morbidities decline after 32 weeks' gestation, minor morbidities continue up to 35 to 36 weeks' gestation and may lengthen neonatal hospitalization.

The apparently isolated choroid plexus cyst: importance of minor abnormalities in predicting the risk for aneuploidy.

OBJECTIVES: To assess the risk of aneuploidy in cases of isolated choroid plexus cysts (CPCs) and to compare the risk when associated with minor or major anomalies. METHODS: All fetuses with CPCs and known karyotype were identified. CPCs were categorized as 'isolated' or associated with minor or major sonographic anomalies. Preexisting risk factors for aneuploidy were compared between groups. The frequency of aneuploidy was compared between fetuses with isolated CPCs and those with CPCs associated with minor or major anomalies. Continuous and categorical variables were analyzed using one-way analysis of variance or chi-square as appropriate with p < 0.05 considered significant. RESULTS: One hundred and forty-nine fetuses with CPCs diagnosed at a mean gestational age of 19 weeks were identified. No significant differences in the frequency of preexisting risk factors for aneuploidy were identified between groups. Eighteen of 149 (12%) fetuses with CPCs had other sonographic anomalies; in 10 they were minor, and 2 of the 10 had abnormal karyotypes. Four of 8 fetuses with major anomalies were aneuploid. All 131 fetuses with isolated CPCs had normal karyotypes, and all aneuploid fetuses had additional anomalies. CONCLUSIONS: The overall rate of aneuploidy in patients with CPCs was 4% with no abnormal karyotypes among isolated CPCs. The presence of even minor sonographic abnormalities substantially increased the risk of aneuploidy. Isolated CPCs identified sonographically may not place the patient at risk of aneuploidy, but should prompt a diligent search for other minor or major anomalies. The finding of any other anomaly warrants consideration for karyotypic evaluation.

Telemedicine and fetal ultrasonography: assessment of technical performance and clinical feasibility.

OBJECTIVE: Our aim was to determine the performance and clinical feasibility of telesonography for the interpretation of fetal anatomic scans sent from a remote location compared with those obtained at a tertiary care prenatal ultrasonography center. STUDY DESIGN: Routine ultrasonographic studies from 35 patients were remotely interpreted. Evaluation included a blinded comparison of the sonographer's assessment of 38 fetal structures with that of the physician at the tertiary care center. Technical evaluation included system reliability and the number of digital telephone lines required for adequate real-time visualization. RESULTS: The mean gestational age at the time of the ultrasonography was 25.84 +/- 6.8 weeks (range 14 to 38). There was complete consistency of interpretation for 25 of 38 (66%) fetal structures. Thirteen structures had discrepancies in visualization, reflecting a difference in the adequacy of visualization, not the normalcy or identity of the structures. Three digital (integrated switching digital network, ISDN) telephone lines were required for real-time visualization. CONCLUSION: Our preliminary experience supports telesonography as a clinically useful tool for remote interpretation of fetal ultrasonographic examinations. Further studies are warranted for the continued evaluation of this emerging technology.

Limited clinical utility of midtrimester fetal morphometric percentile rankings in screening for birth weight abnormalities.

OBJECTIVE: Our purpose was to determine whether midtrimester fetal ultrasonographic morphometric percentile rankings are sensitive screening tests for preterm labor or birth weight abnormalities. STUDY DESIGN: Stepwise multiple regression and chi 2 analysis were used to identify midtrimester fetal measurements predicting birth weight and gestational age. Receiver-operator characteristics curves were used to evaluate abdominal circumference percentiles as a test for large-for-gestational-age and small-for-gestational-age infants. RESULTS: Extremes in abdominal circumference and head measurement percentiles were associated with large- and small-for gestational-age infants but not with preterm delivery. Abdominal circumference predicted birth weight in regression analysis; however, receiver-operator characteristic curves showed abdominal circumference percentiles to be poor screening tests for large- or small-for-gestational-age infants. The positive predictive value of 10th and 90th abdominal circumference percentiles for small- and large-for-gestational-age infants was < 20%. CONCLUSION: Midtrimester percentile rankings offer no clear benefit in targeting fetuses with potential birth weight abnormalities or risk of preterm delivery and may provide clinically misleading information.

Maternal thrombocytopenia. Predicting neonatal thrombocytopenia with cordocentesis.

OBJECTIVE: To evaluate the efficacy of cordocentesis for predicting fetal thrombocytopenia in the presence of maternal thrombocytopenia. STUDY DESIGN: We studied platelet counts obtained by cordocentesis from 42 consecutive immune thrombocytopenia purpura patients. Platelet counts were obtained on 36 neonates, and the statistical analysis included only these infants. Presence of maternal antiplatelet antibodies, interval from fetal sampling to delivery, neonatal platelet counts and outcome were evaluated. Thrombocytopenia was defined as a platelet count < or = 150,000/microL, with < or = 50,000 microL considered severe. RESULTS: No procedure-related complications occurred. A moderate correlation existed between fetal and neonatal platelet counts (r = .48, P = .003), unrelated to the interval between sampling and delivery. Eight of 36 fetuses had thrombocytopenia, and 4 were confirmed at delivery. Two neonates had thrombocytopenia at birth but not at cordocentesis. Two neonatal thrombocytopenia cases were severe. Neither was categorized as severe antenatally. The sensitivity, specificity, and positive and negative value for predicting severe neonatal thrombocytopenia were 0%, 100%, 0%, and 94%, respectively. Grade 1 intraventricular hemorrhages occurred in two neonates delivered at 35 weeks' with normal platelet counts. CONCLUSION: Cordocentesis was not reliable in predicting severe neonatal thrombocytopenia; however, the high negative predictive value was reassuring. The clinical utility of the technique and the population in which it should be used remain to be defined.

Differences in measurements of the atria of the lateral ventricle: does gender matter?

OBJECTIVE: To evaluate possible differences in measurements of the width of atria of the lateral cerebral ventricles of male and female fetuses. STUDY DESIGN: A prospectively entered database was reviewed to identify patients undergoing ultrasound examination at > 13 weeks between July 1, 1994 and June 30, 1995. Inclusion criteria included identification of fetal gender, measurement of the atria, and the absence of fetal anomalies. RESULTS: The atrial width of the lateral ventricles was statistically greater in male than in female fetuses (7.1 vs. 7.0 mm, p < 0.001). CONCLUSION: Although statistically significant, the difference between genders in the measurement of the ventricular atria is too small to be of clinical utility.

Neonatal outcome following methadone exposure in utero.

To examine the relationship between maternal methadone exposure and neonatal head circumference and abstinence syndrome, we examined the records of 172 opiate-addicted gravidas enrolled in a methadone maintenance program in an urban hospital over a 2-year period. Higher doses of methadone in the third trimester were associated with increased head circumference reflecting both increased gestational duration and improved overall growth. Neonatal withdrawal was positively correlated with gestational age at delivery and race, with nonblack infants exhibiting higher neonatal abstinence scores than blacks following adjustment for maternal dose and gestational age at delivery. Selection of optimal methadone dosage is a complex problem in which the favorable neurobehavioral outcome associated with increased growth and gestational age must be weighed against the risks associated with more severe neonatal withdrawal. Our findings of improved overall fetal growth and gestational duration associated with higher methadone doses suggest that more liberal methadone dosing in pregnancy may improve long-term neonatal outcome.