Philippe Jeanty

The diagnosis of fetal microcephaly

Of 16 fetuses in whom microcephaly was suspected, nine (56.2%) were affected with microcephaly, and seven (43.8%) were unaffected. Subsequently, nomograms with mean and SDs for biparietal diameter, occipitofrontal diameter, head perimeter: bdominal perimeter, biparietal diameter:femur length, and femur length:head perimeter we derived. With the use of the data from 27 sonograms of the 16 fetuses, different thresholds of abnormality were tested. Three standard deviations from the mean for biparietal diameter, occipitofrontal diameter, head perimeter, and femur length:head perimeter were sensitive thresholds for the diagnosis of fetal microcephaly with no false negative diagnoses. Four standard deviations from the mean for occipitofrontal diameter, head perimeter:abdominal perimeter, and femur length:head perimeter were specific tests with no false positive diagnoses. The use of multiple diagnostic tests was necessary to improve accuracy in the diagnosis of fetal microcephaly. Further clinical studies are needed to delineate more clearly optimal tests and thresholds of abnormality.

Estimation of gestational age from measurements of fetal long bones

The general practice of using fetal long bone growth charts to derive gestational age does not yield mathematically valid results. The authors tried to calculate gestational age from the lengths of long bones (femur, humerus, tibia, ulna) from 12 to 40 weeks of gestation. The combined use of the four bones allows a good estimation of gestational age that may be useful should the biparietal diameter measurement be unreliable, unobtainable, or abnormal.

Antenatal diagnosis of renal anomalies with ultrasound: III. Bilateral renal agenesis

Bilateral renal agenesis is a lethal congenital anomaly. A reliable prenatal diagnosis is extremely important, since it may offer options for pregnancy termination or may change obstetric management in the third trimester. This study examined the accuracy of ultrasound in making an antenatal diagnosis of bilateral renal agenesis in three different populations: (1) patients with a family history of bilateral renal agenesis, (2) patients diagnosed during the course of a routine scan, and (3) patients referred because of a previous suspicious ultrasound examination in a level I ultrasound facility. In group A there were three true positive, 13 true negative, no false negative, and no false positive diagnoses. In group B there were three true positive and no false positive diagnoses. In group C there were 12 true positive, 17 true negative, one false negative, and no false positive diagnoses. The value and potential pitfall of the different diagnostic criteria are discussed. We conclude that ultrasound is a valuable tool in the detection of intrauterine renal failure, although there are limitations to a specific diagnosis of bilateral renal agenesis.

The value of serial human chorionic gonadotropin testing as a diagnostic tool in ectopic pregnancy

This study examines the sensitivity of serial human chorionic gonadotropin determinations in the detection of ectopic pregnancy for patients who present with human chorionic gonadotropin titers less than 6500 mIU/ml. A log human chorionic gonadotropin time curve was used to calculate the slope of change. A slope below 0.11 (85% confidence limit for intrauterine gestations) is used as the cutoff value. Of 50 patients with serial titers at sampling intervals of 2 to 5 days, 26 (49%) had falling values and 22 had subnormal slopes. Only five had initially normal slopes and two of these patients eventually had falling titers. The sensitivity of an abnormal slope (below 0.11) in the detection of ectopic pregnancy was 90%. A 12.5% false positive rate was found in a group of 24 intrauterine pregnancies.

Three-dimensional sonographic evaluations of embryonic brain development.

The purpose of this presentation is to show 3‐dimensional development of the ventricles of the brain in early pregnancy, from 6 to 13 weeks, and to provide a reference for early diagnosis of central nervous system anomalies such as hydrocephalus and holoprosencephaly.

The diagnosis of congenital renal anomalies with ultrasound

Infantile polycystic kidney disease in an autosomal recessive disorder which in its severe form is characterized by bilateral renal enlargement and renal failure. The present study was undertaken to assess the diagnostic accuracy of antenatal sonography in a population at risk. Nineteen patients with fetuses at risk for infantile polycystic kidney disease were referred for ultrasound examination to the Perinatal Unit at Yale-New Haven Hospital. Ten infants had infantile polycystic kidney disease (53%). A positive antenatal sonographic diagnosis was made by the presence of oligohydramnios, an absent urinary bladder, bilateral renal enlargement as measured by the kidney circumference-to-abdominal circumference ratio, and the typical hyperechogenic appearance of the kidneys in the disease. A correct antenatal diagnosis was made in nine of the 10 affected infants. There were no false positive diagnoses. A false negative diagnosis occurred in an infant with a less severe form of the disease. Ultrasound is a valuable tool in the antenatal diagnosis of infantile polycystic kidney disease.

The value of single umbilical artery in the prediction of fetal aneuploidy: findings in 12,672 pregnant women.

Objectives: To assess the risk of the association of single umbilical artery and aneuploidies. Methods: In a general unselected obstetric population of 12,672 singleton pregnant women from January 1998 to December 2002, we detected 61 fetuses (prevalence, 0.48%) with single umbilical artery (SUA) on prenatal ultrasound at 16 to 23 menstrual weeks. Results: Among the 61 fetuses with 2-vessel cord, 39 (64%) had SUA as an isolated finding, and 22 (36%) had additional findings, either minor or major. One (2.56%) of the 39 fetuses with SUA as an isolated finding had aneuploidy (trisomy 21 at maternal age of 32 years), whereas 5 (41.6%) of the 12 fetuses with SUA concomitant with major anomalies were aneuploid. None of the 10 fetuses with SUA and minor anomalies had aneuploidy. Among the 12,611 women with 3-vessel cord, we instead found 8 cases of trisomy 21 (0.06%), 1 case of translocation 14-21 (0.007%), 5 cases of trisomy 18 (0.04%), 1 case of trisomy 13 (0.007%), 1 case of 47,XXX (0.007%), and 2 cases of monosomy X (0.01%). Conclusions: In an unselected population, second trimester sonographic detection of SUA and major fetal anomalies indicate increased risk for fetal aneuploidy. However, even if this study is based on a large population, the only 1 case of trisomy 21 among the fetuses with SUA as an isolated finding is not sufficient to draw a conclusion, and larger studies are needed to confirm or infirm this single case.

An isolated echogenic heart focus is not an indication for amniocentesis in 12,672 unselected patients.

Objective. To evaluate the risk of Down syndrome in fetuses with a heart echogenic focus using the Bayes theorem and likelihood ratios in an unselected population. Methods. We prospectively evaluated 12,672 second‐trimester sonographic features and extracted and examined a population with an echogenic focus for chromosomal anomalies. Results. There were 479 cases of echogenic focus; 90.4% were isolated, whereas 9.6% had associated findings. Eleven patients had fetuses with trisomy 21 (9 per 10,000). Eight of those did not have an echogenic focus, whereas 3 had a heart echogenic focus. Only 1 fetus with trisomy 21 had an isolated echogenic focus. The positive likelihood ratio for total cases of a heart echogenic focus and trisomy 21 was 7.25, whereas for an isolated echogenic focus, the positive likelihood ratio was 2.66. Conclusions. The results of the statistical analysis showed that the risk of aneuploidy is increased in fetuses with an echogenic intracardiac focus; however, the finding should prompt a detailed structural survey and correlation with a priori risk. Amniocentesis need not be offered to patients who are otherwise at low risk and have an isolated echogenic intracardiac focus.

Karyotyping of Fetuses With Isolated Choroid Plexus Cysts Is Not Justified in an Unselected Population

Objective. The main objective of this study was to determine whether isolated choroid plexus cysts are a risk factor for trisomy 18. Methods. A total of 12,672 unselected patients were examined, and the outcome of fetuses with choroid plexus cysts was assessed. The cases with choroid plexus cysts were selected from the 12,672 patients and further divided into cases with minor markers of aneuploidy and cases with associated structural anomalies. Previous similar work was reviewed, analyzed, and, where possible, compared with the results of this study. Results. The findings revealed 366 fetuses with choroid plexus cysts (2.9%). Thirty‐three percent of fetuses with trisomy 18 had choroid plexus cysts, and, in every case, structural anomalies were also present. From the 12 cases with choroid plexus cysts in addition to major associated anomalies, amniocentesis revealed 2 cases of trisomy 18. Forty‐three patients who had choroid plexus cysts and minor anomalies within our population had normal outcomes. Conclusions. These results indicate that the risk of amniocentesis is not acceptable if isolated choroid plexus cysts are isolated findings. More data are needed to establish whether choroid plexus cysts and other soft signs independently increase the risk of aneuploidy.

Air-contrast sonohysterography as a first step assessment of tubal patency

We assessed the use of air as a sonographic contrast agent in the investigation of tubal patency by sonohysterography. We examined 115 women assessed for infertility. After saline sonohysterography, small amounts of air were insufflated, and the tubal passage of bubbles was monitored. In five patients (excluded from the results), cervical stenosis prevented the procedure. Ninety‐one tubes (right side) and 86 tubes (left side) were definitively patent; 5 and 7, respectively, were probably patent; and 12 and 16, respectively, were nonvisualized. Nine patients had polyps, 3 had synechiae, and 2 had submucosal fibroids. None of the patients had infectious complications. Air‐sonohysterography and laparoscopy with chromopertubation showed agreement in 79.4%. In 17.2% of patients, the tubes were considered nonvisualized by air‐sonohysterography when they were patent. The sensitivity was 85.7% and specificity 77.2%. In conclusion, air‐sonohysterography is a comfortable, simple, and inexpensive first line of tubal patency investigations yielding high accuracy.