Ivan E. Zador

Transabdominal versus transcervical and transvaginal multifetal pregnancy reduction: International collaborative experience of more than one thousand cases * ** *

OBJECTIVES Two major approaches for multifetal pregnancy reduction have been developed over the past several years: transabdominal potassium chloride by injection and pelvic procedures by either transcervical aspiration or transvaginal potassium chloride injection or by an automated spring-loaded puncture device. The purpose of this study was to create the largest database from among the worlds largest centers to assess possible differences in efficacy and complication rates by transabdominal or transcervical or multifetal pregnancy reduction. STUDY DESIGN Data on over 1000 completed pregnancies that underwent multifetal pregnancy reduction by both methods from major centers with among the highest worldwide experience were combined. Transabdominal cases were divided temporally (1986 through 1991 and 1991 through 1993). RESULTS Transabdominal multifetal pregnancy reduction was successfully performed on 846 patients and transcervical or transvaginal on 238 patients. Transcervical or transvaginal reduction is performed earlier and starts and finishes with fewer embryos. In 12.6% of cases transcervical or transvaginal reduction left a singleton as opposed to 4.4% for transabdominal reduction. Pregnancy losses (up to 24 weeks) were observed in 13.1% of transcervical or transvaginal cases and in 16.2% of transabdominal cases early in the series and 8.8% of late transabdominal cases. Transcervical or transvaginal reduction may be safer very early in gestation and transabdominal safer later in the first trimester. Premature deliveries were comparable, with only about 5% delivered between 25 and 28 weeks. The smaller starting numbers for transcervical and transvaginal reduction may explain a slightly higher term delivery rate. The transabdominal route tends to reduce the fundal embryos and the transcervical and transvaginal the lower ones. The significance of this is not clear. CONCLUSIONS (1) Multifetal pregnancy reduction by either method is a relatively safe and efficient method for improving outcome in multifetal pregnancies. (2) More than 84% are delivered at > 33 weeks. (3) The experience and preference of the operator are probably the key determinants for an individual patient. (4) An inverse relationship of starting and finishing number to loss rates and gestational age at delivery suggests that there still is a cost of iatrogenic multifetal pregnancies, even if multifetal pregnancy reduction can be successfully performed.

The clinical utility of maternal body mass index in pregnancy

To describe maternal body mass index and to compare the use of maternal weight and body mass index for risk assessment at the initial prenatal visit, 6270 gravid women who were consecutively delivered of infants were studied. Body mass index increased with advancing maternal age, parity, and advancing gestational age and was significantly greater in black women than in nonblack women. Risks for the development of adverse outcome associated with maternal obesity, including development of gestational diabetes, preeclampsia, fetal macrosomia, and shoulder dystocia, were comparably predicted by either maternal weight or body mass index greater than 90th percentile. Maternal weight was as predictive of preeclampsia, macrosomia, and shoulder dystocia as was body mass index when these factors were analyzed as continuous variables, whereas increasing body mass index was more predictive of gestational diabetes. The prediction of factors associated with low maternal weights, small-for-gestational-age birth, prematurity, low birth weight, and perinatal death was equivalent for maternal weight and body mass index that was less than 10th percentile. This study indicates that in the initial risk assessment of outcomes related to maternal weight, the calculation of maternal body mass index offers no advantage over simply weighing the patient. This finding contrasts with results in nonpregnant women.

International, collaborative experience of 1789 patients having multifetal pregnancy reduction: a plateauing of risks and outcomes.

Objective: To develop the most up-to-date, complete data base of multifetal pregnancy reduction (MFPR) from cases, and to provide the best counseling for couples with multifetal pregnancies. Methods: From nine centers in five countries, 1789 completed MFPR cases were collected and outcomes evaluated. Pregnancy losses were defined as through 24 weeks and deliveries categorized in groups of 25-28, 29-32, 33-36, and 37 or more weeks. Results: Overall, the pregnancy loss rate was 11.7% but varied from a low of 7.6% for triplets to twins and increased with each additional starting number to 22.9% for sextuplets or higher. Early premature deliveries (25-28 weeks) were 4.5% and varied with starting number. Loss rates by finishing number were highest for triplets and lowest for twins, but gestational age at delivery was highest for singletons. Conclusions: Multifetal pregnancy reduction has been shown to be a safe and effective method to improve outcome in multifetal pregnancies. Outcomes are worse with higher-order gestations and support the need for continued vigilance of fertility therapy.

Classification of human fetal movement

A study of fetal activity was undertaken as the first step in a series of physiologic fetal movement studies. A simple, safe, noninvasive, clinically applicable method for studying fetal movement with a tocodynamometer is described. Four basic types of fetal movement have been seen and defined in terms of their durations, recorded patterns, and descriptive terminologies for identifying each movement.

Single umbilical artery: Accurate diagnosis?

OBJECTIVE We sought to evaluate the accuracy of ultrasonographic, obstetric, and neonatal diagnosis of a single umbilical artery. STUDY DESIGN We studied 17,777 consecutive singleton births from women who had undergone ultrasonographic examination at our hospital. A single umbilical artery was confirmed in 37 cases (0.2%) by two clinical methods or by pathologic assessment. Outcome of neonates with a single umbilical artery was compared with the outcome of neonates with either two or three vessel cords. RESULTS Ultrasonographic diagnosis had a 65% sensitivity and positive predictive value. Obstetricians and pediatricians failed to diagnose 24% and 16% of the cases, respectively. On average, neonates with a single umbilical artery weighed 320 gm less, were delivered 1 week earlier, and had lower Apgar scores than neonates with three vessel cords (p < 0.01 in each case.) CONCLUSION Although early gestational age may account for some cases not diagnosed by ultrasonography, there is a little justification for missing the diagnosis after delivery. Greater emphasis on clinical examination of the umbilical cord is needed to identify neonates at risk of associated malformations.

Genetic diagnosis in the first trimester: The norm for the 1990s

Increasing technical capabilities and patient motivation for earlier and more private prenatal genetic diagnosis have allowed us to alter the concept of first-trimester genetic diagnosis from being rare to routine in our tertiary Reproductive Genetics Center. As public awareness of available services has increased, we have seen steadily increasing numbers and proportion of patients who are referred by their physicians earlier, who schedule tests earlier, opting to have earlier testing, and accept slightly higher risks in return for earlier results and privacy. Analysis of our clinical and laboratory results and complication rates suggests that first-trimester genetic diagnosis by either chorionic villus sampling or early amniocentesis may be offered to virtually all patients who would be candidates in the midtrimester. We believe that this trend will accelerate, making first-trimester diagnosis the norm, rather than the exception, for the 1990s.

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 sonographers 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.

Antenatal investigation of human fetal systolic time intervals

A noninvasive method for measuring the antenatal human fetal systolic time intervals with the use of the transabdominal fetal electrocardiogram and Doppler cardiogram is described. Unique interactive computer routines were developed for rapid and accurate determination of the pre-ejection period (PEP), ventricular ejection time (VET), PEP/VET ratio, and fetal heart rate (FHR). Thirty normal patients were monitored between 20 and 40 weeks of gestation. A regression analysis of the fetal systolic time intervals and FHR against gestational age was done. PEP and PEP/VET ratio were significantly correlated to the gestational age, while VET and FHR were not.

Integration of genetics and ultrasonography in prenatal diagnosis: Just looking is not enough

OBJECTIVE There has been a gradual shift of the focus of prenatal diagnosis from genetics to ultrasonography. We assessed our primary genetics approach to determine what would be missed without the genetics component. STUDY DESIGN We evaluated referral indications for patients with normal and abnormal prenatal findings from Jan. 1, 1990, to March 31, 1995, and categorized them according to type of fetal anomalies and genetic abnormalities found. Discordance among initial indication, identified risk factors, and observed abnormalities was assessed. RESULTS The proportion of patients referred for very-high-risk indications increased over time; 13.5% of all patients (1992 of 14,725) had abnormalities. Abnormal outcomes were categorized as 26% chromosomal, 58% ultrasonographic dysmorphologic features, 11% biochemical or deoxyribonucleic acid disorders, 5% infectious, and 11% other. Of the cases of ultrasonographic dysmorphism (exclusive of the aneuploidies), 3.5% were ultimately determined to be syndromic and 2.5% to be discrepant, that is, having a different abnormality than the referred diagnosis. Including the whole spectrum of disorders seen, half of the abnormalities would not be detectable with even high-quality ultrasonography. CONCLUSION A large number of abnormal findings were not consistent with initial indication for referral. Correct diagnosis depended on increased acuity provided by genetic pedigree analysis and recognition of syndromes. Diligence in the search for associated anomalies, aneuploidy, pedigree analysis, and syndromic abnormalities remain critical components in the differential diagnosis. The elucidation of unexpected findings suggests the advantages of early counseling and a genetics-based approach combined with tertiary rather than primary ultrasonography with counseling only when anomalies are detected.

Human fetal respiratory movements: a technique for noninvasive monitoring with the use of a tocodynamometer.

A tocodynamometer applied to the maternal abdomen is used for monitoring human fetal respiratory movements (FRM). This provides a recording of fetal chest wall movements from which observations and measurements relating to fetal respiratory physiology may be made. The FRM must be differentiated from materanal vascular and respiratory movements, as well as fetal movements and cardiac pulsations. The technique lends itself to extended periods of observation, since it does not transmit energy to the fetus as in other techniques. The simplicity of the technique, combined with the use of monitoring devices already available in most hospitals, warrants further observation of this method of respiratory movement monitoring in the developing fetus.