Search

Objective: To determine the relationship between gestational age and the ultrasonic measurement of umbilical coiling index (UCI), and to assess the ability of second-trimester ultrasonic measurements of UCI to predict the true UCI, determined at birth., Subjects/methods: Five hundred and thirty-one consecutive women with uncomplicated pregnancies, booking for delivery with a singleton pregnancy, were recruited during a routine second-trimester fetal morphology scan. Multiple ultrasonographic measurements of the intercoil distance were performed between two to three coils of the umbilical cord, along its entire visible length. Three hundred and seventy-four patients (70%) were followed until delivery when the true UCI was measured., Results: An adequate portion of umbilical cord for assessment of coiling was visualized in 99% of cases. Adequate ultrasonographic visibility rates for the fetal, middle and placental regions of the cord were different. All three regions of the umbilical cord could only be visualized adequately in 10% of cases, and two regions were visible in 75%. The UCI progressively decreased along the cord from the fetal insertion to the placental insertion. The mean decrease in UCI with increasing gestational age was similar in all parts of the cord before the 23rd week (160 days) of pregnancy, and plateaued off after this point, except in measurements performed near the fetal insertion. The sensitivity of second-trimester ultrasound examination for predicting hypercoiling at birth was 17.3% and for predicting hypocoiling was 9.1%., Discussion: Whilst UCI can be measured easily and reliably in the second trimester these estimates do not accurately reflect the UCI at term. Our original assumption that umbilical coiling does not alter after the initial formation of coils in the first trimester is incorrect; mixed patterns occurred in about 25% of cases. These patterns develop during the second and third trimesters, presumably due to snarls in the cord, and influence the final coiling number and therefore the relationship between the two measurements of UCI.

The umbilical cord is crucial to the growth and development of the fetus. Careful inspection in the delivery room and throughout the newborn period is essential. Part 1 of this 2-part series, entitled "Look Before You Clamp: Delivery Room Examination of the Umbilical Cord" (Advances in Neonatal Care, Vol. 2, No. 1, pp 19-26), reviewed umbilical problems that present in the delivery room. A number of subtle but significant umbilical cord abnormalities present outside the delivery room. These abnormalities will be the focus of Part 2 of this series. A review of the embryologic development of the umbilical cord enhances the clinician's understanding of umbilical abnormalities that present in the newborn period. The process of umbilical cord separation is outlined. Conditions associated with delayed cord separation are discussed. A systematic approach to the physical examination of the umbilicus is offered, with an emphasis on early detection of abnormalities. Common and uncommon physical findings, such as omphalitis, periumbilical necrotizing fascitis, vitelline duct remnants, and urachal anomalies are presented along with select photographs. A brief discussion of the clinical implications for newborn care is provided for the practicing clinician.

Objective: To provide reference values for the umbilical coiling index in uncomplicated pregnancy., Methods: Umbilical cords were collected from livebom singleton infants born after uncomplicated pregnancies. The umbilical coiling index (UCI) was calculated as the number of coils divided by the cord length in centimeters. The mean value (SD) for the UCI was calculated, and possible correlations of the UCI with maternal age, parity, gestational age at delivery, mode of delivery, sex and birth weight of the infant were examined., Results: A total of 122 umbilical cords were included. The frequency distribution of the UCI was skewed to the right. The mean (SD) UCI was 0.17 (0.009) coils/cm. There were no significant correlations of the UCI with maternal age, parity, gestational age at delivery, mode of delivery, sex or birth weight of the infant., Conclusions: This is the first study to determine the UCI in a group exclusively consisting of uncomplicated pregnancies. The mean value that we found for the UCI may serve as the standard reference, allowing proper interpretation of umbilical coiling in complicated pregnancy.

The objective of this study is to determine the risk of adverse pregnancy outcomes resulting from a true umbilical knot. We analyzed 288 singleton pregnancies with a true umbilical knot among the women who gave birth at Kuopio University Hospital from January 1990 to December 1999. Logistic regression analysis was used to compare pregnancy outcomes of the affected cases with those of the general obstetric population (n = 23,027). The incidence of true knot was 1.25% and it was associated with advanced maternal age, multiparity, previous miscarriages, obesity, prolonged gravidity, male fetus, long cord, and maternal anemia. The women having a fetus with a cord knot underwent cesarean delivery less frequently than unaffected controls. Fetal death and low Apgar score at 1 min occurred significantly more frequently in the study group than in the general obstetric population, the adjusted odds ratios being 3.93 (95% CI, 1.41-11.0) and 1.73 (95% CI, 1.10-2.72), respectively. Otherwise, the pregnancy outcome measures were comparable in the two groups. Fetuses with true umbilical knots are at a four-fold increased risk of stillbirth, but little can be done to prevent fetal deaths during pregnancy. Surviving fetuses with true knots are likely to suffer temporary distress during delivery, but affected newborns recover soon after birth. Thus, monitored vaginal delivery appears to be a safe option for fetuses with true knots.

The umbilical cord is a critical connection between the embryo (and later, the fetus) and the placenta. The umbilical cord houses the blood vessels that are responsible for nourishing the fetus. Proper umbilical cord function is essential for growth and development before birth. A review of the embryologic origin of the umbilical cord aids in understanding abdominal wall and umbilical cord defects that can present in the newborn period. In the delivery room, inspection of the umbilical cord is an integral part of the first minutes of life. Any abnormality either within the cord structure or in the areas surrounding the base of the cord may necessitate a delay in shortening the cord. Surgical consultation may also be indicated. This issue of Focus on the Physical will provide a step-by-step guide to cord assessment in the delivery room setting. Pictures showing normal, atypical, and abnormal umbilical cords and common abdominal wall defects will be presented along with a brief discussion of the significance and clinical implications of each of these findings.

Objectives: To generate a nomogram for the sonographic measurement of Wharton's jelly area (WJA) during gestation and to investigate whether WJA is related to fetal biometric parameters., Method: The sonographic cross-sectional area of the umbilical cord and of its vessels was measured in 659 fetuses between 15 and 42 weeks of gestation. The WJA was calculated by subtracting the vascular area from the umbilical cord area. The conventional biometric parameters were measured and correlated with the WJA. Polynomial regression analysis was utilized for statistical purposes., Results: The WJA increased as a function of gestational age (r = 0.63, P < 0.001). The regression equation for the mean WJA (y) according to gestational age (x) was y = -114.7 + 4.142x - 0.01x2 and for the standard deviation (y') was y' = -7.567 + 1.319x. There was a strong correlation between the WJA and the umbilical cord area (r = 0.97, P < 0.001). A significant correlation was also found between the WJA and fetal biometric parameters before 32 weeks of gestation (WJA and biparietal diameter: r = 0.82, P < 0.001; WJA and abdominal circumference: r = 0.79, P < 0.001; WJA and femur length: r = 0.81, P < 0.001) while after 32 weeks of gestation no correlations were found between WJA and fetal anthropometric parameters., Conclusion: A nomogram for the WJA has been generated. The WJA increases as a function of gestational age and it is correlated with fetal size up to 32 weeks of gestation.

Triage is the sorting and allocation of treatment according to a system of priorities in order to maximize treatment. Placental triage promptly after delivery of the placenta, with documentation of the findings in the medical record, only takes a few minutes, and allows for the identification of abnormal placentas to be submitted for detailed gross and microscopic pathology examination. It requires familiarity with normal gross placental anatomy and variations of normal, and the development of a systematic procedure for comprehensive examination of the placental disk as a whole, the umbilical cord, the extraplacental membranes, the fetal surface, the maternal surface, and the parenchyma. This article provides a systematic approach to gross examination of the placenta. It also reviews the clinical and legal impact of placenta examination, and suggests procedures that will optimize the information available in the placenta.

Objective: To determine reference ranges for the diameter and the cross-sectional area of the umbilical cord during pregnancy and to determine if umbilical cord morphometry is related to fetal size., Methods: A prospective cross-sectional study was designed to assess the sonographic cross-sectional diameter and area of the umbilical cord. The sonographic umbilical cord measurements were obtained in a plane adjacent to the insertion of the cord into the fetal abdomen. Nomograms for the umbilical cord diameter and area were computed. Fetal biometry included: biparietal diameter, abdominal circumference, and femur length. Polynomial regression analysis was conducted., Results: Five hundred and fifty seven patients were included into the study. The regression equation for the umbilical cord diameter (y) according to gestational age (x) was y=-10.0563+1.4265x+0.0194x2 and for the umbilical cord area (y') was y'=91.6-3.3x+0.03x2-0.00007x3. A significant relationship was found between umbilical cord measurements and fetal anthropometric parameters., Conclusion: Reference ranges for umbilical cord diameter and area have been generated. The sonographic diameter and cross-sectional area of the umbilical cord increase as a function of gestational age and both diameter and area correlate with fetal size.

Several characteristics of newborns were investigated in our population from northwestern Greece, for the first time during the last 30 years, providing useful data. The study included 5,278 pregnant women who delivered from 1992-1996, and the following parameters have been studied: (1) age of pregnancy at the parturition, (2) weight of newborn, (3) weight of placenta, (4) age of the pregnant woman, and (5) length of the umbilical cord, all five in relation with parity. Statistically significant relationships were found between: (1) age of the pregnant woman and the parity (but not between paras-2 and paras-3), (2) weight of the newborns between primiparas, paras-3, and paras-4 as also paras-2 and paras-4, (3) length of the umbilical cord between primiparas and paras-3 and paras-4. No significant relationship was found between placenta weight and parity, nor between gestational age at the parturition and parity. The study gives these features for the first time, to our best knowledge, of the birth characteristics of a certain and very homogeneous population of northwestern Greece, and these useful data could be the basis for future studies and comparisons with other populations.

This paper reviews the principle features of human placenta structure and development, and it highlights areas of needed future research. The complexity of placental histology is discussed and comparison of the human placenta with other mammalian taxa is made. A more widespread appreciation of the value of studying this challenging organ and a more profound understanding of the regulation of the placental transport functions is advocated. Simple, routine examination of the placenta should be resurrected.

Ultrasonographic prenatal diagnosis of single umbilical artery (UA) is well documented, but the exact siding of the single UA and its correlation with the occurrence of other congenital malformations and the outcome of the baby remain unclear. We report our experience with 46 cases of prenatally diagnosed single UA. This is the first prospective study of a large number of consecutive pregnancies in which the side of the existing artery was identified in fetuses with a single UA. Most of the cases were identified by transvaginal sonography at 14-16 weeks' gestation. A right artery was detected in 25 fetuses (54.3 per cent), and a left artery in 21 cases (45.7 per cent). Six fetuses (13 per cent) had associated anomalies, five of them in the urinary system. No correlation was found between the type or severity of the malformations and the side of the missing (or existing) UA. In our experience, the exact location of the single UA can be reliably determined by ultrasonography from the beginning of the second trimester of pregnancy. The selection process of the missing (or existing) vessel is likely to be random, even though a right single artery was seen slightly more often.

We have frequently observed that fetuses born with nuchal cords have umbilical cords that contain less vascular coiling. To study the association between umbilical vascular coiling and nuchal entanglement, the density of umbilical coiling was objectively assessed in relationship to nuchal entanglement of the umbilical cord using the "umbilical coiling index" in 200 consecutive liveborn neonates. The umbilical coiling index of each cord was determined by dividing the number of complete vascular coils by the total length of the cord in centimeters. The mean umbilical coiling index among those with nuchal cords (0.18 +/- 0.09 coils/cm) was significantly less than that among the group without nuchal entanglement (0.21 +/- 0.07 coils/cm), P = 0.01. Among those with umbilical coiling indices < or = 0.10 coils/cm, 42% had nuchal cords, while only 4.8% of cords with indices > or = 0.30 coil/cm had nuchal cords (P = 0.007). It is concluded that a relationship exists between the density of umbilical vascular coiling and nuchal entanglement of the cord.

To investigate the clinical significance of umbilical cord length in human pregnancies, 1087 deliveries at Kaohsiung Chang Gung Memorial Hospital from May 1995 to August 1995 were studied. Our data showed that male fetuses had longer cord length than female and vertex presentation had longer cord length than breech presentation. The cord length and placental weight were significantly related to the birth weight. We found that: 1) only intrauterine growth retardation was associated with the increased risk of fetal distress; 2) secondary arrest of labor and advanced gestational age were correlated with meconium stain; and 3) birth weight and presence of meconium stain were correlated with the secondary arrest (p < 0.05). However, there was no significant correlation between umbilical cord length and fetal well-being. As a result of multivariate analyses, we conclude that the umbilical cord length does not significantly correlate with either maternal age, gestational age (> or = 28 weeks), parity fetal outcome or intrauterine fetal well-being. Birth weight is the only characteristic that is correlated with cord length.

Infection-mediated inflammation may be responsible for premature delivery in cases of preterm prelabour amniorrhexis. Histological examination of the cord and placenta was performed in 54 such pregnancies, in addition to amniocentesis and cordocentesis at presentation. Histological chorioamnionitis was more likely in those with positive amniotic fluid and/or fetal blood cultures, and in those cases with histological evidence of inflammation, the interval to delivery was short regardless of the culture results. Inflammation rather than infection per se may be the best indicator of preterm delivery in preterm prelabour amniorrhexis.

The cellular branch of the immune defence in the newborn has been shown to differ from adults in a number of ways. This report presents new data on the functions of the histamine-secreting cells of the newborn. Mast cells of the newborn were obtained from the human umbilical cord by enzymatic dispersion. The granules of the mast cells of the umbilical cord were found to contain both chymase and tryptase by immunohistochemical staining, and the presence of cell-bound IgE on the mast cell surface was demonstrated by staining sections of umbilical cord with peroxidase-conjugated anti-IgE. The enzymatic dispersion yielded 12,660 mast cells per gram umbilical cord (median), range 2,500-60,300 (n = 48). The mast cells were found to constitute 3.1% of the total nucleated cells in the dispersate (median), range 1.5-3.8%. The histamine release from these cells was measured using a glass microfibre-based method. Both the umbilical cord mast cells and the cord blood basophils released histamine stimulated with anti-IgE, concanavalin A and the calcium ionophore A23187. In contrast to mast cells from adult tissue, the phorbol ester TPA was found to be an efficient secretagogue in both mast cells and basophils from the newborn. After maximal stimulation with anti-IgE and phorbol ester the quantity of histamine released per millilitre of blood was significantly higher in cord blood than in adult blood. The spontaneous histamine release from cord blood basophils was also significantly higher than from adult blood basophils. The mast cells found in the umbilical cord matrix and the cord blood basophils represent a readily available source of metabolically active histamine releasing cells for exploration of the role of histamine-secreting cells in newborn immune defence.

Neonatal and placental factors and compartment volumes of placental parenchyma in relation to variations of cord insertions in normal human placentae were examined. The results of our investigation suggest that the mode of umbilical cord insertion has no significant effect on examined components. Stated differences are probably the effect of biological variations during normal placental and fetal development.

Objective: The length of the umbilical cord varies widely from one pregnancy to another. Although its average length is 50 cm, this measurement could vary from as little as 20 cm to more than one metre. The purpose of our study was to evaluate, in utero, the length of the umbilical cord during the third trimester of pregnancy knowing the propagation velocity of the pressure wave along the cord., Material and Methods: The computation of the apparent length requires two ultrasound transducers, one situated at the aortic fetal arch, the other at the placental extremity of the umbilical artery. Knowing the velocity of the pressure wave (v), as well as the time interval between the systolic peak of two waves (delta t), we can deduce the length of the umbilical cord (delta t x v)., Results: The comparison between the calculated length and the actual length measured shows a significant correlation with a probability of 1%., Conclusion: The knowledge of the length of the umbilical cord is quite useful in the physio-pathological interpretation of the placental resistance index. It is also of interest, before the delivery, to know the length of the cord in order to foresee dystocy and how it relates cord which is either too short or too long.

A study on the anthropometric indices of 3835 singleton newborn babies was conducted over a four months period at Sree Avittom Thirunal Hospital, Trivandrum. Of these, 1921 (50.1%) were male babies and 1914 (49.9%) were female babies. The majority of infants (43%) were born to the middle socio-economic groups and the mean birth weight of babies was high among the high-income groups. Five hundred and ninety six (15.5%) babies weighed less than 2500 g; of these 121 (20.2%) were preterm and 477 (79.8%) were full term. The prevalence of low birth weight (LBW) was high (22.0%) among the mothers aged between 15 and 19 years. There was a significant difference (p < 0.001) in the mean birth weight (BW) of term male and female babies but there was no significant differences in their body length, head circumference and cord length. The mean ponderal index of term newborn babies was 2.3 g/cm3. The mean placental weight of LBW term and preterm babies was less than that of the corresponding normal weight babies. The birth weight of babies was directly proportional to their placental weight.

Normal limits of periumbilical skin were determined in 304 newborn babies in the first 24 h. Cranial umbilical skin (SD) was 12.36 (3.23) mm and caudal umbilical skin (SD) was 8.76 (3.10) mm on the average. It is recommended that cranial umbilical skin measurement should be included in the examination of dysmorphic neonates, and those with cranial skin length above 18.82 mm (> 2 SD) should be carefully evaluated for Rieger syndrome.

The paper presents some salient aspects of a study on the placentation of camel at gross, light and electron microscopic levels. The study involved factors analysis on five pregnant uteri from camel slaughter house in Yazd, Iran. The experimental observations confirmed that unlike other animals, in camel, the fetus only developed in the left horn of the uterus. Based on the distribution type of the chorionic villi, in camel, similar to horse, the placenta was found to be in diffused form. At light microscopic level, the results revealed six layers between the fetal and maternal blood. From this it inferred that camel's placenta was also of epitheliochorial form. The detailed examination further showed that similar to cow and sheep umbilical cord in camel was also limited to the amniotic sac but it contained two arteries, two veins and one urachus. Little amount of elastic fibers were also observed in the histological and electron microscopical sections. At the electron microscopic level, both binucleated and mononucleated cells in trophoblastic layer were confirmed.

Umbilical cord length was measured sonographically in 53 normal fetuses and 15 fetuses with an intrauterine demise. The age of the fetuses ranged from 6.1 weeks to 11 weeks, menstrual age. Intra- and interobserver differences in measurements were not significantly different from zero. A close linear relationship (r2 = 0.89) was found between umbilical cord length and menstrual age in the normal group. The cord lengths of 9 of 15 fetuses (60%) with an intrauterine fetal demise were more than 2 SD below the expected value for menstrual age in normal fetuses.

Objective: The null hypothesis is that fetuses with noncoiled umbilical cords diagnosed in the antepartum period will have outcomes no different from those with normally coiled cords., Study Design: We prospectively gathered data from Jan. 1 through May 18, 1992, from all fetuses undergoing routine ultrasonographic evaluation. The outcomes of fetuses noted to have noncoiled umbilical cords were compared with those of a control group of fetuses with normally coiled cords. The control group consisted of those subjects undergoing ultrasonography during the study period who were ultimately transferred to our perinatal practice for the remainder of the pregnancy (i.e., the highest-risk patients). Two outcome parameters were selected for comparison: fetal anomalies and fetal death., Results: Six hundred eighty-seven consecutive ultrasonographic examinations were performed. Twenty-five subjects (3.7%) had noncoiled umbilical cords identified ultrasonographically (mean gestational age at diagnosis 20.3 +/- 3.5 [SD] weeks). The control group had 197 subjects. The combined incidence of fetal anomalies or death in the noncoiled group (16%) was significantly greater (p < or = 0.05, relative risk 4.6 [95% confidence interval 1.41 to 14.15]) than that of the control group (3.5%). The noncoiled group had two fetal deaths (8%), whereas two deaths (1%) occurred among controls (p < or = 0.05, relative risk 8 [95% confidence interval 1.16 to 50]). Two (8%) fetal anomalies (anencephaly, prune-belly syndrome) occurred in the noncoiled group, whereas the controls (n = 197) had five fetuses (2.5%) with anomalies (not significant)., Conclusion: The antepartum identification of noncoiled umbilical cords appears to be a risk factor for suboptimal pregnancy outcome.

We investigated whether variations in mode of attachment of umbilical cords and vessels coincided with differences in maternal haemoglobin genotype and neonatal factors or placental micro-volumetric composition. The incidence of placentae with marginally inserted cords, or those in which umbilical vessels separated prior to insertion, was not statistically different in samples from sickle cell patients having haemoglobin-SS and haemoglobin-SC genotypes, as compared with haemoglobin-AA controls. Results obtained from analysis of variance (ANOVA) suggest that the mode of insertion (status) of umbilical vessels may have clinical significance, because it produced differences in the main effects associated with neonatal gestational age, placental weight, and placental index. Point counting stereology was employed to estimate the microscopic compartment volumes of placentae prior to an assessment of statistical association between the data obtained and the status of umbilical vessels and maternal haemoglobin genotype. Furcate placentae (with separated umbilical vessels) had statistically greater than normal volumes of villi, villous trophoblast, and syncytial knots. We deduce that furcate placentae are prone to early delivery, because they are heavier, having more voluminous villi with more trophoblast and syncytial knots than controls.

The fine structure of the umbilical cord and appendiculae in the Atlantic sharpnose shark, Rhizoprionodon terraenovae, is examined by light, scanning and transmission electron microscopy. During ontogeny of placental sharks, the yolk sac and stalk become progressively modified as a functional hematrophic placenta and umbilical cord respectively. In most placental sharks the umbilical cord is smooth. In the Atlantic sharpnose shark, the epithelial ectoderm of the somatopleure forms richly vascularized extensions termed appendiculae. Scanning electron microscopy reveals that the base and shaft of appendiculae are flattened while the distal portion may be expanded to form one to three lobes. The surface of appendiculae is composed of two distinct cell types, the most plentiful are microvillar cells. The second cell type contains prominent granules. These cells are much larger than the former and are partially submerged below the surface, except for the cell apex. These cells undergo secretory cycles ending in expulsion of their contents. The possible function of the granulated cells is discussed. The umbilical cord contains an umbilical vein, umbilical artery, ductus vitellointestinalis and extraembryonic coelom. The endodermal ductus initially conveys yolk from the yolk sac to the fetal gut by activity of ciliated cells lining it. The ductus persists in the adult. Microvillar cells, also present in the ductus, may play a role in the absorption of yolk metabolites early in development, prior to yolk depletion. Enteroendocrine cells are wedged between the ciliated and microvillar cells. These cells may exert paracrine regulation of local areas of the ductus.

A frozen segment was prepared from each of 398 consecutively collected umbilical cords after stripping them of blood. Three cross-sections were obtained from each cord, and dye imprints were made. Their surface area was measured by placing a transparency with a grid of squares over the imprint and counting the number of squares it occupied. An average of these three cross-sectional areas was taken to estimate the quantity of Wharton's jelly at any point along the umbilical cord. Of the 14 maternal and fetal variables studied, those that were found to be independently related to the estimated quantity of Wharton's jelly in the umbilical cord were male gender (P = < .01), weight of the fetus (P = .05) and maternal prepregnancy weight (P = < .01). These variables, however, explained only 7% of the observed variation in quantity. A further 3.3% was explained by measurement error, leaving 89.7% of the observed variation unexplained.

Objective: To establish base-line data on cord length among Igbo parturients of Eastern Nigeria, especially relationship between age and parity, gestation length, sex and weight of newborn, placental weight., Design: Retrospective analysis of 1,000 consecutive deliveries., Setting: Mission hospital., Materials and Methods: Placental length of umbilical cord, placental weight, and prenatal data., Results: Cord length varied between 15 cm and 130 cm (mean, 51.5 cm). No relationship found to parity, maternal age, or sex of baby. Increase in cord length with birthweight and gestational age, up to term. Correlation between umbilical length and placental weight, with a variation according to lie of the fetus: longest in cord encirclement and unstable lie, shortest in breech presentation, transverse lie, and twin birth.

Object: To determine the chiral varieties of the vascular helix of the umbilical cord and find their normal proportions., Design: Differences between the sexes were tested by a chi 2 test and the hypothesis that left-handed types occur in 50% of cases was tested using the binomial distribution., Setting: United Arab Emirates., Subject: Gulf Arab singletons from consecutive normal births, 100 male and 100 female., Results: Left-handed helices predominate at 76.5%; right-handed contribute 15.5%; mixed forms, where both chiralities co-exist, were found in 6.5%; indeterminable chirality due to poor helix formation, or varices, reached 1.5%. A significant sex difference could not be established. Chiral generation, on genetic and mechanical-rotational hypotheses, is discussed., Conclusion: The chirality of the cord is easily determined and is the sole distinguishing feature of the cord. Chirality should be entered in the birth record and in pathological descriptions for whatever value it may have in relation to fetal, or postnatal, characteristics and morbidity.

The distances between the xyphoid appendix and the insertion point of the umbilical cord (XU) and between the xyphoid appendix and upper edge of the pubic symphysis (XP) were measured in 201 newborn infants. The mean ratio XU/XP was 0.62 (S.D. 0.044) with no differences between sexes nor correlations with weight or length. Ratios lying between 0.53 and 0.71 can be considered as within the normal range.

Differences in cord length between weight-concordant pairs were studied in 43 monochorionic, 59 same-sex dichorionic and 42 different-sex dichorionic sets of twins and comparisons were made between groups. Of obvious and curious note was the narrow range of cord length differences between twins in monochorionic pairs (range, 0-5 cm; mean, 2.1 +/- 1.6 cm). Same-sex and different-sex dichorionic groups had significantly wider ranges of cord length differences than the monochorionic group (range, 0-34 cm; means, 7.7 +/- 6.4 and 11.0 +/- 6.1 cm, respectively). In the same-sex dichorionic group no pair whose cord lengths differ by > 5 cm has yet been found to be identical. Discordant monochorionic twins had greater differences in cord length. All other factors being equal, the remarkably similar cord lengths of concordant identical twins strongly supports the hypothesis that a genetic component influences cord length.

Malformations of the umbilicus are a feature of many dysmorphic syndromes including Rieger syndrome, Robinow syndrome, and Aarskog syndrome. The characteristic umbilical malformation in Rieger syndrome consists of redundant periumbilical skin which extends along the cord for an excessive distance. Although the measurement of umbilical skin length plays an important role in the neonatal diagnosis of Rieger syndrome, normal values for this measurement in healthy neonates have not been established. Umbilical skin length was measured in 104 healthy neonates. The length to which the umbilical skin extended along the cranial aspect of cord (mean 11.53 mm, SD 3.58) was significantly longer than the umbilical skin length along the caudal aspect (mean 8.71 mm, SD 2.89) (P less than .05). Multiple regression analysis revealed a significant association between age and umbilical skin length. Birth weight, length, and gestational age were not significantly associated with umbilical skin length when adjusted for the other three variables. No significant differences in umbilical skin length were observed between male and female groups. The above normal values should aid in the neonatal diagnosis of Rieger syndrome, and furthermore it is recommended that cranial umbilical skin length measurement be included in the examination of the dysmorphic child.

The authors, based on a bibliographic search, present a brief survey of the history of the anatomical aspects of the funiculus in mammals, including the evolution of their interpretation and their relationship with the evolution of scientific and technological approaches to their study.

The average length of the umbilical cord is 50-60 cm in the normal full term newborn infant. The length of the cord is an index of foetal activity and is dependent on the tension caused by the freely moving foetus, primarily during the second trimester. The short cord is associated with foetal akinesis or maldevelopment of the central nervous system and is a significant early marker of developmental abnormalities including Down syndrome. Abnormal girth of the cord should make one suspicious of a patent urachus or an umbilical hernia and caution should be used before clamping. The importance of the twist is that, if not present, one should suspect congenital anomalies. The twist should be to the left or counter clockwise. The cord stump separates from the baby at about two weeks of age at present in the era of triple dye care with a large variability due to multiple factors.

The factors controlling the length of the human umbilical cord are uncertain. In the generally accepted 'tension theory', the length of the umbilical cord is proposed to increase the tensile force on it in the uterus. The greatest tensile force is supposed to be fetal movement. If this is so, the length of the umbilical cord should be shorter in multiple pregnancy than in single pregnancy. To examine this possibility we measured the umbilical cord lengths in 3314 singleton births, 82 twins births (164 infants), and 11 triplet or quadruplet births (35 infants). The cord lengths in multiple pregnancies (twins 51.3 cm, triplets and quadruplets 50.1 cm) tended to be shorter than that in singleton pregnancies (57.2 cm). However, no significant difference was found in the ratio of the umbilical cord length to the infant body weight in these groups. Therefore, we conclude that an important factor in determining the cord length is the size of the infant.

The length of the umbilical cord was studied in 179 Indonesian newborns to determine the normal range of cord length and its influence on the occurrence of intrapartum complications such as meconium stained amniotic fluid, asphyxia and entanglement of the cord around the fetus. The authors also attempted to investigate whether unfavourable intra uterine conditions could influence cord length. Therefore a correlation between cord length, sex, gestational age, birthweight and head-circumference was sought. The mean length of the umbilical cord was 52.2 cm., with a S.D. of 10.2 cm, ranging from 31-100 cm. Male infants had significantly longer umbilical cords than females (p = 0.02). The risk of complications increased parallel with cord length.

Fascicles of human sural (peripheral sensory) nerve were used as external fiducial points (FP) for accurate registration of serial light microscopic sections in three-dimensional reconstruction of human umbilical cord. This paper describes a method for embedding the FPs within the paraffin wax block simultaneously with the specimen to be sectioned. Using a new design of embedding box, the FPs are embedded close to the specimen and are transferred to the slides as part of the tissue sections. Three to four FPs were used to align and scale the serial tissue sections for digitization and computerized reconstruction, using a commercially available software program on IBM-compatible 80386 hardware. A three-dimensional solid surface graphic model of a segment of human umbilical cord was generated.

Six hundred and sixty-one consecutive umbilical cords of babies at term in an African obstetric population were studied. The mean cord length was 58.4 +/- 12.02 cm. The pattern of frequency distribution of cord length in this study conforms to previous findings from other racial groups, establishing the fact that cord length and its variability are not racially determined. There is a significant correlation between the cord length and weights of the fetus and placenta but not with the mother's parity.

The Poiseuille equation of fluid flow suggests that umbilical cord length and cord blood viscosity may affect resistance to flow and thus affect the systolic/diastolic ratio. In this prospective study of 40 uncomplicated term pregnancies, we sought to define the relationship of umbilical cord length and cord blood hematocrit level (as an index of viscosity) to the umbilical artery systolic/diastolic ratio. To focus on these factors, we minimized known sources of systolic/diastolic ratio variability and controlled for fetal heart rate. Linear regression revealed that fetal heart rate contributed 18% of the systolic/diastolic ratio variability. Conversely, umbilical cord length and cord blood hematocrit level were not related to umbilical artery systolic/diastolic ratio. We conclude that normal variations in cord blood hematocrit level and umbilical cord length do not significantly affect systolic/diastolic ratio.

Sonograms from 1622 consecutively scanned singleton pregnancies at a mean gestational age of 28.5 weeks were analyzed to determine whether maternal obesity affected visualization of fetal anatomy. Fetal head (cerebral ventricles), heart (four-chamber view), stomach, kidneys, bladder, diaphragm, intestines, spinal column, extremities, and umbilical cord were classified as visualized or suboptimally visualized. Maternal body mass index was used as a measure of relative leanness. No significant impairment of ultrasound visualization was noted until a body mass index above the 90th percentile, when visualization fell by an average of 14.5%. Reduction in visualization was most marked for the fetal heart, umbilical cord, and spine. Among non-obese women, advancing gestation and decreasing body mass index were the most important determinants of visualization. However, among obese women, body mass index was the best predictor of visualization, with no improvement seen with advancing gestation or duration of examination.

Umbilical cord length was measured in 9620 male and 9068 female infants and related to gestational age in order to construct a growth chart for umbilical cords. In addition to providing a standard for the US white population, these growth charts illustrate that umbilical cord length is widely divergent at the same gestational age, males have longer cords than females (P less than 0.0001), and umbilical cord growth continues throughout the third trimester.

Almond glycopeptidase is an enzyme which cleaves specifically beta-aspartylglucosylamine linkages in glycoproteins with asialo-carbohydrate moieties. With this enzyme, it was possible to demonstrate the localization of asparagine-linked oligosaccharides in glycoproteins of human placenta and umbilical cord tissues. In these tissues, the oligosaccharides were shown to react positively for a series of histochemical procedures for neutral complex carbohydrates such as periodic acid-Schiff (PAS), peroxidase-labelled Ricinus communis agglutinin-I-diaminobenzidine (PO-RCA-DAB) and concanavalin A-peroxidase-diaminobenzidine (Con A-PO-DAB). The asparagine-linked carbohydrates were localized in the placental villi, blood vessels and perivascular tissues and the umbilical cord blood vessels and matrix. The results of previous biochemical analyses performed upon the same tissues (Takahashi et al., 1981) have corroborated the results of the histochemical studies. The present results appear to substantiate the usefulness of almond glycopeptidase for the histochemical demonstration of the particular oligosaccharides of glycoproteins in tissues in general.

A quintuplet gestation after ovulation induction with clomiphene and HCG is described. This is the first quintuplet birth reported in Israel. The pregnancy was associated with ovarian hyperstimulation syndrome, toxemia of pregnancy, and pruritus gravidarum. Diagnosis and management of these cases pose a special problem for the obstetrician and neonatologist. The problem of multiple pregnancies and their control in the treatment of infertility with ovulation-inducing drugs is discussed.