Spatial and temporal epidemiology of sporadic human cases of Escherichia coli O157 in Scotland, 1996-1999

In Scotland, between 1995 and 2000 there were between 4 and 10 cases of illness per 100000 population per year identified as being caused by Escherichia coli O157, whereas in England and Wales there were between 1 and 2 cases per 100000 population per year. Within Scotland there is significant regional variation. A cluster of high rate areas was identified in the Northeast of Scotland and a cluster of low rate areas in central-west Scotland. Temporal trends follow a seasonal pattern whilst spatial effects appeared to be distant rather than local. The best-fit model identified a significant spatial trend with case rate increasing from West to East, and from South to North. No statistically significant spatial interaction term was found. In the models fitted, the cattle population density, the human population density, and the number of cattle per person were variously significant. The findings suggest that rural/urban exposures are important in sporadic infections.

The progesterone receptor in human term amniochorion and placenta is isoform C

The mechanism that initiates human parturition has been proposed to be functional progesterone withdrawal whereby the 116-kDa B isoform of the progesterone receptor (PR-B) switches in favor of the 94-kDa A isoform (PR-A) in reproductive tissues. Recently other PR isoforms, PR-S, PR-C, and PR-M generated from the same gene have been identified and partially characterized. Using immunohistochemical, Western blotting, and RT-PCR techniques, evidence is provided that the major PR isoform present in human term fetal membranes (amnion and chorion) and syncytiotrophoblast of the placenta is neither of the classical nuclear PR-B or PR-A isoforms but is the N terminally truncated 60-kDa PR-C isoform. Evidence is also provided that the PR-C isoform resides in the cytoplasm of the expressing cell types. Data are also presented to show that PR-B, PR-A, and PR-S isoforms are essentially absent from the amnion and chorion, whereas PR isoforms A, B, C, and S are all present in the decidua, with PR-A being the major isoform. The syncytiotrophoblast of the placenta contains the cytoplasmic PR-C isoform but not PR-A, PR-B, or PR-S. The major PR isoform in the amnion, chorion, and placenta is PR-C, suggesting that the cytoplasmic PR-C isoform has a specific role in extraembryonic tissues and may be involved in the regulation of human parturition.

Preliminary x-ray characterization of authentic providence virus and attempts to express its coat protein gene in recombinant baculovirus

Providence Virus (PrV) is a non-envoloped, T = 4 icosahedral beta-tetravirus that undergoes autocatalytic cleavage of its coat protein precursor after capsid assembly. This is also a well characterized function of Nudaurelia capensis omega virus (NomegaV), a member of the related omegatetraviruses, whose x-ray structure has been determined. Virus-like particle (VLP) production of PrV in a recombinant baculovirus expression system was attempted to obtain high VLP yields for comparison of structural and autocatalytic active site properties between these virus groups. This resulted in insoluble aggregates of PrV coat protein even though NomegaV VLPs have been successfully produced in the same system. Betatetraviruses may be more dependent on compartmentalization and availability of their full-length genome for proper folding and assembly. However, crystals were grown of limited quantities of authentic PrV produced in cell culture and a partial X-ray data set collected to 3.8 A resolution. The virus particle position and orientation in the unit cell was determined by space group consideration and rotation function analysis. A phasing model, based on NomegaV, was developed to initiate the structure solution of PrV.

The effect of prepartum antibiotics on the type of neonatal bacteraemia: insights from the MRC ORACLE trials

We analysed the type of bacteraemia before discharge from Neonatal Intensive Care Units in babies born to women randomised to the MRC ORACLE Trials. There was no evidence for an effect of oral antibiotics given prior to delivery on bacteraemia due to gram negative or enterococci bacteria, but Group B streptococcal (GBS) bacteraemia was significantly reduced in women with preterm prelabour rupture of the membranes (1.58% to 0.55%, relative risk 0.34; 95% CI: 0.17-0.70). There was no detectable effect in women in spontaneous preterm labour with intact membranes as the risk of GBS bacteraemia in their babies was very small regardless of treatment.

Retrospective study of bacterial infective arthritis in 31 dogs

OBJECTIVES

To characterise the presenting signs and pathological changes of canine bacterial infective arthritis in 31 dogs, and to document the response to different treatment regimens. Risk factors that may predispose joints to bacterial infective arthritis and influence the success of treatment were also investigated.

METHODS

A retrospective review of cases of bacterial infective arthritis that were presented to three university veterinary referral hospitals over a five-year period (January 1997 to January 2002) was performed.

RESULTS

The elbow joint (38 per cent) and stifle joint (44 per cent) were most commonly affected. Radiographic changes consistent with pre-existing osteoarthritis were identified in 14 joints, which had no history of previous surgery (articular or periarticular) or penetrating wound. No significant difference (P = 0.78) was identified between the outcome of combined surgical and medical management, and medical management alone. There were trends for poorer outcomes with increased bodyweight of the dog, longer duration of lameness and a higher nucleated cell count of the affected joint fluid at presentation. The overall infection rate for articular surgical procedures at one institution was 1-3 per cent.

CLINICAL SIGNIFICANCE

Medical and/or surgical management were usually successful in resolving infection (94 per cent). However, they were frequently unsuccessful in restoring full joint function; this may in part have been due to the nature of the underlying joint

Relationship between antenatal inflammation and antenatal infection identified by detection of microbial genes by polymerase chain reaction

Although antenatal infection is thought to play an important role in the pathogenesis of preterm labor and neonatal diseases, the exact mechanisms are largely unknown. We sought to clarify the relationship between antenatal infection and intrauterine and neonatal inflammation. Samples were obtained from 41 preterm infants of <33 wk gestation delivered to 36 mothers and analyzed for the presence of 16s ribosomal RNA (16s rRNA) genes using PCR and for the proinflammatory cytokines IL-6 and IL-8. In 16 (44%) mother-baby pairings, at least one sample was found to be positive for the presence of 16s rRNA genes. All but one of the positive samples were from mothers presenting with preterm prelabor rupture of membranes (pPROM) or in spontaneous idiopathic preterm labor. A strong association was found between the presence of 16s rRNA genes and chorioamnionitis and with funisitis. A marked increase in IL-6 and IL-8 was noted in all tissues positive for 16s rRNA genes, including placenta, fetal membranes, cord blood serum, and, where samples were available, in bronchoalveolar lavage fluid (BAL) and in amniotic fluid. Interestingly, gastric fluid was always positive for 16s rRNA genes if any other intrauterine or BAL sample was positive, suggesting that this sample may provide an alternative to amniotic fluid to identify antenatal infection. In conclusion, we have found that microbial genes are particularly prevalent in pPROM and spontaneous preterm labor groups and that their presence is strongly associated with a marked intrauterine inflammatory response.

Normative values of Doppler velocimetry of five major fetal arteries as determined by color power angiography

OBJECTIVE

To produce normograms of Doppler indices of major fetal arteries and their ratios relative to the ascending aorta in a cohort of appropriately grown for gestational age fetuses.

METHODS

Prospective longitudinal study of 70 women with appropriately grown for gestational age fetuses between 24 and 38 weeks' gestation attending the Fetal Growth Clinic of a large UK teaching hospital. Doppler velocimetry of the middle cerebral (MCA), umbilical (UmA) and renal arteries (RA) and the ascending (AAO) and descending (DAO) aortas were studied using color power angiography. Ratios of the Doppler indices [pulsatility index (PI), resistance index (RI), systolic/diastolic (S/D) ratio] were then calculated using the ascending aorta as the reference numerator for the other four vessels to produce normograms. Regression analysis was performed to determined the significance, if any, of the changes in these ratios with gestation.

RESULTS

The normograms of the various Doppler indices were similar for the middle cerebral artery, ascending and descending aortas. There was an initial rise to a peak between 30 and 32 weeks and then a gradual return to values at 38 weeks similar to those at 24 weeks' gestation. In the renal artery, the indices showed very little variation with gestation. However, there was a gradual fall in the indices with gestation in the umbilical artery. The ratios of the various indices relative to that of the ascending aorta demonstrated an increase with gestation. The changes with gestation were statistically significant for the ratios of the indices from the ascending aorta to those of the middle cerebral, renal and umbilical arteries but not for those of the descending aorta.

CONCLUSIONS

The vascular resistance in the five fetal arteries decreased towards the end of pregnancy and the ratios of their indices relative to those of the ascending aorta decreased from 24 to 38 weeks' gestation. Early subtle changes in circulation in compromised fetuses may be identified early from deviations in these normograms.

Effects of Carnitine Supplementation on Muscle Metabolism by the Use of Magnetic Resonance Spectroscopy and Near-Infrared Spectroscopy in End-Stage Renal Disease

BACKGROUND/AIM

A defect in skeletal muscle mitochondrial metabolism develops in patients with chronic renal failure on haemodialysis. Treatment with carnitine, a compound essential for normal mitochondrial function, has been suggested to have significant benefits in such patients, so we carried out a study to see if carnitine acts by improving muscle bioenergetics and function.

METHODS

In a phase II randomised double-blind trial, patients with end-stage renal disease received placebo or intravenous L-carnitine (20 mg/kg dry body weight three times weekly after haemodialysis) for 16 weeks (n = 13 in each group). 31P magnetic resonance spectroscopy, 1H magnetic resonance imaging and near-infrared spectroscopy were used to measure muscle bioenergetics and function at baseline and at 16 weeks.

RESULTS

There were no significant differences between groups at baseline. Mean plasma carnitine rose 10-fold in the carnitine group but was unchanged in the placebo group. L-carnitine had no statistically significant effect on any of the parameters measured. The rate of proton efflux from muscle, as a measure of tissue perfusion, was low in both groups and was not affected by treatment.

CONCLUSIONS

The study failed to show any significant effect of 16 weeks' L-carnitine supplementation on these objective measures of muscle metabolism and function. Slow proton efflux from muscle provides evidence supporting low blood flow and, therefore, decreased oxygen availability, as an underlying mechanism for muscle mitochondrial dysfunction in this disorder.

Plasma levels of the endocannabinoid anandamide in women--a potential role in pregnancy maintenance and labor?

Although exposure to exocannabinoids (e.g. marijuana) is associated with adverse pregnancy outcome, little is known about the biochemistry, physiology, and consequences of endocannabinoids in human pregnancy. In these studies, we measured the levels of the endocannabinoid anandamide (N-arachidonoylethanolamine, AEA) by HPLC-mass spectrometry in 77 pregnant and 25 nonpregnant women. The mean +/- sem plasma AEA levels in the first, second, and third trimesters were 0.89 +/- 0.14, 0.44 +/- 0.12, and 0.42 +/- 0.11 nm, respectively. The levels in the first trimester were significantly higher than those in either the second or third trimester. During labor, AEA levels were 3.7 times nonlaboring term levels (2.5 +/- 0.22 vs. 0.68 +/- 0.09 nm, P < 0.0001). During the menstrual cycle, levels in the follicular phase were significantly higher than those in the luteal phase (1.68 +/- 0.16 vs. 0.87 +/- 0.09 nm, P < 0.005). Postmenopausal and luteal-phase levels were similar to those in the first trimester. These findings suggest that successful pregnancy implantation and progression requires low levels of AEA. At term, AEA levels dramatically increase during labor and are affected by the duration of labor, suggesting a role for AEA in normal labor.

Neuropsychological and Information Processing Performance and Its Relationship to White Matter Changes Following Moderate and Severe Traumatic Brain Injury: A Preliminary Study

Reductions in information processing speed have frequently been reported following moderate and severe traumatic brain injuries (TBIs), consistent with the effects of diffuse white matter damage. Although the corpus callosum (CC) is a common site for diffuse damage following TBI, the effects of this damage on information processing speed have not been adequately examined. This study assessed a TBI group and a matched control group on tests of attention, memory, fluency, and set shifting ability, together with reaction time (RT) tasks requiring the inter- and intrahemispheric processing of visual and tactile information. The RT tasks were designed to target the cognitive functions that are likely to be affected by diffuse white matter damage, including damage to the CC. The TBI group demonstrated deficits in verbal and visual fluency and verbal memory. They were also slower on the visual and tactile RT tasks, were more affected by task complexity, and slower on RT tasks requiring the interhemispheric transfer of information. In fact, one of the interhemispheric tactile RT tasks proved to be the most discriminating of all the cognitive and RT measures. MRIs completed on a subset of TBI participants indicated that the mean CC measurements were 5% to 19% smaller than a normative control group, with the most atrophied areas being the isthmus and anterior midbody. Although white matter atrophy was moderately related to visual and tactile RT performance, and total hippocampal volume related to memory performance, CC area was not related to many of the tasks that were designed to tap interhemispheric processing. None of the standard cognitive tests correlated with outcome in the TBI group, but 1 of the tactile RT measures was significantly related to 2 measures of outcome.

Antenatal screening and intrapartum management of Group B Streptococcus in the UK

OBJECTIVE

To determine whether there has been any change in UK policy for the screening and intrapartum management of Group B Streptococcus in pregnancy over a two year period.

DESIGN

Two national survey's of practice carried out in 1999 and 2001.

SETTING

All obstetric units in the UK.

POPULATION

Clinical directors of maternity services.

METHODS

A questionnaire was sent to all clinical directors of maternity services in the UK requesting information about their policy and practice with respect to antenatal screening for Group B Streptococcus colonisation. Reminders were sent after one month.

MAIN OUTCOME MEASURES

Number of maternity units in the UK screening and offering intrapartum antibiotic prophylaxis for Group B Streptococcus colonisation in pregnancy.

RESULTS

The response rates were 84% in 1999 and 82% in 2001. Of the responding units, six (3%) in 1999 and four (2%) in 2001 used vaginal swab based screening for Group B Streptococcus colonisation in the antenatal period. In 1999, intrapartum antibiotic prophylaxis was offered to women with a previous baby affected by Group B Streptococcus in 85% (176/207) of maternity units and in 2001 this had risen to 95% (193/203). Similarly, in 1999 intrapartum antibiotic prophylaxis was offered to women who were known carriers of Group B Streptococcus in 87% (179/207) of maternity units and in 2001 this had risen to 95% (193/203). Appropriate dosage of a recommended antibiotic was prescribed in 7% (9/123) units in 1999 and in 20% (35/178) units in 2001.

CONCLUSIONS

Although intrapartum antibiotic prophylaxis for women at high risk of giving birth to babies with Group B Streptococcus is widely practiced in the UK, a programme of antenatal screening for Group B Streptococcus colonisation has not been adopted along the lines advocated in the USA. There therefore remains an opportunity to evaluate such a screening programme in a randomised trial.

Frozen storage of Escherichia coli O157 in buffered peptone water and its detection on bovine carcasses

The adaptation of a standard Escherichia coli O157 isolation method involving immunomagnetic separation and a period of frozen storage was investigated. A series of experiments was designed to test the recovery of a bovine strain of E. coli O157 from buffered peptone water after a period of frozen storage at -80 degrees C. The effects of the addition of glycerol at 5 and 10%, freezing time, the number of freeze-thaw cycles, the method of freezing and the method of thawing, the inclusion of a resuscitation-and-incubation step, and the sensitivity of the isolation method were investigated. The most effective method of storing frozen samples for 6 months and recovering strains of E. coli O157 after storage was found to involve 6 h of incubation of sample material in buffered peptone water at 37 degrees C before frozen storage at -80 degrees C with 10% glycerol, a rapid thaw after frozen storage, and resuscitation at 27 degrees C for 1 h and incubation at 37 degrees C for 1 h to allow freeze-injured and stressed bacteria to recover with a period of growth prior to immunomagnetic separation isolation. There was no significant decrease in log counts of a bovine strain E. coli O157 over 6 months of frozen storage in buffered peptone water with 10% glycerol. With this method, it was possible to isolate E. coli O157 from naturally infected bovine carcasses after a period of frozen storage.

Mapping of zones of altered morphology and chorionic connective tissue cellular phenotype in human fetal membranes (amniochorion and decidua) overlying the lower uterine pole and cervix before labor at term

OBJECTIVE

The purpose of this study was to determine the location, frequency, and extent of altered fetal membrane morphology before term labor and its relation to myofibroblast activation in their connective tissue layers.

STUDY DESIGN

Fetal membranes that were obtained from 10 women who underwent prelabor cesarean delivery at 38 to 39 weeks of gestation underwent biopsy examination with respect to the internal os of the cervix. The thickness of their constituent layers was measured, and the numbers of alpha-smooth muscle actin immunoreactive cells (ie, marker of myofibroblast activation) within the reticular layer were counted.

RESULTS

A region that measured 119+/-21cm(2), that exhibited altered morphology of the fetal membranes from the lower uterine pole, and that was characterized by increased connective tissue thickness and decreased thickness of the cellular layers was demonstrated in all patients. In 8 of 10 patients, this region was centered on the location of the Babcock tissue forceps. Within this region was an area of fetal membranes that exhibited alpha-smooth muscle actin immunoreactivity in the cells of the reticular layer and whose number correlated with parameters of altered morphology.

CONCLUSION

All patients before labor at term possess an area of fetal membranes that are located in the lower uterine pole that exhibit altered morphology that is associated with myofibroblastic activation in the chorionic connective tissue.

3-dimensional colour power angiography for staging human placental development

Maldevelopment of placental villous trees and their blood vessels results in impaired fetal growth, which can greatly compromise fetal, neonatal, childhood, and adulthood health. There are no means of directly assessing such maldevelopment. We have applied a new technique of imaging (colour power angiography [CPA]) with 3-dimensional reconstruction to assess directly villous development in human pregnancy in vivo in 20 uncomplicated pregnancies from 13 to 38 weeks' gestation. The chronology of villous trees was much the same in 3-dimensional CPA, scanning electron micrography, and classical histology from controls matched by age. This approach provides a unique opportunity to examine normal placental development directly, and should provide the bases for real-time investigation of placental pathology and a robust method for diagnosis and surveillance during pregnancy.

Testing paleolimnological predictions with molecular data: the origins of Holarctic Eubosmina

Zooplankton of the family Bosminidae have a unique paleolimnological record in many Holarctic lakes that provides a near continuous record of morphological change for thousands of years. If this morphological change could be interpreted reliably, then a rarely achieved direct observation of macroevolution would be feasible. We tested paleolimnological predictions derived from morphological variation found in the genus Eubosmina using mtDNA and nuclear DNA sequence variation from geographically distant Holarctic sites. The mtDNA and nDNA trees were congruent but genetic divergence was inversely associated with morphological divergence. The three most genetically divergent groups belonged to Eubosmina longispina, whose phylogeography and genetic divergence was consistent with glacial vicariance. The genetic evidence also supported the hypothesis that at least two Nearctic species were recent European introductions. Finally, the genetic evidence was consistent with paleolimnology in the finding of several proposed species undergoing rapid morphological evolution and being post-glacially derived from European E. longispina. The results suggested that lacustrine bosminids are susceptible to geographic speciation processes, and that morphological interpretation of diversity in paleolimnology can be markedly improved by genetic studies.

Development of a youth survey to measure risk behaviors, attitudes and assets: examining multiple influences

Currently, most surveys assessing adolescent health concerns focus primarily on risk behaviors and negative influences rather than positive influences such as assets. The purpose of this paper is to describe the development and validation of the Adolescent Health Attitude and Behavior Survey (AHABS). This instrument was developed to measure the prevalence of youth health risk behaviors, attitudes towards adolescent sexual behavior and youth assets in a statewide evaluation effort. The questionnaire was completed by 4368 public high school students in Grades 9-12. Content validity was established through an extensive review of literature, a group process and factor analyses. Reliability was established through Cronbach's alpha coefficients. Factor loadings ranged from 0.48 to 0.84 for scales measuring attitudes towards adolescent sexual behavior and alpha coefficients ranged from 0.61 to 0.81. Factor loadings ranged from 0.34 to 0.90 for scales measuring youth assets and alpha coefficients ranged from 0.69 to 0.85. Because of several limitations (e.g. construct validity was not measured), additional development work is needed. Therefore, the AHABS is still in a developing, but promising, state. Additional psychometric work will provide program practitioners and evaluators with a psychometrically sound tool to measure behaviors, attitudes and assets.

Evaluation of diagnostic procedures for subclinical mastitis in meat-producing sheep

Samples of foremilk were collected from 261 clinically normal glands of 150 ewes, and tested using the California mastitis test (CMT). Further samples were collected from 195 of these glands for determination of automated somatic cell counts (SCC), and from 60 of these glands for bacteriological assessment. The sensitivity and specificity of CMT for detecting samples with SCC above different threshold levels and for CMT and SCC in determining bacteriological status were evaluated using two-graph receiver operating characteristics (TG-ROC). Milk samples were obtained subsequently from ten CMT positive, and five CMT negative first- and second-lactation ewes. Samples were cultured using a variety of media, incubation temperatures and atmospheric conditions, immediately after collection, and 1 week after storage at 4 degrees C and -21 degrees C. Results suggested that CMT is best used as a diagnostic test for ovine subclinical mastitis (SCM) with a cut-off of 3 (distinct gel formation), and that automated SCC thresholds of > 1200 x 10(3) cells/ml are appropriate, especially where low prevalences are expected (e.g. < 5%). Additionally, this study showed that routine bacteriological methods were appropriate for isolation of most species of pathogen responsible for ovine SCM, but storage of samples prior to culture, either at 4 degrees C or -21 degrees C, was detrimental to the isolation of several of these organisms.

Cessation of feline calicivirus shedding coincident with resolution of chronic gingivostomatitis in a cat

Feline calicivirus (FCV) shedding and oral bacterial flora were monitored over a period of 22 months in a case of feline gingivostomatitis (FGS). The cat was treated daily with 50 mg thalidomide capsules by mouth, and 200 mg lactoferrin powder was applied directly to the lesions. Clinical signs began to resolve after 11 months when, in addition to treatment, the diet had been changed to an additive-free cat food supplemented with antioxidant vitamins A, D3 and E. Resolution of clinical signs of FGS coincided with the cessation of FCV shedding, and this is the first report documenting such an association. Which part of the treatment, if any, contributed to the cure requires further investigation.

Quantitative criteria for insomnia

Formal diagnostic systems (DSM-IV, ICSD, and ICD-10) do not provide adequate quantitative criteria to diagnose insomnia. This may not present a serious problem in clinical settings where extensive interviews determine the need for clinical management. However, lack of standard criteria introduce disruptive variability into the insomnia research domain. The present study reviewed two decades of psychology clinical trials for insomnia to determine common practice with regard to frequency, severity, and duration criteria for insomnia. Modal patterns established frequency (> or =3 nights a week) and duration (> or =6 months) standard criteria. We then applied four versions of severity criteria to a random sample and used sensitivity-specificity analyses to identify the most valid criterion. We found that severity of sleep onset latency or wake time after sleep onset of: (a) > or =31 min; (b) occurring > or =3 nights a week; (c) for > or =6 months are the most defensible quantitative criteria for insomnia.

Longitudinal quantification of uterine artery blood volume flow changes during gestation in pregnancies complicated by intrauterine growth restriction

OBJECTIVE

To quantify and compare longitudinal uterine artery volume flow changes in appropriate for gestational age (AGA) pregnancies and those complicated by intrauterine growth restriction (IUGR).

DESIGN

Serial longitudinal study.

SETTING

Large UK Teaching Hospital Obstetrics and Gynaecology Department and Institute of Anatomy, RWTH Aachen, Germany.

POPULATION

Pregnant women with accurately dated singleton pregnancies.

METHODS

Quantified uterine volume flow was prospectively measured by colour power angiography in (a) 32 women with abnormal uterine artery Doppler velocimetry at 20 and 24 weeks of gestation and with risk factors for IUGR (IUGR group) and (b) 25 women with normal uterine artery Doppler velocimetry and no risk factors for IUGR (AGA group) between 20 and 38 weeks of gestation. Values obtained from each gestation were compared using unpaired t test.

MAIN OUTCOME MEASURES

Gestational age at delivery, birthweight and total quantified volume flow (mL/min) per gestation in IUGR and AGA pregnancies.

RESULTS

Twenty of the 32 women recruited into the IUGR group and 18 of the 25 controls fulfilled the criteria for inclusion in the analyses. The mean birthweight [SD] and gestational age [SD] at delivery in the IUGR and AGA groups were 2634 [277] versus 3429 [349] g and 39.5 [1.2] and 41.1 [2.3] weeks, respectively. The diameter of the proximal uterine artery just after it crosses the external iliac artery was smaller in the IUGR group from as early as 20 weeks of gestation but this difference only became statistically significant from 24 weeks of gestation and widened as pregnancy advanced. The quantified volume flow in the IUGR group was significantly less than that in the AGA throughout the study period (287 [117] versus 328 [159] mL/min at 20 weeks (P < 0.05), 334 [169] versus 538 [181] mL/min at 24 weeks [P < 0.004] and 534 [332] versus 830 [284] mL/min at 38 weeks of gestation [P < 0.002]). Volume flow in the IUGR group was 12.5% and 36.7% less than that in the AGA group at 20 and 28 weeks of gestation, respectively.

CONCLUSIONS

Proximal uterine artery diameter and quantified volume flow change with gestation and show significant differences between AGA pregnancies and those complicated by IUGR. These changes occur early and become more marked as pregnancy advances. Early use of these measurements may identify pregnancies at risk of complications.