David Ellwood

A randomized controlled trial of aspirin in patients with abnormal uterine artery blood flow

Objective To evaluate color Doppler imaging of the uterine arteries as a screening test in nulliparous women, and to examine the role of low-dose aspirin therapy in pregnancies with abnormal uteroplacental resistance. Methods At the routine 18-week fetal morphology ultrasound scan, 955 nulliparous women underwent color Doppler imaging of the uterine arteries. Abnormal uteroplacental vascular resistance was defined with respect to both the systolic-diastolic ratio of the flow velocity waveform and the presence of an ipsilateral early diastolic notch. Those with abnormal uterine artery waveforms were asked to participate in a randomized controlled trial of aspirin therapy. Pregnancy outcomes were compared in women with normal or abnormal flow velocity waveforms, as well as in the two arms of the intervention study. Results Of 186 women with abnormal uteroplacental resistance according to criteria defined previously, 102 agreed to randomization to either low-dose aspirin (100 mg/day) or placebo for the remainder of the pregnancy. Abnormal uterine artery flow velocity waveforms were associated with statistically significant increases in preeclampsia (11 versus 4%), birth weith below the tenth percentile (28 versus 11%), and adverse pregnancy outcome (45 versus 28%). Prophylactic aspirin therapy did not result in a significant reduction in pregnancy complications. Conclusion Abnormal uteroplacental resistance at 18 weeks gestation was associated with a significant increase in adverse pregnancy outcome. Low-dose aspirin did not reduce pregnancy complications in women with uteroplacental insufficiency.

The cervix as a predictor of preterm delivery in ‘at‐risk’ women

Objectiveu2002To examine the relationship between ultrasound‐determined cervical status and pregnancy outcome in women ‘at‐risk’ of spontaneous preterm delivery.

Renal tubular dysgenesis and neonatal hemochromatosis without pulmonary hypoplasia.

Renal tubular dysgenesis is a rare disorder of differentiation of the fetal kidney. The condition has previously been reported as a postmortem diagnosis in infants who have had oligohydramnios commencing after 20xa0weeks gestation and have died of renal or respiratory failure shortly after birth with a clinical description of Potter sequence. The absence of clinically significant pulmonary hypoplasia in our case serves to emphasize that renal tubular dysgenesis, fetal anuria and long-standing oligohydramnios can occur without pulmonary insufficiency. The coexistence of renal tubular dysgenesis with neonatal hemochromatosis has been previously described in four published cases. The link between these two rare conditions is clinically important if dialysis or liver transplantation is considered in infants with hepatic and renal failure. Antemortem diagnosis by renal biopsy in our case enabled parental counseling and avoided the inappropriate use of peritoneal dialysis.

Antenatal transfer of rural women to perinatal centres

Summary: The aim of this study was to describe antenatal transfers of rural women to perinatal centres, and among transferred women, to assess the use of selected evidence‐based therapies and determine the predictors of preterm and imminent births. The clinical records of rural women antenatally transferred to perinatal centres in NSW and the ACT during 1997–1998 were reviewed. Of 453 rural antenatal transfers, 408 (90%) were emergency transfers. Increasing remoteness was associated with increased rates of antenatal transfer but not with a lower probability of giving birth. Of all transferred women, 64% delivered; 58% of preterm transfers delivered preterm and of those delivering preterm, 76% delivered within 7 days.

Color Doppler imaging of the uteroplacental circulation in the middle trimester: observations on the development of a low-resistance circulation.

We aimed to study the changes in the flow dynamics of the uteroplacental and umbilical circulations in the middle trimester of normal pregnancy, and establish normal ranges for indices of the Doppler flow velocity waveforms (FVWs) from both circulations at 14, 18 and 24 weeks. A longitudinal study was conducted with the use of color Doppler imaging to localize both uterine arteries and umbilical arteries and obtain FVWs from 106 healthy nulliparous women with a singleton pregnancy. Of these, 70 did not have a complicated pregnancy outcome, defined as hypertension, growth retardation, preterm delivery or perinatal death. We measured the resistance index (RI), pulsatility index (PI), systolic/diastolic (S/D) ratio and presence of early diastolic notching in both uterine arteries, and RI, PI and S/D in one umbilical artery. The results showed a fall in all measured indices of blood flow impedance in the uteroplacental and umbilical circulations and a marked reduction in the incidence of the early diastolic notch in the uterine artery FVWs during the mid‐trimester. Our conclusion was that color Doppler imaging allows for the accurate localization of both uterine and umbilical arteries. Doppler FVWs then obtained confirm the development of the low‐resistance uteroplacental and umbilical circulations in the mid‐trimester. Diastolic notching is common at 14 weeks in normal pregnancy but uncommon at 24 weeks. Copyright

Should obstetricians support a ‘term cephalic trial’?

Recent analyses of the published data suggest that the risks of elective Caesarean delivery in an uncomplicated pregnancy may not outweigh the benefits of vaginal birth by as much as has been supposed. Indeed, this balance may be so close that the place of elective Caesarean delivery of a term cephalic baby might be considered as a worthwhile subject of a randomised controlled trial. We discuss the potential consequences of such a trial and what effect it could have on obstetric practice.

Colour Doppler Imaging of the Uteroplacental Circulation in the Mid‐Trimester: Features of the Uterine Artery Flow‐Velocity Waveform that Predict Abnormal Pregnancy Outcome

EDITORIAL COMMENT: We accepted this paper for publication because it presents data on the use of colour Doppler imaging in a screening test in healthy nulliparas to assess whether abnormal pregnancy outcome can be identified. Unexpectedly there were 4 perinatal deaths in this series and table 4 indicates that in the only case in which the perinatal death was potentially avoidable the 24‐week uterine Doppler studies were normal. There is mounting evidence that Doppler imaging of uteroplacental circulation is useful in the management of identified high‐risk pregnancies but the value of the method as a screening test remains unproven. If larger studies confirm the reliability of this investigation to detect patients who are destined to develop preeclampsia then a possible application of this is identification of women who warrant prophylactic aspirin therapy since recent results show that aspirin therapy is not indicated routinely in nulliparas

46,XY sex-reversal (Swyer syndrome) and congenital diaphragmatic hernia

XY sex-reversal associated with congenital diaphragmatic hernia is a rare clinical entity and was reported with and without gonadal tissue and other congenital anomalies [Meacham et al., 1991; Maaswinkel-Mooij and StokvisBranstma, 1992; Devriendt et al., 1995; Manouvrier-Hanu et al., 2000]. We describe an infant with XY sex-reversal, female genital phenotype, testicular tissue, and left diaphragmatic hernia. A 33-year-old woman had undergone in-vitro fertilization (without ICSI) and was referred at 18 weeks of gestation with a dichorionic diamniotic twin pregnancy complicated by a diaphragmatic hernia (cardiac displacement to the right with stomach and intestine noted to be in the left hemithorax) in twin 1. The condition of both twins remained satisfactory with normal growth. The twins were delivered by caesarean section at 31 weeks of gestation due to spontaneous onset of labor and breech presentation of twin 2. The Apgar scores of twin 1 at 1, 5, and 10 min were 5, 6, and 7, respectively. Birth weight was 1,780 g that was appropriate for gestational age. She was intubated soon after delivery and Survanta administered via the endotracheal tube. She eventually stabilized with bilateral chest drains, high frequency oscillatory ventilation and nitric oxide for bilateral pneumothorax, pulmonary hypoplasia, hyaline membrane disease, and persistent pulmonary hypertension. On the third day of life repair of the left diaphragmatic hernia was performed using a silastic patch since minimal diaphragm was available for a primary closure. Clitoromegaly was observed on day 3 with an otherwise normal introitus, a 17 hydroxy-progesterone level was 19.2 nmol/L (normal 0–24.0 nmol/L). Karyotype was 46,XY genotype in 55 cells. FISH analysis showed no deletion of the SRY gene on the short arm of the Y chromosome using the SRY/ DXZ1 probes. Pelvic ultrasonography indicated presence of uterus and vagina, however, no gonads were visible. At 2 months of age, the clitoromegaly became more pronounced, her testosterone levels were elevated at 8.9 nmol/L (normal< 4.0 nmol/L). At this time, she was stable enough for surgical exploration. Laparotomy showed presence of a uterus, fallopian tubes, and testes attached to vessels enveloped by the broad ligament bilaterally (Fig. 1). The parents had made the decision to rear this infant as a girl therefore all gonadal tissue was removed at laparotomy. Histology with analysis demonstrated benign infantile testes consisting of seminiferous tubules with intervening Leydig cells and epididymi with no ovarian tissue present. The seminiferous tubules were wellformed and both testes contained spermatogonia (Fig. 2). No renal histology is available. Due to severe pulmonary hypoplasia and chronic lung disease, it was not possible to successfully extubate the infant and she died at age 3 months. The parents declined an autopsy.

Categories of intrauterine growth retardation

Originally all low birthweight infants were considered to be premature. When prematurity was redefined in terms of gestational age (SGA) and not preterm. With the large scale collection of obstetric data the distributions of birthweight at different gestational ages were described and from these, infants who were SGA could be defined. SGA became synonymous with terms such as growth retardation, but it soon became appearent that the two were not necessarily interchangeable. Scott and Usher found that it was the degree of soft tissue wasting rather than birthweight that related to poor perinatal outcome. Miller and Hassanein stated that: “birthweight by itself is not a valid measure of fetal growth impairment”. They used Rorher’s Ponderal Index (weight (g) × 100/length (cm)) to diagnose the malnourished or excessively wasted infants with reduced soft tissue mass. Most studies of intrauterine growth retardation (IUGR) still use low birthweight for gestational age centile as their only definition of IUGR or only study infants who have a low birthweight. Altman and Hytten expressed disquiet about this definition and stated: “There is now an urgent need to establish true measures of fetal growth from which deviations indicating genuine growth retardation can be derived” and that “it is particularly important that some reliable measures of outcome should be established”. In large series of term deliveries published recently, two groups of IUGR infants with different growth patterens have been identified. These studies confirm that birthweight alone is inadequate to define the different types of IUGR. They established that low Ponderal Index (PI) is a measure of IUGR associated with an increased incidence of perinatal problems and that it is time to re-evaluate IUGR in terms of the different types of aberrant fetal growth.

Is there a relationship between uterine activity and the length of the cervix in the second trimester

Objective: The purpose of this study was to determine if a relationship could be detected between uterine activity and cervical change in the second trimester.