Multiple courses of antenatal corticosteroids for preterm birth study: outcomes in children at 5 years of age (MACS-5)

IMPORTANCE

A single course of antenatal corticosteroid therapy is recommended for pregnant women at risk of preterm birth between 24 and 33 weeks' gestational age. However, 50% of women remain pregnant 7 to 14 days later, leading to the question of whether additional courses should be given to women remaining at risk for preterm birth. The Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study (MACS) was an international randomized clinical trial that compared multiple courses of antenatal corticosteroids with a single course in women at risk of preterm birth.

OBJECTIVE

To determine the effects of single vs multiple courses of antenatal corticosteroid therapy on death or neurodevelopmental disability (neuromotor, neurosensory, or neurocognitive/neurobehavioral function) at 5 years of age in children whose mothers participated in MACS. Our secondary aims were to determine the effect on height, weight, head circumference, blood pressure, intelligence, and specific cognitive (visual, spatial, and language) skills.

DESIGN, SETTING, AND PARTICIPANTS

Cohort follow-up study of children seen between June 2006 and May 2012 at 55 centers. In total, 1724 women (2141 children) were eligible for the study, of whom 1728 children (80.7% of the 2141 eligible children) participated and 1719 children contributed to the primary outcome.

INTERVENTION

Single and multiple courses of antenatal corticosteroid therapy.

MAIN OUTCOMES AND MEASURES

The primary outcome was death or survival with a neurodevelopmental disability in 1 of the following domains: neuromotor (nonambulatory cerebral palsy), neurosensory (blindness, deafness, or need for visual/hearing aids), or neurocognitive/neurobehavioral function (abnormal attention, memory, or behavior).

RESULTS

There was no significant difference between the groups in the risk of death or neurodevelopmental disability: 217 of 871 children (24.9%) in the multiple-courses group vs 210 of 848 children (24.8%) in the single-course group (odds ratio, 1.02 [95% CI, 0.81 to 1.29]; P = .84).

CONCLUSIONS AND RELEVANCE

Multiple courses, compared with a single course, of antenatal corticosteroid therapy did not increase or decrease the risk of death or disability at 5 years of age. Because of a lack of strong conclusive evidence of short-term or long-term benefits, it remains our opinion that multiple courses not be recommended in women with ongoing risk of preterm birth.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00187382.

Maternal side-effects after multiple courses of antenatal corticosteroids (MACS): the three-month follow-up of women in the randomized controlled trial of MACS for preterm birth study

OBJECTIVE

A single course of antenatal corticosteroids (ACS) is associated with a reduction in respiratory distress syndrome and neonatal death. Multiple Courses of Antenatal Corticosteroids Study (MACS), a study involving 1858 women, was a multicentre randomized placebo-controlled trial of multiple courses of ACS, given every 14 days until 33+6 weeks or birth, whichever came first. The primary outcome of the study, a composite of neonatal mortality and morbidity, was similar for the multiple ACS and placebo groups (12.9% vs. 12.5%), but infants exposed to multiple courses of ACS weighed less, were shorter, and had smaller head circumferences. Thus for women who remain at increased risk of preterm birth, multiple courses of ACS (every 14 days) are not recommended. Chronic use of corticosteroids is associated with numerous side effects including weight gain and depression. The aim of this postpartum assessment was to ascertain if multiple courses of ACS were associated with maternal side effects.

METHODS

Three months postpartum, women who participated in MACS were asked to complete a structured questionnaire that asked about maternal side effects of corticosteroid use during MACS and included the Edinburgh Postnatal Depression Scale. Women were also asked to evaluate their study participation.

RESULTS

Of the 1858 women randomized, 1712 (92.1%) completed the postpartum questionnaire. There were no significant differences in the risk of maternal side effects between the two groups. Large numbers of women met the criteria for postpartum depression (14.1% in the ACS vs. 16.0% in the placebo group). Most women (94.1%) responded that they would participate in the trial again.

CONCLUSION

In pregnancy, corticosteroids are given to women for fetal lung maturation and for the treatment of various maternal diseases. In this international multicentre randomized controlled trial, multiple courses of ACS (every 14 days) were not associated with maternal side effects, and the majority of women responded that they would participate in such a study again.

Multiple courses of antenatal corticosteroids for preterm birth study: 2-year outcomes

OBJECTIVE

The aim of this study was to determine the effects of repeated courses of prenatal corticosteroid therapy versus placebo on death or neurologic impairment among the children enrolled in the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study, at 18 to 24 months of age.

METHODS

A total of 2305 infants were eligible for follow-up evaluation; 2104 infants (1069 in the prenatal corticosteroid therapy group and 1035 in the placebo group) were monitored. The primary outcome was death or neurologic impairment, defined as either cerebral palsy or cognitive delay, at 18 to 24 months of age. The secondary outcomes were measurements of growth (height, weight, and head circumference).

RESULTS

Children exposed to multiple courses of prenatal corticosteroid therapy had similar rates of death or neurologic impairment, compared with children exposed to placebo (148 children [13.8%] vs 142 children [13.7%]; odds ratio: 1.001[95% confidence interval: 0.75-1.30]; P = .95). They had a mean weight of 11.94 kg, compared with 12.14 kg in the placebo group (P = .04), a mean height of 85.51 cm, compared with 85.46 cm (P = .87), and a mean head circumference of 48.18 cm, compared with 48.25 cm (P = .45).

CONCLUSIONS

Multiple courses of prenatal corticosteroid therapy, given every 14 days, did not increase or decrease the risk of death or neurologic impairment at 18 to 24 months of age, compared with a single course of prenatal corticosteroid therapy. Continued follow-up monitoring of these children is necessary to assess neurobehavioral function, school performance, and possible susceptibility to disease.

Multiple courses of antenatal corticosteroids for preterm birth (MACS): a randomised controlled trial

BACKGROUND

One course of antenatal corticosteroids reduces the risk of respiratory distress syndrome and neonatal death. Weekly doses given to women who remain undelivered after a single course may have benefits (less respiratory morbidity) or cause harm (reduced growth in utero). We aimed to find out whether multiple courses of antenatal corticosteroids would reduce neonatal morbidity and mortality without adversely affecting fetal growth.

METHODS

1858 women at 25-32 weeks' gestation who remained undelivered 14-21 days after an initial course of antenatal corticosteroids and continued to be at high risk of preterm birth were randomly assigned to multiple courses of antenatal corticosteroids (n=937) or placebo (n=921), every 14 days until week 33 or delivery, whichever came first. The primary outcome was a composite of perinatal or neonatal mortality, severe respiratory distress syndrome, intraventricular haemorrhage (grade III or IV), periventricular leucomalacia, bronchopulmonary dysplasia, or necrotising enterocolitis. Analysis was by intention to treat. All patients and caregivers were unaware of the treatment given. This trial is registered as number ISRCTN2654148.

FINDINGS

Infants exposed to multiple courses of antenatal corticosteroids had similar morbidity and mortality to those exposed to placebo (150 [12.9%] vs 143 [12.5%]). Those receiving multiple doses of corticosteroids also weighed less at birth than those exposed to placebo (2216 g vs 2330 g, p=0.0026), were shorter (44.5 cm vs 45.4 cm, p<0.001), and had a smaller head circumference (31.1 cm vs 31.7 cm, p<0.001).

INTERPRETATION

Multiple courses of antenatal corticosteroids, every 14 days, do not improve preterm-birth outcomes, and are associated with a decreased weight, length, and head circumference at birth. Therefore, this treatment schedule is not recommended.

FUNDING

Canadian Institutes of Health Research.

Effects of spinal cord injury on lower-limb passive joint moments revealed through a nonlinear viscoelastic model

We developed a mathematical model to describe the lower-limb passive joint moments to investigate and compare these moments in a small sample of able-bodied volunteers and individuals with long-standing motor complete paraplegia. Isokinetic tests, which were performed on a sample of four subjects with spinal cord injuries (SCIs) and five uninjured individuals, measured the passive moments at the ankle, knee, and hip joints throughout their ranges of motion in the sagittal and coronal planes. We fitted an 11-parameter nonlinear viscoelastic model to the acquired passive moment data (mean square error ranging from 0.020 to 5.1 Nm2) to compare subject populations and to determine the influences of joint velocity and passive coupling between adjacent joints. Although the passive moment curves of the SCI and able-bodied groups exhibited many similarities in shape, a repeated measures analysis of variance (ANOVA) that compared the passive moment curves of the two groups indicated a statistically significant (p < 0.01) difference for every joint except the knee. This new model for passive joint moments should prove to be useful in examining how changes in passive properties affect bipedal function and movement.

The costs of planned cesarean versus planned vaginal birth in the Term Breech Trial

BACKGROUND

The Term Breech Trial compared the safety of planned cesarean and planned vaginal birth for breech presentations at term. The combined outcome of perinatal or neonatal death and serious neonatal morbidity was found to be significantly lower among babies delivered by planned cesarean section. In this study we conducted a cost analysis of the 2 approaches to breech presentations at delivery.

METHODS

We used a third-party-payer (i.e., Ministry of Health) perspective. We included all costs for physician services and all hospital-related costs incurred by both the mother and the infant. We collected health care utilization and outcomes for all study participants during the trial. We used only the utilization data from countries with low national rates of perinatal death (< or = 20/1000). Seven hospitals across Canada (4 teaching and 3 community centres) were selected for unit cost calculations.

RESULTS

The estimated mean cost of a planned cesarean was significantly lower than that of a planned vaginal birth (7165 dollars v. 8042 dollars per mother and infant; mean difference -877 dollars, 95% credible interval -1286 dollars to -473 dollars). The estimated mean cost of a planned cesarean was lower than that of a planned vaginal birth for both women having a first birth (7255 dollars v. 8440 dollars) and women having had at least one prior birth (7071 dollars v. 7559 dollars). Although the treatment effect was largest in the subgroup of women having their first child, there was no statistically significant interaction between treatment and parity since the 95% credible intervals for difference in treatment effects between parity equalling zero and parity of one or greater all include zero.

INTERPRETATION

Planned cesarean section was found to be less costly than planned vaginal birth for the singleton fetus in a breech presentation at term in the Term Breech Trial.

A model-based study of passive joint properties on muscle effort during static stance

This study examined the impact of lower extremity joint stiffnesses and simulated joint contractures on the muscle effort required to maintain static standing postures after a spinal cord injury (SCI). Static inverse computer simulations were performed with a three-dimensional 15 degree of freedom musculoskeletal model placed in 1600 different standing postures. The required lower extremity muscle forces were calculated through an optimization routine that minimized the sum of the muscle stresses squared, which was used as an index of the muscle effort required for each standing posture. Joint stiffnesses were increased and decreased by 100 percent of their nominal values, and contractures were simulated to determine their effects on the muscle effort for each posture. Nominal muscle and passive properties for an individual with a SCI determined the baseline muscle effort for comparisons. Stiffness changes for the ankle plantar flexion/dorsiflexion, hip flexion/extension, and hip abduction/adduction directions had the largest effect on reducing muscle effort by more than 5 percent, while changes in ankle inversion/eversion and knee flexion/extension had the least effect. For erect standing, muscle effort was reduced by more than 5 percent when stiffness was decreased at the ankle plantar flexion/dorsiflexion joint or hip flexion/extension joint. With simulated joint contractures, the postural workspace area decreased and muscle effort was not reduced by more than 5 percent for any posture. Using this knowledge, methods can be developed through the use of orthoses, physical therapy, surgery or other means to appropriately augment or diminish these passive moments during standing with a neuroprosthesis.

Mothers’ Views of Their Childbirth Experiences 2 Years Mter Planned Caesarean Versus Planned Vaginal Birth for Breech Presentation at Term, in the International Randomized Term Breech Trial

OBJECTIVE

To compare mothers' views at 2 years postpartum after participation in a randomized trial of planned Caesarean and planned vaginal birth for a singleton fetus in breech presentation at term.

STUDY DESIGN

In selected centres in the Term Breech Trial, mothers completed a structured questionnaire at approximately 2 years postpartum to assess their likes and dislikes about their childbirth experiences and their views about their intrapartum care and care providers.

RESULTS

Of 1159 mothers from 85 centres, 917 (79.1%) completed a follow-up questionnaire at 2 years postpartum. Baseline information was similar for both the planned Caesarean and planned vaginal birth groups. Planned Caesarean was associated with less worry about the baby's health (P < 0.001). While other differences were noted in likes and dislikes about their childbirth experiences, women's evaluations of the quality of intrapartum care, the helpfulness of staff, and their involvement in decision-making did not differ in the planned Caesarean delivery and planned vaginal birth groups.

CONCLUSION

Planned mode of delivery influences aspects of women's evaluations of their childbirth experiences but does not affect evaluations of the quality of intrapartum care, support from care providers, or amount of involvement in decision-making.

Maternal outcomes at 2 years after planned cesarean section versus planned vaginal birth for breech presentation at term: the international randomized Term Breech Trial

OBJECTIVE

This study was undertaken to compare maternal outcomes at 2 years postpartum after planned cesarean section and planned vaginal birth for the singleton fetus in breech presentation at term.

STUDY DESIGN

In selected centers in the Term Breech Trial, mothers completed a structured questionnaire at 2 or more years postpartum to determine their health in the previous 3 to 6 months.

RESULTS

A total of 917 of 1159 (79.1%) mothers from 85 centers completed a follow-up questionnaire at 2 years postpartum. There were no differences between groups in breast feeding, relationship with child or partner, pain, subsequent pregnancy, incontinence, depression, urinary, menstrual or sexual problems, fatigue, or distressing memories of the birth experience. Planned cesarean section was associated with a higher risk of constipation (P = .02).

CONCLUSION

Maternal outcomes at 2 years postpartum are similar after planned cesarean section and planned vaginal birth for the singleton breech fetus at term.

Outcomes of children at 2 years after planned cesarean birth versus planned vaginal birth for breech presentation at term: the International Randomized Term Breech Trial

OBJECTIVE

The purpose of this study was to determine whether planned cesarean delivery for the singleton fetus in breech presentation at term reduces the risk of death or neurodevelopmental delay at 2 years of age.

STUDY DESIGN

In selected centers in the Term Breech Trial, children were screened for abnormalities at > or =2 years of age with the Ages and Stages Questionnaire, followed by a neurodevelopmental assessment if the Ages and Stages Questionnaire score was abnormal.

RESULTS

A total of 923 of 1159 children (79.6%) from 85 centers were followed to 2 years of age. The risk of death or neurodevelopmental delay was no different for the planned cesarean than for the planned vaginal birth groups (14 children [3.1%] vs 13 children [2.8%]; relative risk, 1.09; 95% CI, 0.52- 2.30; P = .85; risk difference, +0.3%; 95% CI, -1.9%, +2.4%).

CONCLUSION

Planned cesarean delivery is not associated with a reduction in risk of death or neurodevelopmental delay in children at 2 years of age.

External cephalic version beginning at 34 weeks' gestation versus 37 weeks' gestation: a randomized multicenter trial

OBJECTIVE

In about 3% to 4% of all pregnancies at term, the fetal presentation will be noncephalic. External cephalic version (ECV) at term has been shown to decrease the rate of noncephalic presentation at birth and to decrease the rate of cesarean section associated with breech presentation. However, success rates for ECV are low. We did a randomized trial to compare a policy of beginning ECV early, at between 34 and 36 weeks' gestation, and beginning ECV at 37 to 38 weeks' gestation.

STUDY DESIGN

At 25 centers in seven countries, 233 women with a singleton breech fetus were randomly assigned to having an ECV procedure done early (at between 34 weeks 0 days and 36 weeks 0 days), or delayed (at between 37 weeks 0 days and 38 weeks 0 days). An experienced practitioner undertook the ECV procedure, and repeat ECV procedures were allowed. Tocolytics and use of epidural analgesia were included as part of the protocol. The primary outcome was the rate of noncephalic presentation at birth. An intention-to-treat analysis was used.

RESULTS

Data were received for 232 women, with 116 women in each of the early and delayed ECV groups. Of these, 86.2% in the early ECV group and 67.2% in the delayed ECV group had at least one ECV performed. The rate of noncephalic presentation at birth in the early ECV group was 66 of 116 (56.9%) and 77 of 116 (66.4%) in the delayed ECV group (relative risk [RR] [95% CI] 0.86 [0.70-1.05], P =.09). The rate of serious fetal complications and the rate of preterm birth at <37 weeks were not significantly increased in the early ECV group compared with the delayed ECV group (6.9% vs 7.8%, RR [95% CI] 0.89 [0.36-2.22], P =.69 and 8.6% vs 6.1%, RR [95% CI] 1.42 [0.56-3.59], P =.31, respectively). The rate of cesarean section in the early ECV group was 75 of 116 (64.7%) and 83 of 116 (71.6%) in the delayed ECV group (RR [95% CI] 0.90 [0.76-1.08], P =.32). Neonatal outcomes were comparable in the two groups. The rate of reversion to noncephalic was low in both groups. The majority of women in both groups indicated that they would consider having an ECV in another pregnancy.

CONCLUSION

Early ECV performed at 34 to 36 weeks compared with 37 to 38 weeks may reduce the risk of noncephalic presentation at delivery. A large pragmatic trial of early ECV is now required to assess this approach further in terms of cesarean section rates and neonatal outcomes before changes in clinical practice.

Abdominal versus vaginal cerclage after a failed transvaginal cerclage: a systematic review

OBJECTIVE

The purpose of this study was to compare the outcomes of pregnancy after transabdominal cerclage versus after transvaginal cerclage in patients with a failed transvaginal cerclage during a previous pregnancy.

STUDY DESIGN

MEDLINE and EMBASE were searched in English. We included studies that reported perinatal and/or maternal outcomes in women who had a transabdominal cerclage or a transvaginal cerclage placed at or before 20 weeks of gestation, after having had a failed nonemergent transvaginal cerclage in a previous pregnancy. Data were included for individual patients if they met the inclusion criteria, and their outcomes were reported separately. We excluded patients with cervical amputation because transvaginal cerclage is not an option for these women because of technical difficulty.

RESULTS

Fourteen studies met the inclusion criteria. Thirteen of the studies were case series (12 retrospective and 1 prospective), and one study was a retrospective cohort study. In total, 157 women in the studies had a failed vaginal cerclage in a previous pregnancy; 117 women had a subsequent transabdominal cerclage; 40 women had a subsequent transvaginal cerclage. The likelihood of perinatal death or delivery at <24 weeks was 6.0% (95% CI, 3.8%-8.2%) after transabdominal cerclage and 12.5% (95% CI, 2.7%-22.7%) after transvaginal cerclage. The likelihood of serious operative complications after transabdominal cerclage was 3.4% (95% CI, 0.01%, 6.8%). There were no serious operative complications after transvaginal cerclage.

CONCLUSION

Transabdominal cerclage may be associated with a lower risk of perinatal death or delivery at <24 weeks of gestation, but it may be associated with a higher risk of serious operative complications. A multicenter randomized controlled trial should be conducted to address this question.

Outcomes at 3 months after planned cesarean vs planned vaginal delivery for breech presentation at term: the international randomized Term Breech Trial

CONTEXT

The Term Breech Trial found a significant reduction in adverse perinatal outcomes without an increased risk of immediate maternal morbidity with planned cesarean delivery compared with planned vaginal birth. No randomized controlled trial of planned cesarean delivery has measured benefits and risks of postpartum outcomes months after the birth.

OBJECTIVE

To compare maternal outcomes of planned cesarean delivery and planned vaginal birth at 3 months post partum.

DESIGN

Follow-up study to the Term Breech Trial, a randomized controlled trial conducted between January 9, 1997, and April 21, 2000.

SETTING AND PARTICIPANTS

A total of 1596 of 1940 women from 110 centers worldwide who had a singleton fetus in breech presentation at term responded to a follow-up questionnaire at 3 months post partum.

MAIN OUTCOME MEASURES

Breastfeeding; infant health; ease of caring for infant and adjusting to being a new mother; sexual relations and relationship with husband/partner; pain; urinary, flatal, and fecal incontinence; depression; and views regarding childbirth experience and study participation.

RESULTS

Baseline information was similar for both the cesarean and vaginal delivery groups. Women in the planned cesarean delivery group were less likely to report urinary incontinence than those in the planned vaginal birth group (36/798 [4.5%] vs 58/797 [7.3%]; relative risk, 0.62; 95% confidence interval, 0.41-0.93). Incontinence of flatus was not different between groups but was less of a problem in the planned cesarean delivery group when it occurred (P =.006). There were no differences between groups in other outcomes.

CONCLUSIONS

Planned cesarean delivery for pregnancies with breech presentation at term may result in a lower risk of incontinence and is not associated with an increased risk of other problems for women at 3 months post partum, although the effect on longer-term outcomes is uncertain.

Repeated doses of antenatal corticosteroids in animals: a systematic review

OBJECTIVE

The purpose of this review was to assess the effects of repeated doses of antenatal corticosteroids on lung and brain function and on growth restriction in animals.

STUDY DESIGN

MEDLINE and EMBASE were searched for randomized controlled trials that compared repeated doses of antenatal corticosteroids versus a single dose, with or without placebo, in pregnant animals.

RESULTS

Nineteen studies were included. The animals that were studied included sheep, monkeys, rabbits, and mice. There were 8 studies that assessed the effects of repeated doses of antenatal corticosteroids on lung function. All the studies reported improvement in lung function after repeated doses of antenatal corticosteroids. Seven studies investigated the effects of repeated doses of antenatal corticosteroids on brain or nervous system function or growth; all the studies found adverse effects with repeated doses of antenatal corticosteroids. Eleven studies looked at the effect of repeated doses of antenatal corticosteroids on fetal growth. Nine studies found evidence of fetal growth restriction with repeated doses of antenatal corticosteroids. One study assessed long-term behavioral outcomes in mice and found no effect.

CONCLUSION

Evidence from randomized controlled trials in animals suggests that repeated doses of antenatal corticosteroids may have beneficial effects in terms of lung function but may have adverse effects on brain function and fetal growth. Because of the differences between animals and humans, it is difficult to extrapolate directly the results of these studies to humans. Therefore, randomized controlled trials in humans are needed to assess the effects of repeated courses of antenatal corticosteroids for pregnant women who are at increased risk of preterm birth in terms of important perinatal, neonatal, and maternal outcomes.

Multiple versus single courses of antenatal corticosteroids for preterm birth: a pilot study

OBJECTIVES

(1) To determine the feasibility of a multicentre, randomized, double-masked, placebo-controlled trial to investigate the effects of multiple courses of antenatal corticosteroids (ACS), more than 7 days following the initial course of ACS therapy, on perinatal or neonatal mortality or neonatal morbidity. (2) To determine the risk of complications that would require discontinuation of ACS therapy. (3) To determine if multiple courses of ACS have an effect on the concentrations of plasma cortisol and adrenocorticotropin hormone (ACTH) in cord blood and in maternal blood immediately following delivery, compared to a single course of ACS.

METHODS

Women at 24 to 30 weeks' gestation, at continued increased risk of preterm birth 7 or more days following a single course of ACS, were randomized to receive weekly courses of betamethasone or placebo until 33 weeks' gestation or delivery.

RESULTS

Women were recruited at two hospitals in Toronto from 01 September 1999 to 31 August 2000. Of the 78 women who were approached and were eligible for the study, 12 (15%) were recruited and 66 (85%) refused to participate. Of the 66 refusals, 38 (58%) did not feel their physicians were supportive of the study, 10 (15%) did not want to be randomized, and 4 (6%) had other personal reasons for refusing to enter the trial. Fourteen women (21%) had physicians who did not allow them to join the study. The lack of physician support was due to concerns related to the potential adverse effects of multiple courses of ACS. There were no complications requiring discontinuation of ACS. Plasma cortisol and ACTH concentrations in cord and maternal blood taken after delivery were not significantly different between ACS and placebo groups.

CONCLUSION

A multicentre randomized controlled trial is required to determine the benefits and risks of multiple versus a single course of ACS. If the study protocols are supported by physicians and their patients, a multicentre randomized controlled trial is feasible.

Multiple courses of antenatal corticosteroids: a systematic review and meta-analysis

OBJECTIVE

To assess the effects of multiple courses of antenatal corticosteroids on perinatal and neonatal death and neonatal, infant, and maternal disease.

METHODS

MEDLINE and Embase were searched for human studies published in English. Studies that compared multiple courses of antenatal corticosteroids versus a single course were included if they were published in full and were controlled for gestational age at birth. Meta-analyses (odds ratio and 95% confidence interval) were undertaken when possible.

RESULTS

Eight observational studies were included. Selection bias was present in all studies. Multiple courses of antenatal corticosteroids were associated with a decreased risk of respiratory distress syndrome (odds ratio, 0.79; 95% confidence interval, 0.64 to 0.98) and patent ductus arteriosus (odds ratio, 0.56; 95% confidence interval, 0.35 to 0.90) and were associated with an increased risk of endometritis (odds ratio, 3.42; 95% confidence interval, 1.92 to 6.11). There was no significant effect on other neonatal and maternal outcomes.

CONCLUSION

It is not possible to establish the true effects of multiple courses of antenatal corticosteroids by a review of the results of observational studies because of the effect of confounding variables. Randomized controlled trials are needed to address this important issue.

Fetal response to maternally administered morphine

OBJECTIVE

We sought to determine the effects of maternally administered morphine on fetal response.

STUDY DESIGN

Singleton pregnancies requiring fetal blood sampling were enrolled. Only study patients were given morphine intramuscularly. Maternal vital signs, fetal heart rate, biophysical profile score, and umbilical artery Doppler indices (systolic/diastolic ratio, resistance index, and pulsatility index) were completed before and after fetal blood sampling. Maternal and cord blood morphine concentrations were measured.

RESULTS

Ten study and 6 control patients were enrolled. A significantly lower biophysical profile score was observed in study patients (P =.001) as a result of absent fetal breathing movements and nonreactive nonstress tests. Gross and fine fetal movements were unaffected. A significant correlation was measured between the biophase morphine concentration and each of the Doppler indices.

CONCLUSION

Morphine administered to the mother causes a significant decrease in the biophysical profile score. Correlation between the biophase morphine concentration and the Doppler indices was calculated. These results suggest that morphine acts as a vasoconstrictor of the placental vasculature but do not support the use of intramuscular morphine to suppress fetal movement.

Prediction of perinatal outcome in fetuses suspected to have intrauterine growth restriction: Doppler US study of fetal cerebral, renal, and umbilical arteries

PURPOSE

To determine and compare the diagnostic performance of fetal middle cerebral (MCA), renal (RA), and umbilical (UA) arterial Doppler ultrasonography (US) for prediction of adverse perinatal outcome in suspected intrauterine growth restriction (IUGR).

MATERIALS AND METHODS

Two hundred ninety-three small-for-gestational age fetuses (24-39 weeks at recruitment and US-estimated weight or abdominal circumference below 10th percentile) were prospectively examined with Doppler US of the UA, MCA, and RA. Clinicians were blinded to MCA and RA Doppler measurements.

RESULTS

Seventy-six fetuses (25.9%) had at least one major or minor adverse perinatal outcome. Major outcomes included stillbirth, neonatal death, neurologic complication, and necrotizing enterocolitis. The MCA pulsatility index (PI), compared with the UA PI and RA PI, was more sensitive (72.4% vs 44.7% and 8.3%) but less specific (58.1% vs 86.6% and 92.6%) in predicting adverse outcome. The UA PI had the highest positive likelihood ratio (ratio, 3.3); the MCA PI had the lowest negative likelihood ratio (ratio, 0.48). When gestational age at the first Doppler US examination was less than 32 weeks, the MCA PI had a sensitivity of 95.5% and negative predictive value of 97.7% for major adverse outcome (negative likelihood ratio, 0.10).

CONCLUSION

In suspected IUGR, while an abnormal UA PI is a better predictor of adverse perinatal outcome than an abnormal MCA or RA PI, a normal MCA PI may help to identify fetuses without major adverse perinatal outcome, especially before 32 weeks gestational age.

Does endothelin-1 reduce superior mesenteric artery blood flow velocity in preterm neonates?

AIM

To compare plasma endothelin-1 (ET-1) concentrations in preterm neonates from pre-eclamptic and normal mothers; and to evaluate whether ET-1 has a role in altered arterial blood flow velocity.

METHODS

Umbilical arterial blood and neonatal arterial blood were sampled on days 1 and 3 for gas analysis and measurement of plasma ET-1. Doppler ultrasonography of the middle cerebral, renal, and superior mesenteric arteries (SMA) was performed.

RESULTS

Neonates in the pre-eclampsia (n = 18) and control (n = 18) groups had mean (SD) gestational ages of 31.1 (2.5) weeks and 30.4 (2.1) weeks; their birth-weights were 1432 (SD 676) g and 1692 (SD 500) g, respectively. In the pre-eclampsia group mean umbilical arterial PO2 was lower--1.88 (0.75) kPa compared with 3.27 (1.41) kPa (p < 0.01)--and mean plasma ET-1 concentration was higher in the umbilical artery--40.6 (SD 15.0) compared with 30.5 (SD 13.8) pg/ml (p = 0.04) and day 1 blood--54.9 (35.0) pg/ml compared with 33.6 (14.6) pg/ml (p = 0.03). Middle cerebral artery peak systolic velocity was higher and SMA time averaged, peak systolic, and mean peak velocities were lower in the pre-eclampsia group. SMA time averaged velocity was inversely related to plasma ET-1 concentration.

CONCLUSION

The association between increased production of ET-1 and reduction in SMA time averaged velocity suggests a possible mechanism for hypoperfusion of the intestinal wall in neonates.

Counseling sexually active teenagers treated with potential human teratogens

Adolescents with hemoglobinopathies need daily chelation therapy with drugs which are known or suspected to be teratogenic. The prevention of fetal exposure to such drugs is therefore a major task for health professionals caring for these patients. We describe a pilot program aiming to prevent pregnancy among sexually active adolescents treated with iron chelators in Toronto. Most of them had normal response to GnRH, suggesting endocrinologic fertility, and unlike the literature concerning their healthy peers, all sexually active patients in this study reported use of at least one form of contraception.

Doppler velocimetry of the fetal middle cerebral and renal arteries: interobserver reliability

Using color and pulsed Doppler ultrasonography, the interobserver reliability of measurements in the fetal circulation was evaluated in 41 pregnancies of 25 to 39 weeks' gestation. Two observers recorded flow velocity waveforms from the middle cerebral and renal arteries for measurement of peak systolic, minimum diastolic, and mean velocities, pulsatility index, and resistive index. Intraclass correlation coefficient of reliability was calculated by analysis of variance. Substantial interobserver agreement was found for pulsatility index and minimum diastolic velocity in both arteries. Therefore, these measurements have the greatest clinical applicability.

The prognostic factors in the prenatal diagnosis of the echogenic fetal lung

The prenatal diagnosis of an echogenic fetal lung (EFL) is now often made in the early second trimester using high-resolution ultrasound. This ultrasound appearance is usually caused by a congenital cystic adenomatoid lung malformation (CCAM), an intrapulmonary lung sequestration or obstruction of a major airway. In order to provide prognostic guidelines to parents who may be considering termination of a fetus with these findings, we have analysed a series of 11 cases diagnosed in our centre over the past 2 years in conjunction with 60 cases from major published series. The data suggest that in the absence of non-immune hydrops fetalis (NIHF) or other anomalies, the outcome for the fetuses is excellent, with over 90 per cent survival. Neither early diagnosis (24 weeks) nor the presence of mediastinal shift is a poor prognostic indicator. In addition, it appears that if NIHF is absent at diagnosis, the chance that it will develop as the pregnancy continues is small (6 per cent). Furthermore, there is a significant (up to 30 per cent) chance that this ultrasound finding will resolve in utero. The development of in utero fetal surgical techniques may be the only hope for those hydropic fetuses who appear to have a dismal prognosis.

Uterine and umbilical blood flow velocity during epidural anaesthesia for caesarean section

The purpose of this study was to use colour Doppler to determine the effect of epidural anaesthesia on the uterine and umbilical blood flow velocities. After determining the precision of the technique, Doppler insonation of the uterine and umbilical arteries was performed in consenting non-labouring patients requesting epidural anaesthesia for Caesarean section. Patients in Group I were normal and those in Group II were at high risk for uteroplacental blood flow abnormalities. The pulsatility indexes (PI) of both uterine and umbilical arteries were compared at the following times: control, after fluid and after anaesthesia using repeated measure analysis of variance. In Group I (n = 30) the PI increased from 0.72 to 0.82 in the left uterine artery and from 0.71 to 0.85 in the right uterine artery (P < 0.05). In Group II (n = 10) the PI increased from 0.67 to 0.85 in the left uterine artery (NS) and from 0.98 to 1.38 in the right uterine artery (P < 0.05). There was no change in the PI in the umbilical artery. We conclude that the PI of the uterine arteries increases after epidural anaesthesia with lidocaine, epinephrine and fentanyl but there is no change in the umbilical PI. While these changes do not appear to be clinically important in the low-risk population, further studies are required to determine the impact on fetuses at high risk for in utero hypoxaemia.