Effect of maternal tocolysis on the incidence of severe periventricular/intraventricular haemorrhage in very low birthweight infants

Tocolytic treatment and maternal characteristics, obstetric outcomes, and offspring childhood outcomes among births at and after 37 weeks of gestation: the Japan environment and children's study

PURPOSE

To evaluate differences in maternal characteristics and obstetric and offspring childhood outcomes between births at and after 37 weeks of gestation (referred to as term and post-term births) according to the use of tocolytic treatment.

METHODS

Data for 63,409 women with singleton births at and after 37 weeks of gestation were analyzed using data from the Japan Environment and Children's Study (JECS). We compared maternal characteristics, obstetric outcomes, and offspring childhood outcomes between term and post-term births exposed and not exposed to tocolytic treatment. Additionally, multivariable logistic regression models were used to calculate adjusted odds ratios for offspring childhood outcomes with significant between-group differences in the univariable analysis, with term and post-term births without tocolytic agents as the reference group.

RESULTS

We observed differences in maternal characteristics and obstetric outcomes between term and post-term births exposed and not exposed to tocolytic treatment. The incidence of offspring childhood developmental disorders showed no significant between-group differences. However, participants exposed to tocolytic agents had higher incidence of offspring childhood allergic disorders. The adjusted odds ratio for any of the offspring childhood allergic disorders in term and post-term births with tocolytic agents was 1.08 (95% confidence interval, 1.03-1.13).

CONCLUSION

This study found no significant difference in the incidence of offspring developmental disorders between term and post-term births exposed and not exposed to tocolytic treatment. However, tocolytic treatment was associated with differences in maternal characteristics and obstetric outcomes, along with a marginal increase in the incidence of childhood allergic disorders in offspring.

Pharmacological neuroprotection and clinical trials of novel therapies for neonatal peri-intraventricular hemorrhage: a comprehensive review

Peri-intraventricular hemorrhage (PIVH) is a serious condition for preterm infants, caused by traumatic or spontaneous rupture of the germinal matrix (GM) capillary network in the cerebral ventricles. It is a common source of morbidity and mortality in neonates, and risk correlates with earlier delivery, low birth weight, maternal-fetal infection, and vital sign derangements, among others. PIVH typically occurs in the first 72 h of life, and symptoms, when present, manifest most commonly within the first week of life. Prevention remains the primary goal in management, predominantly via prolonging of gestation. Current therapy protocols are center-dependent without consistent consensus guidelines, but infant positioning, homeostatic stabilization, and neuroprotection offer potential options. In this update of pharmacologic neuroprotective therapies for PIVH, we highlight commonly utilized therapies and review the investigative literature. Further multi-institutional clinical trials and basic research studies are required.

Intracranial Hemorrhage and 2-Year Neurodevelopmental Outcomes in Infants Born Extremely Preterm

OBJECTIVES

To determine the incidence, timing, progression, and risk factors for intracranial hemorrhage (ICH) in infants 24^0/7 to 27^6/7 weeks of gestational age and to characterize the association between ICH and death or neurodevelopmental impairment (NDI) at 2 years of corrected age.

STUDY DESIGN

Infants enrolled in the Preterm Erythropoietin Neuroprotection Trial had serial cranial ultrasound scans performed on day 1, day 7-9, and 36 weeks of postmenstrual age to evaluate ICH. Potential risk factors for development of ICH were examined. Outcomes included death or severe NDI as well as Bayley Scales of Infant and Toddler Development, 3rd Edition, at 2 years of corrected age.

RESULTS

ICH was identified in 38% (n = 339) of 883 enrolled infants. Multiple gestation and cesarean delivery reduced the risk of any ICH on day 1. Risk factors for development of bilateral Grade 2, Grade 3, or Grade 4 ICH at day 7-9 included any ICH at day 1; 2 or more doses of prenatal steroids decreased risk. Bilateral Grade 2, Grade 3, or Grade 4 ICH at 36 weeks were associated with previous ICH at day 7-9. Bilateral Grade 2, any Grade 3, and any Grade 4 ICH at 7-9 days or 36 weeks of postmenstrual age were associated with increased risk of death or severe NDI and lower Bayley Scales of Infant and Toddler Development, 3rd Edition, scores.

CONCLUSIONS

Risk factors for ICH varied by timing of bleed. Bilateral and increasing grade of ICH were associated with death or NDI in infants born extremely preterm.

Association between maternal ritodrine hydrochloride administration during pregnancy and childhood wheezing up to three years of age: The Japan environment and children's study

BACKGROUND

The effects of maternal ritodrine hydrochloride administration (MRA) during pregnancy on fetuses and offspring are not entirely clear. The present study aimed to evaluate the association between MRA and childhood wheezing using data from a nationwide Japanese birth cohort study.

METHODS

This study analyzed the data of the participants enrolled in the Japan Environment and Children's Study, a nationwide prospective birth cohort study, between 2011 and 2014. Data of women with singleton live births after 22 weeks of gestation were analyzed. The participants were divided according to MRA status. Considering childhood factors affecting the incidence of wheezing, including smoking environment and childhood viral infections, a logistic regression model was used to calculate odds ratios for "wheezing ever," diagnosis of asthma in the last 12 months, and "asthma ever" in women with MRA, with women who did not receive MRA as the reference. Additionally, participants were stratified by term births, and odds ratios for outcomes were calculated using a logistic regression model.

RESULTS

A total of 68,123 participants were analyzed. The adjusted odds ratio for wheezing was 1.17 (95% confidence interval, 1.12-1.22). The adjusted odds ratios for the other outcomes did not significantly increase after adjusting for childhood factors. The same tendency was confirmed after excluding women with preterm births.

CONCLUSION

MRA was associated with a slightly increased incidence of childhood wheezing up to three years, irrespective of term or preterm birth status. It is important that perinatal physicians consider the potential effects of MRA on the offspring's childhood health.

Antenatal magnesium sulphate and adverse neonatal outcomes: A systematic review and meta-analysis

BACKGROUND

There is widespread, increasing use of magnesium sulphate in obstetric practice for pre-eclampsia, eclampsia, and preterm fetal neuroprotection; benefit for preventing preterm labour and birth (tocolysis) is unproven. We conducted a systematic review and meta-analysis to assess whether antenatal magnesium sulphate is associated with unintended adverse neonatal outcomes.

METHODS AND FINDINGS

CINAHL, Cochrane Library, LILACS, MEDLINE, Embase, TOXLINE, and Web of Science, were searched (inceptions to 3 September 2019). Randomised, quasi-randomised, and non-randomised trials, cohort and case-control studies, and case reports assessing antenatal magnesium sulphate for pre-eclampsia, eclampsia, fetal neuroprotection, or tocolysis, compared with placebo/no treatment or a different magnesium sulphate regimen, were included. The primary outcome was perinatal death. Secondary outcomes included pre-specified and non-pre-specified adverse neonatal outcomes. Two reviewers screened 5,890 articles, extracted data, and assessed risk of bias following Cochrane Handbook and RTI Item Bank guidance. For randomised trials, pooled risk ratios (RRs) or mean differences, with 95% confidence intervals (CIs), were calculated using fixed- or random-effects meta-analysis. Non-randomised data were tabulated and narratively summarised. We included 197 studies (40 randomised trials, 138 non-randomised studies, and 19 case reports), of mixed quality. The 40 trials (randomising 19,265 women and their babies) were conducted from 1987 to 2018 across high- (16 trials) and low/middle-income countries (23 trials) (1 mixed). Indications included pre-eclampsia/eclampsia (24 trials), fetal neuroprotection (7 trials), and tocolysis (9 trials); 18 trials compared magnesium sulphate with placebo/no treatment, and 22 compared different regimens. For perinatal death, no clear difference in randomised trials was observed between magnesium sulphate and placebo/no treatment (RR 1.01; 95% CI 0.92 to 1.10; 8 trials, 13,654 babies), nor between regimens. Eleven of 138 non-randomised studies reported on perinatal death. Only 1 cohort (127 babies; moderate to high risk of bias) observed an increased risk of perinatal death with >48 versus ≤48 grams magnesium sulphate exposure for tocolysis. No clear secondary adverse neonatal outcomes were observed in randomised trials, and a very limited number of possible adverse outcomes warranting further consideration were identified in non-randomised studies. Where non-randomised studies observed possible harms, often no or few confounders were controlled for (moderate to high risk of bias), samples were small (200 babies or fewer), and/or results were from subgroup analyses. Limitations include missing data for important outcomes across most studies, heterogeneity of included studies, and inclusion of published data only.

CONCLUSIONS

Our findings do not support clear associations between antenatal magnesium sulphate for beneficial indications and adverse neonatal outcomes. Further large, high-quality studies (prospective cohorts or individual participant data meta-analyses) assessing specific outcomes, or the impact of regimen, pregnancy, or birth characteristics on these outcomes, would further inform safety recommendations. PROSPERO: CRD42013004451.

Fetal Neuroprotection by Magnesium Sulfate: From Translational Research to Clinical Application

Despite improvements in perinatal care, preterm birth still occurs regularly and the associated brain injury and adverse neurological outcomes remain a persistent challenge. Antenatal magnesium sulfate administration is an intervention with demonstrated neuroprotective effects for preterm births before 32 weeks of gestation (WG). Owing to its biological properties, including its action as an N-methyl-d-aspartate receptor blocker and its anti-inflammatory effects, magnesium is a good candidate for neuroprotection. In hypoxia models, including hypoxia-ischemia, inflammation, and excitotoxicity in various species (mice, rats, pigs), magnesium sulfate preconditioning decreased the induced lesions’ sizes and inflammatory cytokine levels, prevented cell death, and improved long-term behavior. In humans, some observational studies have demonstrated reduced risks of cerebral palsy after antenatal magnesium sulfate therapy. Meta-analyses of five randomized controlled trials using magnesium sulfate as a neuroprotectant showed amelioration of cerebral palsy at 2 years. A meta-analysis of individual participant data from these trials showed an equally strong decrease in cerebral palsy and the combined risk of fetal/infant death and cerebral palsy at 2 years. The benefit remained similar regardless of gestational age, cause of prematurity, and total dose received. These data support the use of a minimal dose (e.g., 4 g loading dose ± 1 g/h maintenance dose over 12 h) to avoid potential deleterious effects. Antenatal magnesium sulfate is now recommended by the World Health Organization and many pediatric and obstetrical societies, and it is requisite to maximize its administration among women at risk of preterm delivery before 32 WG.

Risk factors associated with post-hemorrhagic hydrocephalus among very low birth weight infants of 24-28 weeks gestation

OBJECTIVE

Post-hemorrhagic hydrocephalus (PHH) is associated with morbidity and mortality among very low birth weight (VLBW) infants. This study aimed to determine risk factors for PHH among VLBW infants with peri-intraventricular hemorrhage (PIVH).

STUDY DESIGN

This is a population-based cohort of VLBW infants of 24 to 28 weeks gestation, born in Israel from 1995 to 2012. Infants in whom a brain ultrasound was not performed before 28 days or with major congenital malformations were excluded. Univariate and multivariable analyses identified risk factors associated with PHH.

RESULTS

The final study cohort comprised 2811 infants with grade 2 or higher PIVH, of whom 610 (21.7%) developed PHH. PHH was independently associated with PIVH severity, with bilateral grade 3 PIVH and PIVH grade 3 and contralateral grade 4 having the highest risks (odds ratio (OR) 12.2, 95% confidence interval (CI) 8.56 to 17.4 and OR 13.7, 95% CI 9.4 to 20.1, respectively). Unilateral grade 3 or 4 PIVH's had moderately increased risks of PHH (OR 3.50, 95% CI 2.26 to 5.42 and OR 3.79, 95% CI 2.35 to 6.12, respectively). PHH was independently associated with increasing gestational age (GA) and with neonatal morbidities including patent ductus arteriosus (OR 1.47, 95% CI 1.15 to 1.88 if medically treated and OR 3.01, 95% CI 2.11 to 4.29 if surgically treated), sepsis (OR 1.79, 95% CI 1.44 to 2.22) and necrotizing enterocolitis (OR 1.60, 95% CI 1.18 to 2.17).

CONCLUSIONS

Among VLBW infants with PIVH, PHH was independently associated with PIVH severity group, increasing GA and acute neonatal morbidities. Unilateral grade 3 or 4 PIVH was associated with a moderate risk of developing PHH compared with bilateral severe hemorrhages.

Variables associated with the decreased risk of intraventricular haemorrhage in a large sample of neonates with respiratory distress syndrome

OBJECTIVE

Prematurity and other risk factors are associated with the development of intraventricular haemorrhage (IVH) in newborns with respiratory distress syndrome (RDS). Conversely, further analysis can determine what characteristics might be associated with a decreased risk of IVH.

STUDY DESIGN

By using International Classification of Diseases, Ninth Revision, Clinical Modification codes from data obtained from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project from 2000 to 2009, we identified a large number of cases of RDS. Multivariable logistic regression analysis identified potential variables associated with decreased risk of IVH.

RESULT

Our cohort included 194 621 neonates with RDS, of whom 20 386 (10.5%) developed IVH. Variables associated with decreased risk of both all grades of IVH and severe IVH only included infant of diabetic mother (IDM) status (OR 0.62 (0.54 to 0.70), p<0.001; OR 0.56 (0.42 to 0.74), p<0.001), Trisomy 21 (OR 0.45 (0.30 to 0.69), p<0.001; OR 0.38 (0.16 to 0.93), p=0.034), maternal hypertension (OR 0.62 (0.53 to 0.72), p<0.001; OR 0.28 (0.18 to 0.43), p<0.001), caesarean birth (OR 0.79 (0.74 to 0.84), p<0.001; OR 0.83 (0.73 to 0.94), p<0.001) and, consistent with prior studies, female gender (OR 0.85 (0.82 to 0.88), p<0.001; OR 0.76 (0.72 to 0.80), p<0.001). Polycythaemia (OR 0.67 (0.49 to 0.92), p=0.013; OR 0.79 (0.43 to 1.45), p=0.449) and hypothermia (OR 0.86 (0.75 to 0.99), p=0.039; OR 1.01 (0.81 to 1.28), p=0.903) were associated with lower risk of all IVH but not severe IVH only.

CONCLUSIONS

Previous associations with IVH such as lower birth weight were confirmed. However, infants in whom new variables such as IDM status were present were less likely to develop all IVH grades. Further analysis of these potential protective variables is necessary to better understand the pathophysiology of IVH.

Effects and Safety of Magnesium Sulfate on Neuroprotection: A Meta-analysis Based on PRISMA Guidelines

To evaluate the evidence of effects and safety of magnesium sulfate on neuroprotection for preterm infants who had exposure in uteri. We searched electronic databases and bibliographies of relevant papers to identify studies comparing magnesium sulfate (MgSO4) with placebo or other treatments in patients at high risk of preterm labor and reporting effects and safety of MgSO4 for antenatal infants. Then, we did this meta-analysis based on PRISMA guideline. The primary outcomes included fatal death, cerebral palsy (CP), intraventricular hemorrhage, and periventricular leukomalacia. Secondary outcomes included various neonatal and maternal outcomes. Ten studies including 6 randomized controlled trials and 5 cohort studies, and involving 18,655 preterm infants were analyzed. For the rate of moderate to severe CP, MgSO4 showed the ability to reduce the risk and achieved statistically significant difference (odd ratio [OR] 0.61, 95% confidence interval [CI] 0.42-0.89, P = 0.01). The comparison of mortality rate between the MgSO4 group and the placebo group only presented small difference clinically, but reached no statistical significance (OR 0.92, 95% CI 0.77-1.11, P = 0.39). Summarily, the analysis of adverse effects on babies showed no margin (P > 0.05). Yet for mothers, MgSO4 exhibited obvious side-effects, such as respiratory depression, nausea and so forth, but there exited great heterogeneity. MgSO4 administered to women at high risk of preterm labor could reduce the risk of moderate to severe CP, without obvious adverse effects on babies. Although there exit many unfavorable effects on mothers, yet they may be lessened through reduction of the dose of MgSO4 and could be tolerable for mothers. So MgSO4 is both beneficial and safety to be used as a neuroprotective agent for premature infants before a valid alternative was discovered.

Use and attitudes of obstetricians toward 3 high-risk interventions in MFMU Network hospitals

OBJECTIVE

We sought to evaluate the frequency of, and factors associated with, the use of 3 evidence-based interventions: antenatal corticosteroids for fetal lung maturity, progesterone for prevention of recurrent preterm birth, and magnesium sulfate for fetal neuroprotection.

STUDY DESIGN

A self-administered survey was conducted from January through May 2011 among obstetricians from 21 hospitals that included 30 questions regarding their knowledge, attitudes, and practice of the 3 evidence-based interventions and the 14-item short version of the Team Climate for Innovation survey. Frequency of use of each intervention was ascertained from an obstetrical cohort of women between January 2010 and February 2011.

RESULTS

A total of 329 obstetricians (74% response rate) who managed 16,946 deliveries within the obstetrical cohort participated in the survey. More than 90% of obstetricians reported that they incorporated each intervention into routine practice. Actual frequency of administration in women eligible for the treatments was 93% for corticosteroids, 39% for progesterone, and 71% for magnesium sulfate. Provider satisfaction with quality of treatment evidence was 97% for corticosteroids, 82% for progesterone, and 57% for magnesium sulfate. Obstetricians perceived that barriers to treatment were most frequent for progesterone (76%), 30% for magnesium sulfate, and 17% for corticosteroids. Progesterone use was more frequent among patients whose provider reported the quality of the evidence was above average to excellent compared with poor to average (42% vs 25%, respectively; P < .001), and they were satisfied with their knowledge of the intervention (41% vs 28%; P = .02), and was less common among patients whose provider reported barriers to hospital or pharmacy drug delivery (31% vs 42%; P = .01). Corticosteroid administration was more common among patients who delivered at hospitals with 24 hours a day-7 days a week maternal-fetal medicine specialist coverage (93% vs 84%; P = .046), CONCLUSION: Obstetricians in Maternal-Fetal Medicine Units Network hospitals frequently use these evidence-based interventions; however, progesterone use was found to be related to their assessment of evidence quality. Neither progesterone nor the other interventions were associated with overall climate of innovation within a hospital as measured by the Team Climate for Innovation. National Institutes of Health Consensus Conference Statements may also have an impact on use; there is such a statement for antenatal corticosteroids but not for progesterone for preterm prevention or magnesium sulfate for fetal neuroprotection.

Antenatal exposure to indomethacin increases the risk of severe intraventricular hemorrhage, necrotizing enterocolitis, and periventricular leukomalacia: a systematic review with metaanalysis

OBJECTIVE

The purpose of this study was to provide an updated summary of the literature regarding the effects of tocolysis with indomethacin on neonatal outcome by systematically reviewing previously and recently reported data.

STUDY DESIGN

All previously reported studies pertaining to indomethacin tocolysis and neonatal outcomes along with recently reported data were identified with the use of electronic databases that had been supplemented with references that were cited in original studies and review articles. Observational studies that compared neonatal outcomes among preterm infants who were exposed and not exposed to indomethacin were included in this systematic review. Data were extracted and quantitative analyses were performed on those studies that assessed the neonatal outcomes of patients that received antenatal tocolysis with indomethacin.

RESULTS

Twenty-seven observational studies that met criteria for systematic review and metaanalysis were identified. These studies included 8454 infants, of whom 1731 were exposed to antenatal indomethacin and 6723 were not exposed. Relative risks with 95% confidence intervals were calculated for dichotomous outcomes with the use of random and fixed-effects models. Metaanalysis revealed no statistically significant differences in the rates of respiratory distress syndrome, patent ductus arteriosus, neonatal mortality rate, neonatal sepsis, bronchopulmonary dysplasia, or intraventricular hemorrhage (all grades). However, antenatal exposure to indomethacin was associated with an increased risk of severe intraventricular hemorrhage (grade III-IV based on Papile's criteria; relative risk, 1.29; 95% confidence interval, 1.06-1.56), necrotizing enterocolitis (relative risk, 1.36; 95% confidence interval, 1.08-1.71), and periventricular leukomalacia (relative risk, 1.59; 95% confidence interval, 1.17-2.17).

CONCLUSION

The use of indomethacin as a tocolytic agent for preterm labor is associated with an increased risk for severe intraventricular hemorrhage, necrotizing enterocolitis, and periventricular leukomalacia.

Preterm labour: association between labour physiology, tocolysis and prevention

INTRODUCTION

In developed countries, preterm birth is the major cause of perinatal morbidity, mortality and the most important public health problem in the obstetric field. In the past decades, an increasing trend has been observed regardless of the great efforts focussed on the improvement of our understanding of the physiopathological mechanisms behind preterm labour (PTL) and the improvement in the use of tocolytic drugs.

AREAS COVERED

In this review, the authors focus on some points of the physiopathology of labour in order to understand the rationality behind the different management approaches developed for the PTL syndrome.

EXPERT OPINION

There is a need to develop new tools for the treatment of patients with PTL. Research focussed on improving tocolysis, the physiology of labour and pathological processes involved in PTL would afford new approaches for the treatment of PTL, allowing clinicians to provide integrative solutions for this multifactorial disease. Recently, the prophylactic use of progesterone pessary and cerclage in women with high risk of premature labour has been reported to reduce the incidence of premature births and improve neonatal outcomes. These results highlight the importance of prediction models in order to establish preventative strategies early in pregnancy.

Magnesium sulphate at 30 to 34 weeks' gestational age: neuroprotection trial (MAGENTA)--study protocol

Background

Magnesium sulphate is currently recommended for neuroprotection of preterm infants for women at risk of preterm birth at less than 30 weeks’ gestation, based on high quality evidence of benefit. However there remains uncertainty as to whether these benefits apply at higher gestational ages.

The aim of this randomised controlled trial is to assess whether giving magnesium sulphate compared with placebo to women immediately prior to preterm birth between 30 and 34 weeks’ gestation reduces the risk of death or cerebral palsy in their children at two years’ corrected age.

Methods/design

Design: Randomised, multicentre, placebo controlled trial.

Inclusion criteria: Women, giving informed consent, at risk of preterm birth between 30 to 34 weeks’ gestation, where birth is planned or definitely expected within 24 hours, with a singleton or twin pregnancy and no contraindications to the use of magnesium sulphate.

Trial entry & randomisation: Eligible women will be randomly allocated to receive either magnesium sulphate or placebo.

Treatment groups: Women in the magnesium sulphate group will be administered 50 ml of a 100 ml infusion bag containing 8 g magnesium sulphate heptahydrate [16 mmol magnesium ions]. Women in the placebo group will be administered 50 ml of a 100 ml infusion bag containing isotonic sodium chloride solution (0.9%). Both treatments will be administered through a dedicated IV infusion line over 30 minutes.

Primary study outcome: Death or cerebral palsy measured in children at two years’ corrected age.

Sample size: 1676 children are required to detect a decrease in the combined outcome of death or cerebral palsy, from 9.6% with placebo to 5.4% with magnesium sulphate (two-sided alpha 0.05, 80% power, 5% loss to follow up, design effect 1.2).

Discussion

Given the magnitude of the protective effect in the systematic review, the ongoing uncertainty about benefits at later gestational ages, the serious health and cost consequences of cerebral palsy for the child, family and society, a trial of magnesium sulphate for women at risk of preterm birth between 30 to 34 weeks’ gestation is both important and relevant for clinical practice globally.

Trial registration

Australian New Zealand Clinical Trials Registry - ACTRN12611000491965

Antenatal magnesium individual participant data international collaboration: assessing the benefits for babies using the best level of evidence (AMICABLE)

BACKGROUND

The primary aim of this study is to assess, using individual participant data (IPD) meta-analysis, the effects of administration of antenatal magnesium sulphate given to women at risk of preterm birth on important clinical outcomes for their child such as death and neurosensory disability. The secondary aim is to determine whether treatment effects differ depending on important pre-specified participant and treatment characteristics, such as reasons at risk of preterm birth, gestational age, or type, dose and mode of administration of magnesium sulphate.

METHODS

DESIGN

The Antenatal Magnesium Individual Participant Data (IPD) International Collaboration: assessing the benefits for babies using the best level of evidence (AMICABLE) Group will perform an IPD meta-analysis to answer these important clinical questions. SETTING/TIMELINE: The AMICABLE Group was formed in 2009 with data collection commencing late 2010.

INCLUSION CRITERIA

Five trials involving a total 6,145 babies are eligible for inclusion in the IPD meta-analysis. PRIMARY STUDY OUTCOMES: For the infants/children: Death or cerebral palsy. For the women: Any severe maternal outcome potentially related to treatment (death, respiratory arrest or cardiac arrest).

DISCUSSION

Results are expected to be publicly available in 2012.

Different magnesium sulphate regimens for neuroprotection of the fetus for women at risk of preterm birth

BACKGROUND

The effectiveness of antenatal magnesium sulphate for neuroprotection of the fetus, infant, and child prior to very preterm birth, when given to women considered at risk of preterm birth, has been established. There is currently no consensus as to the regimen to use in terms of the dose, duration, the use of repeat dosing and timing.

OBJECTIVES

To assess the comparative effectiveness and adverse effects of different magnesium sulphate regimens for neuroprotection of the fetus in women considered at risk of preterm birth.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 December 2011).

SELECTION CRITERIA

Randomised trials comparing different magnesium sulphate regimens when used for neuroprotection of the fetus in women considered at risk of preterm birth. We planned to include cluster trials. We planned to exclude quasi-randomised trials and those with a crossover design. We planned to include trials published as full-text papers, along with those published in abstract form only.

DATA COLLECTION AND ANALYSIS

We planned that at least two review authors would assess trial eligibility.

MAIN RESULTS

No eligible completed trials were identified.

AUTHORS' CONCLUSIONS

Although strong evidence supports the use of antenatal magnesium sulphate for neuroprotection of the fetus prior to very preterm birth, no trials comparing different treatment regimens have been completed. Research should be directed towards comparisons of different dosages and other variations in regimens, evaluating both maternal and infant outcomes.

Tocolytic therapy for acute preterm labor

The pathophysiology leading to preterm labor is not well understood and often multifactorial; initiating factors include intrauterine infection, inflammation, ischemia, overdistension, and hemorrhage. Given these different potential causes, directing therapy for preterm labor has been difficult and suboptimal. To date, no single drug has been identified as successful in treating all of the underlying mechanisms leading to preterm labor. In addition, the methodology of many of the tocolytic studies is limited by lack of sufficient patient numbers, lack of comparison with a placebo, and inconsistent use of glucocorticoids. The limitations in these individual studies make it difficult to evaluate the efficacy of a single tocolytic by meta-analysis. Despite these limitations, the goals for tocolysis for preterm labor are clear: To complete a course of glucocorticoids and secure the appropriate level of neonatal care for the fetus in the event of preterm delivery. The literature demonstrates that many tocolytic agents inhibit uterine contractility. The decision as to which tocolytic agent should be used as first-line therapy for a patient is based on multiple factors, including gestational age, the patient’s medical history, common and severe side effects, and a patient’s response to therapy. In a patient at less than 32 weeks gestation, indomethacin may be a reasonable first choice based on its efficacy, ease of administration, and minimal side effects. Concurrent administration of magnesium for neuroprotection may be given. At 32 to 34 weeks, nifedipine may be a reasonable first choice because it does not carry the fetal risks of indomethacin at these later gestational ages, is easy to administer, and has limited side effects relative to beta-mimetics. In an effort to review a commonly faced obstetrical complication, this article has provided a summary of the most commonly used tocolytics, their mechanisms of action, side effects, and clinical data regarding their efficacy.

Prenatal or postnatal indomethacin exposure and neonatal gut injury associated with isolated intestinal perforation and necrotizing enterocolitis

OBJECTIVE

To examine the role of indomethacin in neonatal gut injury.

STUDY DESIGN

Infants born at gestational age 23 weeks and with birth weights 400-1200 g were included in this prospective prevalence study of neonatal gut injury. Infants with isolated intestinal perforation (IIP) confirmed at laparotomy or at autopsy or with necrotizing enterocolitis (NEC) were identified. Data were abstracted bi-weekly.

RESULT

Among 992 study infants, 58 infants exposed solely to prenatal indomethacin did not show an increased rate of neonatal gut injury. Any postnatal indomethacin exposure (n=611) increased the odds of IIP (OR 4.17, CI, 1.24-14.08, P=0.02) but decreased the odds of NEC (OR 0.65, CI 0.43-0.97, P=0.04). There was a negative association between the timing of indomethacin-exposure and the odds of developing IIP (OR 0.30, CI 0.11-0.83, P=0.02). Compared with NEC, IIP occurred at an earlier age (P<0.05) and was more common (P<0.05) among infants who received early indomethacin (first dose at <12 h of age) to prevent intraventricular hemorrhage than among infants who were treated with late indomethacin for closure of a patent ductus arteriosus (PDA). Unlike the classic hemorrhagic ischemic lesions of NEC in which large areas of tissue were inflamed or necrotic, the IIP lesions were small and discrete.

CONCLUSION

Early (<12 h) postnatal indomethacin exposure was associated with an increased odds of IIP in very low birth weight infants whereas its later use for closure of a PDA appeared to provide protection against NEC. The paradoxical effect of the timing of indomethacin on IIP versus on NEC may be related to the different pathogeneses of the two diseases. Our findings also suggest that PDA may contribute to NEC.

Indomethacin tocolysis and white matter injury in preterm infants

OBJECTIVE

This study aims to clarify the relationship between indomethacin tocolysis and neonatal white matter injury (WMI) in preterm infants.

METHODS

We conducted a retrospective review of preterm infants born at 24-32 weeks who had sufficient cranial ultrasound examinations (CUS) to determine the incidence and severity of abnormalities. Infants with normal CUS were compared on univariate and multivariate analyses with infants with the different forms of WMI.

RESULTS

On multivariate logistic regression analysis, indomethacin tocolysis was significantly correlated with periventricular echogenicity (PVE; OR 2.84 95% CI 1.41-5.7, p = 0.003), but not with periventricular leucomalacia (PVL; OR 1.83 95% CI0.6-5.6, p = 0.29). Indomethacin was not related to increased risk for periventricular-intraventricular hemorrhage or periventricular hemorrhagic infarction.

CONCLUSION

These findings suggest caution in the use of indomethacin as a tocolytic therapy.

High dose magnesium sulfate exposure induces apoptotic cell death in the developing neonatal mouse brain

BACKGROUND

Magnesium sulfate (MgSO4) is often used as a treatment for pre-eclampsia/eclampsia and preterm labor, resulting in the exposure of a significant number of neonates to this drug despite a lack of evidence suggesting that it is safe, or effective as a tocolytic. While there is evidence that MgSO4 may be neuroprotective in perinatal brain injury, recent reviews have suggested that the effects are dependent upon dose, and that higher doses may actually increase neonatal morbidity and mortality. There is a lack of evidence investigating the neurotoxic effects of neonatal magnesium (Mg) exposure on the developing brain, specifically in terms of neurodevelopmental apoptosis, a cell-killing phenomenon known to be potentiated by other drugs with mechanisms of action at Mg-binding sites (i.e. NMDA receptor antagonists such as MK-801, ketamine, and PCP).

OBJECTIVE

To investigate the effects of Mg exposure on the neonatal mouse brain at different postnatal ages to determine whether MgSO4 treatment causes significant cell death in the developing mouse brain.

METHODS

C57Bl/6 mice were treated with four doses of MgSO4 (250 mg/kg) on postnatal days 3 (P3), 7 (P7) or 14 (P14). Caspase-3 immunohistochemistry, cupric silver staining, and electron microscopy techniques were used to examine Mg-treated brains for neurotoxic effects.

RESULTS

Qualitative evaluation using cupric silver staining revealed widespread damage throughout the brain in P7 animals. Results of electron microscopy confirmed that the cell death process was apoptotic in nature. Quantitative evaluation of damage to the cortex, caudate-putamen, hippocampus, thalamus, and cerebellum showed that Mg treatment caused significant brain damage in animals treated on P3 and P7, but not P14.

CONCLUSIONS

Administration of high doses of Mg may be detrimental to the fetal brain, particularly if exposure occurs during critical periods of neurodevelopment.

Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus

BACKGROUND

Epidemiological and basic science evidence suggests that magnesium sulphate before birth may be neuroprotective for the fetus.

OBJECTIVES

To assess the effects of magnesium sulphate as a neuroprotective agent when given to women considered at risk of preterm birth.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2008).

SELECTION CRITERIA

Randomised controlled trials of antenatal magnesium sulphate therapy in women threatening or likely to give birth at less than 37 weeks' gestational age. For one subgroup analysis, studies were broadly categorised by the primary intent of the study into "neuroprotective intent", or "other intent (maternal neuroprotective - pre-eclampsia)", or "other intent (tocolytic)".

DATA COLLECTION AND ANALYSIS

At least two authors assessed trial eligibility and quality, and extracted data.

MAIN RESULTS

Five trials (6145 babies) were eligible for this review. Antenatal magnesium sulphate therapy given to women at risk of preterm birth substantially reduced the risk of cerebral palsy in their child (Relative Risk (RR) 0.68; 95% Confidence interval (CI) 0.54 to 0.87; five trials; 6145 infants). There was also a significant reduction in the rate of substantial gross motor dysfunction (RR 0.61; 95% CI 0.44 to 0.85; four trials; 5980 infants). No statistically significant effect of antenatal magnesium sulphate therapy was detected on paediatric mortality (RR 1.04; 95% CI 0.92 to 1.17; five trials; 6145 infants), or on other neurological impairments or disabilities in the first few years of life. Overall there were no significant effects of antenatal magnesium therapy on combined rates of mortality with cerebral palsy, although there were significant reductions for the neuroprotective groups RR 0.85; 95% CI 0.74 to 0.98; four trials; 4446 infants, but not for the other intent subgroups. There were higher rates of minor maternal side effects in the magnesium groups, but no significant effects on major maternal complications.

AUTHORS' CONCLUSIONS

The neuroprotective role for antenatal magnesium sulphate therapy given to women at risk of preterm birth for the preterm fetus is now established. The number of women needed to be treated to benefit one baby by avoiding cerebral palsy is 63 (95% confidence interval 43 to 87). Given the beneficial effects of magnesium sulphate on substantial gross motor function in early childhood, outcomes later in childhood should be evaluated to determine the presence or absence of later potentially important neurological effects, particularly on motor or cognitive function.

Metaanalysis of the effect of antenatal indomethacin on neonatal outcomes

OBJECTIVE

The objective of the study was to determine whether indomethacin used as a tocolytic agent is associated with adverse neonatal outcomes.

STUDY DESIGN

We used published guidelines of the Metaanalysis of Observational Studies in Epidemiology Group (MOOSE) to perform the metaanalysis. The search strategy used included computerized bibliographic searches of MEDLINE (1966-2005), PubMed (1966-2005), abstracts published in Obstetrics and Gynecology (1991-2005), abstracts published in Pediatric Research (1991-2005), and references of published manuscripts. Study inclusion criteria were publication in English, more than 30 deliveries less than 37 weeks' gestation, and meeting diagnostic criteria for individual neonatal outcomes. Exclusion criteria included case reports, case series, and multiple publications from the same author. Metaanalysis was performed using random effects model if there were more than 2 observational studies for a specific outcome. Eggers test was performed to exclude publication bias. Sensitivity analysis was performed to evaluate the effect of antenatal steroid exposure, gestation, and recent antenatal indomethacin exposure (duration of 48 hours or more between the last dose and delivery).

RESULTS

Fifteen retrospective cohort studies and 6 case-controlled studies met inclusion criteria. Antenatal indomethacin was associated with an increased risk of periventricular leukomalacia (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.3-3.1). Recent exposure to antenatal indomethacin was associated with necrotizing enterocolitis (OR, 2.2; 95% CI; 1.1-4.2). Antenatal indomethacin was not associated with intraventricular hemorrhage, patent ductus arteriosus, respiratory distress syndrome, bronchopulmonary dysplasia, and mortality.

CONCLUSION

Antenatal indomethacin may be associated with an increased risk of periventricular leukomalacia and necrotizing enterocolitis in premature infants and therefore should be used judiciously for tocolysis.

Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus

BACKGROUND

Epidemiological and basic science evidence suggests that magnesium sulphate before birth may be neuroprotective for the fetus.

OBJECTIVES

To assess the effectiveness and safety of magnesium sulphate as a neuroprotective agent when given to women considered at risk of preterm birth.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (October 2006), CENTRAL (The Cochrane Library 2006, Issue 3), MEDLINE (1966 to October 2006), EMBASE (1980 to October 2006), Current Contents (1992 to October 2006), references of retrieved articles, and abstracts submitted to the Society for Pediatric Research (1996 to 2006).

SELECTION CRITERIA

Randomised controlled trials of antenatal magnesium sulphate therapy given to women threatening or likely to give birth at less than 37 weeks' gestational age.

DATA COLLECTION AND ANALYSIS

We independently extracted data regarding clinical outcomes including paediatric mortality, neurologic outcome of survivors (including blindness, deafness, cerebral palsy and major neurosensory disability), and maternal complications and side-effects. At least two authors assessed trial eligibility and quality, and extracted data.

MAIN RESULTS

Four trials (3701 babies) were eligible for this review. No statistically significant effect of antenatal magnesium sulphate therapy was detected on any major paediatric outcome, including mortality (e.g., paediatric mortality relative risk (RR) 0.97; 95% confidence interval (CI) 0.74 to 1.28; four trials; 3701 infants), and neurological outcomes in the first few years of life, including cerebral palsy (RR 0.77; 95% CI 0.56 to 1.06; four trials; 3701 infants), neurological impairments or disabilities. There were also no significant effects of antenatal magnesium therapy on combined rates of mortality with neurologic outcomes. There was a significant reduction in the rate of substantial gross motor dysfunction (RR 0.56; 95% CI 0.33 to 0.97; two trials; 2848 infants). There were higher rates of minor maternal side-effects in the magnesium groups, but no significant effects on major maternal complications.

AUTHORS' CONCLUSIONS

The role for antenatal magnesium sulphate therapy as a neuroprotective agent for the preterm fetus is not yet established. Given the possible beneficial effects of magnesium sulphate on gross motor function in early childhood, outcomes later in childhood should be evaluated to determine the presence or absence of later potentially important neurologic effects, particularly on motor or cognitive function. Further information will be available from one of the studies where outcomes are being evaluated again at eight to nine years of age, and from another trial currently in progress.

Bruising at birth: antenatal associations and neonatal outcome of extremely low birth weight infants

BACKGROUND

Early studies have identified severe cranial bruising as a risk factor for intraventricular hemorrhage (IVH) in premature infants but the nature of this association has not been evaluated.

OBJECTIVE

To identify antenatal predictors and associations with neonatal outcome of bruised extremely low birth weight infants.

METHODS

A cohort study comparing 34 bruised and 116 non-bruised infants (birth weight <or=1,000 g), delivered in two 'Hadassah' university hospitals in Jerusalem between 2000 and 2004. Bruised patients were divided according to the severity of bruising. A univariate model was first applied to examine the associations of the individual independent variables with the outcome variable, followed with a logistic stepwise regression model, performed for each of the outcome variables.

RESULTS

In a stepwise logistic regression on 'Any bruising' and 'Severe bruising', only increasing gestational age and exposure to antenatal steroids prior to delivery maintained a protective association with bruising (OR = 0.74; 95% CI: 0.58-0.94; p = 0.015, OR = 0.38; 95% CI: 0.16-0.90; p = 0.028, respectively, for 'Any bruising', and OR = 0.77; 95% CI: 0.59-1.01; p = 0.055, OR = 0.29; 95% CI: 0.12-0.73; p = 0.008, respectively, for 'Severe bruising'). In a stepwise logistic regression analysis, with 'Any bruising' and 'Severe bruising' as forced-in variables and controlling for gestational age, small for gestational age, Apgar scores, respiratory distress syndrome and pneumothorax, 'Severe bruising', but not 'Any bruising', was found to be associated significantly with severe IVH (OR = 5.60; 95% CI: 1.86-16.82; p = 0.002), whereas both 'Any bruising' and 'Severe bruising' were significantly associated with mortality (OR = 6.31; 95% CI: 2.37-16.83; p = 0.000, OR = 3.33; 95% CI: 1.16-9.52; p = 0.025 respectively).

CONCLUSION

Antenatal exposure to steroids and increasing gestational age are associated with a lower incidence of bruising at birth in extremely low birth weight infants. Severe bruising at birth is associated with increased incidence of severe intraventricular hemorrhage and mortality.

Neonatal neurodevelopmental outcomes following tocolysis with glycerol trinitrate patches

OBJECTIVE

The object of this study was to determine the effects of maternal tocolysis with glycerol trinitrate (GTN) patches on the neurodevelopment of infants.

STUDY DESIGN

This was a randomized, multicenter, controlled trial comparing the efficacy of GTN patches with standard beta2 agonist as tocolytic therapy. The previously reported outcomes of this study indicated no difference in neonatal mortality or morbidity to hospital discharge. One hundred fifty-six surviving infants from 2 Australian centers were psychometrically assessed using the Griffiths Mental development Scales (revised) at 18 months of age.

RESULTS

There was no difference in psychometric performance between those infants enrolled in either the GTN (81 infants) or beta2 agonist (75 infants) arm of the study.

CONCLUSION

This randomized trial supports no significant difference between GTN patches in comparison with standard beta2 agonist for tocolytic therapy. The results underscore the association between premature labor and adverse infant outcomes.

Periventricular hemorrhagic infarction: risk factors and neonatal outcome

The aim of this study was to define the incidence, clinical associations, and short-term outcome of periventricular hemorrhagic infarction in the modern neonatal intensive care unit. From 5774 infants (birth weight<2500 gm), periventricular hemorrhagic infarction diagnosed by cranial ultrasound was identified and confirmed. gestational age-matched control infants were identified with normal cranial ultrasounds and detailed clinical data were obtained in both groups. Periventricular hemorrhagic infarction was confirmed in 58 infants. Incidence was 0.1% (1500-2500 gm), 2.2% (750-1500 gm), and 10% (<750 gm). Data across 6 study years reveal increased incidence in infants<750 gm. Compared with control infants, infants with periventricular hemorrhagic infarction had significantly greater association with assisted conception, intrapartum factors (emergency cesarean section, low Apgar scores), early neonatal complications (patent ductus arteriosus, pneumothorax, pulmonary hemorrhage), blood gas disturbances, and need for pressor, volume infusion, and respiratory support. Neonatal mortality of this group was 40% (n=23). Survivors had longer duration of mechanical ventilation and critical care stay compared with control subjects. Thirty-seven percent of survivors required cerebrospinal fluid shunt placement. Periventricular hemorrhagic infarction remains an important neurologic complication of prematurity. A growing population of survivors is apparent among infants with birth weight<750 gm. Multiple hemodynamic factors associated with periventricular hemorrhagic infarction cluster in the intrapartum and early neonatal periods.

Ultrasonographic features and severity scoring of periventricular hemorrhagic infarction in relation to risk factors and outcome

OBJECTIVE

Early diagnosis of periventricular hemorrhagic infarction in premature infants is based on bedside neonatal cranial ultrasonography. Currently, evaluation of its morphology and evolution by cranial ultrasound relies largely on data predating major advances in perinatal care and lacks a consistent classification system for determining severity of injury. The objective of this study was to examine the ultrasonographic morphology and evolution of periventricular hemorrhagic infarction in the modern NICU and to determine the value of a cranial ultrasonography-based severity score for predicting outcome.

METHODS

We retrospectively evaluated all cranial ultrasounds and medical records of 58 premature infants with periventricular hemorrhagic infarction. We assigned each subject a severity score based on extent of echodensity, unilateral versus bilateral, and presence or absence of midline shift. A neurologic examination was performed after 12 months adjusted age.

RESULTS

The parenchymal echodensity of periventricular hemorrhagic infarction most often involved parietal and frontal territories and evolved into single and/or multiple cysts. One quarter of cases were bilateral, and nearly 70% were extensive. Higher severity scores were significantly associated with pulmonary hemorrhage and low bicarbonate levels and with outcomes of fatality, early neonatal seizures, and motor disability.

CONCLUSIONS

Despite advances in perinatal medicine, periventricular hemorrhagic infarction remains an important complication of prematurity. Periventricular hemorrhagic infarction can be graded using a scoring system based on sonographic characteristics. Higher severity scores predict worse outcome. Such severity scoring could improve the clinician's ability to counsel parents regarding management decisions and early intervention strategies.

Risk factors and clinical outcomes of pulmonary interstitial emphysema in extremely low birth weight infants

OBJECTIVE

We studied the ante- and postnatal risk factors and clinical outcomes associated with pulmonary interstitial emphysema (PIE) in extremely low birth weight infants (ELBW, <1000 g at birth) in the present era of tocolytics, antenatal steroid and postnatal surfactant administration.

STUDY DESIGN

This was a retrospective case-controlled study of all ELBW admitted consecutively during a designated study-period in a level III nursery. Data were analyzed by performing univariate and multivariate analysis as applicable.

RESULTS

Infants with PIE had lower 1 and 5 min Apgar scores (P=0.04 and 0.003 respectively), increased surfactant utilization (P=0.004), higher maximum inspired oxygen concentration (P=0.04) and mean airway pressure administration (P=0.02) during the first week of life, and increased neonatal mortality (P=0.01). They received higher antenatal doses of magnesium sulfate (MgSO(4)) (P=0.02). 56% of infants with PIE were exposed to more than 10 g of MgSO(4) (Mg10), compared to 15% in non-PIE group (P=0.01). The multivariate logistic regression analysis including significant co-variates revealed an independent association between Mg10 and PIE (P=0.01, Odds ratio 19.8, 95% CI 1.5-263).

CONCLUSION

Pulmonary interstitial emphysema is associated with increased mortality in ELBW infants. Mg10 is an independent risk factor for PIE in this population.

beta-Agonist tocolytic therapy

With the advent of preterm birth prevention programs, increasing numbers of patients are now considered candidates for tocolytic management. Tocolysis' chief benefit is significantly prolonging pregnancy in the hope of avoiding or ameliorating the sequelae of preterm delivery. Three principal indications dominate the use of tocolysis in the treatment of preterm labor: (1) prophylaxis, (2) acute therapy, and (3) maintenance.

Assessing the Neonatal Safety of Indomethacin Tocolysis

OBJECTIVE

To systematically review and summarize the medical literature regarding the effects of tocolysis with indomethacin on neonatal outcome.

DATA SOURCES

We supplemented a search of entries in electronic databases with references cited in original studies and review articles to identify studies pertaining to indomethacin tocolysis and neonatal outcome.

METHODS OF STUDY SELECTION

We evaluated, abstracted data, and performed quantitative analyses in studies assessing the neonatal outcomes of patients undergoing tocolysis with indomethacin. Observational studies and randomized trials were included in this systematic review.

TABULATION, INTEGRATION, AND RESULTS

Forty-six studies were identified, 28 of which met criteria for systematic review and meta-analysis. These 28 studies included 6,008 infants. Of these infants, 1,621 were exposed to indomethacin for tocolysis antenatally; 4,387 infants not exposed to indomethacin served as the comparison group. An estimate of pooled odds ratios with 95% confidence intervals was calculated for dichotomous outcomes using random- and fixed-effects models. Observational studies and randomized trials were analyzed separately. Pooled estimates from observational studies and randomized trials revealed no significant differences in the rates of intraventricular hemorrhage, patent ductus arteriosus, necrotizing enterocolitis, or neonatal mortality between infants exposed to indomethacin antenatally and those not exposed. Meta-analysis of randomized trials revealed increased risk of bronchopulmonary dysplasia. However, the meta-analysis included only 3 randomized clinical trials, one of which showed increased risk. An association of bronchopulmonary dysplasia and indomethacin use was not noted in our analysis of observational studies.

CONCLUSION

Although our pooled results did not identify significantly increased risks of adverse effects, the limited statistical power of published randomized trials does not allow us to exclude the possibility that indomethacin tocolysis increases the risk of adverse neonatal outcomes.

Germinal matrix-intraventricular hemorrhage in the premature newborn: management and outcome

Germinal matrix-intraventricular hemorrhage (GMH-IVH) in the premature newborn results from rupture of fragile capillaries in the germinal matrix. Its pathogenesis is multifactorial and relates principally to a pressure-passive cerebral circulation, fluctuations in cerebral blood flow, and derangements of coagulation and fragility of the germinal matrix microvasculature. Several interventions have beneficial effects for prevention of GMH-IVH. Outcome after GMH-IVH relates largely to the severity of hemorrhage, the extent of hemorrhagic and ischemic parenchymal involvement, and complications (e.g., posthemorrhagic hydrocephalus). Even in the absence of neuroimaging abnormalities, VLBW infants have a high incidence of academic and behavioral problems which persist into adolescence and early adulthood.

Risk factors for intraventricular hemorrhage in very low birth weight premature infants: a retrospective case-control study

OBJECTIVE

High-grade intraventricular hemorrhage (IVH) is an important cause of severe cognitive and motor neurologic impairment in very low birth weight infants and is associated with a high mortality rate. The risk of IVH is inversely related to gestational age and birth weight. Previous studies have proposed a number of risk factors for IVH; however, lack of adequate matching for gestational age and birth weight may have confounded the results. The purpose of this study was to identify variables that affect the risk of high-grade IVH, using a retrospective and case-control clinical study.

METHODS

From a cohort of 641 consecutive preterm infants with a birth weight of <1500 g, 36 infants with IVH grade 3 and/or 4 were identified. A control group of 69 infants, closely matched for gestational age and birth weight, was selected. Maternal factors, labor and delivery characteristics, and neonatal parameters were collected in both groups. Results of cranial ultrasound examinations, whether routine or performed in presence of clinical suspicion, were also collected. Univariate analysis and multivariate logistic regression analysis were performed.

RESULTS

High fraction of inspired oxygen in the first 24 hours, pneumothorax, fertility treatment (mostly IVF), and early sepsis were associated with an increased risk of IVH. A higher number of suctioning procedures, a higher first hematocrit, and a relatively low arterial pressure of carbon dioxide during the first 24 hours of life were associated with a lower occurrence. In the multivariate logistic regression model, early sepsis (odds ratio [OR]: 8.19; 95% confidence interval [CI]: 1.55-43.1) and fertility treatment (OR: 4.34; 95% CI: 1.42-13.3) were associated with a greater risk of high-grade IVH, whereas for every dose of antenatal steroid treatment there was a lower risk of high-grade IVH (OR: 0.52; 95% CI: 0.30-0.90) and each decrease in a mmHg unit of arterial pressure of carbon dioxide during the first 24 hours was associated with a lower risk of IVH (OR: 0.91; 95% CI: 0.83-0.98). This multivariate model had a sensitivity of 77%, a specificity of 75%, and a positive predictive value of 76%. The area under the curve derived from the receiver operator characteristic plots is 0.82.

CONCLUSIONS

Our results confirm that the development of IVH is associated with early sepsis and failure to give antenatal steroid treatment. We propose that fertility treatment (and especially IVF) may be a new risk factor, and more research is needed to assess its role.

Neonatal and long-term outcomes of very low birth weight infants from single and multiple pregnancies

The revolution in artificial reproductive technologies has resulted in a dramatic rise in the incidence of multiple pregnancies. Many of these infants are born prematurely, often extremely so. Consequently, perinatal morbidity and mortality are highly correlated with plurality. The primary mechanism for this increased risk is prematurity. Studies of the relationship between plurality and outcome are frequently hampered by major differences in case mix between singletons, twins and high multiples. For example, high multiples tend to receive earlier prenatal care, receive more antenatal steroids, are more often delivered by Caesarean section and more often suffer from respiratory distress syndrome. However, recent studies that appropriately account for relevant confounding variables have suggested that very low birth weight infants from high multiple pregnancies are at excess risk for mortality when compared with twins and singletons. This article reviews the current available evidence.

Drug therapy and adverse drug reactions to terbutaline in obstetric patients: a prospective cohort study in hospitalized women

BACKGROUND: Adverse drug reactions (ADR's) could be expected more frequently in pregnant women. This study was performed in order to identify ADR's to tocolytic drugs in hospitalised pregnant women. METHODS: A prospective cohort study was performed in two General Hospitals of the Instituto Mexicano del Seguro Social (IMSS) in Mexico City. Two hundred and seven women undergoing labor, premature labor, threatened abortion or suffering any obstetric related disease were included. Drug prescription and signs and symptoms of any potential ADR were registered daily during the hospital stay. Any potential ADR to tocolytic drugs was evaluated and classified by three of the authors using the Kramer's algorithm. RESULTS: Of the 207 patients, an ADR was positively classified in 25 cases (12.1%, CI95% 8.1 to 17.5%). All ADR's were classified as minor reactions. Grouping patients with diagnosis of threatened abortion, premature labor or under labor (n= 114), 24 ADR's were related to terbutaline, accounting for a rate of 21.1 ADR's per 100 obstetric patients. Obstetric patients suffering an ADR were older than obstetric patients without any ADR. However, the former received less drugs/day x patient-1 and had a shorter hospital stay (p < 0.05) whereas the dose of terbutaline was similar between the two groups. Terbutaline inhibited uterine motility in women with and without any ADR at a similar rate, 70 and 76% respectively (x2 = 0.07; p = 0.8). CONCLUSION: Terbutaline, used as a tocolytic drug, was related to a high frequency of minor ADRs and to a high rate of effcicacy.