Corrigendum to "population-based placental weight ratio distributions".

[This corrects the article DOI: 10.1155/2014/291846.].

Caesarean section rates in Southwestern Ontario: changes over time after adjusting for important medical and social characteristics.

OBJECTIVE: To compare Caesarean section rates in a cohort of women in Southwestern Ontario over time, overall, and in patient subgroups defined by the Robson criteria, after adjusting for important medical and social characteristics. METHODS: We obtained data from a perinatal database on deliveries at ≥ 22 weeks' gestation at a level II centre and a level III centre in London, Ontario between 1999 and 2010. Caesarean section rates were examined overall and in subgroups defined by parity, presentation, plurality, gestational age, and history of previous Caesarean section. Multivariable modified Poisson regression was used to compare Caesarean section rates in 2003-2006 and 2007-2010 versus 1999-2002. RESULTS: In the fully adjusted models, the overall Caesarean section rate was significantly higher in 2007-2010 than in 1999-2002 for the level II centre (adjusted relative risk [aRR] 1.12; 95% CI 1.05 to 1.21). An increase was also seen in the level III centre in both 2003 to 2006 (aRR 1.19; 95% CI 1.14 to 1.24) and 2007 to 2010 (aRR 1.17; 95% CI 1.12 to 1.22). Similar increases were seen over time among patient subgroups. Notably, repeat Caesarean sections without labour increased at the level II centre (2003 to 2006 aRR 1.21; 95% CI 1.01 to 1.45, and 2007 to 2010 aRR 1.44; 95% CI 1.21 to 1.71) and the level III centre (2003 to 2006 aRR 1.72; 95% CI 1.53 to 1.94, and 2007 to 2010 aRR 1.77; 95% CI 1.57 to 2.00). CONCLUSION: There has been a significant increase over time in the Caesarean section rate overall and in important subgroups. This increase remains even after controlling for other factors which may explain the trend.

Objectif : Comparer les taux de césarienne constatés dans une cohorte de femmes du Sud-Ouest de l'Ontario au fil du temps, de façon globale et au sein de sous-groupes de patientes définis au moyen des critères de Robson, à la suite de la neutralisation de l'effet d'importantes caractéristiques médicales et sociales. Méthodes : Nous avons obtenu, auprès d'une base de données périnatale, des données sur les accouchements à ≥ 22 semaines de gestation s'étant déroulés dans un centre de niveau II et un centre de niveau III de London, en Ontario, entre 1999 et 2010. Les taux de césarienne ont été examinés de façon globale et dans le cadre de sous-groupes définis en fonction de la parité, de la présentation, de la pluralité, de l'âge gestationnel et des antécédents de césarienne. Une régression de Poisson multivariée modifiée a été utilisée pour comparer les taux de césarienne constatés au cours des périodes 2003-2006 et 2007-2010 à ceux qui ont été constatés au cours de la période 1999-2002. Résultats : Dans le cadre des modèles entièrement corrigés, le taux global de césarienne a été considérablement plus élevé pour la période 2007-2010 que pour la période 1999-2002 au sein du centre de niveau II (risque relatif corrigé [RRc], 1,12; IC à 95 %, 1,05 - 1,21). Une hausse a également été constatée au sein du centre de niveau III tant au cours de la période 2003-2006 (RRc, 1,19; IC à 95 %, 1,14 - 1,24) qu'au cours de la période 2007-2010 (RRc, 1,17; IC à 95 %, 1,12 - 1,22). Des hausses semblables ont été constatées au fil du temps au sein des sous-groupes de patientes. Notamment, le taux de césarienne itérative sans travail a connu une hausse au sein du centre de niveau II (2003-2006 : RRc, 1,21; IC à 95 %, 1,01 - 1,45 et 2007-2010 : RRc, 1,44; IC à 95 %, 1,21 - 1,71) et du centre de niveau III (2003-2006 : RRc, 1,72; IC à 95 %, 1,53 - 1,94 et 2007-2010, RRc, 1,77; IC à 95 %, 1,57 - 2,00). Conclusion : Au fil du temps, nous avons constaté une hausse significative du taux de césarienne, tant de façon globale qu'au sein d'importants sous-groupes. Cette hausse est demeurée la même à la suite de la neutralisation de l'effet d'autres facteurs qui auraient pu expliquer la tendance.

Mild prematurity, proximal social processes, and development.

OBJECTIVE: To elucidate the role of gestational age in determining the risk of poor developmental outcomes among children born late preterm (34-36 weeks) and early term (37-38 weeks) versus full term (39-41 weeks) by examining the contribution of gestational age to these outcomes in the context of proximal social processes. METHODS: This was an analysis of the Canadian National Longitudinal Survey of Children and Youth. Developmental outcomes were examined at 2 to 3 (N= 15099) and 4 to 5 years (N= 12302). The sample included singletons, delivered at 34 to 41 weeks, whose respondents were their biological mothers. Multivariable modified Poisson regression was used to directly estimate adjusted relative risks (aRRs). We assessed the role of parenting by using moderation analyses. RESULTS: In unadjusted analyses, children born late preterm appeared to have greater risk for developmental delay (relative risk = 1.26; 95% confidence interval [CI], 1.01 to 1.56) versus full term. In adjusted analyses, results were nonsignificant at 2 to 3 years (late preterm aRR = 1.13; 95% CI, 0.90 to 1.42; early term aRR = 1.11; 95% CI, 0.96 to 1.27) and 4 to 5 years (late preterm aRR = 1.06; 95% CI, 0.79 to 1.43; early term aRR = 1.03; 95% CI, 0.85 to 1.25). Parenting did not modify the effect of gestational age but was a strong predictor of poor developmental outcomes. CONCLUSIONS: Our findings show that, closer to full term, social factors (not gestational age) may be the most important influences on development.

Population-based placental weight ratio distributions.

The placental weight ratio (PWR) is a health indicator that reflects the balance between fetal and placental growth. The PWR is defined as the placental weight divided by the birth weight, and it changes across gestation. Its ranges are not well established. We aimed to establish PWR distributions by gestational age and to investigate whether the PWR distributions vary by fetal growth adequacy, small, average, and large for gestational age (SGA, AGA, and LGA). The data came from a hospital based retrospective cohort, using all births at two London, Ontario hospitals in the past 10 years. All women who delivered a live singleton infant between 22 and 42 weeks of gestation were included (n = 41441). Nonparametric quantile regression was used to fit the curves. The results demonstrate decreasing PWR and dispersion, with increasing gestational age. A higher proportion of SGA infants have extreme PWRs than AGA and LGA, especially at lower gestational ages. On average, SGA infants had higher PWRs than AGA and LGA infants. The overall curves offer population standards for use in research studies. The curves stratified by fetal growth adequacy are the first of their kind, and they demonstrate that PWR differs for SGA and LGA infants.

Active recruitment strategy in disadvantaged immigrant populations improves the identification of human immunodeficiency but not of hepatitis B or C virus infections.

BACKGROUND: Barriers to access medical screening and care may underestimate the number of diseased subjects among immigrant populations. AIMS: To evaluate the prevalence of human immunodeficiency virus, hepatitis B virus and hepatitis C virus infections among immigrants recruited in a disadvantaged area. METHODS: The study enrolled all subjects seen between 1999 and 2009 at an on-site health and family counselling centre for immigrants. During the first 6 years of the study a pro-active recruitment was performed using a mobile unit. RESULTS: Overall 2681 subjects were enrolled (median age: 31 years; 52.8% males; 82.3% from Sub-Saharan Africa; 13.9% of the women were sex workers). A total of 206 subjects (7.6%) were hepatitis B surface antigen-positive, 84 (3.6%) were anti-hepatitis C virus-positive, 129 (5%) were anti-human immunodeficiency virus-positive, 84 (3.1%) were drug users, and 436 (16.3%) were alcohol abusers. The prevalence of hepatitis B surface antigen and anti-hepatitis C virus remained consistent throughout the study period, while the prevalence of human immunodeficiency virus significantly decreased. At multivariate analysis, hepatitis B virus infection was associated with male gender, hepatitis C virus infection with drug addiction, and human immunodeficiency virus infection was associated with female gender, drug addiction, and active recruitment. CONCLUSIONS: An active recruitment strategy should be considered to reach disadvantaged populations at high risk of human immunodeficiency virus infection.

Neonatal morbidity associated with late preterm and early term birth: the roles of gestational age and biological determinants of preterm birth.

BACKGROUND: The aim of this study was to elucidate the role of gestational age in determining the risk of neonatal morbidity among infants born late preterm (34-36 weeks) and early term (37-38 weeks) compared with those born full term (39-41 weeks) by examining the contribution of gestational age within the context of biological determinants of preterm birth. METHODS: This was a retrospective cohort study. The sample included singleton live births with no major congenital anomalies, delivered at 34-41 weeks of gestation to London-Middlesex (Canada) mothers in 2002-11. Data from a city-wide perinatal database were linked with discharge abstract data. Multivariable models used modified Poisson regression to directly estimate adjusted relative risks (aRRs). The roles of gestational age and biological determinants of preterm birth were further examined using mediation and moderation analyses. RESULTS: Compared with infants born full term, infants born late preterm and early term were at increased risk for neonatal intensive care unit triage/admission [late preterm aRR=6.14, 95% confidence interval (CI) 5.63, 6.71; early term aRR=1.54, 95% CI 1.41, 1.68] and neonatal respiratory morbidity (late preterm aRR=6.16, 95% CI 5.39, 7.03; early term aRR=1.46, 95% CI 1.29, 1.65). The effect of gestational age was partially explained by biological determinants of preterm birth acting through gestational age. Moreover, placental ischaemia and other hypoxia exacerbated the effect of gestational age on poor outcomes. CONCLUSIONS: Poor outcomes among infants born late preterm and early term are not only due to physiological immaturity but also to biological determinants of preterm birth acting through and with gestational age to produce poor outcomes.

Efficiency of glaucoma drug regulation in 5 European countries: a 1995-2006 longitudinal prescription analysis.

PURPOSE: To compare the evolution of prostaglandin analog (PGA) and ß-blocker (BB) prescriptions across 5 European countries. METHODS: Data were extracted from various sources: (1) IMS data for France, Germany, Italy, Spain, and the United Kingdom, (2) glaucoma-treated patients from the United Kingdom General Practice Research Database (UK-GPRD), (3) prescriptions delivered by the territorial pharmaceutical service of Monselice of the Padova region (Italy). Drugs were grouped into 3 classes: PGAs, BBs, and other drugs. Yearly market shares were calculated. Treatment persistence survival curves were estimated for Italian and UK data, and the 3 drug groups were compared using the Cochran Mantel Haenszel test. RESULTS: According to Padova data, BBs decreased in market share, whereas PGAs increased. A linear extrapolation of these market shares, based on 1998 to 2003 data, predicted that the 2 curves should cross in 2005, a prediction reinforced by the European Medicines Agency authorization (2002) of PGAs as first-line glaucoma treatments. That this did not occur may be explained by Italy's refusal to reimburse PGAs as first-line therapy. IMS data identified Italy and Germany as 2 countries in which BBs are still more frequently prescribed than PGAs. Treatment persistence with PGAs as monotherapy, in PGA-naive patients, was longer than for BBs according to both Padova and UK-GPRD data. This held true for both first-line and second-line PGA prescriptions (UK-GPRD); the persistence of second-line PGA equalled first-line BB treatment. CONCLUSION: Health care regulations impacted upon glaucoma prescribing and may be one of the reasons for different annual evolution rates of PGA and BB prescriptions.

International vision requirements for driver licensing and disability pensions: using a milestone approach in characterization of progressive eye disease.

OBJECTIVE: Low vision that causes forfeiture of driver's licenses and collection of disability pension benefits can lead to negative psychosocial and economic consequences. The purpose of this study was to review the requirements for holding a driver's license and rules for obtaining a disability pension due to low vision. Results highlight the possibility of using a milestone approach to describe progressive eye disease. METHODS: Government and research reports, websites, and journal articles were evaluated to review rules and requirements in Germany, Spain, Italy, France, the UK, and the US. RESULTS: Visual acuity limits are present in all driver's license regulations. In most countries, the visual acuity limit is 0.5. Visual field limits are included in some driver's license regulations. In Europe, binocular visual field requirements typically follow the European Union standard of ≥120°. In the US, the visual field requirements are typically between 110° and 140°. Some countries distinguish between being partially sighted and blind in the definition of legal blindness, and in others there is only one limit. CONCLUSIONS: Loss of driving privileges could be used as a milestone to monitor progressive eye disease. Forfeiture could be standardized as a best-corrected visual acuity of <0.5 or visual field of <120°, which is consistent in most countries. However, requirements to receive disability pensions were too variable to standardize as milestones in progressive eye disease. Implementation of the World Health Organization criteria for low vision and blindness would help to establish better comparability between countries.

Cost effectiveness of travoprost versus a fixed combination of latanoprost/timolol in patients with ocular hypertension or glaucoma: analysis based on the UK general practitioner research database.

OBJECTIVE: This study aimed to compare the cost effectiveness of travoprost versus a fixed combination of latanoprost/timolol as first-line therapies for ocular hypertension or glaucoma. METHODS: Patient charts were extracted from the UK General Practitioner Research Database. Patients with ocular hypertension or glaucoma who received first-line treatment with either travoprost or latanoprost/timolol and were followed up for >6 months were included. Treatment failure was defined as a treatment change or a glaucoma intervention (laser therapy or surgery). Time to treatment failure was compared using a Cox model and adjusted by the propensity score method. RESULTS: Eligible patients received either travoprost (n=639) or latanoprost/timolol (n=176). Their mean age was 70 years at diagnosis and 48.2% of patients were male. Patient characteristics did not differ significantly between treatment groups. Treatment failure rates at 1 year were 31.3% (travoprost) and 39.4% (latanoprost/timolol) and yielded a hazard ratio for failure in favour of travoprost (0.75; p<0.04) after adjusting for age, sex, co-morbidities and duration of follow-up. Adjusted annual costs of glaucoma management were significantly (p<0.001) less with travoprost (pound215.86) than with latanoprost/timolol (pound327.83). CONCLUSIONS: In everyday practice, travoprost was maintained longer than latanoprost/timolol as first-line therapy for glaucoma. The mean daily costs of travoprost were 50.8% less per patient than those of latanoprost/timolol. Despite adjustments, these results might be confounded, at least partially, by disease severity.

Outcomes of elective labour induction and elective caesarean section in low-risk pregnancies between 37 and 41 weeks' gestation.

OBJECTIVE: To compare maternal and neonatal outcomes after elective induction of labour and elective Caesarean section with outcomes after spontaneous labour in women with low-risk, full-term pregnancies. METHODS: We extracted birth data from 1996 to 2005 from an obstetrical database. Singleton pregnancies with vertex presentation, anatomically normal, appropriately grown fetuses, and no medical or surgical complications were included. Outcomes after elective induction of labour and elective Caesarean section were compared with the outcomes after spontaneous labour, using chi-square and Student t tests and logistic regression. RESULTS: A total of 9686 women met the study criteria(3475 nulliparous, 6211 multiparous). The incidence of unplanned Caesarean section was higher in nulliparous women undergoing elective induction than in those with spontaneous labour (P < 0.001). Postpartum complications were more common in nulliparous and multiparous women undergoing elective induction (P < 0.001 and P < 0.01, respectively) and multiparous women undergoing elective Caesarean section, (P < 0.001). Rates of triage in NICU were higher in nulliparous women undergoing elective Caesarean section (P < 0.01), and requirements for neonatal free-flow oxygen administration were higher in nulliparous and multiparous women undergoing elective Caesarean section (P < 0.01 for each). Unplanned Caesarean section was 2.7 times more likely in nulliparous women undergoing elective induction of labour (95% CI 1.74 to 4.28, P < 0.001) and was more common among nulliparous and multiparous women undergoing induction of labour and requiring cervical ripening (P < 0. 001 and P < 0.05, respectively). CONCLUSION: Elective induction leads to more unplanned Caesarean sections in nulliparous women and to increased postpartum complications for both nulliparous and multiparous women. Elective Caesarean section has increased maternal and neonatal risks.

Opioids in the parturient with chronic nonmalignant pain: a retrospective review.

The purpose of this research was to determine the neonatal outcomes of women who had been taking medically prescribed opioids throughout their pregnancy. A retrospective case study was done of 15 pregnancies associated with maternal opiate use between January 1, 1999, and September 30, 2002. Two cases were excluded due to coaddiction. Neonatal data were collected including gestational age, head circumference, length, birth weight, Apgar score at one and five minutes, details of resuscitation required, and Neonatal Abstinence Score. There were 13 pregnancies, which resulted in 13 live births; opioids prescribed included oxycodone, codeine, meperidine, fentanyl, dilaudid, morphine, and methadone. There were four babies with one-minute Apgar score = -5, and two babies with five-minute Apgar score = 5. It was concluded that neonatal growth markers in this population were within normal limits as plotted on the standard growth and development record of Gairdner-Pearson. Five out of 13 (38.5 percent) neonates were diagnosed with opioid discontinuation syndrome.

Myxoma virus infection of primary human fibroblasts varies with cellular age and is regulated by host interferon responses.

Recent studies have indicated a critical role for interferon (IFN)-mediated antiviral responses in the host range of myxoma virus (MV), a pathogenic poxvirus of rabbits. To investigate the contribution of IFN to MV tropism in nonleporine cells, primary human dermal fibroblasts (HDFs) were tested for permissiveness to MV infection. Low-passage HDFs that underwent fewer than 25 population doublings (PD) were fully permissive for MV infection, supporting productive virus replication and cell-to-cell spread. In contrast, early and late viral gene expression was detectable in high-passage HDF (>75 PD), but MV failed to generate infectious progeny and could not form foci in these cells. Vesicular stomatitis virus (VSV) plaque reduction assays confirmed that constitutive IFN production progressively increased as HDFs were passaged, concurrent with an increase in the expression of transcripts for type I IFN and IFN-responsive genes involved in antiviral responses. These findings correlated with the enhanced sensitivity of higher-passage HDF to inducers of type I IFN responses, such as dsRNA. Furthermore, pretreatment of low-passage HDF with type I IFN abrogated MV spread and replication while treatment of mature HDF with neutralizing antibodies to IFN-beta, but not IFN-alpha, restored the capacity to form foci. These findings emphasize the importance of post-entry events in determining the permissiveness of human cells to MV infection and support a critical role for innate type I IFN responses as key determinants of poxvirus host range and species restriction.

The impact of labor at term on measures of neonatal outcome.

OBJECTIVE: The purpose of this study was to determine risk assessments for a spectrum of neonatal outcomes with elective cesarean delivery versus a trial of labor for previous cesarean section and otherwise healthy patients who deliver at term. STUDY DESIGN: The perinatal/neonatal database of St. Joseph's Health Care, London, Ontario, Canada, was used to obtain the umbilical cord pH and base excess values, incidence of adverse neonatal outcomes, and patient demographics for all term (> or =37 weeks of gestation), singleton, liveborn, or intrapartum demise infants with no major anomalies who were delivered between January 1992 and March 2002 (n = 33,709 infants). Patient groupings (all patient, patient with previous cesarean delivery, and low-risk patient) with no labor versus labor were studied by a comparison of mean values/incidences for those neonatal outcomes that were available from the database with the use of linear and logistic regression analysis and controlling for potentially confounding variables. RESULTS: Labor was associated with a small drop in umbilical artery pH from approximately 7.27 to 7.25 and base excess from approximately -3.1 to -5.4 mmol/L, but this was generally well tolerated, with no difference in the incidence of 5-minute Apgar scores of <7 for any of the patient population groupings. Neonatal respiratory morbidity was increased generally in the group of elective cesarean delivery patients, which resulted in increased neonatal intensive care unit triage/admission even out to 7 days; some of this risk was likely to persist even with a policy of elective cesarean delivery after 39 weeks of gestation. Although we found no significant difference in the incidence of pathologic acidemia at birth with an umbilical artery pH <7.00, there was a risk for intrapartum/neonatal death that could be attributed to labor events per se that ranged from 1 of 882 for the patients with previous cesarean delivery to 1 of 3406 for the low-risk patients. CONCLUSION: For otherwise healthy patients at term, the risk of adverse neonatal outcomes is low, with the choice between elective cesarean delivery and trial of labor in general balancing the low risk of increased respiratory morbidity and thereby neonatal intensive care unit triage/admission against the extremely low risk of labor-related infant death and severe morbidity. However, this balance for the patients with previous cesarean delivery appears shifted, with less benefit from a trial of labor in terms of reduced respiratory morbidity and neonatal intensive care unit triage/admission and with increased labor-related severe morbidity/death, albeit with all of these still at a low level.

Umbilical cord pH and base excess values in relation to adverse outcome events for infants delivering at term.

OBJECTIVE: This study was undertaken to determine the relationship of umbilical cord pH and base excess (BE) values to adverse neonatal outcomes for a large tertiary hospital population delivering at term. Study design The perinatal/neonatal database of St. Joseph's Health Care, London, Canada, was used to obtain the umbilical cord pH and BE values, incidence of adverse neonatal outcomes, and patient demographics for all term (>/=37 weeks' gestation), singleton, liveborn infants with no major anomalies delivering between November 1995 and March 2002 (n=20,456). Statistical analyses included chi(2) analysis, logistic regression models to develop odds ratios and creation of receiver operating characteristic (ROC) curves with area under curve (AUC) calculations. RESULTS: Umbilical vein and artery pH and BE values for this tertiary care population averaged 7.33 +/- 0.06 and 7.24 +/- 0.07, and -4.5 +/- 2.4 and -5.6 +/- 3.0 mmol/L, respectively. Apgar less than 7 at 5 minutes, neonatal intensive care unit (NICU) admission, and assisted neonatal ventilation had significant inverse relationships with both umbilical artery and umbilical vein pH and BE (all P < .0001), with marginal increases in the incidences of these outcomes beginning with cord blood values close to the mean, and more substantial increases with cord values less than 1 or 2 SD below the mean, depending on the outcome studied. The ROC AUC for all these relationships were significant (P < .001) ranging from 0.76 to 0.79 when predicting Apgar less than 7 at 5 minutes to 0.68 to 0.70 when predicting NICU admission, and with cutoff cord blood values at which sensitivity and specificity were maximized again close to mean values. For each of these neonatal outcomes, the relation to cord blood values was similar with little difference in the data analysis whether using pH or BE values, and whether from the umbilical artery or vein. CONCLUSION: There is a progression of risk in term infants for Apgar less than 7 at 5 minutes, NICU admission, and need for assisted ventilation with worsening acidosis at birth, which begins with cord blood values close to mean values indicating a higher threshold for associated acidemia with these outcomes than is seen for more severe neonatal outcomes.

ST segment analysis of the fetal electrocardiogram plus electronic fetal heart rate monitoring in labor and its relationship to umbilical cord arterial blood gases.

OBJECTIVE: This study was undertaken to determine the ability of intrapartum electronic fetal heart rate monitoring (EFM) plus fetal electrocardiogram (ECG) ST segment automated ANalysis (STAN, Neoventa Medical, Goteborg, Sweden) monitoring to predict metabolic acidemia (defined as an umbilical cord artery pH < 7.15 and base deficit > or = 12 mmol/L) at birth. STUDY DESIGN: Women with singleton, term pregnancies who had a clinical indication for internal EFM with a fetal scalp electrode were included in the study. Attending physicians were blinded to the ST analysis information, only using available EFM as per current clinical practice. After delivery, 2 trained observers blinded to neonatal outcome and ST analysis information performed visual classification of the EFM tracing in 10-minute epochs according to FIGO guidelines. ST events automatically detected by the STAN S21 monitor (Neoventa Medical) were combined with the visual EFM classification as per STAN clinical guidelines (Neoventa Medical). RESULTS: When applying STAN clinical guidelines from a sample of 143 women, our data indicated a sensitivity of 43%, specificity of 74%, negative predictive value of 96%, and a positive predictive value of 8% for metabolic acidemia at birth. Poor ECG quality, despite good EFM tracings (ECG signal loss), occurred 11% of the tracing time. CONCLUSION: The STAN clinical guidelines have a poor positive predictive value and a sensitivity of less than 50% for metabolic acidemia at birth.

How prostaglandins have changed the medical approach to glaucoma and its costs: an observational study of 2228 patients treated with glaucoma medications.

PURPOSE: The aim of the present study was to investigate how the medical treatment of glaucoma changed between 1997 and 2002, since the advent of prostaglandin derivatives, with regard to drug prescriptions and pharmaceutical costs. METHODS: A study was made of medical prescriptions for 2228 patients with glaucoma and/or ocular hypertension, in order to investigate the following: (i) the antiglaucoma drugs most commonly prescribed in 1997 and 2002, and any differences between the drugs prescribed in these 2 years; (ii) the number of drugs used per patient in 1997 and 2002, respectively, and (iii) any increase in the prescribing of antiglaucoma drugs and their relative costs from 1997 to 2002. RESULTS: From 1997 to 2002 there was a sharp drop in the prescribing of beta-blockers (79% in 1997 and 55% in 2002). A marked increase in the use of prostaglandin derivatives (0% in 1997 and 18% in 2002) was registered and a marked increase in the prescribing of carbonic anhydrase inhibitors (5% in 1997 and 14% in 2002) was also noted. From 1997 to 2002 there was a trend towards drug addition rather than substitution, so that the number of drugs used per patient increased. The number of patients treated increased enormously (by 98%) from 1997 to 2002. The cost of medical therapy from 1997 to 2002 rose dramatically, with an increase of 148.9% per patient. CONCLUSION: The availability of prostaglandin derivatives has strongly influenced the medical approach to glaucoma. This class of drugs will soon become the type most commonly prescribed for patients with glaucoma and/or ocular hypertension. The increased number of treatments also suggests that the approach of ophthalmologists towards these diseases has changed. Ocular hypertension, as well as glaucoma, is now treated more aggressively. Given the increase in the prescription of prostaglandin derivatives, the pharmaceutical cost of treatment has risen dramatically.

An association of chorionicity with preterm twin birth.

OBJECTIVE: To assess the risk factors for preterm birth in twin pregnancies, particularly monochorionicity. METHODS: A cohort study of 767 sets of twins, each twin weighing more than 500 g, born between January 1, 1992, and December 31, 2001, at St. Joseph's Health Care in London, Ontario. Statistical analysis was performed using forward stepwise logistic regression models, with gestational age at birth less than 28 or 32 weeks as the outcome. RESULTS: Polyhydramnios and chorioamnionitis were significant risk factors for preterm birth prior to 28 or 32 weeks' gestation. Monochorionicity was a risk factor for preterm birth prior to 32 weeks' gestation. Past term birth and maternal age over 30 years were associated with reduced risk for preterm birth. CONCLUSION: Monochorionic placentation is a significant risk factor for preterm twin birth.

Birth can be a hazardous journey: electronic fetal monitoring does not help.

Intrapartum fetal health surveillance, in particular electronic fetal heart-rate monitoring (EFM), is a perinatal issue that has sparked much debate both nationally and internationally. Prevention of cerebral palsy is a major objective of all health-care providers when assessing fetal health in labour. The Fetal Health Surveillance Working Group of the Society of Obstetricians and Gynaecologists of Canada (SOGC) should be commended for its efforts in presenting and discussing the literature and for raising important issues in EFM in the SOGC's Clinical Practice Guideline on Standard Fetal Surveillance in Labour, published in JOGC in March 2002, the first half of the SOGC document Fetal Health Surveillance in Labour. These, as all, SOGC Clinical Practice Guidelines are widely used by hospitals and health-care providers when evaluating practices in their own environments, and we believe, as practitioners of and investigators in fetal health surveillance, that there is not good supporting evidence for recommending continuous intrapartum EFM for pregnancies in which there is an increased risk of perinatal death, cerebral palsy, or neonatal encephalopathy, or when oxytocin is being used for induction of labour, and that if we recommend that the fetal heart be electronically monitored while the nurse is elsewhere, we are on a slippery slope. We encourage reopening discussion regarding these recommendations in the document.