Confidence in performing normal vaginal delivery in the obstetrics clerkship: a randomized trial of two simulators.

OBJECTIVE: To compare clerkship medical students' confidence in performing a simulated normal vaginal delivery (NVD) after participating in a simulation training session using two different models. METHODS: Medical students were randomized to participate in a simulated NVD session using either an obstetrics mannequin or a birthing pelvis model. Questionnaires were used to assess confidence and evaluate the simulation before and immediately after the session and on the last day of the obstetrics clerkship rotation. RESULTS: One hundred ten students were randomized. At the start of the clerkship, both groups had similar obstetrics exposure and confidence levels. Only 15 students (13.9%) agreed they were ready to attempt a NVD with minimal supervision or independently. This increased significantly to 43 students (39.4%) immediately after the session. At the end of the clerkship, 79 of 81 responding students (97.5%) were confident that they could attempt a NVD with minimal supervision or independently. There were no significant differences noted between simulator groups at any point. The sessions were rated as equally useful and realistic, and this remained unchanged at the end of the clerkship. CONCLUSION: Simulated NVD training using either an obstetrics mannequin or a birthing pelvis model provides clerkship students with a positive experience and increases confidence immediately. It should be implemented early in the rotation, as it appears the clerkship experience also plays a large role in terms of students' confidence. Despite this, students maintain this type of learning is useful. Effective simulation training can easily be incorporated into clerkship training.

Objectif : Comparer la confiance des étudiants de médecine en stage clinique, pour ce qui est de l'exécution d'une simulation d'accouchement vaginal normal (AVN), à la suite de leur participation à une session de formation en simulation au moyen de deux modèles différents. Méthodes : Des étudiants de médecine ont été affectés, au hasard, à une session de simulation d'AVN faisant appel à un mannequin obstétrical ou à une session de simulation faisant appel à un modèle de bassin simulant l'accouchement. Des questionnaires ont été utilisés pour évaluer la confiance et la simulation avant et immédiatement après la session, ainsi qu'au cours de la dernière journée de la rotation en obstétrique. Résultats : Cent dix étudiants ont été affectés au hasard à l'un ou l'autre des groupes de simulation. Au début du stage clinique, les deux groupes présentaient des niveaux de confiance et d'exposition à la pratique obstétricale semblables. Seulement 15 étudiants (13,9 %) étaient d'avis qu'ils étaient prêts à tenter un AVN de façon indépendante ou sous une supervision minimale. Cette proportion a connu une hausse considérable en passant à 43 étudiants (39,4 %) immédiatement après la session de simulation. À la fin du stage clinique, 79 des 81 étudiants répondants (97,5 %) étaient confiants de pouvoir tenter un AVN de façon indépendante ou sous une supervision minimale. Aucune différence significative n'a été constatée entre les groupes de simulation à quelque moment que ce soit. Les sessions ont été évaluées comme étant tout aussi utiles et réalistes les unes que les autres; cette constatation est demeurée la même à la fin du stage clinique. Conclusion : La formation faisant appel à la simulation d'un AVN au moyen d'un mannequin obstétrical ou d'un modèle de bassin simulant l'accouchement offre aux étudiants en stage clinique une expérience positive et accroît immédiatement leur confiance. Une telle formation devrait être mise en œuvre tôt au cours de la rotation, puisqu'il semble que l'expérience vécue au cours du stage clinique joue également un rôle important pour ce qui est de la confiance des étudiants. Peu importe la chronologie de la simulation, les étudiants soutiennent que ce type d'apprentissage leur est utile. Une formation efficace en simulation peut facilement être intégrée au stage clinique.

Indications for, timing of, and modes of delivery in a national cohort of women admitted with antepartum hemorrhage at 22+0 to 28+6 weeks' gestation.

OBJECTIVE: Antepartum hemorrhage is associated with preterm birth and operative delivery. Since the Canadian Perinatal Network records obstetric interventions for women admitted to tertiary care hospitals with antepartum hemorrhage, our objective was to describe the delivery characteristics of this cohort. METHODS: Trained abstractors collected data by chart review from women admitted with antepartum hemorrhage between 22+0 and 28+6 weeks' gestation. We included all women with complete follow-up postpartum and used descriptive statistics to report the indications for, timing of, and modes of delivery. RESULTS: The study cohort included 806 women from 13 tertiary perinatal centres in six provinces. The most common causes of bleeding were placental abruption (n = 256) and placenta previa (n = 171). The median gestational age at delivery was 30 weeks, and 497 (61.7%) births occurred at less than 34 weeks. Over one half of the women began labour spontaneously, and 238 (29.5%) were delivered prior to the onset of labour. Overall, 370 (45.9%) women delivered vaginally, including 98 who had induction of labour. Of the 436 Caesarean sections (54.1%), 345 (79.1%) were emergencies. The most common indications for Caesarean section were placenta previa, abnormal fetal presentation, and placental abruption or vaginal bleeding. CONCLUSION: This inpatient cohort of women with antepartum hemorrhage had high rates of spontaneous labour, preterm birth, and emergency Caesarean section. These results can be used as current Canadian benchmark rates of preterm delivery, induction of labour, and Caesarean section in women admitted to tertiary care centres with antepartum hemorrhage between 22+0 and 28+6 weeks' gestation, and can aid in the counselling of similar women.

The Canadian Perinatal Network: a national network focused on threatened preterm birth at 22 to 28 weeks' gestation.

OBJECTIVE: The Canadian Perinatal Network (CPN) maintains an ongoing national database focused on threatened very preterm birth. The objective of the network is to facilitate between-hospital comparisons and other research that will lead to reductions in the burden of illness associated with very preterm birth. METHODS: Women were included in the database if they were admitted to a participating tertiary perinatal unit at 22+0 to 28+6 weeks' gestation with one or more conditions most commonly responsible for very preterm birth, including spontaneous preterm labour with contractions, incompetent cervix, prolapsing membranes, preterm prelabour rupture of membranes, gestational hypertension, intrauterine growth restriction, or antepartum hemorrhage. Data were collected by review of maternal and infant charts, entered directly into standardized electronic data forms and uploaded to the CPN via a secure network. RESULTS: Between 2005 and 2009, the CPN enrolled 2524 women from 14 hospitals including those with preterm labour and contractions (27.4%), short cervix without contractions (16.3%), prolapsing membranes (9.4%), antepartum hemorrhage (26.1%), and preterm prelabour rupture of membranes (23.0%). The mean gestational age at enrolment was 25.9 ± 1.9 weeks and the mean gestation age at delivery was 29.9 ± 5.1 weeks; 57.0% delivered at < 29 weeks and 75.4% at < 34 weeks. Complication rates were high and included serious maternal complications (26.7%), stillbirth (8.2%), neonatal death (16.3%), neonatal intensive care unit admission (60.7%), and serious neonatal morbidity (35.0%). CONCLUSION: This national dataset contains detailed information about women at risk of very preterm birth. It is available to clinicians and researchers who are working with one or more CPN collaborators and who are interested in studies relating processes of care to maternal or perinatal outcomes.

An international trial of antioxidants in the prevention of preeclampsia (INTAPP).

OBJECTIVE: We sought to investigate whether prenatal vitamin C and E supplementation reduces the incidence of gestational hypertension (GH) and its adverse conditions among high- and low-risk women. STUDY DESIGN: In a multicenter randomized controlled trial, women were stratified by the risk status and assigned to daily treatment (1 g vitamin C and 400 IU vitamin E) or placebo. The primary outcome was GH and its adverse conditions. RESULTS: Of the 2647 women randomized, 2363 were included in the analysis. There was no difference in the risk of GH and its adverse conditions between groups (relative risk, 0.99; 95% confidence interval, 0.78-1.26). However, vitamins C and E increased the risk of fetal loss or perinatal death (nonprespecified) as well as preterm prelabor rupture of membranes. CONCLUSION: Vitamin C and E supplementation did not reduce the rate of preeclampsia or GH, but increased the risk of fetal loss or perinatal death and preterm prelabor rupture of membranes.

Influence of oligohydramnios on preterm premature rupture of the membranes at 30 to 36 weeks' gestation.

OBJECTIVE: to evaluate the influence of initial oligohydramnios on the prognosis of women with preterm premature rupture of the membranes (PPROM) at 30 to 36 weeks' gestation. METHODS: the Royal Alexandra Hospital ultrasound database was used to identify singleton pregnancies at 30 to 36 weeks' gestation with an ultrasound performed for confirmed PPROM from January 1992 to December 2006. Records were linked to the electronic provincial delivery record to perform a retrospective cohort study comparing the outcomes of pregnancies with an initial amniotic fluid index (AFI) < 5 cm with the outcomes of pregnancies with an AFI of 5 to 10 cm. Logistic and linear regression were used to analyze the association between binary outcome and explanatory variables. RESULTS: the maternal and perinatal outcomes of 438 pregnancies were analyzed. Univariate analysis suggested statistically significant associations between initial oligohydramnios and decreased latency (P < 0.001), increased histologically proven chorioamnionitis (P = 0.01), neonatal length of stay in hospital (P = 0.002), and NICU (P = 0.003); however, after controlling for confounding variables (gestational age at delivery, parity, presentation, and antenatal antibiotic and corticosteroid administration), only latency remained significant (P = 0.004). No association was found between initial oligohydramnios and any other outcomes assessed, including mode of delivery, postpartum endometritis, maternal length of stay, non-reassuring fetal status, and neonatal morbidity and mortality. CONCLUSION: initial oligohydramnios is associated with decreased latency in singleton pregnancies complicated by PPROM at 30 to 36 weeks' gestation; however, it does not appear to influence maternal or neonatal infectious morbidity, and it may not be useful to determine candidacy for expectant management or intentional delivery.

Effect of older maternal age on the risk of spontaneous preterm labor: a population-based study.

To determine if older maternal age (35 years and older) at first birth was an independent risk factor for spontaneous preterm labor, we conducted a retrospective population-based cohort study. Using provincial perinatal data, we developed separate risk models for low- and high-risk women using multivariate logistic regression. We found that older maternal age exerted a direct and independent effect on spontaneous preterm labor for both nulliparous women with no preexisting chronic illnesses or pregnancy complications (low-risk) and nulliparous women who did not have any preexisting chronic illnesses, but developed one or more pregnancy complications (high-risk).

Modifiable risk factors for term large for gestational age births.

To determine modifiable and nonmodifiable risk factors for term large for gestational age (T-LGA) births in Northern and Central Alberta and their public health importance, a retrospective cohort study (n = 115,198) of singleton live births (1996-2003) was conducted using maternal and newborn data from a provincial perinatal database. After adjusting for potential confounders, predictors of T-LGA births included prepregnancy weight 91 kg or greater, multiparity, and previous LGA birth. The strongest modifiable predictor was prepregnancy weight 91 kg or greater (OR = 2.52; CI 2.39, 2.65). The population-attributable risk percentage for prepregnancy weight 91 kg or greater was 10%.

Surgical site infection following elective Caesarian section: a case-control study of postdischarge surveillance.

OBJECTIVES: To ascertain the incidence of postoperative surgical site infection (SSI) following elective Caesarean section (CS) and to compare demographic characteristics and antibiotic administration between infected cases and noninfected control subjects. METHODS: We conducted a retrospective case-control study of patients undergoing elective CS between 1996 and 2002 at a tertiary centre. Infection-control personnel attempted to contact by telephone all women who had had Caesarean sections, 1 month after their surgery. The women they reached were asked to complete a questionnaire based on CDC-validated criteria for infection to determine whether SSI had occurred. Control subjects without SSI were matched on the basis of having had an elective CS and by date of surgery. We then reviewed the hospital records of both groups. RESULTS: Over the study period, 1250 elective Caesarean sections were performed and 124 infected cases were identified, giving an overall SSI incidence of 9.9%. Of the 342 women reviewed (124 cases, 218 control subjects), 23% received prophylactic intraoperative antibiotics. Cases and control subjects differed significantly in terms of estimated blood loss, with fewer control subjects having excessive blood loss (P = 0.04). Among those women receiving postoperative antibiotics, case subjects received a significantly higher number of doses than did control subjects (P = 0.003). The groups did not differ significantly in terms of overall antibiotic administration or other demographic variables. CONCLUSIONS: The incidence of SSI following elective CS according to postdischarge surveillance was 9.9%, which is higher than expected for a low-risk procedure. Because follow-up was not possible for all cases, this incidence may be an underestimate. Underuse of antimicrobial prophylaxis may also be a contributing factor, because prophylactic antibiotics were administered in less than 25% of cases.

Frequency of newborn behaviours associated with neonatal abstinence syndrome: a hospital-based study.

OBJECTIVES: To determine the frequency of neonatal abstinence syndrome (NAS) among unselected term newborns, using newborn behaviour data only. METHODS: This hospital-based prospective exploratory study used clinical observations of newborn behaviours, mothers' observations of their newborns, and newborn chart data to determine the prevalence of suspected and confirmed cases of NAS in a convenience sample of unselected term newborns "rooming in" with their mothers in a large central city acute-care referral hospital. Over a 4-month period, 824 out of 1008 newborns were observed at between 8 and 30 hours of life by specially trained nurse observers. Behaviours recorded and their weighting were adapted from the Neonatal Abstinence Scoring System (NASS) by Finnegan and Kaltenbach. Newborns with scores of 5 or greater and "suspect for NAS" were referred to their physicians for confirmation or refutation of the clinical findings. The prevalence of "suspect for NAS" and confirmed NAS, as well as of individual neonatal behaviours, was calculated. RESULTS: Thirty-one (3.8%) of 824 term "rooming in" newborns were identified with findings suggestive of NAS. Four newborns were positively identified as having NAS and treated. The identification was confirmed by post hoc affirmation of maternal drug use. Individual behaviours occurring in 10% or more of newborns included excessive sneezing, nasal stuffiness, unsustained suck, tremor, and abnormal nipple latch. CONCLUSIONS: Clinical observation of newborn behaviour may identify NAS. Further studies are recommended to correlate this methodology with laboratory findings, as are more in-depth maternal questionnaires concerning use of mood-altering substances. The prevalence of NAS is likely underestimated because of early hospital discharge. A coordinated system of early identification and infant-specific assessment and treatment, both in hospital and following discharge home, is advocated.

RETIRED: The use of first trimester ultrasound.

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.

History of abortion, preterm and term birth, and risk of gestational hypertension: a population-based study.

OBJECTIVE: To examine the consequence of prior abortion and preterm and term birth on the occurrence of gestational hypertension in the subsequent pregnancy. STUDY DESIGN: A population-based, retrospective, cohort study was conducted based on 140,773 pregnancies delivered between 1993 and 1999 in 49 hospitals in northern and central Alberta, Canada. Multivariate logistic regression was applied to estimate ORs with 95% CIs, adjustedfor confounding variables. RESULTS: The incidence of gestational hypertension was markedly lower in women who previously delivered at term than in primigravid women (2.4% vs. 5.6%) (adjusted OR [aOR]: .41 [.38-.44], p < 0.001). The incidence of gestational hypertension in women with previous preterm birth but without prior abortion or term pregnancy was also lower than in primiparous women (3.9% vs. 5.6%) (aOR: .72 [.54-.95], p<0.05). Moreover, there was a trend toward a decreased incidence of gestational hypertension among women with a longer duration of previous preterm gestation. Although there was a statistically significant decreased incidence of gestational hypertension in pregnancies in women with a previous history of abortion (4.9%) as compared to women without such a history (5.6%) (aOR:.85[95% CI: .77-.93], p < 0.05), 2, 3 or more abortions were not associated with a decreased risk of gestational hypertension, calling into question the clinical significance of the effect of abortion. CONCLUSION: There was a trend toward a decreased incidence of gestational hypertension among women with a longer duration of previous gestation. However, a history of term pregnancy (> or =37 weeks) conveyed the most substantial protection against gestational hypertension in the subsequent pregnancy.

Where and to what extent is prevention of low birth weight possible?

Law birth weight (LBW), due to shortened gestation and/or inadequate fetal growth. is the major determinant of infant mortality and morbidity. Despite improvements in infant mortality, them has been no reduction in LBW rates. The authors examined the relationship between 33 maternal characteristics and the increased risks of preterm (PT) delivery or small-for-gestational-age (SGA) births in 76,444 Alberta women 1994-1997. PT was associated with preexisting medical conditions, obstetrical history, and pregnancy complications. Modifiable factors such as advanced maternal age contributed only 11% to the overall PT risk. SGA births were associated with several modifiable factors, including low prepregnancy weight, maternal age, smoking, drinking, and drug dependency. These contributed to 29% and 31% of PTand term SGA births. Smoking remains an important target for intervention, having contributed to 8% of PT births and about 24% of SGA births. SGA appears to be more amenable to prevention than PT delivery.

Fetus-in-fetu: confirmation of prenatal diagnosis with MRI.

Fetus-in-fetu is a rare form of monozygotic diamniotic twin pregnancy in which one fetus is enclosed within its twin (Khadaroo et al., 2000). This case report highlights the use of prenatal MRI to confirm prenatal diagnosis of an intra-abdominal FIF to aid obstetricians, neonatologists, and pediatric general surgeons in perinatal and surgical management.

A model for foetal growth and diagnosis of intrauterine growth restriction.

A model for foetal growth is developed and used to construct tools for diagnosis of intrauterine growth restriction. Foetal weight estimates are first transformed to normally distributed z-scores. The covariance structure over gestational ages is then estimated using a novel regression model. The diagnostic tools include individual growth curves with error bounds, probabilities to assess whether a foetus is small for its gestational age, and residual scores to determine whether current growth rates are unusual. The methods were developed sing data from 13593 ultrasound examinations involving 7888 foetal subjects. The model shows that median foetal growth velocity increases up to a gestational age of 35 weeks and then decreases during the final weeks of pregnancy. When growth is expressed as change in log weight, or equivalently as change proportional to current weight, the model reveals a constant deceleration as gestational age increases from 14 to 42 weeks.

History of abortion, preterm, term birth, and risk of preeclampsia: a population-based study.

OBJECTIVE: The objective of this study was to examine the effect of previous abortion and preterm and term birth on the incidence of preeclampsia in subsequent pregnancies. STUDY DESIGN: A population-based retrospective cohort study was conducted that was based on 140,773 pregnancies that had delivered between 1993 and 1999 in 49 hospitals in Northern and Central Alberta, Canada. Multivariate logistic regression was applied to estimate odds ratios, with 95% confidence intervals, and to control for confounding variables. RESULTS: No significant difference was found in the incidence of preeclampsia in nulliparous women with previous abortion (2.6%) as compared to nulliparous women without previous abortion (2.9%; adjusted odds ratio, 0.89; 95% confidence interval, 0.78-1.01; P >.05). A single previous abortion was associated with a slightly decreased risk of preeclampsia (adjusted odds ratio, 0.84; 95% confidence interval, 0.72-0.97; P <.05). However, 2 and > or =3 abortions were not associated with a decreased risk of preeclampsia. In women with no history of previous abortion and term pregnancy, there was no significant difference in incidence of preeclampsia between women who had previous preterm birth (2.7%) and primigravid women (2.8%; adjusted odds ratio, 0.71; 95% confidence ratio, 0.48-1.03; P >.05). However, > or =2 previous preterm births were associated with a decreased risk of preeclampsia (adjusted odds ratio, 0.28; 95% confidence interval, 0.09-0.84; P <.01). The incidence of preeclampsia was markedly lower in multiparous women who previously delivered at term (0.9%) as compared to the incidence in primigravida women (2.9%; adjusted odds ratio, 0.29; 95% confidence interval, 0.26-0.33; P <.001). The adjusted odds ratios of preeclampsia for women with 1, 2, 3, and > or =4 previous term pregnancies were 0.32 (95% confidence interval, 0.28-0.36), 0.27 (95% confidence interval, 0.22-0.34), 0.22 (95% confidence interval, 0.15-0.33), and 0.21 (95% confidence interval, 0.12-0.35), respectively. CONCLUSION: A history of term pregnancy (> or =37 weeks) conveys a substantial "protection" against preeclampsia in the subsequent pregnancy.

Impact of preeclampsia and gestational hypertension on birth weight by gestational age.

The predominant etiologic theory of preeclampsia is that reduced uteroplacental perfusion is the unique pathogenic process in the development of preeclampsia. Decreased uteroplacental blood flow would result in lower birth weights. To date, no study has assessed the effect of preeclampsia on birth weight by gestational age. Thus, the authors conducted a retrospective cohort study based on 97,270 pregnancies that resulted in delivery between 1991 and 1996 at 35 hospitals in northern and central Alberta, Canada. Differences in mean birth weight between women with preeclampsia and normotensive women ranged from -547.5 g to 239.5 g for gestational age categories ranging from < or = 32 weeks to > or = 2 weeks. The birth weights were statistically significantly lower among mothers with preeclampsia who delivered at < or = 37 weeks, with an average difference of -352.5 g. However, the birth weights were not lower among preeclamptic mothers who delivered after 37 weeks (average difference of 49.0 g). In Alberta, 61.2% of preeclamptic patients gave birth after 37 weeks of gestation. The authors conclude that babies born to mothers with preeclampsia at term have fetal growth similar to that of babies born to normotensive mothers. This finding does not endorse the currently held theory that reduced uteroplacental perfusion is the unique pathophysiologic process in preeclampsia.