Association between the Mode of Delivery and Vertical Transmission of Human Papillomavirus

Human papillomavirus (HPV) can be vertically transmitted. Our objective was to measure the association between the mode of delivery and the detection of HPV in infants. We used data collected from pregnant women during the HERITAGE study. Self-collected vaginal samples from the first and third trimester were obtained for HPV testing. Specimens from oral, pharyngeal, conjunctival and anogenital mucosa were collected from infants 36-48 h after delivery and at 3 months of age. All samples were tested for HPV DNA by the Linear Array assay. Adjusted odd ratios (aOR) and 95% confidence interval (CI) were estimated using multivariate logistic regressions. From the 282 women revealed to be HPV-positive in both the first and third trimesters, 25 infants were born HPV-positive. The overall probability of transmission was 8.9% (25/282); 3.7% (3/81) in participants with a caesarean section and 10.9% (22/201) for those who delivered vaginally. Vaginal delivery increased the risk of HPV in infants compared to caesarean (aOR: 3.63, 95%CI: 1.03-12.82). Infants born after a caesarean with ruptured membranes were not at increased risk of HPV compared to infants born after an elective caesarean section with intact membranes (aOR: 1.31, 95%CI: 0.10-17.76). Our results support the hypothesis that transmission occurs mostly during the passage in the vaginal canal.

Perinatal morbidity among women with a previous caesarean delivery (PRISMA trial): a cluster-randomised trial

BACKGROUND

Women with a previous caesarean delivery face a difficult choice in their next pregnancy: planning another caesarean or attempting vaginal delivery, both of which are associated with potential maternal and perinatal complications. This trial aimed to assess whether a multifaceted intervention, which promoted person-centred decision making and best practices, would reduce the risk of major perinatal morbidity among women with one previous caesarean delivery.

METHODS

We conducted an open, multicentre, cluster-randomised, controlled trial of a multifaceted 2-year intervention in 40 hospitals in Quebec among women with one previous caesarean delivery, in which hospitals were the units of randomisation and women the units of analysis. Randomisation was stratified according to level of care, using blocked randomisation. Hospitals were randomly assigned (1:1) to the intervention group (implementation of best practices and provision of tools that aimed to support decision making about mode of delivery, including an estimation of the probability of vaginal delivery and an ultrasound estimation of the risk of uterine rupture), or the control group (no intervention). The primary outcome was a composite risk of major perinatal morbidity. This trial was registered with ISRCTN, ISRCTN15346559.

FINDINGS

21 281 eligible women delivered during the study period, from April 1, 2016 to Dec 13, 2019 (10 514 in the intervention group and 10 767 in the control group). None were lost to follow-up. There was a significant reduction in the rate of major perinatal morbidity from the baseline period to the intervention period in the intervention group as compared with the control group (adjusted odds ratio [OR] for incremental change over time, 0·72 [95% CI 0·52-0·99]; p=0·042; adjusted risk difference -1·2% [95% CI -2·0 to -0·1]). Major maternal morbidity was significantly reduced in the intervention group as compared with the control group (adjusted OR 0·54 [95% CI 0·33-0·89]; p=0·016). Minor perinatal and maternal morbidity, caesarean delivery, and uterine rupture rates did not differ significantly between groups.

INTERPRETATION

A multifaceted intervention supporting women in their choice of mode of delivery and promoting best practices resulted in a significant reduction in rates of major perinatal and maternal morbidity, without an increase in the rate of caesarean or uterine rupture.

FUNDING

Canadian Institutes of Health Research (CIHR, MOP-142448).

Prospective Evaluation of Fetal Hemoglobin Expression in Maternal Erythrocytes: An Analysis of a Cohort of 345 Parturients

It is believed that fetal hemoglobin (HbF) expression in adults is largely genetically regulated. The increased expression of HbF in pregnancy has been reported in a small number of articles. Different mechanisms have been proposed, but the description of HbF expression during pregnancy remains unclear. The objectives of this study were to document HbF expression during peri and postpartum periods, confirm its maternal origin, and assess clinical and biochemical parameters potentially associated with HbF modulation. In this observational prospective study, 345 pregnant women were followed. At baseline, 169 had HbF expression (≥1% of total hemoglobin) and 176 did not have HbF expression. Women were followed at the obstetric clinic during their pregnancy. Clinical and biochemical parameters were measured at each visit. Analyses were made to determine which parameters had a significant correlation to HbF expression. Results show that HbF expression of ≥1% during peri and postpartum periods in pregnant women without influencing comorbidities is at its highest peak during the first trimester. In all women, it was proven that HbF was of maternal origin. A significant positive correlation between HbF expression, βeta-human chorionic gonadotropin (β-HCG), and glycosylated hemoglobin (HbA1c) was present. A significant negative association between HbF expression and total hemoglobin was found. HbF expression induction during pregnancy is probably associated with an increase in β-HCG and HbA1C, and a decrease in total hemoglobin, which could temporarily reactivate the fetal erythropoietic system.

Human Papillomavirus Transmission and Persistence in Pregnant Women and Neonates

Importance

The prevalence of human papillomavirus (HPV) infection during pregnancy and its risk of transmission to newborns are not well documented.

Objective

To ascertain the prevalence of HPV in pregnant women, the risk of HPV detection in the placenta and in children at birth, and the probability that HPV detected at birth may persist in newborns.

Design, Setting, and Participants

The Human Papillomavirus Perinatal Transmission and Risk of HPV Persistence Among Children (HERITAGE) study was a prospective cohort study that recruited participants between November 8, 2010, and October 16, 2016. Participant follow-up visits were completed on June 15, 2017. Participants, which included pregnant women of at least 18 years of age and at 14 weeks or earlier of gestation, were recruited from 3 academic hospitals in Montreal, Québec, Canada. Laboratory and statistical analysis were completed on November 15, 2022.

Exposures

HPV DNA testing on self-collected vaginal and placental samples. Among children of mothers positive for HPV, conjunctival, oral, pharyngeal, and genital samples were collected for HPV DNA testing.

Main Outcomes and Measures

Vaginal HPV DNA testing was done on self-collected vaginal samples obtained among pregnant women recruited during their first trimester of pregnancy and in the third trimester for those who had HPV-positive samples in the first trimester. HPV DNA testing was also done on placental samples (swabs and biopsies) collected after birth in all participants. HPV DNA testing among children included conjunctival, oral, pharyngeal, and genital samples collected in children of HPV-positive mothers at birth, 3 months, and 6 months of age.

Results

A total of 1050 pregnant women (mean [SD] age, 31.3 [4.7] years) were included in this study. Prevalence of HPV in pregnant women at recruitment was 40.3% (95% CI, 37.3%-43.3%). Among the 422 HPV-positive women, 280 (66.4%) harbored at least 1 high-risk genotype, and 190 (45.0%) were coinfected with multiple genotypes. HPV was detected in 10.7% of placentas (92 of 860; 95% CI, 8.8%-12.9%) overall, but only 3.9% of biopsies (14 of 361) on the fetal side under the amniotic membrane were positive. Neonatal HPV detection (at birth and/or at 3 months) was 7.2% (95% CI, 5.0%-10.3%) overall, with the most frequent site of infection being the conjunctiva (3.2%; 95% CI, 1.8%-5.6%), followed by the mouth (2.9%; 95% CI, 1.6%-5.2%), the genital area (2.7%; 95% CI, 1.4%-4.9%), and the pharynx (0.8%; 95% CI, 0.2%-2.5%). Importantly, all HPV detected in children at birth cleared before the age of 6 months.

Conclusions and relevance

In this cohort study, vaginal HPV was frequently detected in pregnant women. Perinatal transmission was infrequent, and in this cohort, no infection detected at birth persisted at 6 months. Although HPV was detected in placentas, it remains difficult to differentiate contamination vs true infection.

Risk factors for placental human papillomavirus infection

OBJECTIVE

Human papillomavirus (HPV) has been associated with adverse pregnancy outcomes but placental HPV infection has been rarely studied. The objective was to determine the proportion of HPV-positive placentas and the associated risk factors among HPV-positive women during pregnancy.

METHODS

We analysed data from pregnant women enrolled in HERITAGE cohort study between 2010 and 2016 with positive vaginal HPV infection during the first trimester of pregnancy (n=354). Placental swabs and biopsies were collected. HPV genotyping was performed using Linear Array. The predictors of placental HPV detection were identified by generalised estimating equations models.

RESULTS

HPV was detected in 78 placentas (22.0%) (one among 96 caesarean sections and 77 among 258 vaginal deliveries). Overall, 91% of HPV-positive placentas were positive for a genotype that was detected in vaginal samples during pregnancy. Among women who delivered vaginally, abnormal cytology (adjusted OR (aOR) 1.78 (95% CI 1.02 to 3.10)), other genitourinary infection (aOR 2.41 (95% CI 1.31 to 4.44)), presence of multiple HPV genotypes in the first trimester (aOR 2.69 (95% CI 1.76 to 4.12)) and persistence of high-risk HPV infections during pregnancy (HPV-16/18: aOR 3.94 (95% CI 2.06 to 7.55) and other than HPV-16/18: aOR 2.06 (95% CI 1.05 to 4.02)) were independently associated with placental HPV.

CONCLUSIONS

HPV was frequently detected in the placenta of women who delivered vaginally and may be associated with host immune response characteristics.

Association Between Human Papillomavirus Infection Among Pregnant Women and Preterm Birth

IMPORTANCE

Preterm birth remains a leading cause of perinatal mortality and lifelong morbidity worldwide. The cause of most preterm births is unknown, although several infectious processes have been implicated.

OBJECTIVE

To assess whether human papillomavirus (HPV) infection, a frequent infection among women of childbearing age, is associated with preterm birth.

DESIGN, SETTING, AND PARTICIPANTS

The prospective HERITAGE cohort study was conducted at 3 academic hospitals in Montreal, Québec, Canada, among 899 pregnant women recruited between November 8, 2010, and October 16, 2016. Follow-up was completed on June 15, 2017. Statistical analysis was conducted from February 6, 2020, to January 21, 2021.

EXPOSURES

Vaginal HPV DNA detection in the first and third trimesters of pregnancy and placental HPV infection.

MAIN OUTCOMES AND MEASURES

The main outcome was preterm birth (defined as a live birth or stillbirth between 20 weeks and 0 days and 36 weeks and 6 days of gestation). The association between HPV DNA detection and preterm birth was measured using logistic regression. Odds ratios (ORs) and 95% CIs were adjusted by inverse probability of treatment weights of the propensity score.

RESULTS

The study included 899 women (mean [SD] age, 31.3 [4.6] years [range, 19-47 years]) with singleton pregnancies. A total of 378 women (42.0%) had HPV DNA detected in vaginal samples collected during the first trimester, and it was detected in 91 of 819 placentas (11.1%) at delivery. Fifty-five participants experienced preterm birth (38 spontaneous and 17 medically indicated). Persistent vaginal HPV-16/18 detection was significantly associated with all preterm births (adjusted OR [aOR], 3.72; 95% CI, 1.47-9.39) and spontaneous preterm births (aOR, 3.32; 95% CI, 1.13-9.80), as was placental HPV infection (all preterm births: aOR, 2.53; 95% CI, 1.06-6.03; spontaneous preterm births: aOR, 2.92; 95% CI, 1.09-7.81). Results were similar when restricting the analysis to participants without a history of cervical intraepithelial neoplasia treatment.

CONCLUSIONS AND RELEVANCE

The study's results suggest that persistent HPV-16/18 infection is associated with an increased risk of preterm birth, independent of cervical treatment. Future studies should investigate the association of HPV vaccination and vaccination programs with the risk of preterm birth.

Antibodies to human papillomavirus types 6, 11, 16 and 18: Vertical transmission and clearance in children up to two years of age

Background: There is a paucity of data on the dynamics of human papillomavirus (HPV) antibodies in children. We aimed to describe the vertical transmission and clearance of antibodies against HPV6, 11, 16 and 18 in children. Methods: We used data from pregnant women recruited into the HERITAGE cohort study between 2009 and 2012 who were positive for HPV-DNA at baseline. Dried blood spots were collected during the first trimester in pregnant participants, and at birth, 6, 12, and 24 months of age in children. The level of total immunoglobulin G (IgG) against HPV6, 11, 16 and 18 were measured using Luminex immunoassays. Spearman's coefficients were used to correlate HPV antibody levels between newborns and mothers. Panel and Kaplan-Meier graphics described antibody dynamics in the first 24 months of life. Findings: Antibodies from newborns and mothers (n = 58 pairs) were moderately to highly correlated with coefficients of 0·81 (95% confidence intervals (CI):0·70-0·88), 0·68 (95% CI:0·5-0·80), 0·90 (95% CI:0·83-0·94) and 0·85 (95% CI:0·76-0·91) against HPV6, 11, 16 and 18, respectively. In newborns seropositive at birth, anti-HPV antibodies were cleared by 80% and 100% at 12 and 24 months, respectively. Only two children presented detectable HPV antibodies at 24 months. The first child had no detectable antibodies at birth and the second presented increasing levels after two undetected measures. Interpretation: Correlation between mother and newborn IgG antibodies against HPV suggests vertical transfer. Most children cleared anti-HPV antibodies within six to 12 months. Funding: The Canadian Institutes of Health Research (CIHR).

Exploration of the effect of human papillomavirus (HPV) vaccination in a cohort of pregnant women in Montreal, 2010-2016

HPV vaccination efficacy has been shown in clinical trials but it is important to verify population level vaccine effectiveness (VE). We aimed to explore VE and herd effect using HPV infection data from a cohort study of Canadian pregnant women. We analyzed the baseline data of the HERITAGE study, which includes pregnant women recruited in Montreal between 2010-2012 and 2015–2016. Cervicovaginal samples self-collected in the first trimester were tested for 36 HPV types. Vaccination status was self-reported. VE and 95% confidence intervals (CI) were estimated by comparing the prevalence of HPV between vaccinated and unvaccinated women. Herd effect was explored by comparing HPV prevalence in unvaccinated women between the 2 recruitment periods. Adjusted ORs (95%CI) were estimated using exact logistic regression. The proportion of vaccinated women with at least one dose of 4vHPV was 7.5%. Although most of them were vaccinated after the onset of sexual activity, a high VE was found for HPV-16/18 (86.1% (95%CI: 15.0–99.7)). For HPV-6/11/16/18 and for HPV-31/33/45, VE was 61.9% (-23.5–92.6) and 57.0% (-47.7–92.0%), respectively. We also observed a non-statistically significant reduction in the prevalence of HPV-6/11/16/18 and HPV-31/33/45 among unvaccinated women recruited during the second recruitment period (adjusted OR: 0.8 (0.4–1.8) and 0.8 (0.3–1.7), respectively).

Human papillomavirus (HPV) perinatal transmission and risk of HPV persistence among children: Design, methods and preliminary results of the HERITAGE study

Perinatal route of transmission of human papillomavirus (HPV) has been demonstrated in several small studies. We designed a large prospective cohort study (HERITAGE) to better understand perinatal HPV. The objective of this article is to present the study design and preliminary data. In the first phase of the study, we recruited 167 women in Montreal, Canada, during the first trimester of pregnancy. An additional 850 are currently being recruited in the ongoing phase. Cervicovaginal samples were obtained from mothers in the first trimester and tested for HPV DNA from 36 mucosal genotypes (and repeated in the third trimester for HPV-positive mothers). Placental samples were also taken for HPV DNA testing. Conjunctival, oral, pharyngeal and genital samples were collected for HPV DNA testing in children of HPV-positive mothers at every 3-6 months from birth until 2 years of age. Blood samples were collected in mother and children for HPV serology testing. We found a high prevalence of HPV in pregnant women (45%[95%CI:37-53%]) and in placentas (14%[8-21%]). The proportion of HPV positivity (any site) among children at birth/3-months was 11%[5-22%]. HPV was detected in children in multiple sites including the conjunctiva (5%[10-14%]). The ongoing HERITAGE cohort will help provide a better understanding of perinatal HPV.

A late-preterm, early-term stratified analysis of neonatal outcomes by gestational age in placenta previa: defining the optimal timing for delivery

OBJECTIVE

Though no official guidelines address the issue of the optimal timing of delivery in placenta previa, common practice is to conduct delivery between 36 and 37 weeks gestation. Given the rising concerns regarding unnecessary premature deliveries, the objective of this study was to compare neonatal outcomes among pregnancies complicated by placenta previa delivered at the late-preterm period (35, 36 weeks) relative to the early-term period (37 and 38 weeks).

METHODS

We conducted a retrospective, population-based, cohort study using the CDC’s Linked Birth-Infant Death data files from the U.S. for the year 2004. We stratified the cohort according to gestational age and placenta previa status. Using 38 weeks gestation as reference controls, the effect of delivery in a pregnancy with placenta previa at 35, 36 and 37 weeks gestation on the risk of several neonatal outcomes was estimated using logistic regression analysis, adjusting for relevant confounders.

RESULTS

We analyzed a total of 4 118 956 births, of which 5675 (0.1%) met inclusion criteria. Late-preterm delivery was associated with lower birthweight and increased adequacy of care. Relative to neonates born at 38 weeks, birth at 35, 36 and 37 weeks was associated with no greater odds of meconium passage, fetal distress, fetal anemia, neonatal seizures, increased ventilator needs, or infant death at 1 year. However, odds of 5-min APGAR scores <7 were greater at 35 and 36 weeks (aOR [95% CI]): 3.33 [1.71-6.47] and 2.17 [1.11-4.22], respectively; as were odds of NICU admission rates: 2.25 [2.01-2.50] and 1.57 [1.38-1.76], respectively. Conclusions: Barring maternal indications, early-term delivery in placenta previa is associated with fewer complications and no greater risk than late-preterm delivery. This information may be helpful in the development of future guidelines, which are currently needed to guide the management of these pregnancies.

Bi-cultural, bi-national benchmarking and assessment of clinical reasoning in Obstetrics and Gynaecology

This article was migrated. The article was marked as recommended. Background: The Script Concordance Test (SCT) is being increasingly used in professional development in clinical reasoning (CR) in postgraduate medicine. On-line delivery favours multi-institutional collaboration. Objectives: To establish if: 1) SCT questions developed in the French-speaking University of Montreal were readily adaptable for use in the English-speaking University of Adelaide 2) expert reference panels (ERP) from both institutions could be used interchangeably 3) student cohorts would perform similarly in the same test. Study Design: 82 SCT questions based on 27 clinical cases in Obstetrics and Gynaecology were developed in Montreal and run in a volunteer cohort of year 3 and year 4 medical students (n=154). Local faculty translated all questions, selecting 31 based on 17 clinical cases for use in summative examinations a year 5 student cohort in Adelaide (n=123). Results: Mean (SD) percentage scores using each ERP key were: 74.2 (6.4) versus 73.3 (6.9), p<0.001 for Adelaide students and 72.5 (7.8) versus 70.6 (8.8), p<0.001 for Montreal students. The correlation coefficients were ≥ 0.928 (p<0.001). Conclusions: Student cohorts performed similarly regardless of which ERP key was used. With appropriate editorial control, SCT's can be effectively shared between French and English-speaking institutions located in different hemispheres. Potential advantages include the creation of an international database of assessment items, benchmarking and cost sharing.

Pituitary apoplexy in pregnancy: A case series and literature review

BACKGROUND

Severe headache during pregnancy is a challenging condition that may rarely imply endocrine disturbances. Rapid recognition of pituitary apoplexy is needed to improve pregnancy outcome.

OBJECTIVE

To review and compare maternal and fetal outcomes after pituitary apoplexy.

METHODS

Four cases of pituitary apoplexy during pregnancy in our centre are reported and literature review covering the past 54 years was performed.

RESULTS

In the four cases presented and the 33 reported in the literature, most women presented with severe headaches and systemic symptoms. Overall, 42% were treated surgically, 31% received bromocriptine or cabergoline and 61% were given hormone replacement. No major obstetrical complication was reported and all babies were healthy.

CONCLUSION

Pituitary apoplexy is a rare cause of sudden and severe headache during pregnancy. Rapid identification of this condition with potentially associated endocrine disturbances is important to ensure maternal and fetal well-being. A multidisciplinary team approach seems to reduce morbidity and mortality.

Correlation of cord blood pH, base excess, and lactate concentration measured with a portable device for identifying fetal acidosis

OBJECTIVE

To determine the effectiveness of portable lactate analyzers in identifying fetal acidosis by correlating arterial and venous lactate values from umbilical cord blood with lactate, pH, and base excess measurements from central laboratory analyzers.

METHODS

We performed a prospective study using arterial and venous cord blood from 52 women with a singleton fetus delivered at term. We evaluated the correlation between the cord blood lactate concentration measured using two of the same portable devices (Lactate Plus, Nova Biomedical) with the result from a central laboratory analyzer. Analyses of the correlation between arterial lactate concentration measured on the portable device with arterial pH and base excess were then performed.

RESULTS

We observed a median arterial pH of 7.24 (range 7.05 to 7.35) and a median arterial lactate concentration of 3.7 mmol/L (range 1.7 to 8.8 mmol/L). An excellent correlation was observed between lactate concentrations measured by the two portable devices (arterial R² = 0.98 and venous R² = 0.98), and between the portable device and the central laboratory analyzer (arterial R² = 0.94 and venous R² = 0.95). In our population, the optimal cut-offs to predict a pH < 7.20 or a base excess > -8.0 mmol/L were a lactate concentration of 4.9 mmol/L and 5.3 mmol/L, respectively, according to receiver operator characteristic analysis. With a lactate concentration > 4.9 mmol/L, the portable device had a sensitivity of 82% and a specificity of 90% to identify samples with an arterial pH < 7.20.

CONCLUSION

Cord blood lactate concentration measured with a portable device is a good predictor of cord blood base excess and pH. Future studies should be designed to correlate scalp blood lactate measurements with clinical outcomes.

Preventable obstetrical interventions: how many caesarean sections can be prevented in Canada?

Public health authorities have been alarmed by the progressive rise in rates of Caesarean section in Canada, approaching one birth in three in several provinces. We aimed therefore to consider what were preventable obstetrical interventions in women with a low-risk pregnancy and to propose an analytic framework for the reduction of the rate of CS. We obtained statistical variations of CS rates over time, across regions, and within professional practices from MED-ÉCHO, the Quebec hospitalization database, from 1969 to 2009. Data were extracted from a recent systematic review of the cascade of obstetrical interventions to calculate the population-attributable fractions for each intervention associated with an increased probability of CS. We thereby identified expectant management (as an alternative to labour induction) and planned vaginal birth after CS as the leading strategies for potentially reducing rates of CS in women at low risk. For vaginal birth after CS, an increase to its 1995 level could lower the current CS rate of 23.2% (2009 to 2010) to 21.0%. Other alternatives to obstetrical interventions with a potential for lowering CS rates included non-pharmacological pain control methods (such as continuous support during childbirth) in addition to usual care, intermittent auscultation of the fetal heart (instead of electronic fetal monitoring), and multidisciplinary internal quality assessment audits. We believe, therefore, that the concept of preventable CS is supported by empirical evidence, and we identified realistic strategies to maintain a CS rate in Quebec near 20%.

Brain magnetic resonance spectroscopy in obsessive-compulsive disorder: the importance of considering subclinical symptoms of anxiety and depression

Brain metabolite concentrations have recently been assessed in different cerebral regions presumably targeted in patients with obsessive-compulsive disorder (OCD) using magnetic resonance spectroscopy (MRS). However, results have been divergent. Possible confounding variables, such as the cerebral localisation of investigated regions and metabolites considered, as well as subclinical symptoms of anxiety and depression, could have affected these MRS profiles. The main goal of this study was to assess MRS metabolite differences between 13 individuals with OCD and 12 matched healthy controls in seven brain regions potentially involved in OCD. The secondary objective was to assess the relationships between levels of anxiety and depression and brain metabolite concentrations. No difference was found for N-acetylaspartate, glutamate-glutamine, myo-inositol (mI) and choline relative to creatine (Cr) concentration in either the left or right orbitofrontal area, left or right median temporal lobe, left or right thalamus or the anterior cingulate cortex. A significant negative correlation between the mI/Cr in the left orbitofrontal area and the severity of OCD symptomatology was observed while subclinical anxiety and depression were closely related to brain metabolite ratios. Thus, these subclinical symptoms, commonly associated with OCD, should be considered in assessing brain metabolite concentrations and may be central to the comprehension of this disorder.

Factors influencing the decision to practise obstetrics among Québec medical students: a survey

OBJECTIVE

The objectives of this study were to track changes in medical students' interest in obstetrics from the beginning of their studies in medicine to the end of their pre-clinical clerkships and to identify factors that influenced this interest.

METHODS

This was a cohort study of all Québec medical students who, in 2003, were about to begin their clerkships (n = 500). A questionnaire was administered at this time (T1) and at the end of the clerkship (T2). The main outcome variables were an intention to provide prenatal care without deliveries and an intention to deliver infants in future practice. Logistic regression analysis was used to assess relationships between the various determinants and the decision to practise obstetrics.

RESULTS

A total of 353 students, or 70.6% of the cohort, completed both questionnaires. At the end of their clerkships, 32 students (9.1%) were definitely planning to include complete obstetrical care in their future practices, and 45 (12.7%) said that they probably would. Between the beginning and the end of their clerkships, only 8% of students had changed their minds in favour of an obstetrical career, and 20% had decided against it. An intention to deliver infants is associated with the following factors: considering the practice of obstetrics gratifying (odds ratio [OR] 6.73; 95% confidence intervals [CI] 3.30-13.70); having been exposed to obstetrical care outside the clerkship in obstetrics and gynaecology (OR 4.4; 95% CI 1.6-10.26); having completed university studies before studying medicine (OR 4.08; 95% CI 1.11-15.3); and having had a decisive, positive experience with obstetrics (OR 2.86; 95% CI 0.96-8.50). Students who believed that specialists had played a key role in their decision and that obstetrics is a demanding practice were less likely to plan a career that included delivering infants (OR 0.43; 95% CI 0.23-0.69 and OR 0.35; 95% CI 0.21-0.59, respectively).

CONCLUSION

This study shows that an interest in practising obstetrics emerges very early in medical training. However, a student's learning experiences during an obstetrical rotation affect this decision. Departments of family medicine and obstetrics and gynaecology may be able to work together to create more positive role models.

Postpartum uterine wound dehiscence: a case report

INTRODUCTION

Late postpartum hemorrhage following a Caesarean section (CS) is uncommon. A partial or complete dehiscence of the lower segment CS incision is a rare but possible cause.

CASE

A 33-year-old woman underwent a lower segment CS for chorioamnionitis and failure to progress in labour at 40 weeks and 5 days of gestation. On the 43rd postpartum day, she developed heavy vaginal bleeding. Emergency laparotomy revealed a complete dehiscence of the lower uterine segment incision. A subtotal hysterectomy was performed to control the bleeding, and the postoperative course was uneventful.

CONCLUSION

Dehiscence of a lower uterine segment incision is a rare but potentially dangerous cause of late postpartum hemorrhage.

The effect of old age on supra-span learning of visuo-spatial sequences under incidental and intentional encoding instructions

Recent findings [Turcotte, Gagnon, & Poirier, 2005. The effect of old age on the learning of supra-span sequences. Psychology and Aging, 20, 251-260.] indicate that incidental learning of visuo-spatial supra-span sequences through immediate serial recall declines with old age (Hebb's paradigm). In this study, we examined whether strategies induced by awareness of the repeated sequence might explain age differences. Young (18-35 years old) and older (65-80 years old) participants underwent either incidental or intentional learning instructions. Results indicated that older adults demonstrated reduced learning of the repeated sequence under both incidental and intentional instructions. In comparison, young adults showed superior learning of the repeated sequence in both conditions but intentional instructions triggered faster and greater learning in this age group. The results strongly indicated that knowledge of the repeated sequence enhanced learning only in the group of young adults. Older adults were unable to translate the knowledge of the repetition into elaborate strategies that would increase recall of the repeated sequence. Other findings suggest that incidental learning in young adults was mediated by both non-conscious and conscious recollection processes.

Sublingual nitroglycerine as a tocolytic in external cephalic version: a comparative study

OBJECTIVE

To study the effect of sublingual nitroglycerine as a tocolytic on the success rate of external cephalic version (ECV) in nulliparous and parous women.

METHODS

A retrospective case-controlled study of all ECV cases from February 1996 to February 2000 in a single centre. The rates of successful ECV were compared between women who had their ECV before February 1998 (control group), those who had their ECV after February 1998 and received 0.8 mg sublingual nitroglycerine spray as a tocolytic agent, and those who had their ECV after February 1998 and received no tocolytic agents. Nulliparous and parous women were studied separately. Data were collected for parity, gestational age, maternal age, placental localization, and side effects. Chi-square and Kruskal-Wallis tests were performed for statistical comparison.

RESULTS

Of 150 women who had their ECV after February 1998, 120 (80%) received sublingual nitroglycerine (group 1: cases using 0.8 mg sublingual nitroglycerine spray as a tocolytic agent) and were compared to the 30 patients who did not receive sublingual nitroglycerine or other tocolytics after February 1998 (group 2) and to 137 patients who had their ECV before February 1998 (control group). Of the women who received sublingual nitroglycerine, 5 (4%) had hypotension and 7 (6%) had headaches and/or nausea. The rate of successful ECV was 27% in group 1 versus 30% in group 2 (p = 0.86) versus 28% in the control group (p = 0.88) for nulliparous patients, and 67% versus 80% (p = 0.30) versus 51% (p = 0.09) respectively for parous women. However, the success rate was increased overall in parous women after the introduction of nitroglycerine as a tocolytic for ECV in February 1998 (71% vs. 51%, p = 0.02).

CONCLUSION

Although the success rate of ECV has increased in recent years, the use of sublingual nitroglycerine as a tocolytic was not associated with this higher success rate. A randomized, controlled trial is needed.