PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-5 (5)
 

Clipboard (0)
None

Select a Filter Below

Journals
Authors
more »
Year of Publication
Document Types
author:("benaim, Haim")
1.  Oxytocin in Pregnancy and the Postpartum: Relations to Labor and Its Management 
The purpose of this study was to examine variations in endogenous oxytocin levels in pregnancy and postpartum state. We also explored the associations between delivery variables and oxytocin levels. A final sample of 272 mothers in their first trimester of pregnancy was included for the study. Blood samples were drawn during the first trimester and third trimester of pregnancy and at 8 weeks postpartum. Socio-demographic data were collected at each time point and medical files were consulted for delivery details. In most women, levels of circulating oxytocin increased from the first to third trimester of pregnancy followed by a decrease in the postpartum period. Oxytocin levels varied considerably between individuals, ranging from 50 pg/mL to over 2000 pg/mL. Parity was the main predictor of oxytocin levels in the third trimester of pregnancy and of oxytocin level changes from the first to the third trimester of pregnancy. Oxytocin levels in the third trimester of pregnancy predicted a self-reported negative labor experience and increased the chances of having an epidural. Intrapartum exogenous oxytocin was positively associated with levels of oxytocin during the postpartum period. Our exploratory results suggest that circulating oxytocin levels during the third trimester of pregnancy may predict the type of labor a woman will experience. More importantly, the quantity of intrapartum exogenous oxytocin administered during labor predicted plasma oxytocin levels 2 months postpartum, suggesting a possible long-term effect of this routine intervention, the consequences of which are largely unknown.
doi:10.3389/fpubh.2014.00001
PMCID: PMC3902863  PMID: 24479112
labor; oxytocin; pregnancy; epidural; syntocinon
2.  Modeling Fetal Weight for Gestational Age: A Comparison of a Flexible Multi-level Spline-based Model with Other Approaches 
We present a model for longitudinal measures of fetal weight as a function of gestational age. We use a linear mixed model, with a Box-Cox transformation of fetal weight values, and restricted cubic splines, in order to flexibly but parsimoniously model median fetal weight. We systematically compare our model to other proposed approaches. All proposed methods are shown to yield similar median estimates, as evidenced by overlapping pointwise confidence bands, except after 40 completed weeks, where our method seems to produce estimates more consistent with observed data. Sex-based stratification affects the estimates of the random effects variance-covariance structure, without significantly changing sex-specific fitted median values. We illustrate the benefits of including sex-gestational age interaction terms in the model over stratification. The comparison leads to the conclusion that the selection of a model for fetal weight for gestational age can be based on the specific goals and configuration of a given study without affecting the precision or value of median estimates for most gestational ages of interest.
doi:10.2202/1557-4679.1305
PMCID: PMC3173606  PMID: 21931571
multi-level models; fetal growth; small for gestational age
3.  Comparison of obstetric outcomes between on-call and patients' own obstetricians 
Background
The question “will you be delivering my baby?” is one that pregnant women frequently ask their physicians. We sought to determine whether obstetric outcomes differed between women whose babies were delivered by their own obstetrician (regular-care obstetrician) and those attended by an on-call obstetrician who did not provide antenatal care.
Methods
We performed a cohort study of all live singleton term births between 1991 and 2001 at the Royal Victoria Hospital in Montréal. We excluded breech deliveries, elective cesarean sections and deliveries with placenta previa or prolapse of the umbilical cord. Logistic regression analysis was used to compare obstetric outcomes (e.g., cesarean delivery, instrumental vaginal delivery and episiotomy) between the regular-care and on-call obstetricians after adjustment for potential confounders.
Results
A total of 28 332 eligible deliveries were attended by 26 obstetricians: 21 779 (76.9%) by the patient's own obstetrician and 6553 (23.1%) by the on-call obstetrician. Compared with women attended by their regular-care obstetrician, those attended by an on-call obstetrician had higher rates of cesarean delivery (11.9% v. 11.4%, adjusted odds ratio [OR] 1.13, 95% confidence interval [CI] 1.03–1.24, p < 0.01) and of third-or fourth-degree tears (7.9% v. 6.4%, adjusted OR 1.21, 95% CI 1.07–1.36, p < 0.01) but lower rates of episiotomy (38.5% v. 42.9%, OR 0.77, 95% CI 0.72–0.82, p < 0.001). No differences were observed between the groups in the rate of instrumental vaginal delivery. The increase in the overall rate of cesarean delivery among women attended by an on-call obstetrician was due mainly to an increase in cesarean deliveries during the first stage of labour because of nonreassuring fetal heart tracing (2.9% v. 1.7%, adjusted OR 1.79, 95% CI 1.49–2.15, p < 0.001). The time of day of delivery did not modify the observed effects.
Interpretation
The type of attending obstetrician (regular care v. on call) had a minor effect on obstetric outcomes.
doi:10.1503/cmaj.060920
PMCID: PMC1942095  PMID: 17698823
4.  Ovarian cancer risk in relation to medical visits, pelvic examinations and type of health care provider 
Background
Whether the current recommendations for ovarian cancer prevention and screening (annual history and physical examination) are effective has not been evaluated. We examined the relation between health care use and the risk of ovarian cancer.
Methods
Using a case–control study design, we recorded the frequency of medical visits and pelvic examinations and the type of health care provider visited during a 5-year period from interviews with women with and without ovarian cancer between between July 1998 and July 2003. We used multivariable logistic regression analysis to calculate the adjusted odds ratio of ovarian cancer associated with the frequency of medical visits and pelvic examinations and the type of health care provider. In addition, we stratified cases and controls by menopausal status and cancer histologic subtype and grade.
Results
A total of 668 cases and 721 age-matched controls agreed to participate in the study. We observed an increased risk of ovarian cancer among women who, during the 5-year study period, did not have a medical visit (odds ratio [OR] 2.8, 95% confidence interval [CI] 1.5–5.0) or pelvic examination (OR 3.9, 95% CI 2.2–6.9) or who had no regular health care provider (OR 2.7, 95% CI 1.3–5.7). This increase in risk was most pronounced among women who were postmenopausal (no medical visit, OR 7.7, 95% CI 2.6–23.0; no pelvic examination, OR 3.3, 95% CI 1.7–6.0; no health care provider, OR 12.5, 95% CI 2.7–57.5).
Interpretation
Although the exact mechanism underlying the association between medical visits, pelvic examinations and type of health care provider and ovarian cancer is unknown, women should be encouraged to maintain regular medical care.
doi:10.1503/cmaj.060697
PMCID: PMC1828193  PMID: 17389442
5.  Program description: a hospitalist-run, medical short-stay unit in a teaching hospital 
A hospitalist-run medical short-stay unit (MSSU) was created at a university-affiliated teaching hospital in Montreal in 1989. Its primary aim was to provide efficient and high-quality care to patients requiring a brief stay in hospital for short-lived medical conditions. After evaluation in the emergency department (ED), patients judged to have acute conditions requiring a short hospital stay are admitted directly to the MSSU. Conversely, patients with more complex conditions requiring a longer stay in hospital are admitted to a clinical teaching unit (CTU). Care in the MSSU is provided by a rotating group of hospitalists. Ensuring the admission of appropriate patients during non-daytime hours was the main difficulty identified. Preliminary evaluation of the MSSU suggested that ED consultants were effective at selecting suitable patients for admission to the MSSU, because only 1 in 5 patients later required transfer to other hospital wards. The 5 most common MSSU discharge diagnoses were asthma and chronic obstructive lung disease, pneumonia, congestive heart failure, urinary tract infection and cellulitis. MSSU patients had a shorter length of stay, lower rates of in-hospital complications and lower rates of readmission within 30 days of discharge compared with CTU patients. Our hospitalist-run MSSU appears to offer a workable system of health care delivery for patients with acute, self-limited illness requiring a brief stay in hospital. The MSSU appeared to promote the efficient use of hospital beds without compromising patient outcomes, however, further research is required to compare the efficiency and outcomes of care directly with that provided by the traditional CTU system.
PMCID: PMC80419  PMID: 11192657

Results 1-5 (5)