Patterns of pregnancy exposure to prescription FDA C, D and X drugs in a Canadian population.

OBJECTIVE: To examine prescription Food and Drug Administration (FDA) C, D and X drugs in general obstetric population. STUDY DESIGN: Historical cohort study. RESULT: A total of 18 575 women who gave a birth in Saskatchewan between January 1997 and December 2000 were included. Among them, 3604 (19.4%) received FDA C, D or X drugs at least once during pregnancy. The pregnancy exposure rates were 15.8, 5.2 and 3.9%, respectively, for category C, D and X drugs, and were 11.2, 7.3 and 8.2%, respectively, in the first, second and third trimesters. Salbutamol (albuterol), trimethoprim/sulfamethoxazole (co-trimoxazole), ibuprofen, naproxen and oral contraceptives were the most common C, D, X drugs used during pregnancy. CONCLUSION: About one in every five women uses FDA C, D and X drugs at least once during pregnancy, and the most common prescription drugs in pregnancy are antiasthmatic, antibiotics, nonsteroid anti-inflammation drugs, antianxiety or antidepressants and oral contraceptives.

Haloacetic acids in drinking water and risk for stillbirth.

BACKGROUND: Trihalomethanes (THMs) occurring in public drinking water sources have been investigated in several epidemiological studies of fetal death and results support a modest association. Other classes of disinfection by-products found in drinking water have not been investigated. AIMS: To investigate the effects of haloacetic acid (HAA) compounds in drinking water on stillbirth risk. METHODS: A population based case-control study was conducted in Nova Scotia and Eastern Ontario, Canada. Estimates of daily exposure to total and specific HAAs were based on household water samples and questionnaire information on water consumption at home and work. RESULTS: The analysis included 112 stillbirth cases and 398 live birth controls. In analysis without adjustment for total THM exposure, a relative risk greater than 2 was observed for an intermediate exposure category for total HAA and dichloroacetic acid measures. After adjustment for total THM exposure, the risk estimates for intermediate exposure categories were diminished, the relative risk associated with the highest category was in the direction of a protective effect, and all confidence intervals included the null value. CONCLUSIONS: No association was observed between HAA exposures and stillbirth risk after controlling for THM exposures.

Determination of intervillous flow in early pregnancy.

The process of placentation in the macaque has been extensively studied and found to resemble closely that observed in the human. In this model, histopathologically, intervillous flow is anticipated from week 3 post-conception. We set out to document the nature and onset of intervillous flow in the macaque in vivo using colour Doppler imaging (CDI), colour Doppler energy (CDE) and pulsed-wave Doppler (PWD). Pregnant females were assessed between 15-50 days gestation (term = 165 days) with an Acuson 128/XP10 high-resolution ultrasound scanner, using a 7-MHz linear array probe. The placenta, subjacent decidua and myometrium were assessed using CDI and CDE. Specific regions of flow were interrogated using PWD; the resulting flow velocity waveforms were stored and quantified using conventional Doppler indices. B-mode sonography was able to demonstrate the well-defined placental-decidual interface observed in this species; CDI and CDE clearly visualized the uteroplacental vasculature. Spiral arteries were followed to their point of discharge into the intervillous space, and PWD at these sites obtained a characteristic flow velocity waveform. The indices obtained confirmed a flow of low resistance and pulsatility throughout the gestation studied. Flow within the intervillous space was noted from day 20 of gestation.

Ultrasonographic measurements of fetal ear.

OBJECTIVE: To establish nomograms of fetal ear measurements. Newborns with trisomies have smaller ears than the normal population. This observation led us to believe that ear measurements might be useful in the antenatal prediction of fetuses with abnormal karyotypes. METHODS: Fetal ear length and width were obtained ultrasonographically in 124 normal singleton pregnancies between 18-42 weeks' gestation. Regression analyses were used to create the nomograms. RESULTS: Linear relationships were found between ear length and width and gestational age (r = 0.956 and 0.898, respectively). In addition, there were significant correlations between ear measurements and biparietal diameter, head circumference, abdominal circumference, and femur length. The ear width-length ratio and the biparietal diameter-ear length ratio were independent of gestational age. CONCLUSION: These normative data may be helpful in the antenatal prediction of chromosomal abnormalities.

Cervical ripening and labor induction with intracervical triacetin base prostaglandin E2 gel: a placebo-controlled study.

A double-blind, randomized, placebo-controlled study was undertaken to evaluate the efficacy of a single-dose, shelf-stable preparation of prostaglandin E2 gel (PGE2) when used intracervically in patients with low Bishop scores. Two different preparations (0.5 and 0.25 mg) of PGE2 were used and a total of 45 patients were studied. Both preparations of PGE2 demonstrated a statistically significant increase in the spontaneous labor rate as compared with the placebo gel. Bishop scores were altered in all patients not proceeding to labor spontaneously, but the changes were most significant in the low- and high-dose groups. No significant deleterious affects were noted. The efficacy and safety of this new, sterile, and stable preparation makes it suitable for clinical use.

Ultrasound prediction of pulmonary hypoplasia.

Normograms for ultrasound-measured fetal chest and heart circumferences were constructed from 83 normal pregnancies of 24 to 39 weeks' duration. Of six cases at risk for pulmonary hypoplasia, all of whom ultimately proved to have the condition, four fell below the fifth percentile for chest circumferences. Both cases in which the chest circumference was within the normal range had pleural effusions.

Intrauterine hydrocephalus and ventriculomegaly: associated anomalies and fetal outcome.

Advances in fetal diagnostic techniques have opened many areas to prenatal anatomical scrutiny. Intrauterine hydrocephalus and ventriculomegaly are conditions which are readily diagnosed. Fetal intervention has been undertaken in humans in order to minimize the craniofacial disfigurement and to maximize the growth potential of the brain. To justify such an approach, the significance of all anomalies should be recognized prior to treatment. The authors have reviewed 41 cases of hydrocephalus diagnosed in utero in order to define associated anomalies and patient outcome. 75% of our personal series and 72% of the reviewed literature cases had other anomalies of the central nervous system. Other system malformations, some of which proved fatal, were seen commonly. Prenatal diagnostic techniques did not always reveal these additional problems. The outcome of these pregnancies is not good. Approximately one third of these fetuses have survived to be treated postnatally and to be followed up clinically. Only 7.5% of this series were felt to have attained normal developmental milestones. The remainder of the survivors have various focal and/or global cerebral deficits.

Fetal tumors associated with hydrops: the role of the pediatric surgeon.

Fetal tumors are being diagnosed with increasing frequency and great accuracy by antenatal ultrasound. High-output cardiac failure and hydrops indicate fetal distress. Management may be limited by the gestational age of the fetus. Our experience with three fetal tumors demonstrates the dilemma with respect to timing of delivery and prognosis. Following the diagnosis of a large sacrococcygeal tumor, a 22-week-gestation fetus became hydropic and died. Another fetus with a rapidly growing posterolateral chest wall mass required cesarean section delivery at 29 weeks gestation. Postnatal course was complicated by pulmonary hypoplasia, intratumoral hemorrhage, and death. The third fetus had an enlarging tumor in the right lobe of the liver. Poor biophysical profile and mild hydrops necessitated cesarean section delivery at 34 weeks. Right hepatic lobectomy was performed and the infant was subsequently discharged home at one month of age. The deleterious effects of the fetal tumor and the need for its removal have to be carefully weighed against the ability of the fetus to survive postnatally.

Change in smoking prevalence among pregnant women 1982-93.

Maternal smoking is the most prevalent risk factor for low birthweight in Canada. This study compared the prevalence of maternal smoking before and during pregnancy from 1983 to 1992. Population-based surveys of 3,296 women during six months in 1983 and 7,940 women during 12 months in 1992 were conducted in Ottawa-Carleton using a self-administered questionnaire completed in the hospital postpartum period. The proportion of women smoking after the first trimester of pregnancy decreased from 28.5% in 1983 to 18.7% in 1992. This difference was due mainly to a reduction in the proportion of women who smoked before pregnancy (37.4% to 26.4%). Another factor was that more women stopped smoking early in pregnancy (23.9% to 29.2%). Gradients in levels of smoking by age, education, marital status and poverty level still exist; however, this is true for the general population. Programs to decrease smoking in pregnancy should continue to focus on reducing smoking among women in general and among those in the preconception and early stages of pregnancy in particular.

Education of women about the prevention of preterm birth.

OBJECTIVES: To describe: 1) The education of pregnant women by health care professionals about the prevention of preterm birth; and 2) professionals' views about future initiatives. BACKGROUND: A population survey of health professionals was conducted in Eastern Ontario. The response rate was 73% (608/835). RESULTS: Education materials for women receiving prenatal care about the prevention of preterm birth were available from 10% (12/115) of family physicians, 40% (23/58) of obstetricians, 19% (57/306) of labour room nurses and 76% (94/124) of the prenatal teachers. Only one third of physicians routinely discussed the signs and symptoms of preterm labour prior to 20 weeks. Practitioners' future priorities were smoking cessation programs for pregnant women and increased attendance at early prenatal classes. CONCLUSIONS: Most women are not being educated by anyone in the health care team about the prevention of preterm birth. There is a need for multidisciplinary guidelines about the timing and type of information for women about risk reduction and the early identification and treatment of preterm labour.

Birth patterns: are the Chinese in Guangzhou City different?

Diurnal birth patterns in the City of Guangzhou, China and the City of Calgary in Canada were compared. Chinese data were abstracted from the labor room log book of one large general hospital located in the Hai Zhu district of Guangzhou. Calgary birth data were abstracted from birth notification forms submitted to Calgary Health Services. Information included day of birth, time of delivery, type of delivery and parity. Calgary births are concentrated on Tuesdays to Fridays whereas in Guangzhou weekly patterns varied tremendously according to whether it was assisted or unassisted. Calgary births are below average at night and during evening shift. The time of birth in Guangzhou varied substantially with above average rates for non-assisted births noted at 0800-2400 h, and above average rates for assisted births noted at 0800-1700 h. Differences in hour of birth appeared to be related to obstetric intervention practices. Knowledge of birthing patterns are useful for effective hospital management.

PIP: Diurnal birth patterns in the City of Guangzhou, China and the City of Calgary, Canada were compared. Chinese data were abstracted from the labor room log book of 1 large general hospital located in the Hai Zhu district of Guangzhou. Calgary birth data were abstracted from birth notification forms submitted to Calgary Health Services. Information included day of birth, time of delivery, type of delivery, and parity. Calgary births are concentrated on Tuesdays to Fridays whereas in Guangzhou weekly patterns varied tremendously according to whether it was assisted or unassisted. Calgary births are below average at night and during evening shift. The time of birth in Guangzhou variied substantially with above average rates for nonassisted births noted at 0800--2400 h, and above average rates for assisted births noted at 0800--1700 h. Differences in hour of birth appeared to be related to obstetric intervention practices. Several implications arise from the observations. 1st, better knowledge of birthing patterns could be used to help hospitals establish an appropriate schedule for personnel in the obstetric ward. The concern with safety combined with the reported increase in neonatal mortality associated with birth buring the night has been cited as a reason to examine the pattern. 2nd, considering the poor understanding of the normal physiological factors initiating labor, can the possible consequences of shifting birth patterns from a nighttime phenomenon to a daytime phenomenon be ignored? An explanation for these weekly and diurnal patterns, can, in a strict sense, only be speculative. Nevertheless, they do seem to suggest, especially in the case of assisted deliveries, that the pattern of birth appears to be related to the 24-h work rhythem of hospital personnel, especially in the Calgary hospitals.

Hemodynamic observations on pulmonary edema associated with a beta-mimetic agent. A report of two cases.

Pulmonary edema associated with the use of beta agonists in the treatment of preterm labor is a major risk of tocolytic therapy. The data obtained from echocardiographic and hemodynamic evaluation in one such case and echocardiography in another differ markedly from those in two previously published reports. Specifically, the pulmonary capillary wedge pressure became elevated, and both patients failed to improve with oxygen therapy and positional changes only. Left ventricular dysfunction was ruled out as the possible cause since the left ventricular structure and function were normal on echocardiography. The heart failure was probably the result of increased preload, giving rise to increased end diastolic pressure and hence pulmonary edema. Diuretic therapy is very important in this situation.

Evaluation of a fetal monitoring education program.

OBJECTIVE: To evaluate the effectiveness of a fetal monitoring education program in increasing nurses' knowledge and clinical skills. DESIGN: Multicenter randomized control trial. SETTING: Twelve hospitals in eastern Ontario, Canada. PARTICIPANTS: One hundred nine volunteer registered nurses randomly assigned, within each hospital, to an experimental (n = 47) or control (n = 62) group. Ninety-six nurses (40 in the experimental group and 56 in the control group) completed the 6-month follow-up (88% retention). INTERVENTIONS: The experimental group participated in a 1-day fetal monitoring workshop and a review session 6 months later. MAIN OUTCOME MEASURES: Performance on a 45-item knowledge test and a 25-item skills checklist. The passing score was at least 75% correct on each test. RESULTS: The percentage of nurses in the experimental group passing both the knowledge and the clinical skills tests after the workshop was significantly higher (p < 0.01) than that of the nurses in the control group: 68.1% versus 6.5%, respectively. A large difference between the groups remained at the 6-month follow-up (experimental, 45%; control, 6.5%). The performance of the nurses in the experimental group improved to an 85% pass rate after they attended the 6-month review session. CONCLUSION: This comprehensive, research-based program is effective in increasing fetal monitoring knowledge and clinical skills.

Evaluation of a midwifery birthing center in the Canadian north.

An evaluation of a midwife-operated community birthing center was conducted to identify whether it would be safe, cost-effective, and psychologically and socially satisfying for Inuit women in one community in the Northwest Territories. Two nurse-midwives provided antenatal and postnatal care to all pregnant women and delivered those designated as 'low risk' for complications. Another community similar in size but with no community birthing was used for comparison of the three indices. Data were gathered on reproductive histories and pregnancy risk profiles of all women giving birth in a one-year period. The financial costs were calculated for those women transferred out to hospital for delivery and compared with those who stayed in the community. Pregnant women and their partners in both communities, health staff, and community members were interviewed for their feelings and concerns about the birthing services. Preliminary findings suggest that with experienced midwives community births are safe. A minimum of 25 births is required in the community for this project to be cost effective. The women who had their infants in the community expressed satisfaction for a number of reasons.

Relationship between antenatal group B streptococcal vaginal colonization and premature labour.

OBJECTIVE: To determine whether a population of pregnant women with group B streptococcal (GBS) vaginal colonization had an increased risk of specific epidemiological and intrapartum risk factors for early onset GBS disease. SETTING: Tertiary university centre in Ottawa, Ontario. DESIGN: Hospital-based retrospective cohort study. METHODS: Pregnant women who gave birth during a four-month period in 1994 were included in the study. Potential GBS risk factors were obtained from a review of medical records. The prevalence of each risk factor in colonized and noncolonized women was examined using chi(2) or Fisher's exact test. Multiple logistic regression was performed. RESULTS: A total of 986 women, including 94 (9.5%) women colonized with GBS, were studied. The proportion of women younger than 20 years of age in the colonized group was 2.1% (two of 94) versus 4.6% (41 of 891) in the noncolonized group (P=0.28). Similar rates of multiple births were observed among the colonized and noncolonized groups (2.1% [two of 94] versus 2.5% [22 of 891], respectively) (P=0.94). Likewise, there were no significant differences in either group in the prevalence of a previous pregnancy affected by GBS or diabetes mellitus (P=0.82 and P=0.79, respectively). Multivariable analyses indicated that women who were colonized with GBS were more than twice as likely to deliver prematurely (below 37 weeks' gestational age) (odds ratio [OR] 2.43, 95% CI 1.39 to 4.23). Similarly, colonized women were more likely to be febrile during labour (at least 38 degrees C) (OR 5.05, 95% CI 1.70 to 15.02). CONCLUSION: GBS vaginal colonization was associated with premature labour and intrapartum pyrexia in the population studied. According to Canadian and American guidelines, women with GBS vaginal colonization qualify for intrapartum chemoprophylaxis. The study results suggest that the identification of women at risk of premature labour may be one advantage of early prenatal screening for GBS.

Blood Group Antibodies in Obstetrics: A continuing problem?

A retrospective survey of the frequency, nature, and effect of blood group antibodies on obstetrical outcome was conducted over 4 years in a large community hospital. A total of 189 antibodies were identified in 165 patients. Twenty clinically significant outcomes occurred, including three stillbirths. All clinically significant cases of hemolytic disease of the newborn were caused by Rh antibodies.

The need for a community-wide approach to promote healthy babies and prevent low birth weight.

A community-wide approach offers a potentially more effective way to promote healthy babies in healthy families and to prevent low birth weight. It can address the many factors associated with preterm birth and intrauterine growth restriction, the need to include all members of the community in effecting meaningful change in the incidence rate of adverse outcomes and the development of an effective mechanism to plan and coordinate the delivery of programs. Physicians have an essential role to play in this approach. The evaluation of such a program would complement current biomedical research on the prevention of preterm birth and intrauterine growth restriction. The work for this paper was supported by the Community Health Research Unit, funded by the Ontario Ministry of Health.

Transverse cerebellar diameter in twin gestations.

OBJECTIVE: The purpose of this study was to evaluate the significance of transverse cerebellar diameter measurements in twin pregnancies. STUDY DESIGN: A prospective, cross-sectional ultrasonographic study was done on 329 normal singleton fetuses and 47 normal twin pairs. Fetal biometric measurements including biparietal diameter, head circumference, abdominal circumference, femur length, and transverse cerebellar diameter were compared between concordant (n = 13) and discordant (n = 11) twins. RESULTS: (1) There was no significant difference in transverse cerebellar diameter measurements between normal singleton and twin gestations. (2) There was no significant difference in transverse cerebellar diameter measurements in each twin pair. (3) Transverse cerebellar diameter was unaffected by the chorionicity or discordancy. (4) Predicted gestational age by transverse cerebellar diameter nomogram for singletons provided satisfactory correlation for twins. CONCLUSION: Transverse cerebellar diameter may be a useful predictor of gestational age and may be independent of discordant growth in twins.

Obstetric ultrasound.

This article addresses the current indications for an obstetric ultrasound and describes the findings that it is reasonable to expect when reading an ultrasound report. The authors discuss several common obstetrical problems focussing the attention on the usefulness of the imaging information. Finally, they provide a glimpse into the future direction of obstetric ultrasound by discussing vaginal scanning, Doppler assessment of fetal blood flow, and routine ultrasound in pregnancy.