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.

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.

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.

Sonographic evaluation of intervillous flow in early pregnancy: use of echo-enhancement agents.

The uteroplacental circulation of the cynomolgus monkey was examined in early pregnancy using a high-resolution ultrasound scanner. Intravenous injection of an echo-contrast agent, Albunex (sonicated albumin), was used to enhance the color Doppler images obtained. The flow of blood into and out of the intervillous compartment was readily assessed and quantified using pulsed and color Doppler. Flow within the intracotyledonary space was pulsatile and indicative of a low-resistance system. Flow within the decidual veins was non-pulsatile. The use of echo-contrast agents may assist in the determination of intervillous flow in human pregnancy at a correspondingly early stage.

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.

The role of reduced ear size in the prenatal detection of chromosomal abnormalities.

A prospective ultrasound study was performed between 18 and 38 weeks' gestation on 29 fetuses in a high-risk population, defined by the presence of structural anomalies, in order to investigate the usefulness of fetal ear measurements in the prenatal prediction of chromosomal abnormality. The prevalence of abnormal chromosomes was 34 per cent. The sensitivity (SE), specificity (SC), positive predictive values (PPV), and negative predictive values (NPV) of ear length for the detection of chromosomal abnormality were 80, 84.2, 72.7 and 88.9 per cent. The SE, SC, PPV, and NPV of ear width were 40, 94.7, 80 and 75 per cent. Fetal ear measurements may be a useful adjunct to the various ultrasound parameters in the prenatal detection of chromosome abnormality in a high-risk population of fetuses with structural anomaly(ies).

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.

Assessment of early placental development in the cynomolgus monkey (Macaca fascicularis) using colour and pulsed wave Doppler sonography.

Colour flow mapping and pulsed wave Doppler were used to assess the process of placental growth and development in the cynomolgus monkey from 32 to 71 days gestational age. Fetal and maternal vessels were reliably visualised and insonated. Accurate longitudinal non-invasive assessment of placentation is possible using this technique.

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.

Doppler sonographic studies on the ophthalmic and central retinal arteries in the gravid woman.

The aim of this study was to establish normative data as gestation advances for pulsed Doppler evaluation of both the ophthalmic artery and the central retinal artery. After measuring intraocular pressure and blood pressure, pulsed Doppler ultrasonographic examination was performed on the ophthalmic and central retinal arteries in both eyes of 125 normal pregnant women. Nomograms, with 95% prediction intervals, have been generated for the Doppler indices, reflecting blood flow in both the ophthalmic and the central retinal arteries. The use of this technique in the management of pregnancy induced hypertension can now be better evaluated.

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.

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.

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.

Birthing experience of adolescents at the Ottawa General Hospital Perinatal Centre.

OBJECTIVE: To study the experiences of prenatal care, prenatal classes and birthing among adolescents. DESIGN: Anonymous self-report questionnaire survey. SETTING: Ottawa General Hospital Perinatal Centre. PATIENTS: A total of 100 adolescents (aged less than 20 years) and 100 control subjects (aged over 19 years) who gave birth at the Perinatal Centre from June 1989 to August 1990. MAIN OUTCOME MEASURES: Prenatal experiences, attendance at prenatal classes, experiences in labour and delivery, postpartum care. RESULTS: Only 26% of the adolescent patients sought prenatal care in the first trimester, and only 27% attended prenatal classes, as compared with 87% and 91% of the control subjects (p < 0.001). Most of the adolescents felt uncomfortable in the same waiting room as adult women. During labour and delivery 50% of the adolescents had their mothers with them for support, whereas 83% of the adults had their husbands with them (p < 0.001). Over half (59%) of the adolescents stated that they were not prepared for labour and delivery, as compared with 26% of the adults (p < 0.001). Of the adolescents 85% opted to care for their babies after birth. CONCLUSION: Pregnant adolescents do not avail themselves adequately of the medical and psychosocial services available to them through the health care system. Our findings suggest features of prenatal clinics that would make them attractive and accessible to such patients.

Electronic fetal monitoring: a Canadian survey.

OBJECTIVES: To determine the current status of electronic fetal monitoring (EFM) in Canadian teaching and nonteaching hospitals, to review the medical and nursing standards of practice for EFM and to determine the availability of EFM educational programs. DESIGN: National survey in 1989. PARTICIPANTS: The directors of nursing at the 737 hospitals providing obstetric care were sent a questionnaire and asked to have it completed by the most appropriate staff member. The response rate was 80.5% (593/737); 44 hospitals did not have deliveries in 1988 and were excluded. The remaining hospitals varied in size from 8 to 1800 (mean 162.1) beds and had 1 to 7500 (mean 617.1) births in 1988; 18.8% were teaching hospitals. RESULTS: Of the 549 hospitals 419 (76.3%) reported having at least 1 monitor (range 1 to 30; mean 2.6); the mean number of monitors per hospital was higher in the teaching hospitals than in the nonteaching hospitals (6.2 v. 1.7). Manitoba had the lowest mean number of monitors per hospital (1.1) and Ontario the highest (3.7). In 71.8% of the hospitals with monitors almost all of the obstetric patients were monitored at some point during labour. However, 21.6% of the hospitals with monitors had no policy on EFM practice. The availability of EFM educational programs for physicians and nurses varied according to hospital size, type and region. CONCLUSIONS: Most Canadian hospitals providing obstetric services have electronic fetal monitors and use them frequently. Although substantial research has questioned the benefits of EFM, further definitive research is required. In the meantime, a national committee should be established to develop multidisciplinary guidelines for intrapartum fetal assessment.

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.

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.

Multiple births: trends and patterns in Canada, 1974-1990.

This paper examines Canadian trends and patterns in multiple births in relation to total confinements, singleton births, maternal age, parity, gestational age and birth weight using vital statistics from 1974 to 1990. Multiple-birth rates in Canada increased from 912.8 to 1,058.9 per 100,000 confinements between 1974 and 1990. The increase is especially noticeable for women over 30. The rate of triplet and higher-order births increased from 8.3 to 21.7 per 100,000 confinements between 1974 and 1990. The proportion of multiple-birth babies that were pre-term (< 37 weeks gestation period) increased from 32.8% in 1974 to 45.8% in 1990. Factors associated with the increase in multiple births may include the use of assisted pregnancy techniques, and the fact that women aged 30 and older, who are at higher risk of a multiple birth, and who postponed their child bearing, have increased their fertility. The sharp increase in multiple-birth rates has implications for maternal and child health and health care costs.

Trends in Canadian Birth Weights, 1971 to 1989: Studying weight trends in singleton births.

This paper outlines levels and trends in birth weights of singleton birth weights of singleton births in Canada between 1971 and 1989. It relates these birth weights to maternal age, marital status, and parity and to gestational age. From 1971 to 1989, the median birth weight of all singletons increased by 104g, or 3.1%. The proportion of low birth weight babies declined, probably contributing to improved infant mortality rates.