Contribution of prepregnancy body mass index and gestational weight gain to adverse neonatal outcomes: population attributable fractions for Canada.

BACKGROUND: Low or high prepregnancy body mass index (BMI) and inadequate or excess gestational weight gain (GWG) are associated with adverse neonatal outcomes. This study estimates the contribution of these risk factors to preterm births (PTBs), small-for-gestational age (SGA) and large-for-gestational age (LGA) births in Canada compared to the contribution of prenatal smoking, a recognized perinatal risk factor. METHODS: We analyzed data from the Canadian Maternity Experiences Survey. A sample of 5,930 women who had a singleton live birth in 2005-2006 was weighted to a nationally representative population of 71,200 women. From adjusted odds ratios, we calculated population attributable fractions to estimate the contribution of BMI, GWG and prenatal smoking to PTB, SGA and LGA infants overall and across four obstetric groups. RESULTS: Overall, 6% of women were underweight (<18.5 kg/m(2)) and 34.4% were overweight or obese (≥25.0 kg/m(2)). More than half (59.4%) gained above the recommended weight for their BMI, 18.6% gained less than the recommended weight and 10.4% smoked prenatally. Excess GWG contributed more to adverse outcomes than BMI, contributing to 18.2% of PTB and 15.9% of LGA. Although the distribution of BMI and GWG was similar across obstetric groups, their impact was greater among primigravid women and multigravid women without a previous PTB or pregnancy loss. The contributions of BMI and GWG to PTB and SGA exceeded that of prenatal smoking. CONCLUSIONS: Maternal weight, and GWG in particular, contributes significantly to the occurrence of adverse neonatal outcomes in Canada. Indeed, this contribution exceeds that of prenatal smoking for PTB and SGA, highlighting its public health importance.

Patterns of social inequalities across pregnancy and birth outcomes: a comparison of individual and neighborhood socioeconomic measures.

BACKGROUND: This paper identifies patterns of health inequalities (consistency and magnitude) of socioeconomic disparities for multiple maternal and child health (MCH) outcomes that represent different health care needs of mothers and infants. METHODS: Using cross-sectional national data (unweighted sample = 6,421, weighted =76,508) from the Canadian Maternity Experiences Survey linked with 2006 Canadian census data, we categorized 25 health indicators of mothers of singletons into five groups of MCH outcomes (A. maternal and infant health status indicators; B. prenatal care; C. maternal experience of labor and delivery; D. neonatal medical care; and E. postpartum infant care and maternal perceptions of health care services). We then examined the association of these health indicators with individual socioeconomic position (SEP) (education and income), neighborhood SEP and combined SEP (a four-level measure of low and high individual and neighborhood SEP), and compared the magnitude (odds ratios and 95% confidence intervals) and direction of the associations within and between MCH outcome groups. RESULTS: We observed consistent positive gradients of socioeconomic inequalities within most groups and for 23/25 MCH outcomes. However, more significant associations and stronger gradients were observed for the MCH outcomes in the maternal and infant health status group as opposed to other groups. The neonatal medical care outcomes were weakly associated with SEP. The direction of associations was negative between some SEP measures and HIV testing, timing of the first ultrasound, caesarean section, epidural for vaginal births, infant needing non-routine neonatal care after discharge and any breastfeeding at 3 or 6 months. Gradients were steep for individual SEP but moderate for neighborhood SEP. Combined SEP had no consistent gradients but the subcategory of low individual-high neighborhood SEP often showed the poorest health outcomes compared to the categories within this SEP grouping. CONCLUSION: By examining SEP gradients in multiple MCH outcomes categorized into groups of health care needs, we identified large and consistent inequalities both within and between these groups. Our results suggest differences in pathways and mechanisms contributing to SEP inequalities across groups of MCH outcomes that can be examined in future research and inform prioritization of policies for reducing these inequalities.

Contribution of prepregnancy body mass index and gestational weight gain to caesarean birth in Canada.

BACKGROUND: Overweight and obese women are known to be at increased risk of caesarean birth. This study estimates the contribution of prepregnancy body mass index (BMI) and gestational weight gain (GWG) to caesarean births in Canada. METHODS: We analyzed data from women in the Canadian Maternity Experiences Survey who had a singleton term live birth in 2005-2006. Adjusted odds ratios for caesarean birth across BMI and GWG groups were derived, separately for nulliparous women and parous women with and without a prior caesarean. Population attributable fractions of caesarean births associated with above normal BMI and excess GWG were calculated. RESULTS: The overall caesarean birth rate was 25.7%. Among nulliparous and parous women without a previous caesarean birth, rates in obese women were 45.1% and 9.7% respectively, and rates in women who gained above their recommended GWG were 33.5% and 8.0% respectively. Caesarean birth was more strongly associated with BMI than with GWG. However, due to the high prevalence of excess GWG (48.8%), the proportion of caesareans associated with above normal BMI and excess GWG was similar [10.1% (95% CI: 9.9-10.2) and 10.9% (95% CI: 10.7-11.1) respectively]. Overall, one in five (20.2%, 95% CI: 20.0-20.4) caesarean births was associated with above normal BMI or excess GWG. CONCLUSIONS: Overweight and obese BMI and above recommended GWG are significantly associated with caesarean birth in singleton term pregnancies in Canada. Strategies to reduce caesarean births must include measures to prevent overweight and obese BMI prior to conception and promote recommended weight gain throughout pregnancy.

Socioeconomic position and factors associated with use of a nonsupine infant sleep position: findings from the Canadian Maternity Experiences Survey.

OBJECTIVES: With a focus on socioeconomic position, we examined the association between maternal education and nonsupine infant sleep position, and examined patterns of effect modification with additional sociodemographic, maternal, infant, and health services predictors. METHODS: Data were from the Maternity Experiences Survey, a national population-based sample of 76 178 new Canadian mothers (unweighted n = 6421) aged 15 years or older interviewed in 2006-2007. Using logistic regression, we developed multivariate models for 3 maternal education strata. RESULTS: Level of maternal education was significantly and inversely related to nonsupine infant sleep position. Stratified analyses revealed different predictive factors for nonsupine infant sleep position across strata of maternal education. Postpartum home visits were not associated with use of this sleep position among new mothers with less than high school completion. Adequacy of postpartum information regarding sudden infant death syndrome was not associated with nonsupine infant sleep position in any of the educational strata. CONCLUSIONS: These findings suggest a need to revisit Back to Sleep health promotion strategies and to ensure that these interventions are tailored to match the information needs of all families, including mothers with lower levels of formal education.

Cohort profile: The promotion of breastfeeding intervention trial (PROBIT).

The PROmotion of Breastfeeding Intervention Trial (PROBIT) is a multicentre, cluster-randomized controlled trial conducted in the Republic of Belarus, in which the experimental intervention was the promotion of increased breastfeeding duration and exclusivity, modelled on the Baby-friendly hospital initiative. Between June 1996 and December 1997, 17,046 mother-infant pairs were recruited during their postpartum hospital stay from 31 maternity hospitals, of which 16 hospitals and their affiliated polyclinics had been randomly assigned to the arm of PROBIT investigating the promotion of breastfeeding and 15 had been assigned to the control arm, in which breastfeeding practices and policies in effect at the time of randomization was continued. Of the mother-infant pairs originally recruited for the study, 16,492 (96.7%) were followed at regular intervals until the infants were 12 months of age (PROBIT I) for the outcomes of breastfeeding duration and exclusivity; gastrointestinal and respiratory infections; and atopic eczema. Subsequently, 13,889 (81.5%) of the children from these mother-infant pairs were followed-up at age 6.5 years (PROBIT II) for anthropometry, blood pressure (BP), behaviour, dental health, cognitive function, asthma and atopy outcomes, and 13,879 (81.4%) children were followed to the age of 11.5 years (PROBIT III) for anthropometry, body composition, BP, and the measurement of fasted glucose, insulin, adiponectin, insulin-like growth factor-I, and apolipoproteins. The trial registration number for Current Controlled Trials is ISRCTN37687716 and that for ClinicalTrials.gov is NCT01561612. Proposals for collaboration are welcome, and enquires about PROBIT should be made to an executive group of the study steering committee (M.S.K., R.M.M., and E.O.). More information, including information about how to access the trial data, data collection documents, and bibliography, is available at the trial website (http://www.bristol.ac.uk/social-community-medicine/projects/probit/).

Risk factors for preterm birth and small-for-gestational-age births among Canadian women.

BACKGROUND: Preterm births (PTB) and small-for-gestational-age (SGA) births are distinct but related pregnancy outcomes, with differing aetiologies and short and long-term morbidities. Few studies have compared a broad array of predictors among these two outcomes. The purpose of this study was to compare risk factors for PTB and SGA births using a national sample of Canadian women. METHODS: We analysed data from the Canadian Maternity Experiences Survey (n = 6421). Mothers were ≥ 15 years of age, gave birth to a singleton infant and were living with their infant at the time of the interview (between 5 and 14 months post-partum). Backward stepwise multivariable logistic regression models were constructed for each outcome. RESULTS: Risk profiles for the two outcomes had both differences and similarities. Risk factors specific to PTB were education less than high school, having a previous medical condition, developing a new medical condition or health problem during pregnancy, being a primigravida, or being a multigravida with a previous PTB or a previous miscarriage or abortion. Risk factors unique to SGA were low pre-pregnancy body mass index (<18 kg/m(2) ), smoking during pregnancy and being a recent immigrant. Risk factors for both outcomes included low weight gain during pregnancy (<9.1 kg), short stature (<155 cm) and reporting life as 'very stressful' in the year prior to birth of the baby. CONCLUSION: A greater understanding of the risk factors related to PTB and SGA may help to reduce the prevalence of these conditions and the associated risk of infant mortality and morbidity.

Comparison of adolescent, young adult, and adult women's maternity experiences and practices.

BACKGROUND AND OBJECTIVE: Pregnant adolescents face unique challenges. Understanding the experiences, knowledge, and behaviors of adolescents during the pregnancy and postpartum periods may contribute to improvement of their maternity care. The purpose of this study was to compare the maternity experiences, knowledge, and behaviors of adolescent, young adult, and adult women by using a nationally representative sample. METHODS: This study used data from the Canadian Maternity Experiences Survey (N = 6421). The weighted proportions of each variable were calculated by using survey sample weights. Logistic regression was used to estimate odds ratios. Bootstrapping techniques were used to calculate variance estimates for prevalence and 95% confidence intervals. RESULTS: Adolescents and young adults were more likely to experience physical abuse in the previous 2 years, initiate prenatal care late, not take folic acid before or during pregnancy, have poor prenatal health behaviors, have a lower cesarean delivery rate, have lower breastfeeding initiation and duration rates, experience more stressful life events, experience postpartum depression symptoms, and rate their infant's health as suboptimal than adult women. Adolescents were more likely to rate their own health as suboptimal. CONCLUSIONS: Adolescents have unique needs during pregnancy and postpartum. Health care professionals should seek to provide care in a manner that acknowledges these needs.

Factors associated with perceived stress and stressful life events in pregnant women: findings from the Canadian Maternity Experiences Survey.

Prenatal maternal stress has been linked to multiple adverse outcomes. Researchers have used a variety of methods to assess maternal stress. The purpose of this study was to explore and compare factors associated with stress in pregnancy as measured by perceived stress and stressful life events. We analyzed data from the Canadian Maternity Experiences Survey. A randomly selected sample of 8,542 women who had recently given birth was drawn from the 2006 Canadian Census. Women were eligible if they were at least 15 years of age, had delivered a live, singleton infant, and were living with their infant at the time of the interview (5-14 months postpartum). Prevalence estimates and odds ratios were calculated using sample weights of the survey and their variances were calculated using bootstrapping methods. Bivariate analyses identified statistically significant factors associated with each stress measure. Backward stepwise multivariate logistic regression models were constructed. A total of 6,421 women (78%) participated in the computer assisted telephone interview. Twelve percent of women experienced high levels of perceived stress and 17.1% reported having three or more stressful life events in the year prior to the birth of their baby. In the final model, psychosocial variables were associated with both outcomes, whereas demographic factors were associated only with life event stress. Different factors contributed to perceived stress and life event stress, suggesting that these concepts measure different aspects of stress. These findings can inform routine psychosocial risk assessment in pregnancy.

The language of birth.

Our language both reflects and influences our attitudes and behavior. This Roundtable Discussion explores the language used in obstetrics and in the interactions between caregivers and women or their families: What do practitioners say to mothers and families during labor? At birth? In consultations? To describe what is happening? To encourage a woman's efforts? To lighten the atmosphere? When advising about possible interventions? Medical terminology in perinatal care can often be deceptive or confusing, not only for mothers but for caregivers. The authors of this Roundtable, representing health professionals from different specialties and interests in the field, have examined some examples of such language use, misuse, and abuse in perinatal care. (BIRTH 39:2 June 2012).

Rates of interventions in labor and birth across Canada: findings of the Canadian Maternity Experiences Survey.

BACKGROUND: Rates of interventions in labor and birth should be similar across a country if evidence-based practice guidelines are followed. This assumption is tested by comparison of some practices across the 13 provinces and territories of Canada. The objective of this study was to describe the wide provincial and territorial variations in rates of routine interventions and practices during labor and birth as reported by women in the Maternity Experiences Survey of the Canadian Perinatal Surveillance System. METHODS: A sample of 8,244 eligible women was identified from a randomly selected sample of recently born infants drawn from the May 2006 Canadian Census. The sample was stratified by province and territory. Computer-assisted telephone interviews were conducted with participating birth mothers by Statistics Canada on behalf of the Public Health Agency of Canada. Interviews took an average of 45 minutes and were completed when infants were between 5 and 10 months old (9-14 mo in the territories). Completed responses were obtained from 6,421 women (78%). RESULTS: Provincial and territorial variations in rates of routine intervention used during labor and birth are reported. The percentage range of mothers' experience of induction (range 30.9%), epidural (53.7%), continuous electronic fetal monitoring (37.9%), and medication-free pain management during labor (40.7%) are provided, in addition to the use of episiotomy (14.1%) or "stitches" (48.3%), being in a "flat lying position" (42.2%), and having their legs in stirrups for birth (35.7%). Wide variations in the use of most of the interventions were found, ranging from 14.1 percent to 53.7 percent. CONCLUSIONS: Rates of intervention in labor and birth showed considerable variation across Canada, suggesting that usage is not always evidence based but may be influenced by a variety of other factors.

Childbirth across cultures: research and practice.

Countries and cultures differ in their approach to childbirth, as well as in their research practices. This paper examines 10 surveys of women's reports of their labor and birth in seven countries spanning North America and Western Europe and Eastern Europe. Similarities and differences in practice are highlighted, and the methodological difficulties of conducting research in cross-cultural settings are examined. This paper discusses innovative and culturally unique perinatal practices that are not revealed by such surveys and stresses the importance of sharing such ideas globally.

Use of routine interventions in labour and birth in Canadian hospitals: comparing results of the 1993 and 2007 Canadian hospital maternity policies and practices surveys.

OBJECTIVES: To compare policies and practices of routine interventions in labour and birth in Canadian hospitals in 1993 and 2007 and to describe trends regarding adherence to evidence-based guidelines. METHODS: We used data from surveys of Canadian hospitals in 1993 and 2007 on routine maternity care practices and policies, including interventions in labour and birth. RESULTS: The response rate of hospitals in 1993 was 91% (523/572), and in 2007 it was 92% (323/353). In 1993, 65% of hospitals (335/516) had a policy that all women should have initial electronic fetal heart rate monitoring, and in 2007, 74% (235/319) had such a policy. In 1993, 55% of hospitals (284/516) used epidural anaesthesia as one of the methods for pain control, and in 2007, 87% of hospitals (278/318) did so. In 1993, 37% of hospitals (193/521) had a "no enema/suppository" policy on admission, and in 2007, 88% (282/322) did. In 1993, 87% of hospitals (450/516) had a policy encouraging the presence of both the woman's partner and other labour support people in the room during the course of labour; in 2007, 80% (259/323) did. In 1993, hospitals estimated that 62% of primiparous women and 44% of multiparous women had an episiotomy in their units. In 2007, the episiotomy rate, irrespective of parity, was 17%. In 1993, 20% of hospitals (98/498) had a policy specifying the length of the second stage of labour, and in 2007, 33% (101/307) had such a policy. CONCLUSION: Positive and negative trends in adherence to best practices were seen in policies and practices of routine interventions during labour and birth in Canadian hospitals between 1993 and 2007.

Comparison of maternity experiences of Canadian-born and recent and non-recent immigrant women: findings from the Canadian Maternity Experiences Survey.

OBJECTIVE: To compare the maternity experiences of immigrant women (recent, ≤ 5 years in Canada; non-recent > 5 years) with those of Canadian-born women. METHODS: This study was based on data from the Canadian Maternity Experiences Survey of the Public Health Agency of Canada. A stratified random sample of 6421 women was drawn from a sampling frame based on the 2006 Canadian Census of Population. Weighted proportions were calculated using survey sample weights. Multivariable logistic regression was used to estimate odds ratios comparing recent immigrant women with Canadian-born women and non-recent immigrant women with Canadian-born women, adjusting for education, income, parity, and maternal age. RESULTS: The sample comprised 7.5% recent immigrants, 16.3% non-recent immigrants, and 76.2% Canadian-born women. Immigrant women reported experiencing less physical abuse and stress, and they were less likely to smoke or consume alcohol during pregnancy, than Canadian women; however, they were more likely to report high levels of postpartum depression symptoms and were less likely to have access to social support, to take folic acid before and during pregnancy, to rate their own and their infant's health as optimal, and to place their infants on their backs for sleeping. Recent and non-recent immigrant women also had different experiences, suggesting that duration of residence in Canada plays a role in immigrant women's maternity experiences. CONCLUSION: These findings can assist clinicians and policy-makers to understand the disparities that exist between immigrant and non-immigrant women in order to address the needs of immigrant women more effectively.

The experience of pregnancy and birth with midwives: results from the Canadian maternity experiences survey.

BACKGROUND: In Canada maternity care is publicly funded, and although women may choose their care providers, choices may be limited. The purpose of this study was to compare perceptions of maternity outcomes and experiences of those who received care from midwives with those who received care from other providers. METHODS: Based on the 2006 Canadian census, a random sample of women (n = 6,421) who had recently given birth in Canada completed a computer-assisted telephone interview for the Maternity Experiences Survey. The sample was stratified according to province or territory where birth occurred, age, rural or urban residence, and presence of other children in the home. Those who were 15 years of age and older, gave birth to a singleton baby, and were living with their infant were eligible for inclusion. RESULTS: Women whose primary prenatal providers were midwives had fewer ultrasounds and were more likely to attend prenatal classes and have at least five or more prenatal visits. They were also more likely to rate satisfaction with their maternity experience as "very positive" and be satisfied with information provided on a variety of pregnancy and birth topics if their primary prenatal provider was a midwife. They were almost half as likely to experience induction and 7.33 times more likely to experience a medication-free delivery. They were more likely to initiate and maintain breastfeeding at 3 and 6 months. CONCLUSIONS: Evidence shows that midwifery outcomes and levels of satisfaction meet or exceed Canadian maternity care standards. Facilitation of the continuing integration of midwives as autonomous practitioners throughout Canada is recommended. (BIRTH 38:3 September 2011).