Trends in obesity and impact on obstetric outcomes in a regional hospital in Victoria, Australia

"It's just too far…": A qualitative exploration of the barriers and enablers to accessing perinatal care for rural Australian women

PURPOSE

Rural women and their babies experience poorer perinatal outcomes than their urban counterparts and this inequity has existed for decades. This study explored the barriers and enablers that exist for rural women in Australia in accessing perinatal care.

METHODS

A qualitative descriptive design, using reflexive thematic analysis, was employed. Semi-structured interviews were conducted in 2023 with women who had recently given birth in rural Victoria, Australia (n=19). A purposive sampling strategy was used, recruiting women via social media platforms from rural communities across the state. The Socioecological Model (SEM) was used as a framework to organise the findings.

RESULTS

Study participants reported multilevel barriers and enablers to accessing perinatal care in their own communities. Intrapersonal factors included financial resources, transportation, self-advocacy, health literacy, rural stoicism, personal agency, and cost of care. Interpersonal factors included factors such as ineffective relationships, poor communication, and care provider accessibility. Organisational factors included inequitable distribution of services, under-resourcing of perinatal services in rural areas, technology-enabled care models and access to continuity of care. Community factors included effective or ineffective interprofessional or interorganisational collaboration. Policy factors included centralisation of perinatal care, lack of funded homebirth and midwifery care pathways and access to free perinatal care.

CONCLUSION

Participants in this study articulated several key barriers influencing access to perinatal care in rural areas. These factors impede help-seeking behaviour and engagement with care providers, compounding the impact of rurality and isolation on perinatal outcomes and experience of care. Key enablers to accessing perinatal care in rural communities were also identified and included personal agency, health literacy, social capital, effective collaboration and communication between clinicians and services, technology enabled care and free perinatal care.

Obesity in women giving birth in Victoria, 2010-2019: a retrospective cohort study

OBJECTIVE

To assess the prevalence of obesity in pregnant women in Victoria, 2010-2019.

STUDY DESIGN

Retrospective cohort study; analysis of Victorian Perinatal Data Collection data.

SETTING, PARTICIPANTS

Women who gave birth in seventeen Victorian Department of Health areas (eight metropolitan, nine regional), 2010-2019.

MAIN OUTCOME MEASURES

Proportions of births to women with obesity (body mass index ≥ 30 kg/m2), by Department of Health area and year.

RESULTS

A total of 710 364 births with records that included the mothers' BMI were recorded in Victoria during 2010-2019. The proportion of births to women with obesity rose from 19.6% (95% confidence interval [CI], 19.3-19.9%) in 2010 to 21.5% (95% CI, 21.2-21.8%) in 2019; the proportion of births to women with normal weight declined from 49.0% (95% CI, 48.6-49.4%) to 46.8% (95% CI, 46.4-47.1%). In metropolitan areas, the proportion of births to women with obesity rose from 17.7% (95% CI, 17.7-17.8%) to 19.4% (95% CI, 19.3-19.4%); in regional areas, it increased from 25.0% (95% CI, 25.0-25.1%) to 29.1% (95% CI, 29.0-29.2%). The increase in prevalence of obesity was greater among women living in the lowest socio-economic standing (Index of Relative Socio-Economic Disadvantage) quintile than for those residing in the quintile of least disadvantage (adjusted rate ratio, 2.16; 95% CI, 2.12-2.20).

CONCLUSION

The proportion of births to Victorian women with obesity rose during 2010-2019, particularly in regional areas. Ensuring that regional health services are adequately resourced to meet the needs of the increasing number of women at risk of obesity during pregnancy is vital.

Common mental disorders and perinatal outcomes in Victoria, Australia: A population-based retrospective cohort study

PURPOSE

Common mental disorders (non-psychotic mental health conditions which impact on day-to-day functioning) are increasingly common in childbearing women and may impact significantly on both maternal and neonatal outcomes. Our study examines the associations between common mental disorders and perinatal outcomes.

METHODS

We used routinely collected perinatal data (2009-2016) for this population-based retrospective cohort study (n = 597,522 singleton births). We undertook multiple logistic regression adjusting for key maternal medical conditions and sociodemographic factors to determine associations between maternal common mental disorders and adverse perinatal outcomes with confidence intervals set at 95%.

RESULTS

Women with common mental disorders were more likely to have an induction of labour and caesarean birth, have a postpartum haemorrhage (PPH), and be admitted to the Intensive Care Unit (ICU) than women without common mental disorders. Neonates of women with common mental disorders were more likely to have an Apgar score at five minutes of less than seven (a measure of neonatal wellbeing at birth), be born preterm and low birthweight, be admitted to the Special Care Nursery or Neonatal Intensive Care Unit (SCN/NICU) and have a congenital anomaly than neonates of women without common mental disorders.

CONCLUSION

Common mental disorders during the perinatal period were associated with poorer perinatal outcomes for mothers and their neonates. Strategies that enable early recognition and response to maternal common mental disorders should be developed to mitigate the consequential impact on maternal and infant wellbeing.

Differences in neonatal adverse outcomes among women with gestational diabetes mellitus managed by diet or medication: a propensity score matched analysis of a population-based sample

OBJECTIVE

Neonatal outcomes in women with and without medically managed gestational diabetes mellitus (GDM) were compared after accounting for differences in maternal baseline characteristics using a propensity score (PS) analysis.

METHODS

Women without preexisting diabetes, delivering singletons during 2010-2017 in a large hospital, were eligible for inclusion. Using nearest-neighbour PS matching, women with non-pharmacological managed GDM were matched with women whose GDM was medically managed. A conditional logistic regression consequently compared the neonatal adverse outcomes between the groups after adjusting for gestational age, induction of labor, birth type, and number of ultrasounds conducted during the pregnancy.

RESULTS

Of the overall 10028 births, GDM was diagnosed in 930 (9.3%), of whom 710 (76.3%) were successfully matched. The conditional regressions found higher risk of neonatal adverse outcomes in neonates of women with non-pharmacological managed GDM compared to neonates of women with medically managed GDM. These included a higher risk of hypoglycemia (odds ratio (OR) 1.56, 95% confidence interval (CI) 1.03-2.38, p = 0.037), hypothermia (OR 2.29, 95%CI 1.05-5.00, p = 0.037), and birth injuries (OR 3.50, 95%CI 1.62-7.58, p = 0.001), and a higher risk of being small for gestational age (OR 2.06, 95%CI 1.01-4.18, p = 0.046) and being admitted to a special care unit (OR 2.04, 95%CI 1.29-3.21, p = 0.002).

CONCLUSIONS

The increased neonatal morbidity associated with non-medicated GDM identified in our study may indicate that diet and lifestyle changes alone are not sufficient to achieve glycaemic control in some women with GDM. Our findings indicate that gestational diabetes management approach is independently associated with neonatal outcomes.

Perinatal outcomes of socially disadvantaged women in Australia: A population-based retrospective cohort study

OBJECTIVE

To examine the perinatal outcomes of women who experience social disadvantage using population-based perinatal data collected between 1999 and 2016.

DESIGN

Population-based, retrospective cohort study.

SETTING

Victoria, Australia.

POPULATION OR SAMPLE

A total of 1 188 872 singleton births were included.

METHODS

Cohort study using routinely collected perinatal data. Multiple logistic regression was performed to determine associations between social disadvantage and adverse maternal and neonatal outcomes with confidence limits set at 99%. Time-trend analysis for perinatal outcomes was performed in relation to area-level disadvantage measures.

MAIN OUTCOME MEASURES

Incidence of maternal admission to intensive care unit (ICU), postpartum haemorrhage (PPH) and caesarean section, perinatal mortality, preterm birth, low birthweight (LBW), and admission to special care nursery/neonatal intensive care unit (SCN/NICU).

RESULTS

Social disadvantage was associated with higher odds of adverse perinatal outcomes. Disadvantaged women were more likely to be admitted to ICU, have a PPH or experience perinatal mortality (stillbirth or neonatal death) and their neonates were more likely to be admitted to SCN/NICU, be born preterm and be LBW. A persistent social gradient existed across time for the most disadvantaged women for all outcomes except caesarean section.

CONCLUSIONS

Social disadvantage has a marked negative impact on perinatal outcomes. This aligns with national and international evidence regarding the impact of disadvantage. Strategies that improve access to, and reduce fragmentation in, maternity care in addition to initiatives that address the social determinants of health may contribute to improving perinatal outcomes for socially disadvantaged women.

Hyperinsulinaemia in pregnancy and gestational outcomes: A case series

Background: Pathological insulin resistance in pregnancy is associated with an increased risk for complications such as gestational diabetes mellitus and pre-eclampsia. Individuals with pathological insulin resistance also exhibit hyperinsulinaemia. Currently, there are no diagnostic criteria for pathological hyperinsulinaemia in pregnancy that may be used to indicate risk of adverse outcomes.Aim: This case series aimed to explore the relationship between first trimester insulin response patterns and gestational outcomes.Setting: Auckland, New Zealand.Methods: Participants included four pregnant women with prepregnancy body mass index ≥ 25 kg/m2 and aged 25–35 years. Glucose and insulin response patterns were examined following a 120 min oral glucose tolerance test (OGTT) at 12–15 weeks of gestation using a modified Kraft methodology. Outcomes assessed at 25 and 35 weeks of gestation included gestational weight gain (GWG), blood pressure, fasting capillary blood glucose and foetal growth. Lifestyle and medical information were collected at each trimester. After delivery, total GWG, infant size, delivery method and clinical outcomes were recorded.Results: Kraft pattern IIB hyperinsulinaemia was identified in two cases. Amongst them, Case #1 experienced excessive GWG, induction of labour and surgically assisted delivery. Case #4 delivered by emergency caesarean, and the neonate required intensive care admission for 17 h. No cases developed hyperglycaemia or hypertension. Infant weights were between 3.75 kg and 3.86 kg.Conclusion: Dynamic insulin assay provides a promising template to assess metabolic risk in the first trimester of pregnancy. Diagnosing hyperinsulinaemia early in pregnancy means that lifestyle-based initiatives could be introduced earlier to mitigate excess GWG and potential adverse outcomes.

Incidence of obese parturients and the outcomes of their pregnancies: A nationwide register study in Finland

OBJECTIVES

We analyzed the incidence of obese and severely obese parturients and the impact of maternal obesity on mode of delivery, perinatal and neonatal mortality, and neonatal health.

STUDY DESIGN

We included all singleton births from the medical birth register of Finland from 2004 to 2018 (n = 792 437). Maternal body mass index (BMI) was categorized into three classes: non-obese (BMI < 30 kg/m²), obese (BMI 30 - 39.9 kg/m²), and morbidly obese (BMI 40 kg/m² or more). The yearly incidence of obese and severely obese parturients per 10000 births was calculated. Logistic regression was used to calculate adjusted odds ratios (aOR) with 95% confidence intervals (CI).

RESULTS

Between 2004 and 2018, the incidence of obese and morbidly obese parturients increased by 44% and 103%, respectively. Cesarean section rates were 23.6% and 30%, respectively (aOR 1.63 CI 1.61 - 1.66 and 2.33 CI: 2.23 - 2.44). Neonates born to morbidly obese parturients had an increased need for intensive care unit treatment (aOR 2.21 CI: 2.10 - 2.32), higher perinatal mortality (aOR 1.65 CI: 1.28 - 2.14), and higher neonatal mortality (aOR 1.68 CI: 1.04 - 2.72). The need for neonatal intensive care (aOR 1.50 CI: 1.47 - 1.53), perinatal mortality (aOR 1.25 CI: 1.13 - 1.39), and neonatal mortality (aOR 1.33 CI: 1.09 - 1.62) increased also among obese parturients.

CONCLUSIONS

We report a worrying increase in obese and morbidly obese parturients. Neonates born to these parturients were more likely delivered by cesarean sections and had higher rates of perinatal and neonatal mortality, and intensive care unit treatment. This highlights the importance of preventing obesity among fertile-aged females.

Young-Onset Gastrointestinal Adenocarcinoma Incidence and Survival Trends in the Northern Territory, Australia, with Emphasis on Indigenous Peoples

Background and Aims: A concerning rise in incidence of young-onset cancers globally led to the examination of trends in incidence and survival of gastrointestinal (GI) adenocarcinomas in the Northern Territory (NT), Australia, over a 28-year period, with a special emphasis on Indigenous peoples. Methods: This cross-sectional analysis of a prospective longitudinal database, NT Cancer Registry (1990−2017), includes all reported cases of GI (oesophagus, gastric, small intestinal, pancreas, colon, and rectum) adenocarcinomas. Poisson regression was used to estimate incidence ratio ratios, and survival was modelled using Cox proportional hazard models separately for people aged 18−50 years and >50 years. Results: A total of 1608 cases of GI adenocarcinoma were recorded during the time of the study. While the overall incidence in people 18−50 years remained unchanged over this time (p = 0.51), the rate in individuals aged >50 years decreased (IRR = 0.65 (95% CI 0.56−0.75; p < 0.0001)). Incidence rates were significantly less in females >50 years (IRR = 0.67 95% CI 0.59−0.75; p < 0.0001), and their survival was significantly better (HR = 0.84 (95%CI 0.72−0.98; p < 0.03)) compared to males. Overall survival across all GI subsites improved in both age cohorts, especially between 2010 and 2017 (HR = 0.45 (95%CI 0.29−0.72; p < 0.0007) and HR = 0.64 (95%CI 0.52−0.78; p < 0.0001), respectively) compared to 1990−1999, driven by an improvement in survival in colonic adenocarcinoma alone, as the survival remained unchanged in other GI subsites. The incidence was significantly lower in Indigenous patients compared to non-Indigenous patients, in both age cohorts (18−50 years IRR = 0.68 95% CI 0.51−0.91; p < 0.009 and >50 years IRR = 0.48 95% CI 0.40−0.57; p < 0.0001). However, Indigenous patients had worse survival rates (18−50 years HR = 2.06 95% CI 1.36−3.11; p < 0.0007 and >50 years HR = 1.66 95% CI 1.32−2.08; p < 0.0001). Conclusions: There is a trend towards an increased incidence of young-onset GI adenocarcinomas in the NT. Young Indigenous patients have lower incidence but worse survival across all GI subsites, highlighting significant health inequities in life expectancy. Targeted, culturally safe Indigenous community-focussed programs are needed for early detection and patient-centred management of GI adenocarcinomas.

Pre-pregnancy lifestyle characteristics and risk of miscarriage: the Australian Longitudinal Study on Women's Health

Background

Previous studies of lifestyle characteristics and risk of miscarriage have mostly been retrospective and failed to account for induced abortions. We examine whether pre-pregnancy body-mass index, alcohol intake and smoking influence the risk of miscarriage after accounting for induced abortions.

Methods

We conducted a prospective cohort study of 9213 women with 26,594 pregnancies participating in the Australian Longitudinal Study on Women’s Health. We examined whether body-mass index, smoking and alcohol intake prior to pregnancy was associated with miscarriage. We estimated adjusted relative risks (RR) using generalized estimating equations with an exchangeable correlation matrix. We explored the impact of accounting for induced abortion by first excluding all induced abortions, and secondly including 50% of induced abortions in the comparison group.

Results

Of the 26,592 pregnancies which occurred during the follow-up period, 19% ended in a miscarriage. We observed an increased risk of miscarriage according to pre-pregnancy obesity compared to normal weight (adjusted RR 1.13; 95% CI 1.05, 1.21), smoking between 10 and 19 cigarettes per day compared to not smoking (adjusted RR 1.13; 95% CI 1.02, 1.25), but not smoking 20 or more cigarettes per day (adjusted RR 1.07; 95% CI 0.94, 1.21) and risky drinking (≥2 units per day; adjusted RR 1.15; 95% CI 1.03, 1.28) compared to low risk drinking (< 2 units per day). The results for smoking (adjusted RR 1.09 for 10–19 cigarettes per day; 95% CI 0.98, 1.21) was attenuated after including 50% of induced abortions in the comparison group.

Conclusions

We observed a modest increased risk of miscarriage according to obesity and risky alcohol intake prior to pregnancy. There was no evidence of a dose-response relationship with smoking, and the association between smoking and risk of miscarriage was attenuated after accounting for induced abortions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04482-9.

Trends in percentages of gestational diabetes mellitus attributable to overweight, obesity, and morbid obesity in regional Victoria: an eight-year population-based panel study

BACKGROUND

Gestational diabetes mellitus (GDM) is the fastest growing type of diabetes in Australia with rates trebling over the past decades partially explained by rising obesity rates and maternal age among childbearing women. Percentage of GDM attributable to obesity has been documented, mostly focusing on metropolitan populations. In parts of regional (areas outside capital cities) and rural Australia where overweight, obesity and morbid obesity are more prevalent, intertwined with socioeconomic disadvantage and higher migrant communities, trends over time in adjusted percentages of GDM attributed to obesity are unknown.

METHODS

In this population-based retrospective panel study, women, without pre-existing diabetes, delivering singletons between 2010 and 2017 in a tertiary regional hospital that serves 26% of Victoria's 6.5 million Australian population were eligible for inclusion. Secular trends in GDM by body mass index (BMI) and age were evaluated. The percentage of GDM that would have been prevented each year with the elimination of overweight or obesity was estimated using risk-adjusted regression-based population attributable fractions (AFp). Trends in the AFp over time were tested using the augmented Dickey-Fuller test.

RESULTS

Overall 7348 women, contributing to 10,028 births were included. The age of expecting mothers, their BMI, proportion of women born overseas, and GDM incidence significantly rose over time with GDM rising from 3.5% in 2010 to 13.7% in 2017, p <  0.001, increasing in all BMI categories. The incidence was consistently highest among women with obesity (13.8%) and morbid obesity (21.6%). However, the highest relative increase was among women with BMI < 25 kg/m2, rising from 1.4% in 2010 to 7.0% in 2017. Adjusting for age, country of birth, socioeconomic status, comorbidities, antenatal and intrapartum factors, an estimated 8.6% (confidence interval (CI) 6.1-11.0%), 15.6% (95% CI 12.2-19.0%), and 19.5% (95% CI 15.3-23.6%) of GDM would have been prevented by eliminating maternal overweight, obesity, and morbid obesity, respectively. However, despite the rise in obesity over time, percentages of GDM attributable to overweight, obesity, and morbid obesity significantly dropped over time. Scenario analyses supported these findings.

CONCLUSIONS

Besides increasing prevalence of obesity over time, this study suggests that GDM risk factors, other than obesity, are also increasing over time.

Maternal and neonatal complications in women with medical comorbidities and preeclampsia

OBJECTIVES

To evaluate how medical comorbidities - chronic hypertension, pre-gestational or gestational diabetes and obesity - influence maternal and neonatal complications from preeclampsia.

STUDY DESIGN

We undertook a retrospective cohort study of women delivering in Victoria, Australia, between 2009 and 2017. We compared the likelihood of having a maternal complication before delivery or neonatal complication after birth between women with and without comorbidities. We used causal mediation analysis for neonatal outcomes to separate the effects of comorbidities and of prematurity on morbidity.

MAIN OUTCOME MEASURES

Pregnancy complications (eclampsia; haemolysis, elevated liver enzymes, low platelets syndrome; placental abruption; stillbirth) and neonatal complications (respiratory distress syndrome; neonatal sepsis; a 5-minute APGAR < 5; neonatal intensive care unit admission).

RESULTS

Women with comorbidities delivered at a median (interquartile range) of 37.0 (36.0-39.0) weeks gestation, earlier than women without comorbidities (38.0 (36.0-39.0) weeks, p < 0.001). Women with comorbidities were less likely than those without to suffer any pregnancy complication prior to delivery (adjusted relative risk 0.78, 95% confidence interval 0.72-0.86); however, their neonates suffered more respiratory distress syndrome (aRR 1.43, 95% CI 1.31-1.57), neonatal sepsis (aRR 1.42, 95% CI 1.17-1.72) and NICU admission (aRR 1.37, 95% CI 1.23-1.53). Earlier delivery was a major contributor to worse neonatal outcomes.

CONCLUSIONS

Medical comorbidities are associated with earlier delivery among women with preeclampsia. This is associated with fewer maternal complications, but worse neonatal outcomes.

The effect of preexisting medical comorbidities on the preeclamptic phenotype: a retrospective cohort study

Objective:To compare the effect of comorbidities on the phenotype and outcomes of preeclampsia.Methods: A matched retrospective cohort study of women delivering at a tertiary maternity center following a diagnosis of preeclampsia. We collected data on signs and symptoms, biochemical markers, and maternal and perinatal outcomes.Results:We studied 474 women; 158 women with and 316 without comorbidities. Compared to women without comorbidities, women with comorbidities delivered earlier. They suffered fewer maternal but more neonatal complications.Conclusion: Women with comorbidities receive earlier intervention than women without comorbidities, which may lead to fewer maternal complications but worse neonatal outcomes.

Relationship between obesity and lower rates of breast feeding initiation in regional Victoria, Australia: an 8-year retrospective panel study

OBJECTIVES

Using routinely collected hospital data, this study explored secular trends over time in breast feeding initiation in a large Australian sample. The association between obesity and not breast feeding was investigated utilising a generalised estimating equations logistic regression that adjusted for sociodemographics, antenatal, intrapartum and postpartum conditions, mode of delivery and infant's-related covariates.

DESIGN

Population-based retrospective panel.

SETTING

A regional hospital that serves 26% of Victoria's 6.5 million population in Australia.

PARTICIPANTS

All women experiencing live births between 2010 and 2017 were included. Women with missing body mass index (BMI) were excluded.

RESULTS

A total of 7491 women contributed to 10 234 live births. At baseline, 57.2% of the women were overweight or obese, with obesity increasing over 8 years by 12.8%, p=0.001. Although, breast feeding increased over time, observed in all socioeconomic status (SES) and BMI categories, the lowest proportions were consistently found among the obese and morbidly obese (78.9% vs 87.1% in non-obese mothers, p<0.001). In the multivariable analysis, risk of not breast feeding was associated with higher BMI, teenage motherhood, smoking, belonging to the lowest SES class, gravidity >4 and undergoing an assisted vaginal or caesarean delivery. Compared with women with a normal weight, the obese and morbidly obese were 66% (OR 1.66, 95% CI 1.40 to 1.96, p<0.001) to 2.6 times (OR 2.61, 95% CI 2.07 to 3.29, p<0.001) less likely to breast feed, respectively. The detected dose-response effect between higher BMI and lower breast feeding was not explained by any of the study covariates.

CONCLUSION

This study provides evidence of increasing breast feeding proportions in regional Victoria over the past decade. However, these proportions were lowest among the obese and morbidly obese and those coming from the most disadvantaged backgrounds suggesting the need for targeted interventions to support breast feeding among these groups. The psychosocial and physiological associations between obesity and breast feeding should further be investigated.

Abdominal Cutaneous Thermography and Perfusion Mapping after Caesarean Section: A Scoping Review

Introduction: Caesarean section (CS) is the most prevalent surgical procedure in women. The incidence of surgical site infection (SSI) after CS remains high but recent observations of CS wounds using infrared thermography has shown promise for the technique in SSI prognosis. Although thermography is recognised as a 'surrogate' of skin perfusion, little is known of the relationship between skin temperature and skin perfusion in the context of wound healing. Aim: To assess the extent of literature regarding the application of infrared thermography and mapping of abdominal cutaneous perfusion after CS. Methods: Wide eligibility criteria were used to capture all relevant studies of any design, published in English, and addressing thermal imaging or skin perfusion mapping of the abdominal wall. The CINAHL and MEDLINE databases were searched, with two independent reviewers screening the title and abstracts of all identified citations, followed by full-text screening of relevant studies. Data extraction from included studies was undertaken using a pre-specified data extraction chart. Data were tabulated and synthesised in narrative format. Results: From 83 citations identified, 18 studies were considered relevant. With three additional studies identified from the reference lists, 21 studies were screened via full text. None of the studies reported thermal imaging and cutaneous perfusion patterns of the anterior abdominal wall. However, two observational studies partially met the inclusion criteria. The first explored analysis methodologies to 'interrogate' the abdominal thermal map. A specific thermal signature ('cold spots') was identified as an early 'flag' for SSI risk. A second study, by the same authors, focusing on obesity (a known risk factor for SSI after CS) showed that a 1 °C lower abdominal skin temperature led to a 3-fold odds of SSI. Conclusion: There is a significant gap in knowledge on how to forewarn of wound complications after CS. By utilising the known association between skin temperature and blood flow, thermographic assessment of the wound and adjacent thermal territories has potential as a non-invasive, independent, imaging option with which to identify tissue 'at risk'. By identifying skin 'hot' or 'cold' spots, commensurate with high or low blood flow regions, there is potential to shed light on the underlying mechanisms leading to infective and non-infective wound complications.

Temporal trends in the incidence of and associations between the risk factors for obstetrical anal sphincter injuries

BACKGROUND

Obstetrical anal sphincter injuries are an important complication of vaginal deliveries that may result in short- and long-term pelvic floor morbidity and a diminished quality of life in young, healthy women. The prevalence of obstetrical anal sphincter injuries ranges from 0.1% to 8.7%. Over recent years, there seems to be a trend of increasing occurrence of obstetrical anal sphincter injuries worldwide. It is unclear why the rates are rising. Previous studies have examined the effect of different risk factors on the prevalence of obstetrical anal sphincter injuries. The change in the incidence of some risk factors for obstetrical anal sphincter injuries can partially explain the overall increase in obstetrical anal sphincter injuries. There is no previous study that explored the impact of the changes of individual risk factors over time on the risk for obstetrical anal sphincter injuries.

OBJECTIVE

The main aim of this study was to examine the temporal trends in the prevalence and odds ratio of the major risk factors known to be associated with obstetrical anal sphincter injuries in the period from 1988 to 2016.

STUDY DESIGN

This was a retrospective cohort study that included all women who underwent vaginal deliveries between 1988 and 2016 at a tertiary university medical center. The time intervals were divided into 4 periods (1988-1997, 1998-2007, 2008-2016, and the total time from 1988 to 2016) and the incidence of each risk factor was calculated for each time period. Correlation models and regression analysis were performed to examine the association between obstetrical anal sphincter injuries and the different risk factors over time. Furthermore, the trends in the odds ratios of the important risk factors over the time periods were evaluated using a multivariate regression analysis in which the primiparous women were separated from the multiparous women.

RESULTS

During the study period, there were 295,668 vaginal deliveries. Of these, 591 women were diagnosed with obstetrical anal sphincter injuries (0.2%). The significant risk factors for obstetrical anal sphincter injuries (P<.05) in the multivariable analysis were the following: primiparity, vaginal birth after cesarean delivery, vacuum extraction, and a birthweight of >4 kg. There was a significant (P<.05) increase in the incidence over the study period for the following risk factors: primiparity, vaginal birth after cesarean delivery, and vacuum extraction. No change was found in the incidence of the risk factor of a birthweight of >4 kg. In addition, we found a strengthening of the association between vaginal birth after cesarean delivery and macrosomia with obstetrical anal sphincter injuries, as opposed to a decline in the relative contribution of vacuum extraction to the overall risk for obstetrical anal sphincter injuries. Moreover, we found that obstetrical anal sphincter injuries among primiparous women increased 7-fold over the study period but was unchanged among multiparous women.

CONCLUSION

We have shown significant (P<.05) temporal trends in the incidence and odds ratio of some of the known risk factors for obstetrical anal sphincter injuries. A better understanding of the changes in the incidence and specific contribution of important risk factors for obstetrical anal sphincter injuries may explain, in part, the worldwide increase in the prevalence of this important and detrimental complication of vaginal birth.