The impact of fear of childbirth on mode of delivery, postpartum mental health and breastfeeding: A prospective cohort study in Shanghai, China

BACKGROUND

The prevalence and impact of fear of childbirth (FOC) has not been sufficiently understood. We aimed to investigate the prevalence of FOC among Chinese population and its impact on mode of delivery, postpartum mental health and breastfeeding.

METHODS

We conducted a prospective cohort study, wherein pregnant women in their third trimester who underwent antenatal assessments at Shanghai Changning Maternity and Infant Health Hospital between September 2020 and March 2021 were recruited. Sociodemographic data of the participants were gathered by self-administered questionnaire, and their FOC was assessed using the Wijma Delivery Expectancy Questionnaire. Participants were followed up to 42 days postpartum. Information regarding their modes of delivery was retrieved from medical records, and data regarding postpartum mental health symptoms and one-month postpartum breastfeeding were obtained through self-administered questionnaires.

RESULTS

Among 1287 participants, 461 (35.8 %) had high-level FOC (W-DEQ ≥ 66). Logistic regressions showed that women with high-level of FOC had higher rates of caesarean delivery on maternal request (CDMR) (aOR = 1.55, 95 % CI: 1.00-2.41, p = 0.049), a higher incidence of postpartum mental health symptoms (aOR = 1.68, 95 % CI: 1.09-2.59, p = 0.018), lower rates of one-month postpartum exclusive breastfeeding (aOR = 0.33, 95 % CI: 0.16-0.69, p = 0.003) and mixed feeding (aOR = 0.44, 95 % CI: 0.21-0.91, p = 0.028).

LIMITATIONS

The long-term implications of FOC beyond the immediate postpartum period were not explored in the study.

CONCLUSIONS

High-level FOC during the third trimester was associated with increased CDMR and postpartum mental health symptoms and reduced breastfeeding establishment. These results underscore the significance of FOC screening and tailored interventions for affected women.

Busy day effect on adverse obstetric outcomes using a nationwide ecosystem approach: Cross-sectional register study of 601 247 hospital deliveries

OBJECTIVE

To study the busy day effect on selected neonatal adverse outcomes in different sized delivery hospitals and in the entire nationwide obstetric ecosystem.

DESIGN

A cross-sectional register study.

SETTING

The lowest and highest 10% of the daily delivery volume distribution were defined as quiet and busy days, respectively. The days between (80%) were defined as optimal delivery volume days. The differences in the incidence of selected adverse neonatal outcome measures were analysed between busy versus optimal days and quiet versus optimal days at the hospital category and for the entire obstetric ecosystem level.

POPULATION

A total of 601 247 singleton hospital deliveries between 2006 and 2016, occurred in non-tertiary (C1-C4, stratified by size) and tertiary level (C5) delivery hospitals.

METHODS

Analyses were performed by the methods of the regression analyses with crude and adjusted odds ratios including 99% CI.

MAIN OUTCOME MEASURES

Birth asphyxia.

RESULTS

At the ecosystem level, adjusted odds ratio for birth asphyxia was 0.81 (99% CI 0.76-0.87) on busy versus optimal days. Breakdown to hospital categories show that adjusted odds ratios for asphyxia on busy versus optimal days in non-tertiary hospitals (C3, C4) were 0.25 (99% CI 0.16-0.41) and 0.17 (99% CI 0.13-0.22), respectively, and in tertiary hospitals was 1.20 (99% CI 1.10-1.32).

CONCLUSIONS

Busy day effect as a stress test caused no extra cases of neonatal adverse outcomes at the ecosystem level. However, in non-tertiary hospitals busy days were associated with a lower and in tertiary hospitals a higher incidence of neonatal adverse outcomes.

Trends in Term Intrapartum Stillbirth in Norway

Importance

Fetal death during labor at term is a complication that is rarely studied in high-income countries. There is a need for large population-based studies to examine the rate of term intrapartum stillbirth in high-income countries and the factors associated with its occurrence.

Objective

To evaluate trends in term intrapartum stillbirth over time and to investigate the association between the trends and term intrapartum stillbirth risk factors from 1999 to 2018 in Norway.

Design, Setting, and Participants

This cohort study used data from the Medical Birth Registry of Norway from 1999 to 2018 to examine rates of term intrapartum stillbirth and risk factors associated with this event. A population of 1 021 268 term singleton pregnancies without congenital anomalies or antepartum stillbirths was included in analyses, which were performed from September 2022 to February 2023.

Exposure

The main exposure variable was time, which was divided into four 5-year periods: 1999 to 2003, 2004 to 2008, 2009 to 2013, and 2014 to 2018.

Main Outcomes and Measures

The primary study outcome was term intrapartum stillbirth. Risk ratios were calculated, and multivariable logistic regression analyses were conducted to identify factors associated with secular trends of term intrapartum stillbirth.

Results

The study population consisted of 1 021 268 term singleton births (maternal mean [SD] age, 29.72 [5.01] years; mean [SD] gestational age, 39.69 [1.27] weeks). During the study period, there were 95 term intrapartum stillbirths (0.09 per 1000 births). Maternal age, the proportion of individuals born in a country other than Norway, and the prevalence of gestational diabetes, labor induction, operative vaginal delivery, and previous cesarean delivery increased over the course of the study period. Conversely, the prevalence of infants large for gestational age, hypertensive disorder in pregnancy, and spontaneous vaginal delivery and the proportion of individuals who smoked decreased. The term intrapartum stillbirth rate decreased by 87% (95% CI, 68%-95%) from 0.15 per 1000 births in 1999 to 2008 to 0.02 per 1000 births in 2014 to 2018. Three in 4 term intrapartum stillbirths (70 of 95) occurred during intrapartum operative deliveries. The increased prevalence of older maternal age and obstetric risk factors were not associated with the variation in intrapartum stillbirth rates among the time periods. The prevalence of term intrapartum stillbirth was higher for individuals who gave birth in maternity units with fewer than 3000 annual births (adjusted odds ratio, 1.67; 95% CI, 1.07-2.61) than for those who gave birth in units with 3000 or more annual births.

Conclusions and Relevance

Findings of this study suggest that, despite increases in maternal and obstetric risk factors, term intrapartum stillbirth rates substantially decreased during the study period. Reasons for this decrease may be due to improvements in intrapartum care.

Socioeconomic status, maternal risk factors, and gestational diabetes mellitus across reproductive years: a Finnish register-based study

INTRODUCTION

To evaluate the degree to which socioeconomic differences in gestational diabetes mellitus (GDM) are accounted for by differences in maternal risk factors, to assess whether age-related risks of GDM differ across socioeconomic groups, and to identify priority populations for future interventions.

RESEARCH DESIGN AND METHODS

We performed a register-based study using data from the Finnish Medical Birth Register and Statistics Finland on the 474 166 women who gave birth in Finland from 2008 to 2015. We collected information on GDM based on the International Classification of Diseases 10th Revision codes O24.4 and O24.9. We used multivariable models to examine the association between socioeconomic status, maternal risk factors, and GDM. We further tested interaction on multiplicative and additive scales.

RESULTS

The incidence of GDM was 8.7% in 2008-2011 and 12.5% in 2012-2015. Lower socioeconomic levels than upper level employees were associated with an increased risk of GDM. Up to 64.0% of socioeconomic differences in GDM were attributed to body mass index and 5.5% to smoking. There was evidence for effect modification. Relative to women in the upper level category who were aged less than 19 years, GDM adjusted ORs (95% CIs) for women 35 years or older in upper level versus long-term unemployed groups were 3.28 (2.08-5.18) and 5.29 (3.35-8.35), respectively.

CONCLUSIONS

There is a paradox that socioeconomic advantage increases the incidence of GDM at the population level while reducing the incidence of GDM within the population. Nevertheless, socioeconomic differences in GDM persist and widen with increasing maternal age, even after accounting for maternal risk factors.

Different pathways for preterm birth between singleton and twin pregnancies: a population-based registry study of 481 176 nulliparous women

OBJECTIVE

To explore the contribution of pregnancy-related complications on the prevalence of extremely, very and late preterm births in singleton and twin pregnancies. To study the risk of spontaneous preterm birth in twin pregnancies compared with singleton pregnancies.

DESIGN

Population-based registry study.

SETTING

Medical birth registry of Norway and Statistics Norway.

POPULATION

Nulliparous women with singleton (n = 472 449) or twin (n = 8727) births during 1999-2018.

METHODS

Prevalence rates of pregnancy-related complications for extremely, very and late preterm birth in twin and singleton pregnancies were calculated with 95% confidence intervals. Multivariable logistic regression was applied to assess odds ratios for preterm birth, adjusted for obstetric and socio-economic factors.

MAIN OUTCOME MEASURES

Extremely preterm (<28⁺⁰  weeks of gestation), very preterm (28⁺⁰ -33⁺⁶  weeks of gestation) and late preterm (34⁺⁰ -36⁺⁶  weeks of geatation) birth.

RESULTS

Preterm birth was significantly more prevalent in twin pregnancies than in singleton pregnancies in all categories: all preterm (54.7% vs 6.1%), extremely preterm (3.6% vs 0.4%), very preterm (18.2% vs 1.4%) and late preterm (33.0% vs 4.3%) births. Stillbirth, congenital malformation and pre-eclampsia were more prevalent in twin pregnancies than in singleton pregnancies, but the prevalence of complications differed in the three categories of preterm birth. Pre-eclampsia was more prevalent in singleton than in twin pregnancies ending in extremely and very preterm birth. The adjusted odds of spontaneous preterm live birth were between 19- and 54-fold greater in twin pregnancies than in singleton pregnancies.

CONCLUSIONS

Singleton and twin pregnancies seem to have different pathways leading to extremely, very and late preterm birth.

Busy day effect on the use of obstetrical interventions and epidural analgesia during labour: a cross-sectional register study of 601 247 deliveries

Background

Daily delivery volume might affect the quality of obstetric care. We explored the busy day effect on selected obstetrical interventions and epidural analgesia performed during labour in different sized delivery hospitals and on the Finnish obstetric ecosystem.

Methods

We conducted a cross-sectional study on Finnish Medical Birth Register data of singleton pregnancies (N = 601,247) from 26 delivery hospitals from 2006 to 2016. Delivery hospitals were stratified by annual delivery volume: C (category) 1: < 1000, C2: 1000–1999, C3: 2000–2999, C4: ≥3000, and C5: university hospitals. The exposure variables were defined as quiet, optimal, and busy days determined based on daily delivery volume distribution in each hospital category. Quiet and busy days included approximately 10% of the lowest and highest delivery volume days, while the rest were defined as optimal. Outcome measures were unplanned caesarean section (CS), instrumental delivery, induction of labour, and epidural analgesia. We compared the incidence of outcomes in quiet vs. optimal, busy vs. optimal, and busy vs. quiet days using logistic regression. The statistical significance level was set at 99% to reduce the likelihood of significant spurious findings.

Results

In the total population, the incidence of instrumental delivery was 8% (99% CI 2–15%) lower on quiet than on optimal days. In smaller hospitals (C1 and C2), unplanned caesarean sections were performed up to one-third less frequently on busy than optimal and quiet days. More (27%, 99% CI 12–44%) instrumental deliveries were performed in higher delivery volume hospitals (C4) on busy than quiet days. In C1-C3, deliveries were induced (12–35%) less often and in C5 (37%, 99% CI 28–45%) more often on busy than optimal delivery days. More (59–61%) epidural analgesia was performed on busy than optimal and quiet days in C4 and 8% less in C2 hospitals.

Conclusions

Pooled analysis showed that busyness had no effect on outcomes at the obstetric ecosystem level, but 10% fewer instrumental deliveries were performed in quiet than on busy days overall. Furthermore, dissecting the data shows that small hospitals perform less, and large non-tertiary hospitals perform more interventions during busy days.

Risk factor management matters more than pharmaceutical cyclooxygenase-2 inhibition in the prevention of de novo intracranial aneurysms

BACKGROUND AND PURPOSE

Pathophysiological studies of saccular intracranial aneurysm (sIA) disease have shown that inflammation plays a crucial role in sIA development. Pharmaceutical inhibition of COX-2-PGE2-NF-κB signaling (COX-2, cyclooxygenase-2; PGE2, prostaglandin E2; NF-κB, nuclear factor κB) has been shown in animal models to inhibit sIA formation and progression suggesting that use of medication inhibiting COX-2 could reduce intracranial aneurysm formation also in patients.

METHODS

The impact of COX-2 inhibition on de novo sIA formation was studied in two cohorts: in a previously described angiographically followed cohort of 1419 sIA patients and in a cohort of 117 sIA patients treated with stenting or stent-assisted embolization. Patients were identified from our population-based Kuopio Intracranial Aneurysm Database. Data on the use of anti-inflammatory medications and hospital diagnoses were obtained from national registries. Risk factors were identified by univariate and multivariate analyses.

RESULTS

De novo sIA patients were younger and more often smokers. Use of COX-2 selective inhibitors or nonsteroidal anti-inflammatory drugs did not significantly reduce de novo sIA formation, but the percentage of patients with de novo sIA formation was smaller in patients with prescribed regular acetylsalicylic acid medication (1.1% vs. 3.6%). In the multivariate analysis, however, neither acetylsalicylic acid use nor other type of pharmaceutical inhibition of COX-2 reduced the formation of de novo sIAs. The risk was mostly affected by age, smoking history and irregular usage of antihypertensive medication regardless of used COX-2 inhibition level.

CONCLUSION

For the prevention of de novo sIA formation, risk factor management with focus on cessation of smoking and treating hypertension adequately seems more important than pharmaceutical COX-2 inhibition.

Use of antihypertensive medication and formation of de novo intracranial aneurysms

BACKGROUND

Hypertension is a risk factor for subarachnoid hemorrhage and is also considered a risk factor for saccular intracranial aneurysm (sIA) formation. However, there is little direct evidence that antihypertensive medication would reduce sIA formation.

METHODS

We studied the impact of antihypertensive medication on de novo sIA formation in an angiographically followed cohort of 1419 patients. Patients were identified from our population-based Kuopio Intracranial Aneurysm Database, and data of the purchases of antihypertensive medication was obtained from a national registry. Univariate and multivariate analyses were used to investigate the risk factors.

RESULTS

Of the 966 sIA patients that were prescribed with antihypertensive medication, 841 patients used the medication regularly, 20 of them had de novo sIA. 125 patients used the medication irregularly and 12 of them developed de novo sIAs. 453 patients didn't use antihypertensive medication even though 27 of them had diagnosis of hypertension, and 10 of them developed de novo sIAs. In the multivariate analysis antihypertensive medication didn't significantly reduce de novo sIA formation (HR 1.60, 95% Cl 0.84-3.06). Age at primary diagnosis (HR 0.95, 95% Cl 0.93-0.98) and smoking history (HR 5.53, 95% Cl 2.77-11.05) were significant risk factors for de novo sIA formation. Also, irregular usage of antihypertensive medication was a significant risk factor (HR 3.84, 95% Cl 1.59-9.29) for de novo sIA formation.

CONCLUSIONS

Antihypertensive agents were not associated with a reduction of de novo sIA formation, but irregular use of antihypertensive agents was associated with an increased risk of de novo sIA formation.

Socioeconomic differences in the association between maternal age and maternal obesity: a register-based study of 707,728 women in Finland

AIMS

To examine the association between maternal age and maternal obesity across socioeconomic groups and to determine whether socioeconomic status modifies the association between maternal age and maternal obesity with a view to informing public health policies.

METHODS

Data for this register-based study were sourced from the Finnish Medical Birth Register and Statistics Finland, using the information of 707,728 women who gave birth in Finland from 2004 to 2015. We used multivariable regression models to assess the association between maternal age and maternal obesity across socioeconomic groups. We further assessed interactions on both multiplicative and additive scales.

RESULTS

Across all socioeconomic groups, the adjusted odds ratio for the association between maternal age and maternal obesity increased, peaking for women 35 years or older. Using women below 20 years of age in the category of upper-level employees as a single reference group, in the category of upper-level employees, the adjusted odds ratio and 95% confidence intervals among women 35 years or older was 1.92 (1.39-2.64) for maternal obesity. Equally, the adjusted odds ratio and 95% confidence intervals in the category of long-term unemployed was 4.35 (3.16-5.98). Synergistic interactions on both multiplicative and additive scales were found across age and socioeconomic groups.

CONCLUSIONS

The association between maternal age and maternal obesity was strongest among women 35 years or older with lower socioeconomic status. Population-level interventions that address maternal risk factors from teenage years are needed alongside individual-level interventions that target high-risk mothers in areas of low socioeconomic status and maternal obesity.

Substantial decrease in preeclampsia prevalence and risk over two decades: A population-based study of 1,153,227 deliveries in Norway

OBJECTIVES

Analyze secular trends of preeclampsia in Norway based on risk factors.

STUDY DESIGN

Population-based cohort study of 1,153,227 women using data from Medical Birth Registry of Norway from 1999 to 2018. Aggregated data from Norwegian Prescription Database from 2004 to 2018 were used. Main exposure variable was time period. Descriptive statistics identified the prevalence of preeclampsia, labor induction and aspirin use. Multiple logistic regression analysis was performed to estimate the risk of preeclampsia during the time periods.

MAIN OUTCOME MEASURES

Preeclampsia.

RESULTS

Overall preeclampsia prevalence decreased from 4.3% in 1999-2002 to 2.7% in 2015-2018. A reduction was observed in all subgroups of women with known risk factors (age, nulliparity, diabetes, chronic hypertension, assisted reproduction, twin pregnancy). Adjusted risk of preeclampsia was reduced by 44% from 1999-2002 to 2015-2018 (aOR = 0.56, 95%CI 0.54, 0.58), while the net prevalence of gestational hypertension remained stable over the study period. Labor induction increased 104%. Aspirin prescriptions increased among fertile women in the general Norwegian population.

CONCLUSIONS

Preeclampsia prevalence and risk were reduced regardless of risk factors and despite an increased proportion of high-risk parturients (advanced age, lower parity, use of assisted reproduction). A corresponding increase in aspirin prescriptions among fertile women and an overall increase in labor inductions were also observed, suggesting that clinical interventions may partly explain the observed reduction in preeclampsia prevalence. Lower average blood pressure and improved health in the population may also explain some of the reduction.

Risk of preterm birth in relation to history of preterm birth: a population-based registry study of 213 335 women in Norway

OBJECTIVE

To assess the association between preterm first birth and preterm second birth according to gestational age and to determine the role of placental disorder in recurrent preterm birth.

DESIGN

Population-based registry study.

SETTING

Medical Birth Registry of Norway and Statistics Norway.

POPULATION

Women (n = 213 335) who gave birth to their first and second singleton child during 1999-2014 (total n = 426 670 births).

METHODS

Multivariate logistic regression analyses, adjusted for placental disorders, maternal, obstetric and socio-economic factors.

MAIN OUTCOME MEASURES

Extremely preterm (<28⁺⁰  weeks), very preterm (28⁺⁰ -33⁺⁶  weeks) and late preterm (34⁺⁰ -36⁺⁶  weeks) second birth.

RESULTS

Preterm birth (<37 weeks) rates were 5.6% for first births and 3.7% for second births. Extremely preterm second births (0.2%) occurred most frequently among women with an extremely preterm first birth (aOR 12.90, 95% CI 7.47-22.29). Very preterm second births (0.7%) occurred most frequently after an extremely preterm birth (aOR 12.98, 95% CI 9.59-17.58). Late preterm second births (2.8%) occurred most frequently after a previous very preterm birth (aOR 6.86, 95% CI 6.11-7.70). Placental disorders contributed 30-40% of recurrent extremely and very preterm births and 10-20% of recurrent late preterm birth.

CONCLUSION

A previous preterm first birth was a major risk factor for a preterm second birth. The contribution of placental disorders was more pronounced for recurrent extremely and very preterm birth than for recurrent late preterm birth. Among women with any category of preterm first birth, more than one in six also had a preterm second birth (17.4%).

TWEETABLE ABSTRACT

Preterm first birth is a major risk factor for subsequent preterm birth, regardless of maternal, obstetric or fetal risk factors.

Early Neonatal Mortality among Babies Born with Spina Bifida in Finland (2000-2014)

OBJECTIVE

 We examined early neonatal mortality risk, temporal trends, and selected infant and maternal factors associated with early neonatal mortality among all spina bifida-affected live births in Finland.

STUDY DESIGN

 We linked multiregistry population-based data from the national registers in Finland for infants born with spina bifida from 2000 to 2014. Early neonatal mortality was defined as death in 0 to 6 days after birth. Early neonatal mortality risk and 95% confidence intervals (CI) was estimated by using the Poisson approximation of binomial distribution. Poisson regression was used to examine temporal trend in early neonatal mortality from 2000 to 2014 for spina bifida cases and all births in Finland. Selected infant and maternal characteristics were compared between cases that experienced early neonatal mortality and cases that did not. Exact logistic regression was used to estimate unadjusted odds ratios (uORs) and 95% confidence intervals (CIs).

RESULTS

 A total of 181 babies were born alive with spina bifida in Finland during the study period; 61% had isolated spina bifida. Pooling all study years, 7.2% (95% CI: 4.2-12.4%) of all live-born cases experienced early neonatal death. There was a significant increase in early neonatal mortality among spina bifida births over the study period (p < 0.0001). Low gestational age (<37 weeks; uOR = 6.96; 95% CI: 1.86-29.01), cases occurring as a part of a syndrome (uOR = 125.67; 95% CI: 14.90 to >999.999), and advanced maternal age at gestation (≥35 years; uOR = 5.33; 95% CI: 1.21-21.87) were positively associated with early neonatal mortality.

CONCLUSION

 Using national data from Finland, we found high early neonatal mortality with increasing trend over birth period spanning 15 years (2000-2014), and unadjusted positive associations with some infant and maternal factors. Future studies should pool data from Nordic countries to increase study size allowing multivariable analysis.

KEY POINTS

· Early neonatal mortality in babies affected by spina bifida is 7% in Finland.. · Early neonatal mortality trend showed a significant increase from 2000 to 2014.. · Low gestational age, syndrome case status, and advanced maternal age increased early neonatal mortality risk in spina bifida..

Dietary supplementation with rumen-protected capsicum during the transition period improves the metabolic status of dairy cows

In ruminants, it has been observed that capsicum oleoresin can alter insulin responses and that high-intensity artificial sweetener can increase glucose absorption from the small intestine. Because glucose metabolism and insulin responses are critical during early lactation, these supplements might have an effect on the metabolic status of dairy cows during the transition period. The objective of this experiment was to evaluate the effects of rumen-protected capsicum oleoresin fed alone or in combination with artificial sweetener during the transition period on lactational performance and susceptibility to subclinical ketosis in dairy cows. Fifteen primiparous and 30 multiparous Holstein cows (a total of 39 cows finished the study) were arranged in a randomized complete block design during d -21 to 60 relative to parturition. Cows within block were randomly assigned to one of the following treatments: no supplement (CON), supplementation with 100 mg of rumen-protected capsicum/cow per day (RPCap), or RPCap plus 2 g of high-intensity artificial sweetener/cow per day (RPCapS). For both the RPCap and RPCapS treatments, only rumen-protected capsicum was fed during the dry period. From d 8 to 11 of lactation, intake was limited to 70% of predicted dry matter intake to induce subclinical ketosis. Production variables were recorded daily, samples for milk composition were collected on wk 2, 4, 6, and 8, and blood samples were collected on wk -2, 1, 2, and 4 of the experiment for analysis of metabolic hormones and blood cell counts. Supplementation with rumen-protected capsicum increased serum insulin and decreased β-hydroxybutyrate concentrations precalving, indicating a decrease in lipolysis. During the lactation period, RPCap was associated with a trend for increased milk production and feed efficiency following the ketosis challenge. Supplementation with RPCapS appeared to negate the response to rumen-protected capsicum. All cows developed subclinical ketosis during the challenge, and this was not affected by treatment. We conclude that treatments did not decrease susceptibility to subclinical ketosis; however, dietary supplementation with rumen-protected capsicum was effective at improving energy status precalving and tended to increased milk production and feed efficiency. The mechanism underlying these responses is unclear.

Association between maternal country of birth and preterm birth: A population-based register study of 910,752 deliveries

Aims: The aim of this study was to analyse associations between maternal country of birth and preterm birth among women giving birth in Norway. Methods: A population-based register study was conducted employing official national databases in Norway. All singleton births, with neonates without major anomalies, between 1999 and 2014 were included (N=910,752). We estimated odds ratios (ORs) for extremely preterm birth (<28 weeks gestation), very preterm birth (28–33 weeks gestation) and late preterm birth (34–36 weeks gestation) by maternal country of birth. We conducted multivariable regression analyses, adjusting for maternal, obstetric and socio-economic confounders. Results: For extremely preterm births (0.4% of the study population), women with an unknown country of birth (adjusted OR (aOR)=3.09; 95% confidence interval (CI) 2.26–4.22) and women born in sub-Saharan Africa (aOR=1.66; CI 1.40–1.96) had the highest ORs compared to Norwegian-born women. For very preterm births (1.2% of the study population), women with an unknown country of birth (aOR=1.72; CI 1.36–2.18) and women born in South Asia (aOR=1.48; CI 1.31–1.66) had the highest ORs. For late preterm births (3.8% of the study population), women born in East Asia Pacific/Oceania (aOR=1.33; CI 1.25–1.41) and South Asia (aOR=1.30; CI 1.21–1.39) had the highest ORs. Conclusions: After adjusting for maternal, obstetric and socio-economic risk factors, maternal country of birth remained significantly associated with preterm birth. Women with an unknown country of birth and women born in sub-Saharan Africa were found to be at increased risk of extremely preterm birth.

Busy day effect on intrapartum adverse maternal outcomes - a population-based study of 601 247 singleton deliveries

BACKGROUND

This was a retrospective population-based study, utilizing the data of 601 247 singleton hospital deliveries collected from the Finnish Medical Birth Register (MBR) in 2006-2016. The aim of this study was to analyse the busy day effect on intrapartum adverse maternal outcomes.

METHODS

To implement the study design, daily delivery frequencies and ranges (min-max) for each delivery unit (n = 26) were stratified to the daily delivery volume distributions by the delivery unit's annual delivery volume and profile: Category (C)1 < 1000, C2 1000-1999, C3 2000-2999, C4 ≥ 3000 and C5 the profile of university hospitals. To study the busy day effect, the quiet, optimal and busy days were defined by calculating the number of days (%) with the lowest and highest daily delivery frequencies and summed to the nearest 10 % in each hospital category. Optimal days were determined by calculating approximately 80 % of deliveries occurring between the lowest 10 %, and highest 10 % in each hospital category. Crude and adjusted odd ratios (ORs) with 99 % confidence intervals (CIs) were used to analyze the busy day effect on adverse maternal outcomes, blood transfusions, manual removal of the placenta and obstetric anal sphincter injuries, separately in each hospital category.

RESULTS

The busy day effect was associated with the 28 % (99 % CI 8-52 %) and 25 % (99 % CI 11-40 %) increased need for blood transfusions in C2 and university hospitals (C5), respectively, whereas 22 % (99 % CI 10-31 %) less blood transfusions were needed at university hospitals during quiet days. In C3 hospitals, 83 % (99 % CI 65-92 %) less blood transfusions were needed during busy days. Obstetric and anal sphincter injury rates declined during quiet days by 22 % (99 % CI 3-38 %) only in university hospitals.

CONCLUSIONS

The findings of this study identify no specific pattern to the busy day effect for adverse maternal outcomes defined as manual removal of the placenta or obstetric and anal sphincter injuries. However, both quiet and busy days seem to be associated with increased or decreased need for blood transfusions in different sized delivery units. Findings also suggest that quiet days are associated with a decreased number of obstetric and anal sphincter injuries.

Associations between maternal age and socioeconomic status with smoking during the second and third trimesters of pregnancy: a register-based study of 932 671 women in Finland from 2000 to 2015

OBJECTIVES

This study aimed to explore the association between maternal age and smoking during the second and third trimesters of pregnancy across socioeconomic groups and to evaluate the interacting effect of maternal age and socioeconomic status on smoking with a view to informing public health interventions.

DESIGN

This is a register-based study.

SETTINGS

Data from the Finnish Medical Birth Register were cross-linked with background data from Statistics Finland.

PARTICIPANTS

The information of 932 671 pregnant women who gave birth in Finland from 2000 to 2015.

MAIN OUTCOME MEASURES

Maternal smoking during the second and third trimesters of pregnancy by occupation and maternal age.

RESULTS

The proportion of women who smoked during the second and third trimesters of pregnancy was 10.5%. Using women 30-34 years as the reference group, adjusted ORs (aOR) and 95% CIs for smoking were 6.02 (5.81 to 6.24) in women below 20 years and 2.77 (2.71 to 2.84) in women 20 to 24 years. The prevalence of smoking across socioeconomic groups compared with upper-level employees increased, peaking for women in manual occupations (aOR 3.39, 95% CI 3.25 to 3.52) and unemployed women (aOR 4.49, 95% CI 4.30 to 4.68). Significant interactions on the additive scale with the relative excess risk due to interaction >2 were found for unemployed women aged 25-29 years and for teenage mothers and mothers aged 20-24 years across all socioeconomic groups, but not for self-employed women.

CONCLUSIONS

Smoking during the second and third trimesters of pregnancy was most common among teenage mothers across all socioeconomic groups. The association between maternal age and smoking differed by socioeconomic status for young mothers. Interventions should address a wider range of maternal risk factors among young mothers with low socioeconomic status and simultaneously target a broader number of women who smoke during the pregnancy.

Adverse perinatal outcomes in 665,244 term and post-term deliveries-a Norwegian population-based study

OBJECTIVE

To assess the prevalence and risk of adverse perinatal outcomes in early-term (37⁺⁰-38⁺⁶ weeks), full-term (39⁺⁰-40⁺⁶ weeks), late-term (41⁺⁰-41⁺⁶ weeks), and post-term (>42⁺⁰ weeks) deliveries with spontaneous labor onset.

STUDY DESIGN

A population-based cohort with data from the Medical Birth Registry Norway (MBRN) and Statistics Norway (SSB) was conducted. The study population consisted of 665,244 women with cephalic singleton live births at term or post-term with spontaneous labor onset during the period of 1999-2014 in Norway. Maternal, obstetric, and fetal characteristics were obtained from the MBRN. Maternal education data were obtained from the SSB. The prevalence rates of adverse perinatal outcomes for each gestational age (GA) group were estimated. Inter-group differences were detected with Chi square tests. Multivariable regression analysis adjusted for maternal age, educational level, smoking, parity, maternal diabetes, and preeclampsia was used to assess adverse outcome prevalence for early- late-, and post-term births compared to full-term births.

RESULTS

Deliveries at early-term were associated with an increased prevalence of neonatal jaundice, polyhydramnios, small for gestational age (SGA) status, respiratory support, and neonatal intensive care unit (NICU) admission compared with deliveries at GAs of 39-43 weeks (p < 0.001). Low 5-min Apgar scores and newborn antibiotic treatment occurred at an increased prevalence in both early-term and post-term infants, relative to the full-term group (p < 0.001). The prevalence of oligohydramnios, meconium-stained amniotic fluid, and newborn birth injuries increased with increasing GA.

CONCLUSIONS

More perinatal morbidity was observed among early-term infants compared to infants with later term deliveries, underscoring the need for cautious management of low-risk early-term deliveries.

Association between maternal pregestational diabetes mellitus and spina bifida: A population-based case-control study, Finland, 2000-2014

BACKGROUND

Maternal pregestational diabetes mellitus (PGDM) is a known risk factor for neural tube defects. We examined the association between maternal PGDM and spina bifida in the offspring using PGDM status from medical records in Finland.

METHODS

We conducted a nationally representative, multiregistry, population-based case-control study in Finland. Cases were included if they were live or stillborn infants and diagnosed with spina bifida and delivered between years 2000 and 2014 in Finland. Controls were Finnish infants without spina bifida or other major structural birth defects and delivered during the same time period as cases. Clinical and demographic data were obtained by linking multiple national health registers and census. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CI) for PGDM were estimated using logistic regression analysis. Interaction by maternal obesity was examined.

RESULTS

Our study included 181 spina bifida cases (61% isolated) and 876,672 controls. Overall, 2.2% percent of all case, and 0.5% of control mothers, had PGDM during pregnancy. Maternal PGDM was significantly associated with an increased odds of spina bifida (adjusted OR 4.35; 95% CI 1.37, 13.82). A similar association was found in our subanalysis on isolated spina bifida cases (adjusted OR 4.41; 95% CI 1.07, 18.24). There was no significant interaction by maternal obesity.

CONCLUSIONS

Maternal PGDM was positively associated with spina bifida in Finland, and maternal obesity did not modify this effect. We lacked information on maternal PGDM for electively terminated and spontaneously aborted cases; results should be interpreted with caution.

Production effects of feeding extruded soybean meal to early-lactation dairy cows

The objective of this experiment was to evaluate productive and reproductive effects of replacing solvent-extracted soybean meal (SSBM) with extruded soybean meal (ESBM) in a total mixed ration for early-lactation dairy cows. Thirty-four Holstein cows (12 primiparous and 22 multiparous) were used in a randomized complete block design experiment with 17 cows per treatment. Feeding was ad libitum for 5 to 10% refusals. A fresh-cow diet was fed the first 21 d in milk followed by a lactation diet from 22 to 60 d in milk. Milk and dry matter intake data were collected throughout the experiment, and samples were collected for blood chemistry and amino acid profile, nutrient digestibility, nitrogen utilization, and enteric methane emission using the GreenFeed system (C-Lock Inc., Rapid City, SD). Dry matter intake, milk yield, and feed efficiency were not different between SSBM and ESBM. Energy-corrected milk yield and efficiency were also not different between diets. Diet had no effect on milk composition, except that milk true protein yield was decreased by ESBM. Enteric methane emission, yield, and intensity were not different between SSBM and ESBM. Because of its greater fat content, ESBM triggered expected changes in milk fatty acid (FA) profile: decreased sum of C16, saturated, and odd- and branched-chain FA and increased sum of preformed FA, polyunsaturated, and trans FA. The ESBM diet increased or tended to increase some essential amino acids in plasma. In this study, ESBM did not affect dry matter intake and did not improve lactational performance or onset of ovarian function in early-lactation dairy cows, and it decreased milk protein yield, possibly due to greater unsaturated FA intake compared with SSBM.

Impact of Young Age on the Presentation of Saccular Intracranial Aneurysms: Population-Based Analysis of 4082 Patients

BACKGROUND

Formation and rupture of saccular intracranial aneurysms (sIAs) may have different pathobiologies in patients with younger age at first diagnosis of sIA disease.

OBJECTIVE

To study the phenotype of sIA disease and formation of new (de novo) sIAs in patients below 40 yr.

METHODS

A population-based cohort study was conducted in 613 young (<40 yr) sIA patients with first diagnosis between 1980 and 2014 and total angiographic follow-up of 3768 yr.

RESULTS

Of the 613 sIA patients <40 yr, 508 had aneurysmal subarachnoid hemorrhage (sIA-SAH) and 105 unruptured sIA(s) at first sIA diagnosis. Hypertension was 2 times less common among <40 than >40-yr-old patients (unruptured and ruptured). Smoking was very prevalent in <40-yr-old patients (33% in SAH, 68% unruptured). SAH patients <40 yr more often had family history of sIA, and lower PHASES scores (age omitted, P < .001). Ruptured sIAs were small (<7 mm) in 33% of 39 to 30 yr patients, in 44% of 29 to 20 yr patients, and 57% of <19 yr patients. Their shape was irregular in 90%, 94%, and 95%, respectively. Smoking history (hazard ratio [HR] 2.8, 95% confidence interval [CI] 1.2-7.0), family history for sIAs (HR 3.1, 95% CI 1.3-7.7), and age at presentation (HR .91 per year, 95% CI .85-.98) were risk factors for de novo sIA formation, diagnosed in 4% even after 20 yr (median 11.8 yr).

CONCLUSION

Smoking and family history are risk factors for sIA formation and aneurysmal SAH at young age. Young aneurysmal SAH patients had lower PHASES scores and often rupture from a small sIA, suggesting need for more aggressive management.

Prevalence and risk of pre-eclampsia and gestational hypertension in twin pregnancies: a population-based register study

OBJECTIVES

The aim of this study was to assess the prevalence and risk of pre-eclampsia and gestational hypertension in twin pregnancies compared with singleton pregnancies.

DESIGN

Population-based cohort study.

SETTING

Medical Birth Registry of Norway and Statistics Norway.

PARTICIPANTS

929 963 deliveries with 16 174 twin pregnancies in 1999-2014.

METHODS

Pre-eclampsia prevalences in twin and singleton pregnancies were described in percentages. Multivariable regression analyses were performed to assess the risks of pre-eclampsia and gestational hypertension in twin pregnancies compared with those in singleton pregnancies, adjusted for previously known risk factors.

PRIMARY AND SECONDARY OUTCOME MEASURES

Prevalence and risk of pre-eclampsia and gestational hypertension.

RESULTS

The prevalence of pre-eclampsia in the study population was 3.7% (3.4% in singleton pregnancies, 11.8% in twin pregnancies (p=0.001)). The OR for pre-eclampsia in twin pregnancies was three to fourfold compared with singleton pregnancies (OR 3.78; 95% CI 3.59 to 3.96). After adjustment for known risk factors, twin pregnancy remained an independent risk factor for pre-eclampsia (adjusted OR 4.07; 95% CI 3.65 to 4.54). The prevalence of gestational hypertension was 1.7% in women with singleton pregnancies and 2.2% in those with twin pregnancies (OR 1.27; 95% CI 1.14 to 1.41). After adjustment for known risk factors, gestational hypertension was not significantly associated with twin pregnancy.

CONCLUSIONS

The risk of pre-eclampsia in twin pregnancies was three to fourfold compared with singleton pregnancies, regardless of maternal age, parity, educational level, smoking, maternal comorbidity or in vitro fertilisation. The risk of gestational hypertension was not increased in women with twin pregnancies after adjustment for the main risk factors.

Country of birth and county of residence and association with overweight and obesity—a population-based study of 219 555 pregnancies in Norway

Background

The aim was to study the effect of country of birth, educational level and county of residence on overweight and obesity among pregnant women in Norway.

Methods

Observational study based on Medical Birth Registry Norway and Statistics Norway. The study population consisted of 219 555 deliveries in 2006–2014. Body mass index (BMI) was registered at the first antenatal care visit. Multivariate regression analysis was used to explore the study aims.

Results

Overweight (BMI 25–29.9) was recorded in 22.3% of the women, obesity (BMI ≥30) in 12.2%. Highest rates of overweight (30.8%) and obesity (13.5%) was recorded among women from the Middle East and North Africa or with no education (30.7% and 17.2%). The prevalence of overweight and obesity was 39.5% in sparsely populated counties and 26.4% for women living in Oslo. Adjusted for country of birth, education level, age, parity, smoking and marital status, the relative odds of overweight and obesity were 65% (95% CI 59–72%) higher in sparsely populated counties compared to Oslo.

Conclusions

The prevalence of overweight (BMI ≥25) was 34.5%. The factors associated with overweight were living in rural districts in Norway, lower education and being born in countries in the Middle East or Africa.

Fertility rates and the postponement of first births: a descriptive study with Finnish population data

OBJECTIVES

We described the trend of fertility rates, age-specific fertility rates and associated factors in Finland over a 30-year period.

DESIGN

A descriptive population-based register study.

SETTING

Fertility data, including age at first birth, childlessness and educational levels were gathered from the Finnish Medical Birth Register and Statistics Finland.

PARTICIPANTS

All 1 792 792 live births from 1987 to 2016 in Finland.

MAIN OUTCOME MEASURES

Completed fertility rate, total fertility rate and age-specific fertility rate.

RESULTS

The total fertility rate of Finnish women fluctuated substantially from 1987 to 2016. Since 2010, the total fertility rate has gradually declined and reached the lowest during the study period in 2016: 1.57 children per woman. The mean maternal age at first birth rose by 2.5 years from 26.5 years in 1987 to 29 years in 2016. The proportion of childless women at the age of 50 years increased from 13.6% in 1989 to 19.6% in 2016. By considering the impact of postponement and childlessness, the effect on total fertility rates was between -0.01 and -0.12 points. Since 1987, the distribution of birth has declined for women under the age of 29 and increased for women aged 30 or more. However, start of childbearing after the age of 30 years was related to the completed fertility rate of less than two children per woman. The difference in completed fertility rate across educational groups was small.

CONCLUSIONS

Postponement of first births was followed by decline in completed fertility rate. Increasing rate of childlessness, besides the mean age at first birth, was an important determinant for declined fertility rates, but the relation between women's educational levels and the completed fertility rate was relatively weak.

Acceptance of flavored concentrate premixes by young ruminants following a short-term exposure

Three cafeteria feeding design experiments were conducted to test whether young ruminants have flavor preferences. Experiment 1 was with 11 Dorset × Suffolk weaned lambs of both sexes, aged 5 mo and averaging 47.5 (standard deviation = 5.8) kg of body weight. The lambs were offered a choice of 5 flavored concentrate premixes (FCP) and an unflavored control for 5 min 4 times over 10 d. The FCP were prepared by mixing 200 to 300 g/t (as-is basis) of synthetic flavors (vanilla, milky, spicy/fenugreek, red summer fruits, and molasses) into a basal diet. The unflavored control and the milky flavor were consumed in greater amounts than all other flavors at 83.9 and 65.8 g/test, respectively. The consumption rate of FCP (g/min) was similar among treatments. Lambs spent more time consuming the milky flavor and the control at 123 and 144 s/test, respectively, compared with all other FCP (average of 65 s/test). In experiment 2, 12 weaned female Holstein Friesian calves (56-68 d of age) averaging 75.8 kg (standard deviation = 8.45) of body weight were offered a choice of 4 FCP (vanilla, milky, spicy/fenugreek, and red summer fruits) at an inclusion rate of 150 to 200 g/t (as-is basis) and the unflavored control for 5 min 4 times over 10 d. The average consumption rate was 27.8 g/min, and there were no differences among FCP. In experiment 3, a choice of 4 FCP with 2 different flavor combinations (vanilla-fenugreek and milky-vanilla) included at 75 g/t (as-is basis; low) or 150 g/t (high) was offered to a total of 12 weaned female Holstein Friesian calves (47-62 d of age) with an average body weight of 65.3 kg (standard deviation = 7.91). The FCP were offered daily for 14 d for 30 to 60 min/d. Vanilla-fenugreek (low) was consumed less at 57.5 g/test per calf compared with the other FCP (average of 87.5 g/test per calf). There were no other differences among FCP in experiment 3. Overall, compared with the control, flavors used in the present experiments did not affect feed intake of weaned lambs and calves. Other factors, such as taste, sight, texture of the feed, effect of the dams as previous experience (via maternal ingestion, which influences neonatal feeding), and their interactions, may also play a role in flavor preferences of young ruminants.

Fetal head size and effect of manual perineal protection

OBJECTIVE

The aim of this study was to evaluate whether a previously identified modification of Viennese method of perineal protection remains most effective for reduction of perineal tension in cases with substantially smaller or larger fetal heads.

METHODS

A previously designed finite element model was used to compare perineal tension of different modifications of the Viennese method of perineal protection to "hands-off" technique for three different sizes of the fetal head. Quantity and extent of tension throughout the perineal body during vaginal delivery at the time when the suboccipito-bregmatic circumference passes between the fourchette and the lower margin of the pubis was determined.

RESULTS

The order of effectiveness of different modifications of manual perineal protection was similar for all three sizes of fetal head. The reduction of perineal tension was most significant in delivery simulations with larger heads. The final position of fingers 2cm anteriorly from the fourchette (y = +2) consistently remains most effective in reducing the tension. The extent of finger movement along the anterior-posterior (y-axis) contributes to the effectiveness of manual perineal protection.

CONCLUSION

Appropriately performed Viennese manual perineal protection seems to reduce the perineal tension regardless of the fetal head size, and thus the method seems to be applicable to reduce risk of perineal trauma for all parturients.

A population-based study of the effect of pregnancy history on risk of stillbirth

OBJECTIVE

To examine the effect of pregnancy history on the risk of stillbirth.

METHODS

In a population-based cross-sectional study, data were reviewed from all women aged at least 20 years with singleton pregnancies in Finland between 2000 and 2010. The primary outcome-stillbirth-was defined as fetal death after 22 gestational weeks or death of a fetus weighing at least 500 g.

RESULTS

Among 604 047 singleton pregnancies, the prevalence of stillbirth was 3.17 per 1000 deliveries. Prevalence was lowest for multiparous women without previous pregnancy loss after adjusting for major pregnancy complications associated with stillbirth (placenta previa, placental abruption, and pre-eclampsia) and other confounders. Relative to these women, stillbirth prevalence was higher among multiparous women with previous spontaneous abortion and/or stillbirth (adjusted odds ratio [aOR] 1.20, 95% confidence interval [CI] 1.05-1.36), nulliparous women with no previous pregnancy loss (aOR 1.23, 95% CI 1.10-1.38), and nulliparous women with prior spontaneous abortion (aOR 1.43, 95% CI 1.18-1.74).

CONCLUSION

Previous pregnancy loss was found to be an independent risk factor for stillbirth, irrespective of the number of prior deliveries.

Etiology, syndrome diagnosis, and cognition in childhood-onset epilepsy: A population-based study

Objective

To evaluate the prevalence of various etiologies of epilepsies and epilepsy syndromes and to estimate cognitive function in cases of childhood‐onset epilepsy.

Methods

A population‐based retrospective registry study. We identified all medically treated children with epilepsy born in 1989–2007 in Finland's Kuopio University Hospital catchment area, combining data from the birth registry and the national registry of special‐reimbursement medicines. We reevaluated the epilepsy diagnoses and syndromes and gathered data on etiologies and cognitive impairment.

Results

We identified 289 children with epilepsy. The annual incidence rate of epilepsies and epilepsy syndromes was 38 in 100,000, and the misdiagnosis rate was 3%. A specific etiology was identified in 65% of the cases, with a structural etiology accounting for 29% and a genetic or presumed genetic etiology for 32%. Most patients with unknown‐etiology epilepsy had focal epilepsy and were of normal intelligence. Intellectual disability was detected in 35% of cases, and only 17% in this group had an unknown etiology for the epilepsy. Electroclinical syndromes (mainly West syndrome) were recognized in 35% of the patients.

Significance

Epilepsy is a complex disease that encompasses many etiologies and rare syndromes. The etiology and specific epilepsy syndrome are important determinants of the outcome and key factors in treatment selection. Etiological diagnosis can be achieved for the majority of children and syndromic diagnosis for only a third.

De Novo Aneurysm Formation in Carriers of Saccular Intracranial Aneurysm Disease in Eastern Finland

BACKGROUND AND PURPOSE

Formation of new (de novo) aneurysms in patients carrying saccular intracranial aneurysm (sIA) disease has been published, but data from population-based cohorts are scarce.

METHODS

Kuopio sIA database (http://www.uef.fi/ns) contains all unruptured and ruptured sIA patients admitted to Kuopio University Hospital from its Eastern Finnish catchment population. We studied the incidence and risk factors for de novo sIA formation in 1419 sIA patients with ≥5 years of angiographic follow-up, a total follow-up of 18 526 patient-years.

RESULTS

There were 42 patients with a total of 56 de novo sIAs, diagnosed in a median of 11.7 years after the first sIA diagnosis. The cumulative incidence of de novo sIAs was 0.23% per patient-year and that of subarachnoid hemorrhage from a ruptured de novo sIA 0.05% per patient-year. The risk of de novo sIA discovery per patient-year increased with younger age at the first sIA diagnosis: 2.2% in the patients aged <20 years and 0.46% in the patients aged between 20 and 39 years. In Cox regression analysis, smoking history and younger age at the first sIA diagnosis significantly associated with de novo sIA formation, but female sex, multiple sIAs, and sIA family did not.

CONCLUSIONS

Patients aged < 40 years at the first sIA diagnosis are in a significant risk of developing de novo sIAs, and they should be scheduled for long-term angiographic follow-up. Smoking increases the risk of de novo sIA formation, suggesting long-term follow-up for smokers. Antismoking efforts are highly recommended for sIA patients.

Maternal socioeconomic status and the risk of asthma among offspring

BACKGROUND

To evaluate the association between maternal socioeconomic status (SES) during pregnancy and asthma among offspring.

METHODS

A retrospective observational hospital-based birth cohort study in a university-based Obstetrics and Gynecology department in Finland. A total of 40 118 women with singleton live births between 1989 and 2007 were linked with data from the register for asthma medication for their offspring (n = 2518). Pregnancy and maternal SES factors were recorded during pregnancy and labor. SES was categorized thus: upper white-collar workers (highest SES), lower white-collar workers, blue-collar workers, others (lowest SES) and cases with missing information. Logistic regression analysis was used to determine the association between maternal SES and childhood asthma.

RESULTS

We found no convincing evidence of a direct association between maternal SES and childhood asthma. Parental smoking was the clearest factor affecting asthma among children of lower white-collar workers. Differences in pregnancy and delivery characteristics were observed between the SES groups.

CONCLUSIONS

Maternal socioeconomic status had no significant direct impact on the prevalence of asthma in this Finnish birth cohort. Finnish public health services appeared to offer equal quality services independently of SES.

TRIAL REGISTRATION

The study is registered in Kuopio University Hospital register (TUTKI): ID 5302448 .

Risk factors for and perinatal outcomes of major depression during pregnancy: a population-based analysis during 2002-2010 in Finland

OBJECTIVES

To identify risk factors for and the consequences (several adverse perinatal outcomes) of physician-diagnosed major depression during pregnancy treated in specialised healthcare.

DESIGN

A population-based cross-sectional study.

SETTING

Data were gathered from Finnish health registers for 1996-2010.

PARTICIPANTS

All singleton births (n=511,938) for 2002-2010 in Finland.

PRIMARY OUTCOME MEASURES

Prevalence, risk factors and consequences of major depression during pregnancy.

RESULTS

Among 511,938 women, 0.8% experienced major depression during pregnancy, of which 46.9% had a history of depression prior to pregnancy. After history of depression, the second strongest associated factor for major depression was fear of childbirth, with a 2.6-fold (adjusted OR (aOR=2.63, 95% CI 2.39 to 2.89) increased prevalence. The risk profile of major depression also included adolescent or advanced maternal age, low or unspecified socioeconomic status (SES), single marital status, smoking, prior pregnancy terminations, anaemia and gestational diabetes regardless of a history of depression. Outcomes of pregnancies were worse among women with major depression than without. The contribution of smoking was substantial to modest for small-for-gestational age newborn (<-2 SD below mean birth), low birth weight (<2500 g), preterm birth (<37 weeks) and admission to neonatal intensive care associated with major depression, whereas SES made only a minor contribution.

CONCLUSIONS

Physician-diagnosed major depression during pregnancy was found to be rare. The strongest risk factor was history of depression prior to pregnancy. Other associated factors were fear of childbirth, low SES, lack of social support and unhealthy reproductive behaviour such as smoking. Outcomes of pregnancies were worse among women with major depression than without. Smoking during pregnancy made a substantial to modest contribution to adverse outcomes associated with depression during pregnancy.

Unemployment at municipality level is associated with an increased risk of small for gestational age births--a multilevel analysis of all singleton births during 2005-2010 in Finland

Introduction

Neighbourhood level deprivation has been shown to influence adverse perinatal outcomes independent of individual level socioeconomic status (SES) in countries with high income inequality, such as the United States. The present study evaluates whether municipality level deprivation defined based on education (proportion of inhabitants with university level education), income (mean income per capita) and unemployment were associated with the prevalence of preterm birth (<37 weeks) and small for gestational age (SGA, birth weight <2 standard deviations) after adjustment for individual level socio-demographics (age, parity, prior preterm births, smoking during pregnancy and SES defined based on maternal occupation at birth) in Finland.

Methods

The study design was cross-sectional. The data gathered from the Medical Birth Register included all singleton births (n = 345,952) in 2005–2010. We fitted Generalized Estimating Equations (GEE) models to account for correlation of preterm birth and SGA clustering within municipality.

Results

Of all the women with singleton pregnancies, 4.5% (n = 15,615) gave birth preterm and 3.8% (n = 13,111) of their newborns were classified as SGA. Individual level SES and smoking were important risk factors for each outcome in adjusted models. Controlling for individual level factors, women living in intermediate and high unemployment class municipalities were 6.0% (adjusted odds ratio (aOR) = 1.06; 95% confidence interval (CI) 1.01-1.12) and 13.0% (aOR = 1.13; 95% CI 1.06-1.20), respectively, more likely to give birth to an SGA newborn than women living in low unemployment class municipalities.

Conclusions

After adjustment for individual level socio-demographics, the prevalence of SGA was around 6-13% higher in municipalities with an intermediate or high unemployment rate than municipalities with the lowest unemployment rate. The results suggested that the unemployment rate has an important public health effect with clinical implications since SGA is associated with a higher risk of adverse long-term health outcomes.

Smoking during pregnancy was up to 70% more common in the most deprived municipalities - a multilevel analysis of all singleton births during 2005-2010 in Finland

OBJECTIVE

We investigated whether there was an association between maternal smoking habits during pregnancy and municipality level deprivation defined based on education, income and unemployment after adjustment for individual level covariates, including socioeconomic status (SES), in Finland, a Nordic welfare state.

METHODS

Data were gathered from the Medical Birth Register and comprised all singleton births (n=337,876) during 2005-2010. To account for any correlation of women clustered within a municipality, we fitted generalized estimating equation (GEE) models.

RESULTS

In total, 15.3% of the women with singleton pregnancies smoked during pregnancy. After adjustment for individual level confounders, smoking during pregnancy was 5.4-fold higher among women with the lowest as compared with highest individual SES. Controlling for individual SES, age and year of birth, women living in municipalities defined as intermediately and highly deprived based on education were 53.7% (adjusted odds ratio [aOR] 1.537, 95% confidence interval [CI] 1.493-1.583) and 71.5% (aOR 1.715, 95% CI 1.647-1.785), respectively, more likely to smoke during pregnancy than women in the least deprived municipalities.

CONCLUSIONS

Individual SES is the strongest correlate of smoking during pregnancy but conditional on individual variables; lower municipality aggregate education is associated with up to 70% higher smoking prevalence.

Adverse perinatal outcomes associated with moderate or severe maternal anaemia based on parity in Finland during 2006-10

BACKGROUND

Anaemia during pregnancy is an important public health problem. We investigated whether the association between maternal anaemia during pregnancy and adverse perinatal outcomes differed between nulliparous and multiparous women.

METHODS

A retrospective population-based cohort study was conducted using data on all singleton births (n = 290 662) recorded in the Finnish Medical Birth Register during 2006-10. Maternal anaemia was defined as a maternal haemoglobin level of <100 g/L). Adverse perinatal outcomes that were examined included preterm delivery (<37 weeks), small-for-gestational age (SGA, <2 standard deviation), admission to neonatal intensive care, stillbirth, early neonatal death, and major congenital anomalies. An association between anaemia and adverse outcomes was assessed by logistic regression analysis.

RESULTS

The prevalence of anaemia during pregnancy was 2.5% among nulliparous women and 2.3% among multiparous women. Among nulliparous women, anaemia was not associated with adverse perinatal outcomes. Among multiparous women, anaemia was associated with preterm delivery (adjusted odds ratio [aOR] 1.32, [95% CI 1.14, 1.53]), SGA (aOR 1.27, [95% CI 1.04, 1.55]), and admission to neonatal intensive care (aOR 1.23, [95% CI 1.10, 1.38]); there was a trend towards increased odds of major congenital anomalies (aOR 1.15, [95% CI 0.99, 1.34]).

CONCLUSIONS

These data underscore that maternal anaemia is associated with several adverse perinatal outcomes. This association was, however, confined to multiparous women. Future research should explore in detail the timing of anaemia in these associations.

Placenta previa and the risk of delivering a small-for-gestational-age newborn

OBJECTIVE

To evaluate whether there is an association between placenta previa and delivery of a small-for-gestational-age (SGA) newborn and to quantify the contribution of individual risk factors for SGA that are associated with placenta previa stratified by maternal parity.

METHODS

A cross-sectional study using the Finnish Medical Birth Register during 2000-2010. All singleton births (N=596,562) were included; major congenital anomalies were excluded. An association between SGA (less than 2 standard deviations below the mean) and placenta previa was modeled by parity-specific unadjusted and adjusted statistical models.

RESULTS

Placenta previa complicated 625 of 249,476 singleton births among nulliparous women (2.50/1,000) and 915 of 347,086 singleton births among multiparous women (2.64/1,000). Among nulliparous women, the most common risk factor for placenta previa was in vitro fertilization; placenta previa was not associated with an increased prevalence of SGA controlling for maternal age, smoking, in vitro fertilization, socioeconomic status, and preeclampsia (adjusted odds ratio [OR] 0.81, 95% confidence interval [CI] 0.57-1.17). Among multiparous women, placenta previa was associated with a twofold increased risk of SGA controlling for maternal age, parity, prior preterm birth, prior caesarean delivery, prior SGA newborn, prior preeclampsia, smoking, in vitro fertilization, socioeconomic status, and preeclampsia (adjusted OR 2.08, 95% CI 1.50-2.89). Furthermore, only one-fourth of the association between SGA and placenta previa could be explained by controlling for risk factors clustering with placenta previa among multiparous women.

CONCLUSION

Placenta previa is associated with impaired fetal growth in multiparous but not nulliparous women.

LEVEL OF EVIDENCE

II.

Influence of delivery characteristics and socioeconomic status on giving birth by caesarean section - a cross sectional study during 2000-2010 in Finland

Background

Caesarean section (CS) rates especially without medical indication are rising worldwide. Most of indications for CS are relative and CS rates for various indications vary widely. There is an increasing tendency to perform CSs without medical indication on maternal request. Women with higher socioeconomic status (SES) are more likely to give birth by CS. We aimed to study whether giving birth by CS was associated with SES and other characteristics among singleton births during 2000–2010 in Finland with publicly funded health care.

Methods

Data were gathered from the Finnish Medical Birth Register. The likelihood of giving birth by CS according to CS type (planned and non-planned), parity (nulliparous vs. multiparous), socio-demographic factors, delivery characteristics and time periods (2000–2003, 2004–2007 and 2008–2010) was determined by using logistic regression analysis. SES was classified as upper white collar workers (highest SES), lower white collar workers, blue collar workers (lowest SES), others (all unclassifiable cases) and cases with missing information.

Results

In total, 19.8% (51,511 of 259,736) of the nulliparous women and 13.1% (47,271 of 360,727) of the multiparous women gave birth by CS. CS was associated with several delivery characteristics, such as placental abruption, placenta previa, birth weight and fear of childbirth, among both parity groups. After adjustment, the likelihood of giving birth by planned CS was reduced by 40% in nulliparous and 55% in multiparous women from 2000–2003 to 2008–2010, whereas the likelihood of non-planned CSs did not change. Giving birth by planned and non-planned CS was up to 9% higher in nulliparous women and up to 17% higher in multiparous women in the lowest SES groups compared to the highest SES group.

Conclusions

Giving birth by CS varied by clinical indications. Women with the lowest SES were more likely to give birth by CS, indicating that the known social disparity in pregnancy complications increases the need for operative deliveries in these women. Overall, the CS policy in Finland shows favoring a trial of labor over planned CS and reflects no inequity in healthcare services.

Umbilical cord length in singleton gestations: a Finnish population-based retrospective register study

INTRODUCTION

Many complications of pregnancy and delivery are associated with umbilical cord length. It is important to examine the variation in length, in order to identify normal and abnormal conditions. Moreover, the factors influencing cord growth and development are not precisely known.

OBJECTIVE

The main objectives were to provide updated reference charts for umbilical cord length in singleton pregnancies and to evaluate potential factors affecting cord length.

METHODS

Birth register data of 47,284 singleton pregnant women delivering in Kuopio University Hospital, Finland was collected prospectively. Gender-specific centile charts for cord length from 22 to 44 gestational weeks were obtained using generalized additive models for location, scale, and shape (GAMLSS). Gestational, fetal, and maternal factors were studied for their potential influence on cord length with single variable analysis and stepwise multiple linear regression analysis.

RESULTS

Cord length increased according to gestational age, while the growth decelerated post-term. Birth weight, placental weight, pregravid maternal body mass index, parity, and maternal age correlated to cord length. Gestational diabetes and previous miscarriages were associated with longer cords, while female gender and placental abruption were associated with shorter cords.

DISCUSSION AND CONCLUSIONS

Girls had shorter cords throughout gestation although there was substantial variation in length in both genders. Cord length associated significantly with birth weight, placental weight, and gestational age. Significantly shorter cords were found in women with placental abruption. This important finding requires further investigation.

Fear of childbirth in nulliparous and multiparous women: a population-based analysis of all singleton births in Finland in 1997-2010

OBJECTIVE

To identify risk factors for fear of childbirth (FOC) according to parity and socioeconomic status, and to evaluate associations between FOC and adverse perinatal outcomes.

DESIGN

A cohort study.

SETTING

The Finnish Medical Birth Register.

POPULATION

All 788 317 singleton births during 1997-2010 in Finland.

METHODS

Fear of childbirth was defined according to the International Classification of Diseases code O99.80, and its associations with several risk factors and perinatal outcomes were analysed by multivariable logistic regression.

MAIN OUTCOME MEASURES

Prevalence of, risk factors for and outcomes of FOC.

RESULTS

Fear of childbirth was experienced by 2.5% of nulliparous women and 4.5% of multiparous women. The strongest risk factors for FOC in nulliparous women were depression [adjusted odds ratio (aOR), 6.35; 95% confidence interval (CI), 5.25-7.68], advanced maternal age (aOR, 3.78; 95% CI, 3.23-4.42) and high or unspecified socioeconomic status. In multiparous women, the strongest risk factors for FOC were depression (aOR, 5.47; 95% CI, 4.67-6.41), previous caesarean section (CS) (aOR, 3.02; 95% CI, 2.93-3.11) and high or unspecified socioeconomic status. Among both nulliparous and multiparous women, FOC was associated with higher rates of CS (3.3-fold and 4.5-fold higher, respectively) and a lower incidence of low birthweight (<2500 g), small for gestational age babies, preterm birth and low Apgar scores at 1 minute.

CONCLUSIONS

High and unspecified socioeconomic status, advanced maternal age and depression are predisposing factors for FOC regardless of parity. Among multiparous women, a previous CS increases vulnerability to FOC. FOC is associated with increased rates of CS, but does not adversely affect other pregnancy outcomes.

The burden of childhood asthma and late preterm and early term births

OBJECTIVE

To evaluate the association between gestational age at birth and the risk of subsequent development of asthma.

STUDY DESIGN

We conducted a retrospective observational hospital-based birth case-control study in a university-based obstetrics and gynecology department in Finland. A total of 44,173 women delivering between 1989 and 2008 were linked with the social insurance register to identify asthma reimbursements for their offspring (n = 2661). Pregnancy factors were recorded during pregnancy. Infants were categorized as moderately preterm (≤ 32 weeks), late preterm (33-36 weeks), early term (37-38 weeks), term (39-40 weeks), or late term and postterm (≥ 41 weeks). The main outcome measure was asthma among the infants.

RESULTS

Children born moderately preterm (≤ 32 weeks gestation) had a significantly increased risk of asthma (aOR, 3.9; 95% CI, 3.2-4.8). The risk of asthma was also increased in those born late preterm (aOR, 1.7; 95% CI, 1.4-2.0) and early term (aOR, 1.2; 95% CI, 1.1-1.4). In contrast, delivery at 41 weeks or later seemed to decrease the risk of asthma (aOR, 0.9; 95% CI, 0.8-1.0). The burden of asthma associated with preterm birth was associated mainly with early term infants, in whom 108 extra cases of asthma were observed.

CONCLUSION

Even though the individual risk of asthma was inversely correlated with gestational age at birth, the overall burden brought about by delivery before term was associated with late preterm and early term deliveries. Furthermore, delivery after term was protective against asthma.

Fear of childbirth predicts postpartum depression: a population-based analysis of 511 422 singleton births in Finland

OBJECTIVES

To study how reproductive risks and perinatal outcomes are associated with postpartum depression treated in specialised healthcare defined according to the International Classification of Diseases (ICD)-10 codes, separately among women with and without a history of depression.

DESIGN

A retrospective population-based case-control study.

SETTING

Data gathered from three national health registers for the years 2002-2010.

PARTICIPANTS

All singleton births (n=511 422) in Finland.

PRIMARY OUTCOME MEASURES

Prevalence of postpartum depression and the risk factors associated with it.

RESULTS

In total, 0.3% (1438 of 511 422) of women experienced postpartum depression, the prevalence being 0.1% (431 of 511 422) in women without and 5.3% (1007 of 18 888) in women with a history of depression. After adjustment for possible covariates, a history of depression was found to be the strongest risk factor for postpartum depression. Other strong predisposing factors for postpartum depression were fear of childbirth, caesarean birth, nulliparity and major congenital anomaly. Specifically, among the 30% of women with postpartum depression but without a history of depression, postpartum depression was shown to be associated with fear of childbirth (adjusted OR (aOR 2.71, 95% CI 1.98 to 3.71), caesarean birth (aOR 1.38, 95% CI 1.08 to 1.77), preterm birth (aOR 1.65, 95% CI 1.08 to 2.56) and major congenital anomaly (aOR 1.67, 95% CI 1.15 to 2.42), compared with women with no postpartum depression and no history of depression.

CONCLUSIONS

A history of depression was found to be the most important predisposing factor of postpartum depression. Women without previous episodes of depression were at an increased risk of postpartum depression if adverse events occurred during the course of pregnancy, especially if they showed physician-diagnosed fear of childbirth.

Socioeconomic status affects the prevalence, but not the perinatal outcomes, of in vitro fertilization pregnancies

STUDY QUESTION

Does maternal socioeconomic status (SES) confound or modify the association between IVF and perinatal outcome among singleton births?

SUMMARY ANSWER

There were substantial socioeconomic differences in the frequency of IVF pregnancies, but maternal SES was not associated with the outcome of IVF pregnancies.

WHAT IS KNOWN ALREADY

The use of IVF is associated with SES. Additionally, women with lower SES tend to have an increased risk of adverse perinatal outcomes such as preterm birth and small for gestational age birth.

STUDY DESIGN, SIZE, DURATION

We conducted a population-based cohort study using the Finnish Medical Birth Register (2006-2010).

PARTICIPANTS/MATERIALS, SETTING, METHODS

We analyzed the total population of singleton births in Finland (n = 291 004) and then compared the unadjusted and adjusted incidences of adverse perinatal outcomes for singleton births after IVF (n = 5647) and non-IVF pregnancies (n = 285 357) in relation to SES.

MAIN RESULTS AND THE ROLE OF CHANCE

SES did not confound or modify the association between IVF and perinatal outcomes after adjustments for age, parity, smoking, gestational diabetes, maternal diabetes and pre-eclampsia. However, the prevalence of IVF pregnancies increased with SES; on average 1.9% of singleton infants were born after IVF pregnancies, while the corresponding percentages were 3.2 and 1.2% for the highest and lowest SES strata, respectively. IVF was statistically significantly associated with 1.27-, 1.49-, 1.63-, 1.47-, 1.35-, 1.40-, 4.97- and 1.14-fold higher incidences of admission to a neonatal unit, stillbirth, preterm birth, low birthweight, low Apgar scores (<7 at 5 min), Cesarean section, placenta previa and major congenital anomaly, respectively. Irrespective of the SES group, women who became pregnant through IVF were older and more often nulliparous and non-smokers compared with women with non-IVF pregnancies.

LIMITATIONS, REASONS FOR CAUTION

The occupation of 22% of the women was unknown and that of a further 25% did not match any of the criteria for our SES strata. Additionally, infertility is a problem for couples but the definition of SES in this study was based only on the mother's occupation at the time of birth.

WIDER IMPLICATIONS OF THE FINDINGS

The prevalence of IVF-conceived pregnancies was highest among the highest SES group, but SES did not confound the perinatal outcomes of IVF pregnancies after adjusting for background factors. However, the magnitude of risks associated with the IVF technique itself may be more significant than previously thought.

STUDY FUNDING/COMPETING INTEREST(S)

None of the authors received any funding specifically for this study, and we have no competing interests.

Social disparity affects the incidence of placental abruption among multiparous but not nulliparous women: a register-based analysis of 1,162,126 singleton births

OBJECTIVES

To identify risk factors for placental abruption and to evaluate associations between adverse perinatal outcomes and placental abruption stratified by parity among women with singleton births from 1991 to 2010 in Finland.

STUDY DESIGN

A retrospective population-based case-control study of singleton births in Finland from 1991 to 2010 (n=1,162,126 from the Finnish Medical Birth Register). We modelled the group-specific risk factors for placental abruption in unadjusted and adjusted models.

RESULTS

In total 3.5 and 3.7 per 1000 nulliparous and multiparous women, respectively, were affected by placental abruption. The recurrence rate was 8.6 per 1000 births. The adjusted risk for placental abruption increased in pregnancies characterised by advanced maternal age, low birth weight, smoking, major congenital anomaly, preeclampsia and male foetal sex in both parity groups. In vitro fertilisation increased the risk only in nulliparae whereas anaemia, a prior caesarean section and the lowest socioeconomic status increased the risk in multiparae. Births affected by placental abruption were associated with an increased admission for neonatal intensive care, preterm birth, low birth weight (<2500 g), small for gestational age infants, low Apgar scores, and low newborn umbilical vein pH (<7.15). Placental abruption resulted in increased risks of stillbirth and early neonatal death in both parity groups.

CONCLUSIONS

The burden of placental abruption is equal in nulliparae and multiparae, but risk factors vary substantially. Social disparity only affects the incidence of placental abruption among multiparous women, indicating that factors related to lifestyle and health behaviour have different effects on the parity groups.

The burden of OASIS increases along with socioeconomic position--register-based analysis of 980,733 births in Finland

Background

Obstetric anal sphincter injury (OASIS) has been identified as a major preventable risk factor for anal incontinence.

Objective

Aim was to measure national variation in incidence of OASIS by socioeconomic status (SES).

Methods

A retrospective population based case-control study using the data derived from the Finnish Medical Birth Register for the years 1991–2010. A total population of singleton vaginal births was reviewed. We calculated unadjusted incidences of OASIS stratified by SES and vaginal parity, and adjusted risks for OASIS in each social class, after controlling for parity, birthweight, mode of delivery, maternal age and maternal smoking. SES was recorded into five categories based on mother’s occupation at time of birth; upper white-collar workers such as physicians, lower white-collar workers such as nurses, blue-collar workers such as cleaners, others such as students, and cases with missing information.

Results

Seven per thousand (6,404 of 980,733) singleton births were affected by OASIS. In nulliparae the incidence of OASIS was 18% higher (adjusted OR 1.18 95% CI 1.04−1.34) for upper white-collar workers and 12% higher (adjusted OR 1.12 95% CI 1.02−1.24) for lower white-collar workers compared with blue-collar workers. Among women in these higher SES groups, 40% of the excess OASIS risk was explained by age, non-smoking, birthweight and mode of delivery. Despite the large effect of SES on OASIS, inclusion of SES in multivariable models caused only small changes in estimated adjusted effects for other established risk factors.

Conclusions

OASIS at the first vaginal delivery demonstrates a strong positive social gradient. Higher SES is associated with a number of risk factors for OASIS, including higher birthweight and non-smoking, but only 40% of the excess incidence is explained by these known risk factors. Further research should address other underlying causes including differences in lifestyle or environmental factors, and inequalities in healthcare provision.

Changing associations of episiotomy and anal sphincter injury across risk strata: results of a population-based register study in Finland 2004-2011

OBJECTIVES

To evaluate the changing association between lateral episiotomy and obstetric anal sphincter injury (OASIS) for women with low and high baseline risk of OASIS.

DESIGN

A population-based register study.

SETTING

Data gathered from the Finnish Medical Birth Register for the years 2004-2011.

PARTICIPANTS

All women with spontaneous vaginal or vacuum-assisted singleton births in Finland (n=384 638).

MAIN OUTCOME MEASURE

OASIS incidence.

RESULTS

During the study period, the incidence of OASIS increased from 1.3% to 1.7% in women with first vaginal births, including women admitted for first vaginal birth after a prior caesarean section and from 0.1% to 0.3% in women with at least one prior birth, whereas episiotomy rates declined from 56.7% to 45.5% and 10.1- 5.3%, respectively. At the study onset, when episiotomy was used more widely, it was negatively associated with OASIS in women with first vaginal births, but as episiotomy use declined it became positively associated with OASIS. Women with episiotomy were complicated by OASIS with clearly higher risk scores than women without episiotomy suggesting that episiotomy was clearly protective against OASIS. OASIS occurred with lower mean risk scores among women with and without episiotomy over time. However, OASIS incidences increased only among women with episiotomy, whereas it decreased or remained among women without episiotomy.

CONCLUSIONS

The cross-over effect between episiotomy and OASIS could be explained by increasing disparity in baseline OASIS risk between treated and untreated women, since episiotomy use declined most in women at low OASIS risk. Episiotomy rate can be safely reduced in low-risk women but interestingly along with the policy change the practice to cut the episiotomy became less protective among high-risk women.

A prior cesarean section and incidence of obstetric anal sphincter injury

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injury (OASIS) following birth may have serious, long-term effects on affected women, including fecal incontinence, despite primary repair.

METHODS

This was a retrospective population-based register study. Women with OASIS grouped by order of vaginal delivery and prior cesarean section (CS) were compared separately with women without OASIS using logistic regression analysis. The aim was to assess an association between prior CS and incidence of OASIS across groups of women categorized according to singleton first, second, and third vaginal deliveries between 1997 and 2007 in Finland.

RESULTS

The incidence of OASIS was 1.8 % at a first vaginal delivery after a prior CS compared with 1.0 % at a first vaginal delivery without prior CS. After adjustment prior CS was associated with a 1.42-fold risk of OASIS only at the first vaginal delivery, with no further significant risk after one or two previous vaginal deliveries. One centimeter increase in maternal height was associated with a 2 % decrease in OASIS incidence at the first vaginal delivery.

CONCLUSIONS

Prior CS is a significant risk factor for OASIS at the first vaginal delivery. This suggests that relative fetopelvic disproportion leading to CS for a first delivery also predisposes to OASIS at a first vaginal delivery since 40 % of the increased incidence of OASIS risk was explained by birthweight and 4 % by maternal height.

Contribution of socioeconomic status to the risk of small for gestational age infants--a population-based study of 1,390,165 singleton live births in Finland

Background

Small for gestational age (SGA) infants are at increased risk of short- and long-term adverse outcomes.

Methods

Population-based case–control study using data derived from the Finnish Medical Birth Register for the years 1987–2010 (total population of singleton live births n = 1,390,165). The aim was to quantify the importance of risk factors for SGA and describe their contribution to socioeconomic status (SES) disparities in SGA by using logistic regression analysis.

Results

Of all the singleton live births (n = 1,390,165), 3.1% (n = 42,702) were classified as SGA (defined as below 2 standard deviations of the sex-specific population reference mean for gestational age). The risk of SGA was 11 − 24% higher in the lower SES groups compared to the highest SES group. Smoking alone made the largest contribution, explaining 41.7 − 50.9% of SES disparities in SGA. The risk of SGA was 2.3-fold and 7% higher among women who smoked or had quit smoking during the first trimester of pregnancy (adjusted odds ratio (aOR) 2.34, 95% CI 2.28-2.42 and aOR 1.07, 95% CI 1.00 − 1.15, respectively) compared with the non-smokers.

Conclusions

SGA is substantially affected by SES. Smoking explained up to 50% of the difference in risk of SGA between high and low SES groups. Quitting smoking during the first trimester of pregnancy resulted in a 7% higher incidence of SGA comparable to that of non-smoking women. Thus, interventional attempts to reduce smoking during pregnancy might help to decrease the socioeconomic gradient of SGA.

True umbilical cord knot and obstetric outcome

OBJECTIVE

To identify risk factors for true umbilical cord knot and to evaluate its association with fetal death, premature birth, low birth weight, small-for-gestational-age (SGA) infants, low Apgar score at 1 and 5 minutes, fetal venous pH of 7.15 or lower, and need for neonatal intensive care in singleton pregnancies.

METHODS

The total population of women who delivered at Kuopio University Hospital, Kuopio, Finland, between January 2000 and August 2012 was reviewed. Risk factors for umbilical cord knot and its association with adverse pregnancy outcome were evaluated separately among women with and without true cord knot via logistic regression analysis.

RESULTS

Overall, 340 (1.2%) of 27 537 singleton pregnancies were affected by umbilical cord knot, with increased incidence associated with advanced maternal age, multiparity, previous spontaneous abortion, polyhydramnios, and diabetes mellitus. Umbilical cord knot was associated with a 1.58-, 8.08-, 3.90-, 3.17-, 1.67-, and 2.00-fold increased risk of neonatal intensive care, fetal death, premature birth, SGA infants, and low Apgar score at 1 and 5 minutes, respectively.

CONCLUSION

True umbilical cord knot is relatively common and is associated with increased incidence of SGA infants, premature birth, need for neonatal intensive care, and fetal death.