Adverse maternal and perinatal pregnancy outcomes related to very advanced maternal age in primigravida and multigravida in the Netherlands: A population-based cohort.

INTRODUCTION: The age at which women give birth is rising steadily in the western world. Advanced maternal age has been associated with adverse pregnancy outcomes. We assessed the association between advanced maternal age and the risk of adverse maternal and perinatal outcome in primigravid and multigravid women. MATERIAL AND METHODS: The study was a population-based cohort study and included women giving birth between January 2000 and December 2018 using data from the Dutch perinatal registration of Perined. Women were divided into age groups. We compared outcomes between women of 40-44, 45-49, and over 50 years old (the study groups) with women of 25-29 years old (reference group), stratified for parity. We employed multivariable regression to correct for possible confounders including methods of conception, multiple pregnancies, ethnicity, and socio-economic status. Our primary outcomes were maternal and perinatal mortality. Secondary outcomes included common maternal and perinatal complications, as well as cesarean section rate. RESULTS: A cohort of 3 700 326 women gave birth during the study period. Of these women, 3.2% were above 40 years of age. Maternal mortality was rare in all groups, but significantly higher in multigravid women over 50 years old. Perinatal mortality was significantly higher in all pregnancies of women over 40 years old, but not for primigravida over 50 years old. The most notable results with the steepest increase were in maternal complications. Both primigravida and multigravida over 40 years old were at a two times higher risk of perinatal mortality, cesarean section, gestational diabetes, hypertensive disorders, and a low Apgar score after 5 minutes. The risk for women over 45 was almost tripled for perinatal mortality and gestational diabetes and six times higher for cesarean section. Women over 50 years old had a seven times higher risk of cesarean section, a four times higher risk of gestational diabetes, postpartum hemorrhage, and neonatal intensive care unit admission, and a 10 times higher risk of hypertensive disorders. CONCLUSIONS: The risk of adverse maternal and perinatal outcomes for women over 40 years old surges as age increases. A novel aspect was the consistent increased risks not only for primigravid women but also for multigravida.

From population reference to national standard: new and improved birthweight charts.

BACKGROUND: Antenatal detection of intrauterine growth restriction remains a major obstetrical challenge, with the majority of cases not detected before birth. In these infants with undetected intrauterine growth restriction, the diagnosis must be made after birth. Clinicians use birthweight charts to identify infants as small-for-gestational-age if their birthweights are below a predefined threshold for gestational age. The choice of birthweight chart strongly affects the classification of small-for-gestational-age infants and has an impact on both research findings and clinical practice. Despite extensive literature on pathological risk factors associated with small-for-gestational-age, controversy exists regarding the exclusion of affected infants from a reference population. OBJECTIVE: This study aims to identify pathological risk factors for abnormal fetal growth, to quantify their effects, and to use these findings to calculate prescriptive birthweight charts for the Dutch population. MATERIALS AND METHODS: We performed a retrospective cross-sectional study, using routinely collected data of 2,712,301 infants born in The Netherlands between 2000 and 2014. Risk factors for abnormal fetal growth were identified and categorized in 7 groups: multiple gestation, hypertensive disorders, diabetes, other pre-existing maternal medical conditions, maternal substance (ab)use, medical conditions related to the pregnancy, and congenital malformations. The effects of these risk factors on mean birthweight were assessed using linear regression. Prescriptive birthweight charts were derived from live-born singleton infants, born to ostensibly healthy mothers after uncomplicated pregnancies and spontaneous onset of labor. The Box-Cox-t distribution was used to model birthweight and to calculate sex-specific percentiles. The new charts were compared to various existing birthweight and fetal-weight charts. RESULTS: We excluded 111,621 infants because of missing data on birthweight, gestational age or sex, stillbirth, or a gestational age not between 23 and 42 weeks. Of the 2,599,640 potentially eligible infants, 969,552 (37.3%) had 1 or more risk factors for abnormal fetal growth and were subsequently excluded. Large absolute differences were observed between the mean birthweights of infants with and without these risk factors, with different patterns for term and preterm infants. The final low-risk population consisted of 1,629,776 live-born singleton infants (50.9% male), from which sex-specific percentiles were calculated. Median and 10th percentiles closely approximated fetal-weight charts but consistently exceeded existing birthweight charts. CONCLUSION: Excluding risk factors that cause lower birthweights results in prescriptive birthweight charts that are more akin to fetal-weight charts, enabling proper discrimination between normal and abnormal birthweight. This proof of concept can be applied to other populations.

Evaluating progress towards triple elimination of mother-to-child transmission of HIV, syphilis and hepatitis B in the Netherlands.

BACKGROUND: In 2014 the World Health Organisation (WHO) established validation criteria for elimination of mother-to-child transmission (EMTCT) of HIV and syphilis. Additionally, the WHO set targets to eliminate hepatitis, including hepatitis B (HBV). We evaluated to what extent the Netherlands has achieved the combined WHO criteria for EMTCT of HIV, syphilis and HBV. METHODS: Data of HIV, syphilis and HBV infections among pregnant women and children (born in the Netherlands with congenital infection) for 2009-2015, and data required to validate the WHO criteria were collected from multiple sources: the antenatal screening registry, the HIV monitoring foundation database, the Perinatal Registry of the Netherlands, the national reference laboratory for congenital syphilis, and national HBV notification data. RESULTS: Screening coverage among pregnant women was > 99% for all years, and prevalence of HIV, syphilis and HBV was very low. In 2015, prevalence of HIV, syphilis and HBV was 0.06, 0.06 and 0.29%, respectively. No infections among children born in the Netherlands were reported in 2015 for all three diseases, and in previous years only sporadic cases were observed In 2015, treatment of HIV positive pregnant women was 100% and HBV vaccination of children from HBV positive mothers was > 99%. For syphilis, comprehensive data was lacking to validate WHO criteria. CONCLUSIONS: In the Netherlands, prevalence of maternal HIV, syphilis and HBV is low and congenital infections are extremely rare. All minimum WHO criteria for validation of EMTCT are met for HIV and HBV, but for syphilis more data are needed to prove elimination.

Timing of elective pre-labour caesarean section: A decision analysis.

BACKGROUND: Since caesarean sections (CSs) before 39+0  weeks gestation are associated with higher rates of neonatal respiratory morbidity, it is recommended to delay elective CSs until 39+0  weeks. However, this bears the risk of earlier spontaneous labour resulting in unplanned CSs, which has workforce and resource implications, specifically in smaller obstetric units. AIM: To assess, in a policy of elective CSs from 39+0  weeks onward, the number of unplanned CSs to prevent one neonate with respiratory complications, as compared to early elective CS. MATERIALS AND METHODS: We performed a decision analysis comparing early term elective CS at 37+0-6 or 38+0-6  weeks to elective prelabour CS, without strict medical indication, at 39+0-6  weeks, with earlier unplanned CS, in women with uncomplicated singleton pregnancies. We used literature data to calculate the number of unplanned CSs necessary to prevent one neonate with respiratory morbidity. RESULTS: Planning all elective CSs at 39+0-6  weeks required 10.9 unplanned CSs to prevent one neonate with respiratory morbidity, compared to planning all elective CSs at 38+0-6  weeks. Compared to planning all elective CSs at 37+0-6  weeks we needed to perform 3.3 unplanned CSs to prevent one neonate with respiratory morbidity. CONCLUSION: In a policy of planning all elective pre-labour CSs from 39+0  weeks of gestation onward, between three and 11 unplanned CSs have to be performed to prevent one neonate with respiratory morbidity. Therefore, in our opinion, fear of early term labour and workforce disutility is no argument for scheduling elective CSs <39+0  weeks.

The effectiveness of mediolateral episiotomy in preventing obstetric anal sphincter injuries during operative vaginal delivery: a ten-year analysis of a national registry.

INTRODUCTION AND HYPOTHESIS: Obstetric anal sphincter injuries (OASIS) are associated with an increased risk of faecal incontinence after vaginal delivery. The aim of this retrospective population-based cohort study was to assess whether mediolateral episiotomy is associated with a reduction in the rate of OASIS during operative vaginal delivery. METHODS: We used data from the Dutch Perinatal Registry (Perined) that includes records of almost all births between 2000 and 2010 in The Netherlands. In a cohort of 170,969 primiparous and multiparous women whose delivery was recorded, we estimated the association between mediolateral episiotomy and OASIS following both vacuum and forceps deliveries using univariate and multivariate logistic regression analysis. RESULTS: The incidences of OASIS following vacuum delivery in 130,157 primiparous women were 2.5% and 14% in those with and without a mediolateral episiotomy, respectively (adjusted OR 0.14, 95% CI 0.13-0.15), and in 29,183 multiparous women were 2.0% and 7.5%, respectively (adjusted OR 0.23, 95% CI 0.21-0.27). The incidences of OASIS following forceps delivery in 9,855 primiparous women were 3.4% and 26.7% in those with and without a mediolateral episiotomy, respectively (adjusted OR 0.09, 95% CI 0.07-0.11), and in 1,774 multiparous women were 2.6% and 14.2%, respectively (adjusted OR 0.13, 95% CI 0.08-0.22). CONCLUSIONS: The use of a mediolateral episiotomy during both vacuum delivery and forceps delivery is associated with a fivefold to tenfold reduction in the rate of OASIS in primiparous and multiparous women.

Pregnancy before recurrent pregnancy loss more often complicated by post-term birth and perinatal death.

INTRODUCTION: The cause of recurrent pregnancy loss often remains unknown. Possibly, pathophysiological pathways are shared with other pregnancy complications. MATERIAL AND METHODS: All women with secondary recurrent pregnancy loss (SRPL) visiting Leiden University Medical Center (January 2000-2015) were included in this retrospective cohort to assess whether women with SRPL have a more complicated first pregnancy compared with control women. SRPL was defined as three or more consecutive pregnancy losses before 22 weeks of gestation, with a previous birth. The control group consisted of all Dutch nullipara delivering a singleton (January 2000-2015). Information was obtained from the Dutch Perinatal Registry. Outcomes were preeclampsia, preterm birth, post-term birth, intrauterine growth restriction, breach position, induction of labor, cesarean section, congenital abnormalities, perinatal death and severe hemorrhage in the first ongoing pregnancy. Subgroup analyses were performed for women with idiopathic SRPL and for women ≤35 years. RESULTS: In all, 172 women with SRPL and 1 196 178 control women were included. Women with SRPL were older and had a higher body mass index; 29.7 years vs. 28.8 years and 25.1 kg/m2 vs. 24.1 kg/m2 , respectively. Women with SRPL more often had a post-term birth (OR 1.86, 95% CI 1.10-3.17) and more perinatal deaths occurred in women with SRPL compared with the control group (OR 5.03, 95% CI 2.48-10.2). Similar results were found in both subgroup analyses. CONCLUSIONS: The first ongoing pregnancy of women with (idiopathic) SRPL is more often complicated by post-term birth and perinatal death. Revealing possible links between SRPL and these pregnancy complications might lead to a better understanding of underlying pathophysiology.

Prescriptive birthweight charts can improve the prediction of adverse outcomes in very preterm infants who are small for gestational age.

AIM: We compared three anthropometric charts to determine which provided the best predictions for adverse outcomes in very preterm small for gestational age (SGA) infants to address a lack of consensus on this subject. METHODS: This was a retrospective cohort study of infants born below 32 weeks, who were admitted to two-level three neonatal intensive care units in The Netherlands from 2008 to 2013. The birthweights of 1720 infants were classified as SGA using a conventional, gender-specific birthweight chart, based on births in The Netherlands between 2000 and 2007, a prescriptive, gender-specific birthweight chart, based on the same data but without risk factors for intrauterine growth restriction (IUGR), and a non-gender-specific foetal weight chart derived from American ultrasonographic measurements. RESULTS: The conventional, prescriptive and foetal weight charts classified 126 (7.3%), 494 (28.7%) and 630 (36.6%) infants as SGA. The prescriptive chart, which excluded IUGR, identified 368 SGA infants with significantly increased risks of neonatal mortality and morbidity. The 136 SGA infants just classified by the American foetal weight chart were not at increased risk. CONCLUSION: The prescriptive birthweight chart, which excluded infants with IUGR, was the most effective chart when it came to identifying clinically important risk increases in SGA infants.

Defining small-for-gestational-age: prescriptive versus descriptive birthweight standards.

UNLABELLED: Descriptive population-based birthweight standards possess low sensitivity in detecting infants with growth impairment. A prescriptive birthweight standard based on a 'healthy' subpopulation without risk factors for intrauterine growth restriction might be superior. We created two birthweight standards based on live born, singleton infants with gestational age 24-42 weeks and born in The Netherlands between 2000 and 2007. Inclusion criteria for the prescriptive birthweight standard were restricted to infants without congenital malformations, born to healthy mothers after uncomplicated pregnancies. We defined small-for-gestational-age (SGA) as birthweight <10th percentile and assessed the ability of both standards to predict adverse neonatal outcomes. The prescriptive birthweight standard identified significantly more infants as SGA, up to 38.0 % at 29 weeks gestation. SGA infants classified according to both standards as well as those classified according to the prescriptive birthweight standard only, were at increased risk of both major and minor adverse neonatal outcomes. The prescriptive birthweight standard was both more sensitive and less specific, with a maximum increase in sensitivity predicting bronchopulmonary dysplasia (+42.6 %) and a maximum decrease in specificity predicting intraventricular haemorrhage (-26.9 %) in infants aged 28-31 weeks. CONCLUSION: Prescriptive birthweight standards could improve identification of infants born SGA and at risk of adverse neonatal outcomes. WHAT IS KNOWN: • Descriptive birthweight standards possess low sensitivity in detecting growth restricted infants at risk of adverse neonatal outcomes. • Prescriptive standards could improve identification of very preterm small-for-gestational-age (SGA) infants at risk of intraventricular haemorrhage. What is New: • Prescriptive standards identify more preterm and term SGA infants at risk of major adverse neonatal outcomes. • Late preterm and term SGA infants classified according to the prescriptive standard are at increased risk of minor adverse neonatal outcomes with potentially harmful implications.

Increasing incidence of postpartum hemorrhage: the Dutch piece of the puzzle.

INTRODUCTION: An increase of postpartum hemorrhage (PPH) has been reported in many high-income countries. In addition to this data, this study reports on trends in the incidence of PPH in the Netherlands in 2000-2013, and examines the extent to which temporal changes in risk indicators could explain a possible change in incidence of PPH. MATERIAL AND METHODS: We used data from the Dutch Perinatal Registry, which contains prospectively collected antenatal, peripartum and neonatal data of 95-99% of all women and neonates in the Netherlands. We selected births ≥22 weeks of gestation from January 2000 until December 2013. Changes in the incidence of PPH and its risk indicators were studied over time. Main outcome measure was PPH, defined as blood loss >1000 mL within 24 h following delivery. RESULTS: The data comprised 2 406 784 women. The incidence of PPH rose significantly from 4.1% in 2000 to 6.4% in 2013 (p < 0.0001). The incidence of previously identified risk indicators for PPH increased over time. Manual removal of placenta was strongly associated with PPH (OR 29.3, CI 28.8-29.8). The incidence of PPH-related blood transfusion decreased remarkably. CONCLUSIONS: In line with international observations, Dutch data suggest a considerable increase in the incidence of PPH which can only partly be explained by the studied risk indicators. The decreasing incidence of obstetric blood transfusion suggests an increased incidence of blood loss of 1000-1500 mL.

Variation in referrals to secondary obstetrician-led care among primary midwifery care practices in the Netherlands: a nationwide cohort study.

BACKGROUND: The primary aim of this study was to describe the variation in intrapartum referral rates in midwifery practices in the Netherlands. Secondly, we wanted to explore the association between the practice referral rate and a woman's chance of an instrumental birth (caesarean section or vaginal instrumental birth). METHODS: We performed an observational study, using the Dutch national perinatal database. Low risk births in all primary care midwifery practices over the period 2008-2010 were selected. Intrapartum referral rates were calculated. The referral rate among nulliparous women was used to divide the practices in three tertile groups. In a multilevel logistic regression analysis the association between the referral rate and the chance of an instrumental birth was examined. RESULTS: The intrapartum referral rate varied from 9.7 to 63.7 percent (mean 37.8; SD 7.0), and for nulliparous women from 13.8 to 78.1 percent (mean 56.8; SD 8.4). The variation occurred predominantly in non-urgent referrals in the first stage of labour. In the practices in the lowest tertile group more nulliparous women had a spontaneous vaginal birth compared to the middle and highest tertile group (T1: 77.3%, T2:73.5%, T3: 72.0%). For multiparous women the spontaneous vaginal birth rate was 97%. Compared to the lowest tertile group the odds ratios for nulliparous women for an instrumental birth were 1.22 (CI 1.16-1.31) and 1.33 (CI 1.25-1.41) in the middle and high tertile groups. This association was no longer significant after controlling for obstetric interventions (pain relief or augmentation). CONCLUSIONS: The wide variation between referral rates may not be explained by medical factors or client characteristics alone. A high intrapartum referral rate in a midwifery practice is associated with an increased chance of an instrumental birth for nulliparous women, which is mediated by the increased use of obstetric interventions. Midwives should critically evaluate their referral behaviour. A high referral rate may indicate that more interventions are applied than necessary. This may lead to a lower chance of a spontaneous vaginal birth and a higher risk on a PPH. However, a low referral rate should not be achieved at the cost of perinatal safety.

Regional differences in severe postpartum hemorrhage: a nationwide comparative study of 1.6 million deliveries.

BACKGROUND: The incidence of severe postpartum hemorrhage (PPH) is increasing. Regional variation may be attributed to variation in provision of care, and as such contribute to this increasing incidence. We assessed reasons for regional variation in severe PPH in the Netherlands. METHODS: We used the Netherlands Perinatal Registry and the Dutch Maternal Mortality Committee to study severe PPH incidences (defined as blood loss ≥ 1000 mL) across both regions and neighborhoods of cities among all deliveries between 2000 and 2008. We first calculated crude incidences. We then used logistic multilevel regression analyses, with hospital or midwife practice as second level to explore further reasons for the regional variation. RESULTS: We analyzed 1599867 deliveries in which the incidence of severe PPH was 4.5%. Crude incidences of severe PPH varied with factor three between regions while between neighborhoods variation was even larger. We could not explain regional variation by maternal characteristics (age, parity, ethnicity, socioeconomic status), pregnancy characteristics (singleton, gestational age, birth weight, pre-eclampsia, perinatal death), medical interventions (induction of labor, mode of delivery, perineal laceration, placental removal) and health care setting. CONCLUSIONS: In a nationwide study in The Netherlands, we observed wide practice variation in PPH. This variation could not be explained by maternal characteristics, pregnancy characteristics, medical interventions or health care setting. Regional variation is either unavoidable or subsequent to regional variation of a yet unregistered variable.

Persisting rise in referrals during labor in primary midwife-led care in the Netherlands.

BACKGROUND: There are concerns about the Dutch maternity care system, characterized by a strict role division between primary and secondary care. The objective of this study was to describe trends in referrals and in perinatal outcomes among labors that started in primary midwife-led care. METHODS: We performed a descriptive study of all 789,795 labors that started in primary midwife-led care during 2000 to 2008 in The Netherlands. Referrals to obstetrician-led care or pediatrician were classified as urgent or nonurgent. Perinatal safety was described by perinatal mortality (intrapartum or neonatal 0-7 days), admission to neonatal intensive care unit 0-7 days, and Apgar score < 7 at 5 minutes. RESULTS: The proportion of referrals during labor or after birth declined from 52.6 to 42.6 percent for nulliparous women and from 83.2 to 76.7 percent for multiparous women. Especially nonurgent referrals during the first stage increased, for nulliparous women from 28.7 to 40.7 percent and for multiparous women from 10.5 to 16.5 percent. Referrals were less frequent in planned home births. Perinatal mortality was 0.9 per thousand births for nulliparous women, and 0.6 per thousand for multiparous women. A low Apgar score was registered in 8.6 per thousand births for nulliparous women, and 4.1 per thousand for multiparous women. CONCLUSIONS: There was a considerable rise in nonurgent referrals to obstetrician-led care in primary midwife-led care during labor. Perinatal safety did not improve significantly over time. The persisting rise in referrals challenges the sustainability of the current strict role division between primary and secondary maternity care in The Netherlands.

Neonatal outcome following elective cesarean section of twin pregnancies beyond 35 weeks of gestation.

OBJECTIVE: We sought to assess neonatal morbidity and mortality of elective cesarean section (CS) of uncomplicated twin pregnancies per week of gestation >35(+0). STUDY DESIGN: We performed a retrospective cohort study in our nationwide database including all elective CS of twin pregnancies. Two main composite outcome measures were defined, ie, severe adverse neonatal outcome and mild neonatal morbidity. RESULTS: We report on 2228 neonates. More than 17% were born <37(+0) weeks of gestation. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for severe adverse neonatal outcome at 35(+0-6), 36(+0-6), and 37(+0-6) weeks were, OR, 9.4; 95% CI, 3.2-27.6; OR, 1.7; 95% CI, 0.5-5.3; and OR, 0.7; 95% CI, 0.2-2.0, respectively; and for mild neonatal morbidity, OR, 4.7; 95% CI, 2.6-8.7; OR, 4.9; 95% CI, 3.1-7.9; and 1.4; 95% CI, 0.9-2.1, respectively, compared to neonates born ≥38(+0) weeks of gestation. CONCLUSION: In uncomplicated twin pregnancies elective CS can best be performed between 37(+0) and 39(+6) weeks of gestation.

Effects of hospital delivery during off-hours on perinatal outcome in several subgroups: a retrospective cohort study.

BACKGROUND: Studies have demonstrated a higher risk of adverse outcomes among infants born or admitted during off-hours, as compared to office hours, leading to questions about quality of care provide during off-hours (weekend, evening or night). We aim to determine the relationship between off-hours delivery and adverse perinatal outcomes for subgroups of hospital births. METHODS: This retrospective cohort study was based on data from the Netherlands Perinatal Registry, a countrywide registry that covers 99% of all hospital births in the Netherlands. Data of 449,714 infants, born at 28 completed weeks or later, in the period 2003 through 2007 were used. Infants with a high a priori risk of morbidity or mortality were excluded. Outcome measures were intrapartum and early neonatal mortality, a low Apgar score (5 minute score of 0-6), and a composite adverse perinatal outcome measure (mortality, low Apgar score, severe birth trauma, admission to a neonatal intensive care unit). RESULTS: Evening and night-time deliveries that involved induction or augmentation of labour, or an emergency caesarean section, were associated with an increased risk of an adverse perinatal outcome when compared to similar daytime deliveries. Weekend deliveries were not associated with an increased risk when compared to weekday deliveries. It was estimated that each year, between 126 and 141 cases with an adverse perinatal outcomes could be attributed to this evening and night effect. Of these, 21 (15-16%) are intrapartum or early neonatal death. Among the 3100 infants in the study population who experience an adverse outcome each year, death accounted for only 5% (165) of these outcomes. CONCLUSION: This study shows that for infants whose mothers require obstetric interventions during labour and delivery, birth in the evening or at night, are at an increased risk of an adverse perinatal outcomes.

Advanced maternal age, short interpregnancy interval, and perinatal outcome.

OBJECTIVE: The purpose of this study was to evaluate whether the association between short interpregnancy intervals and perinatal outcome varies with maternal age. STUDY DESIGN: We performed a retrospective cohort study among 263,142 Dutch women with second deliveries that occurred between 2000 and 2007. Outcome variables were preterm delivery (<37 weeks of gestation), low birthweight in term deliveries (<2500 g) and small-for-gestational age (<10th percentile for gestational age on the basis of sex- and parity-specific Dutch standards). RESULTS: Short interpregnancy intervals (<6 months) was associated positively with preterm delivery and low birthweight, but not with being small for gestational age. The association of short interpregnancy interval with the risk of preterm delivery was weaker among older than younger women. There was no clear interaction between short interpregnancy interval and maternal age in relation to low birthweight or small for gestational age. CONCLUSION: The results of this study indicate that the association of short interpregnancy interval with preterm delivery attenuates with increasing maternal age.

Antibodies against Coxiella burnetii and pregnancy outcome during the 2007-2008 Q fever outbreaks in The Netherlands.

BACKGROUND: Q fever has become a major public health problem in The Netherlands. Infection with Coxiella burnetii (Q fever) during pregnancy has resulted in adverse pregnancy outcome in the majority of reported cases. Therefore, we aimed to quantify this risk by examining the earliest periods corresponding to the epidemic in The Netherlands. METHODS: Serum samples that had been collected from the area of highest incidence by an existing national prenatal screening programme and data from the Netherlands Perinatal Registry (PRN) on diagnosis and outcome were used. We performed indirect immunofluorescence assay to detect the presence of IgM and IgG antibodies against C. burnetii in the samples. The serological results were analyzed to determine statistical association with recorded pregnancy outcome. RESULTS: Evaluation of serological results for 1174 women in the PRN indicated that the presence of IgM and IgG antibodies against phase II of C. burnetii was not significantly associated with preterm delivery, low birth weight, or several other outcome measures. CONCLUSION: The present population-based study showed no evidence of adverse pregnancy outcome among women who had antibodies to C. burnetii during early pregnancy.

Neonatal outcome following elective cesarean section beyond 37 weeks of gestation: a 7-year retrospective analysis of a national registry.

OBJECTIVE: We sought to evaluate number and timing of elective cesarean sections at term and to assess perinatal outcome associated with this timing. STUDY DESIGN: We conducted a recent retrospective cohort study including all elective cesarean sections of singleton pregnancies at term (n = 20,973) with neonatal follow-up. Primary outcome was defined as a composite of neonatal mortality and morbidity. RESULTS: More than half of the neonates were born at <39 weeks of gestation, and they were at significantly higher risk for the composite primary outcome than neonates born thereafter. The absolute risks were 20.6% and 12.5% for birth at <38 and 39 weeks, respectively, as compared to 9.5% for neonates born > or = 39 weeks. The corresponding adjusted odds ratios (95% confidence interval) were 2.4 (2.1-2.8) and 1.4 (1.2-1.5), respectively. CONCLUSION: More than 50% of the elective cesarean sections are applied at <39 weeks, thus jeopardizing neonatal outcome.

The role of hospital midwives in the Netherlands.

BACKGROUND: Most midwives in the Netherlands work in primary care where they are the lead professionals providing care to women with 'normal' or uncomplicated pregnancies, while some midwives work in hospitals ("clinical midwives"). The actual involvement of midwives in maternity care in hospitals is unknown, because in all statistics births in secondary care are registered as births assisted by gynaecologists. The aim of this study is to gain insight in the involvement of midwives with births in secondary care, under supervision of a gynaecologist. This is done using data from the PRN (The Netherlands Perinatal Registry), a voluntary registration of births in the Netherlands. The PRN covers 97% to 99% of all births taking place under responsibility of a gynaecologist. METHODS: All births registered in secondary care in the period 1998-2007 (1,102,676, on average 61% of all births) were selected. We analyzed trends in socio-demographic, obstetric and organisational characteristics, associated with the involvement of midwives, using frequency tables and uni- and multivariate logistic regression analyses. As main outcome measure the percentage of births in secondary care with a midwife 'catching' the baby was used. RESULTS: The proportion of births attended by a midwife in secondary care increased from 8.3% in 1998 to 26.06% in 2007, the largest increase involving spontaneous births of a second or later child, on weekdays during day shifts (8.00-20.00 hr) from younger mothers with a gestational age (almost) at term. After 2002, parallel to the growing numbers of midwives working in hospitals, the percentage of instrumental births decreased. CONCLUSIONS: In 2007 more midwives are assisting with more births in secondary care than in 1998. Hospital-based midwives are primarily involved with uncomplicated births of women with relatively low risk demographical and obstetrical characteristics. However, they are still only involved with half of the less complicated births, indicating that there may be room for more midwives in hospitals to care for women with relatively uncomplicated births. Whether an association exists between the growing involvement of midwives and the decreasing percentage of instrumental births needs further investigation.

A systematic review finds methodological improvements necessary for prognostic models in determining traumatic brain injury outcomes.

OBJECTIVES: To describe the modeling techniques used for early prediction of outcome in traumatic brain injury (TBI) and to identify aspects for potential improvements. STUDY DESIGN AND SETTING: We reviewed key methodological aspects of studies published between 1970 and 2005 that proposed a prognostic model for the Glasgow Outcome Scale of TBI based on admission data. RESULTS: We included 31 papers. Twenty-four were single-center studies, and 22 reported on fewer than 500 patients. The median of the number of initially considered predictors was eight, and on average five of these were selected for the prognostic model, generally including age, Glasgow Coma Score (or only motor score), and pupillary reactivity. The most common statistical technique was logistic regression with stepwise selection of predictors. Model performance was often quantified by accuracy rate rather than by more appropriate measures such as the area under the receiver-operating characteristic curve. Model validity was addressed in 15 studies, but mostly used a simple split-sample approach, and external validation was performed in only four studies. CONCLUSION: Although most models agree on the three most important predictors, many were developed on small sample sizes within single centers and hence lack generalizability. Modeling strategies have to be improved, and include external validation.

Some prognostic models for traumatic brain injury were not valid.

OBJECTIVE: Various prognostic models have been developed to predict outcome after traumatic brain injury (TBI). We aimed to determine the validity of six models that used baseline clinical and computed tomographic characteristics to predict mortality or unfavorable outcome at 6 months or later after severe or moderate TBI. STUDY DESIGN AND SETTING: The validity was studied in two selected series of TBI patients enrolled in clinical trials (Tirilazad trials; n = 2,269; International Selfotel Trial; n = 409) and in two unselected series of patients consecutively admitted to participating centers (European Brain Injury Consortium [EBIC] survey; n = 796; Traumatic Coma Data Bank; n = 746). Validity was indicated by discriminative ability (AUC) and calibration (Hosmer-Lemeshow goodness-of-fit test). RESULTS: The models varied in number of predictors (four to seven) and in development technique (two prediction trees and four logistic regression models). Discriminative ability varied widely (AUC: .61-.89), but calibration was poor for most models. Better discrimination was observed for logistic regression models compared with trees, and for models including more predictors. Further, discrimination was better when tested on unselected series that contained more heterogeneous populations. CONCLUSION: Our findings emphasize the need for external validation of prognostic models. The satisfactory discrimination indicates that logistic regression models, developed on large samples, can be used for classifying TBI patients according to prognostic risk.