Counseling pregnant women on calcium: effects on calcium intake.

OBJECTIVES: To evaluate the effect of incorporating calcium advice into early pregnancy counseling on calcium intake during pregnancy in the Netherlands. METHODS: A multicenter prospective before-after cohort study was conducted introducing risk-based care including calculating individual pre-eclampsia risk. Part of the intervention was to incorporate calcium advice into routine counseling. We calculated individual daily calcium intake and adequacy of calcium intake (≥1,000 mg/day) at 16, 24 and 34 weeks of pregnancy. We performed a multiple logistic regression adjusting for covariates to identify any differences in the risk of inadequate calcium intake between RC and CAC. RESULTS: In regular care (RC, 2013-2015, n=2,477) 60% had inadequate calcium intake, compared to 49% during calcium advice care (CAC, 2017-2018, n=774) (aOR 0.75, 95% CI 0.64-0.88). Specific calcium supplements were used by 2% and 29% in RC and CAC, respectively (OR 25.1, 95% CI 17.8-36.0). Determinants of an inadequate calcium intake were lower age (aOR per additional year 0.96, 95% CI: 0.94-0.98), nulliparity (aOR 1.22, 95% CI: 1.03-1.45) and non-Caucasian origin (aOR 1.83, 95% CI 1.09-3.09). In CAC, risk of inadequate intake decreased with increasing predicted pre-eclampsia risk, which was a trend reversal compared to RC. CONCLUSIONS: Incorporating calcium advice into early pregnancy counseling was shown to lead to a decrease in the risk of inadequate calcium intake during pregnancy, but still inadequate intake in half of the women suggesting the need for further study on improving implementation. Awareness of individual increased PE risk had positive effect on calcium intake.

External validation of a prediction model on vaginal birth after caesarean in a The Netherlands: a prospective cohort study.

OBJECTIVES: Discussing the individual probability of a successful vaginal birth after caesarean (VBAC) can support decision making. The aim of this study is to externally validate a prediction model for the probability of a VBAC in a Dutch population. METHODS: In this prospective cohort study in 12 Dutch hospitals, 586 women intending VBAC were included. Inclusion criteria were singleton pregnancies with a cephalic foetal presentation, delivery after 37 weeks and one previous caesarean section (CS) and preference for intending VBAC. The studied prediction model included six predictors: pre-pregnancy body mass index, previous vaginal delivery, previous CS because of non-progressive labour, Caucasian ethnicity, induction of current labour, and estimated foetal weight ≥90th percentile. The discriminative and predictive performance of the model was assessed using receiver operating characteristic curve analysis and calibration plots. RESULTS: The area under the curve was 0.73 (CI 0.69-0.78). The average predicted probability of a VBAC according to the prediction model was 70.3% (range 33-92%). The actual VBAC rate was 71.7%. The calibration plot shows some overestimation for low probabilities of VBAC and an underestimation of high probabilities. CONCLUSIONS: The prediction model showed good performance and was externally validated in a Dutch population. Hence it can be implemented as part of counselling for mode of delivery in women choosing between intended VBAC or planned CS after previous CS.

Nationwide implementation of a decision aid on vaginal birth after cesarean: a before and after cohort study.

OBJECTIVES: Woman with a history of a previous cesarean section (CS) can choose between an elective repeat CS (ERCS) and a trial of labor (TOL), which can end in a vaginal birth after cesarean (VBAC) or an unplanned CS. Guidelines describe women's rights to make an informed decision between an ERCS or a TOL. However, the rates of TOL and vaginal birth after CS varies greatly between and within countries. The objective of this study is to asses nation-wide implementation of counselling with a decision aid (DA) including a prediction model, on intended delivery compared to care as usual. We hypothesize that this may result in a reduction in practice variation without an increase in cesarean rates or complications. METHODS: In a multicenter controlled before and after cohort study we evaluate the effect of nation-wide implementation of a DA. Practice variation was defined as the standard deviation (SD) of TOL percentages. RESULTS: A total of 27 hospitals and 1,364 women were included. A significant decrease was found in practice variation (SD TOL rates: 0.17 control group vs. 0.10 intervention group following decision aid implementation, p=0.011). There was no significant difference in the ERCS rate or overall CS rates. A 21% reduction in the combined maternal and perinatal adverse outcomes was seen. CONCLUSIONS: Nationwide implementation of the DA showed a significant reduction in practice variation without an increase in the rate of cesarean section or complications, suggesting an improvement in equality of care.

External validation of prognostic models predicting pre-eclampsia: individual participant data meta-analysis.

BACKGROUND: Pre-eclampsia is a leading cause of maternal and perinatal mortality and morbidity. Early identification of women at risk during pregnancy is required to plan management. Although there are many published prediction models for pre-eclampsia, few have been validated in external data. Our objective was to externally validate published prediction models for pre-eclampsia using individual participant data (IPD) from UK studies, to evaluate whether any of the models can accurately predict the condition when used within the UK healthcare setting. METHODS: IPD from 11 UK cohort studies (217,415 pregnant women) within the International Prediction of Pregnancy Complications (IPPIC) pre-eclampsia network contributed to external validation of published prediction models, identified by systematic review. Cohorts that measured all predictor variables in at least one of the identified models and reported pre-eclampsia as an outcome were included for validation. We reported the model predictive performance as discrimination (C-statistic), calibration (calibration plots, calibration slope, calibration-in-the-large), and net benefit. Performance measures were estimated separately in each available study and then, where possible, combined across studies in a random-effects meta-analysis. RESULTS: Of 131 published models, 67 provided the full model equation and 24 could be validated in 11 UK cohorts. Most of the models showed modest discrimination with summary C-statistics between 0.6 and 0.7. The calibration of the predicted compared to observed risk was generally poor for most models with observed calibration slopes less than 1, indicating that predictions were generally too extreme, although confidence intervals were wide. There was large between-study heterogeneity in each model's calibration-in-the-large, suggesting poor calibration of the predicted overall risk across populations. In a subset of models, the net benefit of using the models to inform clinical decisions appeared small and limited to probability thresholds between 5 and 7%. CONCLUSIONS: The evaluated models had modest predictive performance, with key limitations such as poor calibration (likely due to overfitting in the original development datasets), substantial heterogeneity, and small net benefit across settings. The evidence to support the use of these prediction models for pre-eclampsia in clinical decision-making is limited. Any models that we could not validate should be examined in terms of their predictive performance, net benefit, and heterogeneity across multiple UK settings before consideration for use in practice. TRIAL REGISTRATION: PROSPERO ID: CRD42015029349 .

Impact on perinatal health and cost-effectiveness of risk-based care in obstetrics: a before-after study.

BACKGROUND: Obstetric health care relies on an adequate antepartum risk selection. Most guidelines used for risk stratification, however, do not assess absolute risks. In 2017, a prediction tool was implemented in a Dutch region. This tool combines first trimester prediction models with obstetric care paths tailored to the individual risk profile, enabling risk-based care. OBJECTIVE: To assess impact and cost-effectiveness of risk-based care compared to care-as-usual in a general population. METHODS: A before-after study was conducted using 2 multicenter prospective cohorts. The first cohort (2013-2015) received care-as-usual; the second cohort (2017-2018) received risk-based care. Health outcomes were (1) a composite of adverse perinatal outcomes and (2) maternal quality-adjusted life-years. Costs were estimated using a health care perspective from conception to 6 weeks after the due date. Mean costs per woman, cost differences between the 2 groups, and incremental cost effectiveness ratios were calculated. Sensitivity analyses were performed to evaluate the robustness of the findings. RESULTS: In total 3425 women were included. In nulliparous women there was a significant reduction of perinatal adverse outcomes among the risk-based care group (adjusted odds ratio, 0.56; 95% confidence interval, 0.32-0.94), but not in multiparous women. Mean costs per pregnant woman were significantly lower for risk-based care (mean difference, -€2766; 95% confidence interval, -€3700 to -€1825). No differences in maternal quality of life, adjusted for baseline health, were observed. CONCLUSION: In the Netherlands, risk-based care in nulliparous women was associated with improved perinatal outcomes as compared to care-as-usual. Furthermore, risk-based care was cost-effective compared to care-as-usual and resulted in lower health care costs.

Calcium intake from diet and supplement use during early pregnancy: the Expect study I.

PURPOSE: Adequate calcium intake during pregnancy is of major importance for the health of both mother and fetus. Up to date, evidence on the prevalence of inadequate calcium intake among pregnant women is sparse for Western countries, and it is unknown to what extent inadequate dietary calcium intake is adequately balanced by supplement use. The objective of this study was to estimate calcium intake from diet and supplement use during the early pregnancy in The Netherlands. METHODS: As part of the Expect cohort study, 2477 pregnant women (8-16 weeks of gestation) completed an online questionnaire including questions on baseline characteristics, the use of calcium containing supplements, and a short food-frequency questionnaire (FFQ). Intake data were used to calculate median calcium intakes from diet, from supplements, and combined, and to compare these values with currently accepted requirement levels. RESULTS: Forty-two percent of the pregnant women had a total calcium intake below the estimated average requirement of 800 mg/day. Median (interquartile range) calcium intake was 886 (611-1213) mg/day. Calcium or multivitamin supplements were used by 64.8% of the women at 8 weeks of gestation, with a median calcium content of 120.0 (60.0-200.0) mg/day. Prenatal vitamins were the most often used supplements (60.6%). CONCLUSIONS: Forty-two percent of Dutch pregnant women have an inadequate calcium intake. Supplements are frequently used, but most do not contain sufficient amounts to correct this inadequate intake.

Low-dose-aspirin usage among women with an increased preeclampsia risk: A prospective cohort study.

INTRODUCTION: Low-dose aspirin (LDA) prophylaxis has been shown to reduce women's preeclampsia risk. Evidence regarding LDA adherence rates of pregnant women is based almost exclusively on clinical trials, giving a potentially biased picture. Moreover, these studies do not report on determinants of adherence. Since 2017, obstetric healthcare professionals in a Dutch region have assessed women's preeclampsia risk by means of a prediction tool and counseled those with an above-population average risk on LDA as a prophylactic measure. MATERIAL AND METHODS: From 2017 to 2018, 865 women were recruited in multiple centers and prospectively followed using web-based surveys (Expect Study II). Rates and determinants of LDA usage among women with an increased preeclampsia risk in daily practice were assessed. Results were compared with findings in a similar cohort from a care-as-usual setting lacking risk-based counseling (Expect Study I, n = 2614). Netherlands Trial Register NTR4143. RESULTS: In total, 306 women had a predicted increased preeclampsia risk. LDA usage was higher for women receiving risk-based care than care-as-usual (29.4% vs 1.5%, odds ratio 19.1, 95% confidence interval 11.2-32.5). Daily LDA usage was positively correlated with both predicted risk and women's concerns regarding preeclampsia. Most reported reasons for non- or incomplete use were unawareness of LDA as a preventive intervention, concerns about potential adverse effects and doubts regarding the benefits. CONCLUSIONS: Risk-based counseling was associated with a higher prevalence of LDA usage, but general usage rates were low. Future research regarding potential factors improving the usage of LDA during pregnancy is necessary.

External validation and clinical utility of prognostic prediction models for gestational diabetes mellitus: A prospective cohort study.

INTRODUCTION: We performed an independent validation study of all published first trimester prediction models, containing non-invasive predictors, for the risk of gestational diabetes mellitus. Furthermore, the clinical potential of the best performing models was evaluated. MATERIAL AND METHODS: Systemically selected prediction models from the literature were validated in a Dutch prospective cohort using data from Expect Study I and PRIDE Study. The predictive performance of the models was evaluated by discrimination and calibration. Clinical utility was assessed using decision curve analysis. Screening performance measures were calculated at different risk thresholds for the best model and compared with current selective screening strategies. RESULTS: The validation cohort included 5260 women. Gestational diabetes mellitus was diagnosed in 127 women (2.4%). The discriminative performance of the 12 included models ranged from 68% to 75%. Nearly all models overestimated the risk. After recalibration, agreement between the observed outcomes and predicted probabilities improved for most models. CONCLUSIONS: The best performing prediction models showed acceptable performance measures and may enable more personalized medicine-based antenatal care for women at risk of developing gestational diabetes mellitus compared with current applied strategies.

Development and internal validation of prediction models for colorectal cancer survivors to estimate the 1-year risk of low health-related quality of life in multiple domains.

BACKGROUND: Many colorectal cancer (CRC) survivors experience persisting health problems post-treatment that compromise their health-related quality of life (HRQoL). Prediction models are useful tools for identifying survivors at risk of low HRQoL in the future and for taking preventive action. Therefore, we developed prediction models for CRC survivors to estimate the 1-year risk of low HRQoL in multiple domains. METHODS: In 1458 CRC survivors, seven HRQoL domains (EORTC QLQ-C30: global QoL; cognitive, emotional, physical, role, social functioning; fatigue) were measured prospectively at study baseline and 1 year later. For each HRQoL domain, scores at 1-year follow-up were dichotomized into low versus normal/high. Separate multivariable logistic prediction models including biopsychosocial predictors measured at baseline were developed for the seven HRQoL domains, and internally validated using bootstrapping. RESULTS: Average time since diagnosis was 5 years at study baseline. Prediction models included both non-modifiable predictors (age, sex, socio-economic status, time since diagnosis, tumor stage, chemotherapy, radiotherapy, stoma, micturition, chemotherapy-related, stoma-related and gastrointestinal complaints, comorbidities, social inhibition/negative affectivity, and working status) and modifiable predictors (body mass index, physical activity, smoking, meat consumption, anxiety/depression, pain, and baseline fatigue and HRQoL scores). Internally validated models showed good calibration and discrimination (AUCs: 0.83-0.93). CONCLUSIONS: The prediction models performed well for estimating 1-year risk of low HRQoL in seven domains. External validation is needed before models can be applied in practice.

Intakes of Vitamin B-12 from Dairy Food, Meat, and Fish and Shellfish Are Independently and Positively Associated with Vitamin B-12 Biomarker Status in Pregnant Dutch Women.

Background: The effect of vitamin B-12 from different animal foods on vitamin B-12 biomarker status has not previously been evaluated in pregnant women. Objective: We examined the association of vitamin B-12 intake from dairy, meat, fish (including shellfish), and eggs with circulating concentrations of vitamin B-12 biomarkers and with the presence of vitamin B-12 deficiency in 1266 pregnant women participating in the KOALA Birth Cohort Study. Methods: Blood samples were collected in weeks 34-36 of pregnancy, and vitamin B-12 intake from foods and supplements was estimated with a semiquantitative food-frequency questionnaire (FFQ). Total vitamin B-12, holotranscobalamin (holoTC), and methylmalonic acid (MMA) were determined in plasma. Vitamin B-12 deficiency was defined as holoTC <35 pmol/L and MMA >0.45 µmol/L. Associations were evaluated with linear and logistic regression analyses, adjusting for potential confounders. Results: Significant dose-response relations were observed between vitamin B-12 intake from dairy, meat, and fish and plasma vitamin B-12, holoTC, and MMA [P-trend for (shell)fish with MMA = 0.002; P-trend for dairy, meat, and fish with all other markers < 0.001]. The OR (95% CI) of vitamin B-12 deficiency in the third compared with the first tertile of dairy-derived vitamin B-12 was 0.13 (0.04, 0.49), and the ORs for vitamin B-12 from meat and fish were 0.33 (0.11, 0.97) and 0.25 (0.08, 0.82), respectively. Egg-derived vitamin B-12 was only associated with holoTC. Additional analyses showed that self-defined vegetarians and FFQ-defined lacto-ovo-vegetarians had lower median total dietary vitamin B-12 intake and considerably worse vitamin B-12 biomarker status than omnivores and pescatarians. Conclusions: In pregnant Dutch women, higher intakes of vitamin B-12 from dairy, meat, and fish were positively associated with vitamin B-12 status, suggesting that dairy, meat, and fish are good sources of bioactive vitamin B-12 in pregnancy. Nevertheless, for (lacto-)vegetarians, vitamin B-12 supplementation is recommended.

Intrauterine insemination: simultaneous with or 36 h after HCG? A randomized clinical trial.

RESEARCH QUESTION: Does intrauterine insemination (IUI) carried out simultaneously with HCG triggering ('simultaneous IUI') increase the ongoing pregnancy rate compared with IUI 32-36 h after HCG triggering ('regular IUI')? STUDY DESIGN: An open-label randomized clinical trial was conducted in seven Dutch fertility clinics. One hundred and sixty-six couples were randomized to receive simultaneous IUI and 208 couples to receive regular IUI. Treatment was allocated using a computer-based randomization algorithm using sealed opaque envelopes. Data were analysed according to the intention-to-treat principle. Couples with unexplained or mild-to-moderate male factor subfertility were eligible. Exclusion criteria were female age 42 years or older, female body mass index 35 kg/m2 or over, double-sided tubal pathology or severe male factor subfertility. Mild ovarian stimulation was carried out by subcutaneous FSH self-administration. 'Simultaneous IUI' was carried out at the point of HCG triggering for ovulation. 'Regular IUI' was carried out 32-36 h after HCG triggering. RESULTS: The cumulative ongoing pregnancy rate after a maximum of four cycles was 26.2% for simultaneous IUI (43 ongoing pregnancies) and 33.7% for regular IUI (70 ongoing pregnancies) (RR 0.78 95% CI 0.57 to 1.07). Ongoing pregnancy rates per cycle in the simultaneous IUI group were 6.8%, 10.5%, 9.5% and 7.4% for the first, second, third and fourth IUI cycle. In the regular IUI group, ongoing pregnancy rates were 8.3%, 16.4%, 13.5% and 9.0% for the first, second, third and fourth IUI cycle. CONCLUSIONS: This multicentre randomized controlled trial did not demonstrate that IUI carried out at the point of HCG triggering increases pregnancy rates compared with IUI carried out around the time of ovulation.

External Validation and Clinical Usefulness of First Trimester Prediction Models for the Risk of Preeclampsia: A Prospective Cohort Study.

INTRODUCTION: This study assessed the external validity of all published first trimester prediction models for the risk of preeclampsia (PE) based on routinely collected maternal predictors. Moreover, the potential utility of the best-performing models in clinical practice was evaluated. MATERIAL AND METHODS: Ten prediction models were systematically selected from the literature. We performed a multicenter prospective cohort study in the Netherlands between July 1, 2013, and December 31, 2015. Eligible pregnant women completed a web-based questionnaire before 16 weeks' gestation. The outcome PE was established using postpartum questionnaires and medical records. Predictive performance of each model was assessed by means of discrimination (c-statistic) and a calibration plot. Clinical usefulness was evaluated by means of decision curve analysis and by calculating the potential impact at different risk thresholds. RESULTS: The validation cohort contained 2,614 women of whom 76 developed PE (2.9%). Five models showed moderate discriminative performance with c-statistics ranging from 0.73 to 0.77. Adequate calibration was obtained after refitting. The best models were clinically useful over a small range of predicted probabilities. DISCUSSION: Five of the ten included first trimester prediction models for PE showed moderate predictive performance. The best models may provide more benefit compared to risk selection as used in current guidelines.

Ovarian stimulation for IVF and risk of primary breast cancer in BRCA1/2 mutation carriers.

BACKGROUND: The effect of in vitro fertilisation (IVF) on breast cancer risk for BRCA1/2 mutation carriers is rarely examined. As carriers may increasingly undergo IVF as part of preimplantation genetic diagnosis (PGD), we examined the impact of ovarian stimulation for IVF on breast cancer risk in BRCA1/2 mutation carriers. METHODS: The study population consisted of 1550 BRCA1 and 964 BRCA2 mutation carriers, derived from the nationwide HEBON study and the nationwide PGD registry. Questionnaires, clinical records and linkages with the Netherlands Cancer Registry were used to collect data on IVF exposure, risk-reducing surgeries and cancer diagnosis, respectively. Time-dependent Cox regression analyses were conducted, stratified for birth cohort and adjusted for subfertility. RESULTS: Of the 2514 BRCA1/2 mutation carriers, 3% (n = 76) were exposed to ovarian stimulation for IVF. In total, 938 BRCA1/2 mutation carriers (37.3%) were diagnosed with breast cancer. IVF exposure was not associated with risk of breast cancer (HR: 0.79, 95% CI: 0.46-1.36). Similar results were found for the subgroups of subfertile women (n = 232; HR: 0.73, 95% CI: 0.39-1.37) and BRCA1 mutation carriers (HR: 1.12, 95% CI: 0.60-2.09). In addition, age at and recency of first IVF treatment were not associated with breast cancer risk. CONCLUSION: No evidence was found for an association between ovarian stimulation for IVF and breast cancer risk in BRCA1/2 mutation carriers.

Prediction models for the risk of spontaneous preterm birth based on maternal characteristics: a systematic review and independent external validation.

INTRODUCTION: Prediction models may contribute to personalized risk-based management of women at high risk of spontaneous preterm delivery. Although prediction models are published frequently, often with promising results, external validation generally is lacking. We performed a systematic review of prediction models for the risk of spontaneous preterm birth based on routine clinical parameters. Additionally, we externally validated and evaluated the clinical potential of the models. MATERIAL AND METHODS: Prediction models based on routinely collected maternal parameters obtainable during first 16 weeks of gestation were eligible for selection. Risk of bias was assessed according to the CHARMS guidelines. We validated the selected models in a Dutch multicenter prospective cohort study comprising 2614 unselected pregnant women. Information on predictors was obtained by a web-based questionnaire. Predictive performance of the models was quantified by the area under the receiver operating characteristic curve (AUC) and calibration plots for the outcomes spontaneous preterm birth <37 weeks and <34 weeks of gestation. Clinical value was evaluated by means of decision curve analysis and calculating classification accuracy for different risk thresholds. RESULTS: Four studies describing five prediction models fulfilled the eligibility criteria. Risk of bias assessment revealed a moderate to high risk of bias in three studies. The AUC of the models ranged from 0.54 to 0.67 and from 0.56 to 0.70 for the outcomes spontaneous preterm birth <37 weeks and <34 weeks of gestation, respectively. A subanalysis showed that the models discriminated poorly (AUC 0.51-0.56) for nulliparous women. Although we recalibrated the models, two models retained evidence of overfitting. The decision curve analysis showed low clinical benefit for the best performing models. CONCLUSIONS: This review revealed several reporting and methodological shortcomings of published prediction models for spontaneous preterm birth. Our external validation study indicated that none of the models had the ability to predict spontaneous preterm birth adequately in our population. Further improvement of prediction models, using recent knowledge about both model development and potential risk factors, is necessary to provide an added value in personalized risk assessment of spontaneous preterm birth.

Should women be advised to use calcium supplements during pregnancy? A decision analysis.

Adequate calcium intake during pregnancy is important in the prevention of pre-eclampsia. A substantial proportion of pregnant women do not meet the recommended daily calcium intake, even in developed countries. Nonetheless, calcium supplementation is not routinely advised to pregnant women in most countries. We aimed to predict the impact of advising pregnant women to use calcium supplements (1,000 mg/day) on the number of cases of pre-eclampsia prevented and related health care costs. By use of a decision-analytic model, we assessed the expected impact of advising calcium supplementation to either (1) all pregnant women, (2) women at high risk of developing pre-eclampsia, or (3) women with a low dietary calcium intake compared with current care. Calculations were performed for a hypothetical cohort of 100,000 pregnant women living in a high-income country, although input parameters of the model can be adjusted so as to fit other settings. The incidence of pre-eclampsia could be reduced by 25%, 8%, or 13% when advising calcium supplementation to all pregnant women, women at high risk of pre-eclampsia, or women with a low dietary calcium intake, respectively. Expected net financial benefits of the three scenarios were of €4,621,465, €2,059,165, or €2,822,115 per 100,000 pregnant women, respectively. Advising pregnant women to use calcium supplements can be expected to cause substantial reductions in the incidence of pre-eclampsia as well as related health care costs. It appears most efficient to advise calcium supplementation to all pregnant women, not subgroups only.

Practice variation of vaginal birth after cesarean and the influence of risk factors at patient level: a retrospective cohort study.

INTRODUCTION: Large practice variation exists in mode of delivery after cesarean section, suggesting variation in implementation of contemporary guidelines. We aim to evaluate this practice variation and to what extent this can be explained by risk factors at patient level. MATERIAL AND METHODS: This retrospective cohort study was performed among 17 Dutch hospitals in 2010. Women with one prior cesarean section without a contraindication for a trial of labor were included. We used multivariate logistic regression analysis to develop models for risk factor adjustments. One model was derived to adjust the elective repeat cesarean section rates; a second model to adjust vaginal birth after cesarean rates. Standardized rates of elective repeat cesarean section and vaginal birth after cesarean per hospital were compared. Pseudo-R2 measures were calculated to estimate the percentage of practice variation explained by the models. Secondary outcomes were differences in practice variation between hospital types and the correlation between standardized elective repeat cesarean section and vaginal birth after cesarean rates. RESULTS: In all, 1068 women had a history of cesarean section, of whom 71% were eligible for inclusion. A total of 515 women (67%) had a trial of labor, of whom 72% delivered vaginally. The elective repeat cesarean section rate at hospital level ranged from 6 to 54% (mean 29.8, standard deviation 11.8%). Vaginal birth after cesarean rates ranged from 50 to 90% (mean 71.8%, standard deviation 11.1%). More than 85% of this practice variation could not be explained by risk factors at patient level. CONCLUSION: A large practice variation exists in elective repeat cesarean section and vaginal birth after cesarean rates that can only partially be explained by risk factors at patient level.

Influence of embryo culture medium (G5 and HTF) on pregnancy and perinatal outcome after IVF: a multicenter RCT.

STUDY QUESTION: Does embryo culture medium influence pregnancy and perinatal outcome in IVF? SUMMARY ANSWER: Embryo culture media used in IVF affect treatment efficacy and the birthweight of newborns. WHAT IS KNOWN ALREADY: A wide variety of culture media for human preimplantation embryos in IVF/ICSI treatments currently exists. It is unknown which medium is best in terms of clinical outcomes. Furthermore, it has been suggested that the culture medium used for the in vitro culture of embryos affects birthweight, but this has never been demonstrated by large randomized trials. STUDY DESIGN, SIZE, DURATION: We conducted a multicenter, double-blind RCT comparing the use of HTF and G5 embryo culture media in IVF. Between July 2010 and May 2012, 836 couples (419 in the HTF group and 417 in the G5 group) were included. The allocated medium (1:1 allocation) was used in all treatment cycles a couple received within 1 year after randomization, including possible transfers with frozen-thawed embryos. The primary outcome was live birth rate. PARTICIPANTS/MATERIALS, SETTING, METHODS: Couples that were scheduled for an IVF or an ICSI treatment at one of the six participating centers in the Netherlands or their affiliated clinics. MAIN RESULTS AND THE ROLE OF CHANCE: The live birth rate was higher, albeit nonsignificantly, in couples assigned to G5 than in couples assigned to HTF (44.1% (184/417) versus 37.9% (159/419); RR: 1.2; 95% confidence interval (CI): 0.99-1.37; P = 0.08). Number of utilizable embryos per cycle (2.8 ± 2.3 versus 2.3 ± 1.8; P < 0.001), implantation rate after fresh embryo transfer (20.2 versus 15.3%; P < 0.001) and clinical pregnancy rate (47.7 versus 40.1%; RR: 1.2; 95% CI: 1.02-1.39; P = 0.03) were significantly higher for couples assigned to G5 compared with those assigned to HTF. Of the 383 live born children in this trial, birthweight data from 380 children (300 singletons (G5: 163, HTF: 137) and 80 twin children (G5: 38, HTF: 42)) were retrieved. Birthweight was significantly lower in the G5 group compared with the HTF group, with a mean difference of 158 g (95% CI: 42-275 g; P = 0.008). More singletons were born preterm in the G5 group (8.6% (14/163) versus 2.2% (3/137), but singleton birthweight adjusted for gestational age and gender (z-score) was also lower in the G5 than in the HTF group (-0.13 ± 0.08 versus 0.17 ± 0.08; P = 0.008). LIMITATIONS, REASONS FOR CAUTION: This study was powered to detect a 10% difference in live births while a smaller difference could still be clinically relevant. The effect of other culture media on perinatal outcome remains to be determined. WIDER IMPLICATIONS OF THE FINDINGS: Embryo culture media used in IVF affect not only treatment efficacy but also perinatal outcome. This suggests that the millions of human embryos that are cultured in vitro each year are sensitive to their environment. These findings should lead to increased awareness, mechanistic studies and legislative adaptations to protect IVF offspring during the first few days of their existence. STUDY FUNDING/COMPETING INTERESTS: This project was partly funded by The NutsOhra foundation (Grant 1203-061) and March of Dimes (Grant 6-FY13-153). The authors declare no conflict of interest. TRIAL REGISTRATION NUMBER: NTR1979 (Netherlands Trial Registry). TRIAL REGISTRATION DATE: 1 September 2009. DATE OF FIRST PATIENT'S ENROLMENT: 18 July 2010.

Age of G-1 PLUS v5 embryo culture medium is inversely associated with birthweight of the newborn.

STUDY QUESTION: Does age of G-1 PLUS v5 embryo culture medium affect IVF outcome? SUMMARY ANSWER: Birthweight of singletons born after IVF showed an inverse association with age of the embryo culture medium, while no association was found between age of culture medium and fertilization rate, embryonic development or ongoing pregnancy. WHAT IS KNOWN ALREADY: It has been reported that IVF culture media can deteriorate during storage, which suggests that the capacity of culture media to support optimal embryo development decreases over time. Some animal studies showed an effect of storage time on embryo development, in contrast to other studies, while the effect of aging culture medium on IVF outcome in humans is unknown. STUDY DESIGN, SIZE, DURATION: We used data on outcome of 1832 IVF/ICSI cycles with fresh embryo transfer, performed in the period 2008-2012 to evaluate the association of fertilization rate, embryonic development, ongoing pregnancy and birthweight of singletons with age of the culture medium (Vitrolife AB G-1 PLUS v5). PARTICIPANTS/MATERIALS, SETTING, METHODS: Age of the culture medium was calculated by subtracting the production date from the date of ovum retrieval. Data analysis included linear regression and logistic regression on continuous and categorical outcomes, respectively. MAIN RESULTS AND THE ROLE OF CHANCE: Age of the culture medium was not associated with fertilization rate (P = 0.543), early cleavage rate (P = 0.155), percentage of embryos containing four or more cells on Day 2 (P = 0.401), percentage of embryos containing eight or more cells on Day 3 (P = 0.175), percentage of embryos with multinucleated blastomeres (P = 0.527), or ongoing pregnancy (P = 0.729). However, birthweight of the newborn was inversely associated with age of the medium (ß = -3.6 g, SE: 1.5 g, P = 0.021), after controlling for possible confounders (day of embryo transfer, number of transferred embryos, child's gender, gestational age at birth, parity, pregnancy complications, maternal smoking, height and weight, and paternal height and weight) and the association was not biased by year of treatment, time since first opening of the bottle or batch variations. This indicates a difference of 234 g in birthweight of newborns for media with an age difference of 65 days. LIMITATIONS, REASONS FOR CAUTION: The results from this study may be specific for the G-1 PLUS v5 culture medium and extrapolation of the results to other media should be done with caution because of the differences in composition and shelf life. WIDER IMPLICATIONS OF THE FINDINGS: Age of G-1 PLUS v5 medium used to culture human embryos affects birthweight of the respective newborn. This could imply that the preimplantation embryo adapts to its in vitro environment with lasting in vivo consequences. Therefore, it is important that companies are transparent about the exact composition of their embryo culture media, which will allow IVF clinics to further investigate the effects of the media or media components on the health of IVF children. STUDY FUNDING/COMPETING INTERESTS: No funding and no competing interests declared. TRIAL REGISTRATION NUMBER: Not applicable.

The influence of preferred place of birth on the course of pregnancy and labor among healthy nulliparous women: a prospective cohort study.

BACKGROUND: Most studies on birth settings investigate the association between planned place of birth at the start of labor and birth outcomes and intervention rates. To optimize maternity care it also is important to pay attention to the entire process of pregnancy and childbirth. This study explores the association between the initial preferred place of birth and model of care, and the course of pregnancy and labor in low-risk nulliparous women in the Netherlands. METHODS: As part of a Dutch prospective cohort study (2007-2011), we compared medical indications during pregnancy and birth outcomes of 576 women who initially preferred a home birth (n = 226), a midwife-led hospital birth (n = 168) or an obstetrician-led hospital birth (n = 182). Data were obtained by a questionnaire before 20 weeks of gestation and by medical records. Analyses were performed according to the initial preferred place of birth. RESULTS: Low-risk nulliparous women who preferred a home birth with midwife-led care were less likely to be diagnosed with a medical indication during pregnancy compared to women who preferred a birth with obstetrician-led care (OR 0.41 95% CI 0.25-0.66). Preferring a birth with midwife-led care - both at home and in hospital - was associated with lower odds of induced labor (OR 0.51 95% CI 0.28-0.95 respectively OR 0.42 95% CI 0.21-0.85) and epidural analgesia (OR 0.32 95% CI 0.18-0.56 respectively OR 0.34 95% CI 0.19-0.62) compared to preferring a birth with obstetrician-led care. In addition, women who preferred a home birth were less likely to experience augmentation of labor (OR 0.54 95% CI 0.32-0.93) and narcotic analgesia (OR 0.41 95% CI 0.21-0.79) compared to women who preferred a birth with obstetrician-led care. We observed no significant association between preferred place of birth and mode of birth. CONCLUSIONS: Nulliparous women who initially preferred a home birth were less likely to be diagnosed with a medical indication during pregnancy. Women who initially preferred a birth with midwife-led care - both at home and in hospital - experienced lower rates of interventions during labor. Although some differences can be attributed to the model of care, we suggest that characteristics and attitudes of women themselves also play an important role.

IVF culture medium affects post-natal weight in humans during the first 2 years of life.

STUDY QUESTION: Is post-natal growth during the first 2 years of life in IVF singletons affected by type of medium used for culturing human embryos during an IVF treatment? SUMMARY ANSWER: The in vitro culture of human embryos in medium from Cook resulted in singletons with a lower weight during the first 2 years of life compared with singletons born after embryo culture in medium from Vitrolife. WHAT IS KNOWN ALREADY: In a previous study, we reported that type of medium used for culturing human IVF embryos during the first few days after fertilization until fresh embryo transfer significantly affects fetal growth and consequently birthweight of the resulting singletons. STUDY DESIGN, SIZE, DURATION: From July 2003 to December 2006, a total of 1432 IVF treatment cycles with fresh embryo transfer were randomly allocated to have all embryos cultured in medium from Vitrolife AB (n = 715) or from Cook (n = 717). Two years after delivery, questionnaires were sent to the parents of all children requesting data about weight, height and head circumference around 1, 2, 3, 4, 6, 7.5, 9, 11, 14, 18 and 24 months of age. These measurements were collected as part of the children's health programme at municipal infant welfare centres in the Netherlands by health professionals unaware of this study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients requiring donor oocytes or applying for PGD were excluded from the study. From the 294 live born singletons that fulfilled our inclusion criteria, 29 were lost to follow-up. The remaining 265 singletons (Cook group: 117, Vitrolife group: 148) were included in the analysis. Data analysis included linear regression, to compare cross-sectionally weight standard deviation score (SDS), height SDS and head circumference, and the first order Berkey-Reed model for a longitudinal analysis of the growth data. MAIN RESULTS AND THE ROLE OF CHANCE: Singletons in the Vitrolife group were heavier during the first 2 years of life compared with singletons in the Cook group. Cross-sectional analyses showed that adjusted weight SDS differed between groups at 1 (0.35 ± 0.14, P = 0.010), 2 (0.39 ± 0.14, P = 0.006), 3 (0.35 ± 0.14, P = 0.011), 4 (0.30 ± 0.13, P = 0.020), 11 (0.28 ± 0.13, P = 0.036), 14 (0.32 ± 0.13, P = 0.014) and 24 (0.39 ± 0.15, P = 0.011) months of age, while adjusted height SDS was only significantly different at 1 (0.21 ± 0.11, P = 0.048) month of age. Head circumference was similar between the two groups at all ages. Longitudinal analyses showed that both post-natal weight (P = 0.005) and height (P = 0.031) differed between the groups throughout the first 2 years of life, while the growth velocity was not significantly different between the two groups. LIMITATIONS, REASONS FOR CAUTION: Factors that might influence post-natal growth were included in the analysis; however, it was not possible to include all such factors, for example childhood diseases or nutrition, as this information was not available. WIDER IMPLICATIONS OF THE FINDINGS: The effect of culture medium during the first few days after fertilization on prenatal growth and birthweight persists during the first 2 years of life. This suggests that the human embryo is sensitive to its very early environment, and that the culture medium used in IVF may have lasting consequences. Further monitoring of the long-term growth, development and health of IVF children is therefore warranted. STUDY FUNDING/COMPETING INTEREST(S): W.V. was funded with an unrestricted research grant from the Stichting Fertility Foundation. The authors declare no conflict of interest. TRIAL REGISTRATION NUMBER: Not applicable.