Search

Introduction: Preterm birth (PTB) is the leading cause of infant mortality and morbidity worldwide. Rates of PTB in the Netherlands are declining, possibly due to the implementation of preventive strategies. In this study we assessed the overall trend in PTB rates in the Netherlands in recent years, and in more detail in specific subgroups to investigate potential groups that require scrutiny in the near future. Material and methods: Based on the national perinatal registry, we included all pregnancies without severe congenital abnormalities resulting in a birth from 24 to 42 completed weeks of gestation between 2011 and 2019 in the Netherlands. We assessed PTB rates in two different clinical subtypes (spontaneous vs. iatrogenic) and in five gestational age subgroups: 24–27+6 weeks (extreme), 28–31+6 weeks (very), 32–33+6 weeks (moderate, 34–36+6 weeks [late] and, in general, 24–36+6 weeks [overall PTB]). Trend analysis was performed using the Cochran Armitage test. We also compared PTB rates in different subgroups in the first 2 years compared to the last 2 years. Singleton and multiple gestations were analyzed separately. Results: We included 1 447 689 singleton and 23 250 multiple pregnancies in our study. In singletons, we observed a significant decline in PTB from 5.5% to 5.0% (p < 0.0001), mainly due to a decrease in iatrogenic PTBs. When focusing on different gestational age subgroups, there was a decrease in all iatrogenic PTB and in moderate to late spontaneous PTB. However, in spontaneous extreme and very PTB there was an significant increase. When assessing overall PTB risk in different subgroups, the decline was only visible in women with age ≥25 years, nulliparous and primiparous women, women with a medium or high socioeconomic status and hypertensive women. In multiples, the rate of PTB remained fairly stable, from 52.3% in 2011 to 54.1% in 2019 (p = 0.57). Conclusions: In the Netherlands, between 2011 and 2019, PTB decreased, mainly due to a reduction in late PTB, and more in iatrogenic than in spontaneous PTB. Focus for the near future should be on specific subgroups in which the decline was not visible, such as women with a low socioeconomic status or a young age. [ABSTRACT FROM AUTHOR]

Abstract Background Preterm labour is the main cause of perinatal morbidity and mortality in the Western world. At present, there is evidence that tocolysis for 48 hours is useful in women with threatened preterm labour at least before 32 weeks. This allows transfer of the patient to a perinatal centre, and maximizes the effect of corticosteroids for improved neonatal survival. It is questionable whether treatment with tocolytics should be maintained after 48 hours. Methods/Design The APOSTEL II trial is a multicentre placebo-controlled study. Pregnant women admitted for threatened preterm labour who have been treated with 48 hours corticosteroids and tocolysis will be eligible to participate in the trial between 26+0 and 32+2 weeks gestational age. They will be randomly allocated to nifedipine (intervention) or placebo (control) for twelve days or until delivery, whatever comes first. Primary outcome is a composite of perinatal death, and severe neonatal morbidity up to evaluation at 6 months after birth. Secondary outcomes are gestational age at delivery, number of days in neonatal intensive care and total days of the first 6 months out of hospital. In addition a cost-effectiveness analysis will be performed. Analysis will be by intention to treat. The power calculation is based on an expected 11% difference in adverse neonatal outcome. This implies that 406 women have to be randomised (two sided test, β 0.2 at alpha 0.05). Discussion This trial will provide evidence as to whether maintenance tocolysis reduces severe perinatal morbidity and mortality in women with threatened preterm labour before 32 weeks. Trial Registration Clinical trial registration: http://www.trialregister.nl, NTR 1336, date of registration: June 3rd 2008.

Objective: To assess the effect of maintenance tocolysis in women who are at high or low risk for preterm delivery according to fetal fibronectin (fFN) status and cervical length (CL).Study Design: We compared the risk of preterm delivery in fFN pos and fFN neg women and in women with a CL <15 mm and ≥15 mm, by using the Cox regression. Differences between the effectiveness of maintenance tocolysis in high- and low-risk women were assessed by using an interaction term.Results: 122 fFN tests were taken, of which 50 were fFN pos. CL was measured in 236 women, of whom 52 women had a CL <15 mm. The median gestational age at delivery was lower in fFN pos women; fFN pos women had a higher hazard for preterm delivery at any point of time (HR 4.7; 95% CI 2.9 to 7.6). Comparable results were seen for CL. Neither fFN status nor CL did alter the effect of maintenance tocolysis, which was ineffective in the total randomized group, on the risk of preterm delivery (p for interaction = 0.87 for fFN and 0.18 for CL).Conclusion: Maintenance tocolytic therapy with nifedipine is ineffective and not dependent on fFN or CL status. [ABSTRACT FROM AUTHOR]

Objective: Spontaneous preterm birth is the leading cause of infant morbidity and mortality in the developed world. Environmental socio-economic factors, such as neighborhood deprivation, are known to negatively affect birth outcomes, including overall preterm birth. However, the role of neighborhood deprivation in spontaneous preterm birth (SPTB) is unclear. The aim of the study is to 1) to determine the effect of neighborhood deprivation on SPTB birth and 2) to investigate the trend in rates of SPTB between 2010 and 2019 for each quintile of neighborhood deprivation., Study Design: Based on the national perinatal registry, we included 1,584,225 singleton pregnancies resulting in a birth from 22 to 42 completed weeks of gestation between 2010 and 2019 in the Netherlands. Deprivation scores per neighborhood were derived from the Netherlands Institute of Social Research and were linked to the perinatal registry data, using the woman's home address. The scores were divided into quintiles (Q). Rates of SPTB were calculated, categorized into <37 weeks, <32 weeks and <28 weeks of gestation. We used logistic regression analysis to adjust for maternal age, parity and ethnicity., Results: Compared to the most affluent neighborhoods (Q1), women in all other quintiles had a statistically significant increased risk for SPTB. The largest effect was observed in the most deprived neighborhoods (Q5); adjusted odds ratio 1.16 (95% confidence interval 1.13 - 1.19). From 2010 to 2019, we observed an overall decrease of 0.21% in SPTB < 37 weeks (p < 0.0001). All quintiles showed a decrease in SPTBs < 37 weeks, but only in Q1, Q2 & Q5 this decline in SPTB was statistically significant., Conclusions: Pregnant women in deprived neighborhoods in the Netherlands are more at risk for spontaneous preterm birth. From 2010 to 2019, the rate of spontaneous preterm birth decreased. Efforts should be made by both governmental and medical professionals to develop intervention programs to reduce spontaneous preterm birth in more deprived neighborhoods., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Introduction: The APOSTEL-II trial was a multicenter randomized placebo-controlled trial, assessing the effectiveness of maintenance tocolysis with nifedipine. The trial showed maintenance tocolysis not to have an effect on perinatal outcome. Objective of the current study is to evaluate the effect of a negative trial on the length of hospital admission of women with threatened preterm labor., Materials and Methods: We evaluated length of hospital admission of all patients admitted with threatened preterm labor with a gestational age <32 weeks in 8 perinatal centers that participated in the APOSTEL-II trial. We studied only the first admission with threatened preterm labor, readmissions were excluded. We distinguished between the period before, the period during and the period after the trial. In a subgroup analysis, we differentiated for the group of women who delivered and for the group of women who did not deliver during the initial admission., Results: The mean length of hospital admission was 9.3 days before the start of the trial, 8.4 days during the recruitment period and 8.1 days after the trial was completed. The difference in mean length of hospital admission before and during the recruitment period was significantly different (p<001)., Comments: The length of hospital admission of women with threatened preterm labor is found to be reduced during the recruitment period of the APOSTEL-II trial. This shows that the conduct of a randomized controlled trial itself has the potential to change daily practice., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Objective: The pharmacokinetics of nifedipine as a tocolytic agent has not been studied in great detail in pregnant women and has instead focused on immediate release tablets and gastrointestinal therapeutic system (GITS) tablets. The aim of this study was to determine nifedipine slow-release half-life and distribution volume in pregnant women and to compare these with pharmacokinetic parameters of nifedipine in non-pregnant subjects described in the literature., Materials: This is a study parallel to a trial studying women with threatened preterm labor between 26 + 0 and 32 + 2 weeks after initial tocolysis and a completed course of corticosteroids, who were randomly allocated to maintenance nifedipine (slow-release tablets 20 mg 4 times daily) or placebo. Exclusion criteria for the pharmacokinetic study were contra-indications for nifedipine, impaired liver function, and concomitant intake of inhibitors or inducers of the cytochrome P450 3A4 isoenzyme. Blood samples for measuring nifedipine plasma concentrations were drawn at t = 0, t = 12 hours, t = 24 hours, t = 48 hours, t = 72 hours, t = 7 days, and t = 9 days., Methods: Pharmacokinetic parameters were estimated using iterative two-stage Bayesian population pharmacokinetic analysis by MWPharm© software. The study was designed to establish a correlation between body weight and nifedipine plasma level., Results: The pharmacokinetic parameters of nifedipine slow-release tablets were determined from the data of 8 pregnant women. Nifedipine slow-release had a half-life of 2 - 5 hours, a mean distribution volume of 6.2 ± 1.9 L/kg (calculated while using a fixed biological availability of 0.45 taken from the literature due to lack of intravenous data in this population) compared to a half-life of 6 - 11 hours, and a distribution volume of 1.2 - 1.3 L/kg described in non-pregnant subjects in the literature. None of the women delivered during study medication. Study medication was continued for the duration of the pharmacokinetic study (9 days) in all women. A correlation between nifedipine plasma levels and maternal body weight was not demonstrated. This may have been caused by lack of power., Conclusion: Pregnant subjects in this study, using nifedipine slow-release tablets, showed a larger volume of distribution and a shorter elimination half-life than for non-pregnant subjects as published in the literature.

When generating guidelines, quality of evidence is frequently reported in tabulated form capturing several domains, for example, study design, risk of bias and heterogeneity. Increasingly, this is done using the Grading of Recommendations Assessment, Development and Evaluation approach. As assimilating large amount of tabulated data across several comparisons and outcomes spread over many pages (sometimes hundreds) is not easy, there is a need to present evidence summaries in a more effective way. A graphic display plotting the several domains used in evidence grading on equiangular spokes starting from the same point, the data length of each spoke proportional to the magnitude of the quality, succinctly captures tabulated information. These plots allow easy identification of deficiencies, outliers and similarities in evidence quality for individual and multiple comparisons and outcomes, paving the way for their routine use alongside tabulated information.