BackgroundPreterm birth is the most common single cause of perinatal and infant mortality, affecting 15 million infants worldwide each year with global rates increasing. Understanding of risk factors remains poor, and preventive interventions have only limited benefit. Large differences exist in preterm birth rates across high income countries. We hypothesized that understanding the basis for these wide variations could lead to interventions that reduce preterm birth incidence in countries with high rates. We thus sought to assess the contributions of known risk factors for both spontaneous and provider-initiated preterm birth in selected high income countries, estimating also the potential impact of successful interventions due to advances in research, policy and public health, or clinical practice.MethodsWe analyzed individual patient-level data on 4.1 million singleton pregnancies from four countries with very high human development index (Czech Republic, New Zealand, Slovenia, Sweden) and one comparator U.S. state (California) to determine the specific contribution (adjusting for confounding effects) of 21 factors. Both individual and population-attributable preterm birth risks were determined, as were contributors to cross-country differences. We also assessed the ability to predict preterm birth given various sets of known risk factors.FindingsPrevious preterm birth and preeclampsia were the strongest individual risk factors of preterm birth in all datasets, with odds ratios of 4.6–6.0 and 2.8–5.7, respectively, for individual women having those characteristics. In contrast, on a population basis, nulliparity and male sex were the two risk factors with the highest impact on preterm birth rates, accounting for 25–50% and 11–16% of excess population attributable risk, respectively (p<0.001). The importance of nulliparity and male sex on population attributable risk was driven by high prevalence despite low odds ratios for individual women. More than 65% of the total aggregated risk of preterm birth within each country lacks a plausible biologic explanation, and 63% of difference between countries cannot be explained with known factors; thus, research is necessary to elucidate the underlying mechanisms of preterm birth and, hence, therapeutic intervention. Surprisingly, variation in prevalence of known risk factors accounted for less than 35% of the difference in preterm birth rates between countries. Known risk factors had an area under the curve of less than 0.7 in ROC analysis of preterm birth prediction within countries. These data suggest that other influences, as yet unidentified, are involved in preterm birth. Further research into biological mechanisms is warranted.ConclusionsWe have quantified the causes of variation in preterm birth rates among countries with very high human development index. The paucity of explicit and currently identified factors amenable to intervention illustrates the limited impact of changes possible through current clinical practice and policy interventions. Our research high...
The non-ablative Er:YAG laser therapy improves the impact of SUI symptoms on quality of life and sexual function in premenopausal parous women significantly better than placebo. It provides a promising minimally-invasive safe treatment alternative for SUI.
ObjectiveInfants from multiple pregnancies have higher rates of preterm birth, stillbirth and neonatal death and differences in multiple birth rates (MBR) exist between countries. We aimed to describe differences in MBR in Europe and to investigate the impact of these differences on adverse perinatal outcomes at a population level.MethodsWe used national aggregate birth data on multiple pregnancies, maternal age, gestational age (GA), stillbirth and neonatal death collected in the Euro-Peristat project (29 countries in 2010, N = 5 074 643 births). We also used European Society of Human Reproduction and Embryology (ESHRE) data on assisted conception and single embryo transfer (SET). The impact of MBR on outcomes was studied using meta-analysis techniques with random-effects models to derive pooled risk ratios (pRR) overall and for four groups of country defined by their MBR. We computed population attributable risks (PAR) for these groups.ResultsIn 2010, the average MBR was 16.8 per 1000 women giving birth, ranging from 9.1 (Romania) to 26.5 (Cyprus). Compared to singletons, multiples had a nine-fold increased risk (pRR 9.4, 95% Cl 9.1–9.8) of preterm birth (<37 weeks GA), an almost 12-fold increased risk (pRR 11.7, 95% CI 11.0–12.4) of very preterm birth (<32 weeks GA). Pooled RR were 2.4 (95% Cl 1.5–3.6) for fetal mortality at or after 28 weeks GA and 7.0 (95% Cl 6.1–8.0) for neonatal mortality. PAR of neonatal death and very preterm birth were higher in countries with high MBR compared to low MBR (17.1% (95% CI 13.8–20.2) versus 9.8% (95% Cl 9.6–11.0) for neonatal death and 29.6% (96% CI 28.5–30.6) versus 17.5% (95% CI 15.7–18.3) for very preterm births, respectively).ConclusionsWide variations in MBR and their impact on population outcomes imply that efforts by countries to reduce MBR could improve perinatal outcomes, enabling better long-term child health.
A retrospective matched-control study to evaluate the effect of uterine anomalies on pregnancy rates after 2481 embryo transfers in conventionally stimulated IVF/intracytoplasmic sperm injection (ICSI) cycles. The study group of 289 embryo transfers before and 538 embryo transfers following hysteroscopic resection of a uterine septum was compared with two consecutive embryo transfers in the control group. Groups were matched for age, body mass index, ovarian stimulation, embryo quality, IVF or ICSI and infertility aetiologies. Number of embryos transferred, embryo quality and absence of uterine anomalies significantly predicted the pregnancy rates in the study group: odds ratios (OR) 1.7, 2.6 and 2.5, respectively (P<0.001). Pregnancy rates after embryo transfer before hysteroscopic metroplasty were significantly lower, both in women with subseptate and septate uterus and in women with arcuate uterus compared with controls. If two or three embryos with at least one best-quality embryo were transferred, the differences were 9.6% versus 43.6%, OR 7.3 (P<0.001) and 20.9% versus 35.5%, OR 2.1 (P<0.03), respectively. Differences in terms of live birth rates were even more evident: 1.9% versus 38.6%, OR 32 (P<0.001) and 3.0% versus 30.4%, OR 14 (P<0.001). After surgery, the differences disappeared. This retrospective matched control study evaluated the influence of septate, subseptate and arcuate uterus on pregnancy and live birth rates after 2481 in conventionally stimulated IVF/intracytoplasmic sperm injection (ICSI) cycles. The study group included 827 embryo transfers (289 embryo transfers before and 538 embryo transfers following hysteroscopic resection of uterine septum ans was compared with two consecutive mebryo transfers in the control group. Both groups were matched by age, body mass index, stimulation protocol, quality of embryos, use of IVF or ICSI, and infertility aetiologies. Multivariate logistic regression analysis of the study group showed that the number of embryos, embryo quality and the absence of uterine anomalies significantly predicted the pregnancy rates: odds ratios (OR) 1.7, 2.6, and 2.5, respectively (P<0.001). The pregnancy and live birth rates before surgery were lower compared with controls, both in women with subseptate or septate uterus and in women with arcuate uterus. If two or three embryos with at least one best quality embryo were transferred, the differences in terms of pregnancy rates were 9.6% versus 43.6%, OR=7.3 (P<0.001) and 20.9% versus 35.5%, OR=2.1 (P<0.03), respectively. The differences in terms of live birth rates were even more evident: 1.9% versus 38.6%, OR=32 (P<0.001) and 3.0% versus 30.4%, OR=14 (P<0.001). After surgery, the differences disappeared. Negative impact of uterine anomalies on pregnancy and on live birth rates are two important arguments for treating uterine anomalies in infertile women.
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