OBJECTIVE: To study the possible associations between advanced maternal age and risk of selected adverse pregnancy outcomes. METHODS: The study used a nationwide cohort of 369,516 singleton pregnancies in Denmark followed from 11–14 weeks of gestation to delivery or termination of pregnancy. Pregnant women aged 35 years or older were divided into two advanced maternal age groups, 35–39 years and 40 years or older, and compared with pregnant women aged 20–34 years. Adverse pregnancy outcomes were chromosomal abnormalities, congenital malformations, miscarriage, stillbirth, and birth before 34 weeks of gestation. Multivariable logistic regression analyses were performed to investigate associations between advanced maternal age and adverse pregnancy outcomes. Furthermore, a risk prediction model for a composite adverse pregnancy outcome was made with prespecified predicting factors. RESULTS: Among the pregnant women aged 40 years or older, 10.82% experienced one or more of the selected adverse pregnancy outcomes compared with 5.46% of pregnant women aged 20–34 years (odds ratio [OR] 2.02, 99.8% CI 1.78–2.29). When pregnant women 40 years or older were compared with women aged 20–34 years, they had a higher risk of chromosomal abnormalities (3.83% vs 0.56%, OR 7.44 [CI 5.93–9.34]), miscarriage (1.68% vs 0.42%, OR 3.10 [CI 2.19–4.38]), and birth before 34 weeks of gestation (2.01% vs 1.21%, OR 1.66 [CI 1.23–2.24]), but no increased risk of congenital malformations and stillbirth. The risk prediction chart showed that advanced maternal age, use of assisted reproductive technology, nulliparous pregnancy, smoking during pregnancy, and obesity increased the absolute predictive risk of an adverse pregnancy outcome. CONCLUSION: Women older than 40 years have a higher risk of chromosomal abnormalities, miscarriage, and birth before 34 weeks of gestation than younger women and should be monitored accordingly. No increased risk was observed for stillbirth and other congenital malformations. Several factors increase the risk of adverse pregnancy outcomes, but advanced maternal age drives a high proportion of the total risk score.

Background: A secular trend towards earlier puberty has been observed in girls, while a similar trend has been more uncertain in boys. We estimated current ages at pubertal development in both boys and girls.Methods: In this population‐based cohort study, 14 759 of 22 439 invited boys and girls born from 2000 to 2003 in the Danish National Birth Cohort gave half‐yearly self‐reported information on puberty from the age of 11.5 years and throughout puberty. This late start of follow‐up limits the estimation of age at onset of puberty but not later pubertal milestones. We estimated mean age at attaining the following pubertal milestones in years with 95% confidence intervals (CI): age at menarche, voice break, first ejaculation of semen and Tanner stages for pubic hair development and breast development or genital development. Further, the difference in mean age at menarche between mothers and daughters was estimated.Results: In boys, voice break occurred at 13.1 (95% CI 13.0, 13.1) years, first ejaculation of semen occurred at 13.4 (95% CI 13.3, 13.4) years, and Tanner Genital Stage 5 occurred at 15.6 (95% CI 15.5, 15.6) years. In girls, age at menarche occurred at 13.0 (95% CI 13.0, 13.1) years and Tanner Breast Stage 5 occurred at 15.8 (95% CI 15.7, 15.9) years. Daughters had menarche 3.6 (95% CI 3.1, 4.2) months earlier than their mothers had.Conclusion: These data indicate that age at menarche has declined and to some extent support a decline in age at attaining other markers of pubertal development among boys.

Our concept of biological membranes has markedly changed, from the fluid mosaic model to the current model that lipids and proteins have the ability to separate into microdomains, differing in their protein and lipid compositions. Since the breakthrough in crystallizing membrane proteins, the most powerful method to define lipid-binding sites on proteins has been X-ray and electron crystallography. More recently, chemical biology approaches have been developed to analyze protein–lipid interactions. Such methods have the advantage of providing highly specific cellular probes. With the advent of novel tools to study functions of individual lipid species in membranes together with structural analysis and simulations at the atomistic resolution, a growing number of specific protein–lipid complexes are defined and their functions explored. In the present article, we discuss the various modes of intramembrane protein–lipid interactions in cellular membranes, including examples for both annular and nonannular bound lipids. Furthermore, we will discuss possible functional roles of such specific protein–lipid interactions as well as roles of lipids as chaperones in protein folding and transport.