Lowest-low fertility, defined as a period total fertility rate at or below 1.3, has rapidly spread in Europe during the 1990s. This article traces the emergence of this new phenomenon to the interaction of five factors. First, tempo and compositional distortions reduce the total fertility rate below the associated level of cohort fertility. Second, socioeconomic changes—including increased returns to human capital and high economic uncertainty in early adulthood—have made late childbearing a rational response for individuals and couples. Third, social interaction effects reinforce this behavioral adjustment and contribute to large and persistent postponement in the mean age at birth. Fourth, institutional settings favor an overall low quantum of fertility. Fifth, postponement–quantum interactions amplify the consequences of this institutional setting when combined with ongoing delays of child-bearing. The article concludes with speculations about future trends in current and prospective lowest-low-fertility countries.

The Emergence of Lowest‐Low Fertility in Europe During the 1990s

Why do girls tend to earn better grades in school than boys? Why are men still far more likely than women to earn degrees in the fields of science, technology, engineering, and mathematics? And why are men on average more likely to be injured in accidents and fights than women? These and many other questions are the subject of both informal investigation in the media and formal investigation in academic and scientific circles. In his landmark book "Male, Female: The Evolution of Human Sex Differences", author David Geary provided the first comprehensive evolutionary model to explain human sex differences. Using the principles of sexual selection such as female choice and male-male competition, the author systematically reviewed and discussed the evolution of sex differences and their expression throughout the animal kingdom, as a means of not just describing but explaining the same process in Homo sapiens. Now, over ten years since the first edition, Geary has completed a massive update, expansion and theoretical revision of his classic text. New findings in brain and genetic research inform a wealth of new material, including a new chapter on sex differences in patterns of life history development; expanded coverage of genetic research (e.g. DNA finger printing to determine paternity as related to male-male competition in primates); fatherhood in humans; cross-cultural patterns of sex differences in choosing and competing for mates; and, genetic, hormonal, and socio-cultural influences on the expression of sex differences. Finally, through his motivation to control framework (introduction in the first edition and expanded in "The Origin of Mind", 2005), Geary presents a theoretical bridge linking parenting, mate choices, and competition, with children's development and sex differences in brain and cognition. The result is an even better book than the original - a lively and nuanced application of Darwin's insight to help explain our heritage and our place in the natural world.

Male, Female: The Evolution of Human Sex Differences

von Willebrand disease (VWD) is a commonly encountered inherited bleeding disorder affecting both males and females, causing mucous membrane and skin bleeding symptoms, and bleeding with surgical or other haemostatic challenges. VWD may be disproportionately symptomatic in women of child-bearing age. It may also occur less frequently as an acquired disorder (acquired von Willebrand syndrome). VWD is caused by deficiency or dysfunction of von Willebrand factor (VWF), a plasma protein that mediates platelet haemostatic function and stabilizes blood coagulation factor VIII. The pathophysiology, classification, diagnosis and management of VWD are relatively complex, but understanding them is important for proper diagnosis and management of patients with VWD. These evidence-based guidelines for diagnosis and management of VWD from the National Heart, Lung, and Blood Institute (NHLBI) Expert Panel (USA) review relevant publications, summarize current understanding of VWD pathophysiology and classification, and present consensus diagnostic and management recommendations based on analysis of the literature and expert opinion. They also suggest an approach for clinical and laboratory evaluation of individuals with bleeding symptoms, history of bleeding or conditions associated with increased bleeding risk. This document summarizes needs for further research in VWF, VWD and bleeding disorders, including clinical research to obtain more objective information about bleeding symptoms, advancements in diagnostic and therapeutic tools, and enhancement in the education and training of clinicians and scientists in bleeding and thrombotic disorders. The NHLBI Web site (http://www.nhlbi.nih.gov/guidelines/vwd) has a more detailed document, a synopsis of these recommendations, and patient education information.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2516.2007.01643.x

von Willebrand disease (VWD): evidence-based diagnosis and management guidelines, the National Heart, Lung, and Blood Institute (NHLBI) Expert Panel report (USA).

http://www.saegre.org.ar/biblioteca/arbol_bibliografico/octubre2006/BJ2005_403-8-wei-risk-pre-preg.pdf

Pre-pregnancy weight and the risk of stillbirth and neonatal death.

Recurrent miscarriage (RM; > or =3 consecutive early pregnancy losses) affects around 1% of fertile couples. Parental chromosomal anomalies, maternal thrombophilic disorders and structural uterine anomalies have been directly associated with recurrent miscarriage; however, in the vast majority of cases the pathophysiology remains unknown. We have updated the ESHRE Special Interest Group for Early Pregnancy (SIGEP) protocol for the investigation and medical management of RM. Based on the data of recently published large randomized controlled trials (RCTs) and meta-analyses, we recommend that basic investigations of a couple presenting with recurrent miscarriage should include obstetric and family history, age, BMI and exposure to toxins, full blood count, antiphospholipid antibodies (lupus anticoagulant and anticardiolipin antibodies), parental karyotype, pelvic ultrasound and/or hysterosalpingogram. Other investigations should be limited to particular cases and/or used within research programmes. Tender loving care and health advice are the only interventions that do not require more RCTs. All other proposed therapies, which require more investigations, are of no proven benefit or are associated with more harm than good.

Evidence-based guidelines for the investigation and medical treatment of recurrent miscarriage

Objective: To estimate the association between maternal age and fetal death (spontaneous abortion, ectopic pregnancy, stillbirth), taking into account a woman9s reproductive history. Design: Prospective register linkage study. Subjects: All women with a reproductive outcome (live birth, stillbirth, spontaneous abortion leading to admission to hospital, induced abortion, ectopic pregnancy, or hydatidiform mole) in Denmark from 1978 to 1992; a total of 634 272 women and 1 221 546 pregnancy outcomes. Main outcome measures: Age related risk of fetal loss, ectopic pregnancy, and stillbirth, and age related risk of spontaneous abortion stratified according to parity and previous spontaneous abortions. Results: Overall, 13.5% of the pregnancies intended to be carried to term ended with fetal loss. At age 42 years, more than half of such pregnancies resulted in fetal loss. The risk of a spontaneous abortion was 8.9% in women aged 20–24 years and 74.7% in those aged 45 years or more. High maternal age was a significant risk factor for spontaneous abortion irrespective of the number of previous miscarriages, parity, or calendar period. The risk of an ectopic pregnancy and stillbirth also increased with increasing maternal age. Conclusions: Fetal loss is high in women in their late 30s or older, irrespective of reproductive history. This should be taken into consideration in pregnancy planning and counselling.

https://www.bmj.com/content/bmj/320/7251/1708.full.pdf

Maternal age and fetal loss: population based register linkage study

Secular and seasonal variation of length and weight at birth

Second-trimester maternal serum alpha-fetoprotein and risk of adverse pregnancy outcome

DESIGN AND SETTING To study the effects of maternal age on fetal loss, data on reproductive outcomes were obtained from three Danish populationbased health registries. Reproductive outcome was defined as live birth, stillbirth, spontaneous abortion, hydatidiform mole, ectopic pregnancy, or induced abortion. The risk of fetal loss according to maternal age was estimated as a proportion of all pregnancies intended to be carried to term—that is, live births, stillbirths, spontaneous abortions (including hydatidiform mole), and ectopic pregnancies. To assess the risk of stillbirth according to maternal age, only pregnancies at risk of becoming a stillbirth (ie, a pregnancy carried to 28 weeks or longer) were taken into consideration, and consequently, the risk constitutes the proportion of stillbirths among all births.

/pdf/is-maternal-age-an-independent-risk-factor-for-fetal-loss-4rfdv3ryfx.pdf

Is maternal age an independent risk factor for fetal loss

Background. Levels of maternal alpha-fetoprotein (AFP) are increased during multiple gestations and preeclampsia but little is known regarding AFP levels in relation to other reproductive factors. Consequently, the objective of this work was to describe the possible relationship between AFP levels during pregnancy and maternal age at birth, maternal age at first birth, parity, time since previous birth and gender of the offspring. Methods. Based on national registries we obtained the reproductive history on a population-based cohort of 44 227 women who had serum AFP levels determined in gestational weeks 14-21 and whose present and previous pregnancies resulted in live-born singletons. Results. Many previous births and an interval of less than 2 years since last birth were significantly associated with extremely low levels of AFP in the mother. However, age at first birth and age at present pregnancy did not influence the AFP level. Women who gave birth to a girl had AFP levels that were 5%[95% confidence...

https://obgyn.onlinelibrary.wiley.com/doi/pdf/10.1111/j.0001-6349.2004.00471.x

Peter Christens

Papers

Maternal age and fetal loss: population based register linkage study

Secular and seasonal variation of length and weight at birth

Second-trimester maternal serum alpha-fetoprotein and risk of adverse pregnancy outcome

Is maternal age an independent risk factor for fetal loss

Reproductive factors and extreme levels of maternal serum alpha-fetoprotein: a population-based study