Sex ratio: Los primeros contrastes de significación

El inicio del estudio de la proporción de nacimientos de niños y niñas (sex ratio) comienza en el siglo XVIII y ha ocupado a grandes matemáticos. En 1712 John Arbuthnott ya trató de explicar el hecho comprobado de que el número anual de nacimientos de niños superaba al de niñas. Esto supone el primer ejemplo de un contraste de significación y el germen de la técnica de los contrastes de hipótesis estadísticas. El objetivo de este artículo es mostrar estos inicios y reflexionar sobre su utilidad didáctica hoy.

Sex talk? overcoming barriers about sex and contraception after childbirth

Anecdotal evidence tells professionals that childbirth is the best form of contraception. However, sexual health problems are the very common after childbirth with Barrett et al (2000) arguing that only 15% of women who have a postnatal sexual problem reported discussing it with a health professional. As health professionals with a predilection for the ‘clinical’ and the ‘prescriptive’ we organise antenatal classes to discuss bathing the baby and post partum reunions to recount birth stories, but often fail to address sexual health problems and contraception after birth.(Glazener 1997). Many women who have carefully used contraception for years prior to pregnancy are often not helped to re-engage with the issues following birth. This would seem to be a particular problem for the most vulnerable parents such as adolescent mothers and their partners (Social Exclusion Unit 1999, 2004) where some young women go on to have more than one baby in a short time period (Reeves 2003). The focus of this paper is to explore the apparent general failure of health professionals to discuss sex after childbirth and provide information regarding reliable contraception. Glazener (1997) tells us that health professionals are encouraged to educate and prepare patients antenatally, for example to be trained to identify problems and deal with them openly and sympathetically. What is brought into question is why this form of rigorous support is not extended to providing sexual health advice in the immediate and often vulnerable postnatal period and why this provision is not a priority for some groups. The paper will explore if this situation caused by a lack of training or is it a symptom of our culture and a British attitude towards sex and contraception.