Fertility, infertility, and loss

Interesting article on fertility, infertility and pregnancy loss.

Excerpt...

Fertility, subfertility and superfertility

Put simply, pregnancy requires little more than implantation of a developmentally
competent embryo into the receptive endometrium. In many species, pregnancy is readily achieved and maintained. In humans, however, the prevalence of subfertility is high and increasing, affecting one in six couples in developed countries (Evers, 2002).

Fertility can be measured by the time taken to achieve pregnancy. Time-to-pregnancy (TTP) is expressed in monthly fecundity rates (MFRs), i.e. the probability of achieving pregnancy within one menstrual cycle. The average MFR in humans is, compared with other mammalian species, relatively low at 20% (Stevens, 1997; Viudes-de-Castro and Vicente, 1997; Evers, 2002). On the basis of this MFR, a simple mathematical model predicts that 74, 93 and 100% of normally fertile couples will conceive in 6, 12 and 24
months, respectively. Along the same lines, moderate and severe subfertilities have been defined by MFRs of 5 and 1%, respectively (Evers, 2002). At the other end of the spectrum, superfertility can be characterized with MFRs of 60% or more. According to this model, superfertile couples achieve 94 and 100% of pregnancies within 3 and 6 months, respectively. On the basis of the Tietze model (Tietze et al., 1950; Evers, 2002), it has been estimated that 79% of the population is fertile, 18% subfertile or infertile and 3% superfertile...

So yes my older sister E is officially a super duper "superfertile" with a 100% hit rate on four tries, and I am an infertile (oh no wait, I think I prefer "moderately to severely subfertile"). Sounds so much better... :/