Subfertility
Helen Bickerstaff, Louise C Kenny in Gynaecology, 2017
A healthy couple having frequent intercourse have about an 18–20% chance of conceiving in a single menstrual cycle. As a species this makes us relatively infertile. There is of course a cumulative increase in pregnancy rates over time as couples try for conception. Within 6 months 70% of couples will have conceived, after 12 months 80% and after 24 months 90% of couples will achieve a pregnancy (Figure 7.1). The most important factor affecting fertility is female age, which is related to a decline in the quality and quantity of eggs. Female fertility tends to fall sharply over the age of 36, with a further dip after the age of 40. However, there is a considerable variation and biological age (or ovarian reserve) does not always precisely correlate with chronological age. Male age is also an important factor; semen quality tends to fall in men over the age of 50, while frequency of intercourse tends to fall in men over the age of 40.
Effects of Caffeine Intake on Female Fertility: A Critical Review
Barry D. Smith, Uma Gupta, B.S. Gupta in Caffeine and Activation Theory, 2006
As briefly mentioned in the introduction, a large number of factors have been shown to be associated with fertility. Table 9.3 summarizes the factors that have been taken into account in the studies under review and shows that some of those studies have failed to consider these. This is important because they may contribute to any evident association between caffeine and fertility. The majority of studies adjusted for the number of previous pregnancies experienced by the women, female alcohol consumption, and some measure of socioeconomic status. All studies took into account female smoking, primarily by adjustment in multivariate analysis, although some stratified their sample (Alderete et al., 1995; Florack et al., 1994; Hakim et al., 1998; Jensen et al., 1998; Williams et al., 1990).
Conceiving a more social model of disability
Michelle Weldon-Johns in Assisted Reproduction, Discrimination, and the Law, 2019
The final condition is that the impairment must have a long-term adverse effect, defined in Sch.1, para.2 as the effect having lasted, or likely to last, for at least 12 months or for the rest of their life. Those with fertility issues should also be able to satisfy this condition, particularly since one of the factors required to diagnose infertility is the inability to conceive after one year of actively trying.197 This would mean that there would be sufficient continuing adverse effects from the impairment (the cause of infertility) on a day-to-day activity (reproduction) for the requisite period. Consequently, the current UK definition of disability offers the potential for infertility to fall within its scope. This is primarily dependent on adopting a broad interpretation of normal day-to-day activities in the first instance and recognising the gendered experiences of infertility in interpreting the requirements of the definition. Nevertheless, the US experience reinforces that such reinterpretations are possible, particularly when viewed through the intersecting lenses of disability and gender.
Reproductive health in adults with congenital heart disease: a review on fertility, sexual health, assisted reproductive technology and contraception
Published in Expert Review of Cardiovascular Therapy, 2023
J.A. van der Zande, G. Wander, K.P. Ramlakhan, J.W. Roos-Hesselink, M.R. Johnson
In biology, ‘fertility’ is defined by fecundity or the ability to reproduce [8]. This should not be confused with the fertility rate, which is defined as the average number of children per woman. On the other hand, ‘infertility’ or ‘impaired fertility’ is defined as failure to achieve a pregnancy after 12 months or more of regular and unprotected sexual intercourse [9]. Infertility can be attributed to the male or female, or to be unexplained (Figure 1) and can be caused by several factors, as presented in Figure 2. In the male reproductive system, infertility is most commonly caused by abnormal sperm function and quality or problems with semen ejection [10]. In women, infertility is most commonly caused by abnormalities of ovulation or structural problems in the uterus or fallopian tubes [11]. Infertility can also be caused in both men and women by problems in the endocrine system causing imbalances of reproductive hormones, but also several environmental and lifestyle factors can influence fertility, such as smoking, alcohol consumption, and obesity [12]. The proportion of couples affected by infertility is progressively increasing, and it is estimated that currently 15–18% of the couples around the world suffer from infertility [13]. However, these numbers may be underestimated as they only include data from couples actively seeking help for fertility issues.
Fertility facts, figures and future plans: an online survey of university students
Published in Human Fertility, 2019
Eugenie Prior, Raelia Lew, Karin Hammarberg, Louise Johnson
Most people aspire to parenthood and having children is as important to men as it is to women (Hammarberg, Collins, Holden, Young, & McLachlan, 2017). Several potentially modifiable factors affect fertility and reproductive outcomes including parental age, smoking and obesity. Of these, female age is the most important factor determining the chance of conception (Schmidt, Sobotka, Bentzen, & Nyboe Andersen, 2012). In high-income countries, the age of childbearing is increasing and the proportion of first-time mothers over the age of 35 years is rising (Heck, Schoendorf, Ventura, & Kiely, 1997; Schmidt et al., 2012). In Australia, the average age of first-time mothers rose from 28.0 years in 2004 to 28.9 years in 2015 (Australian Institute of Health and Welfare, 2017). For all births, between 2005 and 2015 the median maternal age rose from 30.7 years to 31 years and the median paternal age rose from 32.9 years to 33.1 years (Australian Bureau of Statistics, 2016).
Polymorphisms and haplotypes in VDR gene are associated with female idiopathic infertility
Published in Human Fertility, 2020
Jelena Djurovic, Gorana Stamenkovic, Jelena Todorovic, Natasa Aleksic, Oliver Stojkovic
Infertility remains a highly prevalent condition worldwide, affecting between 48.5 and 186 million people (Izzo, Monteleone, & Serafani, 2015). According to the World Health Organization, infertility is defined as disease of reproductive system when pregnancy does not occur after 12 months of unprotected intercourse. Many factors could affect the fertility of a couple, including both genetic and environmental factors, as well as their interactions. Despite known causes of infertility, in some cases fertility tests fail to identify the cause of reproductive failure and infertility remains clinically unexplained-idiopathic. Recent studies have pointed to the link between vitamin D and fertility at various stages of reproductive functions (Aghajafari et al., 2013; Liu & Hewison, 2012). Maternal vitamin D deficiency has been linked to many gynaecologic and obstetric diseases that can affect fertility such as polycystic ovary syndrome, endometriosis, ovarian cancer, as well as gestational diabetes, preeclampsia, preterm birth, bacterial vaginosis and small infants for gestational age (reviewed in Aghajafari et al., 2013; Colonese et al., 2015; Liu & Hewison, 2012).
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