Fertility

About: Fertility is a research topic. Over the lifetime, 29988 publications have been published within this topic receiving 681106 citations.

Fatness and fertility.

Abstract: The relationship between fatness and fecundity in women is explored. The author presents evidence that a woman must store a threshold or minimum amount of body fat in order to be able to reproduce. The possible mechanisms by which the amount of body fat might affect fecundity are examined. Consideration is also given to the effects of dieting and exercise on fecundity. (ANNOTATION)

The impact of individual and aggregate unemployment on fertility in Norway

Abstract: Continuous-time hazard models are estimated from register-based birth, migration, education and unemployment histories for the complete Norwegian population, linked with aggregate data for municipalities. The analysis covers the period 1992-98. First-birth rates are slightly higher among women who had been unemployed twelve months before than among others, whereas higher-order birth rates are slightly lower. Although men’s unemployment has a more pronounced negative effect, according to paternity rate models, the overall conclusion is that unemployment in Norway has had a negligible impact on fertility through individual-level effects. Aggregate-level effects are more important. Higher-order birth rates are lower in municipalities where men’s or women’s unemployment is high than elsewhere. All in all, the peak unemployment level of 6% experienced in 1993 is found to be associated with a reduction of about 0.08 in total fertility. The results accord well with economic theories for first and higher-order births that are based on the assumption that women are still the primary caretakers.

Diet-induced obesity in rats leads to a decrease in sperm motility

Abstract: Obesity is rapidly becoming a worldwide epidemic that affects children and adults. Some studies have shown a relationship between obesity and infertility, but until now it remains controversial. Thus, the aim of the present study was to investigate the effect of high-fat diet-induced obesity on male reproductive parameters. In a first experiment, male Wistar rats were fed a high-fat diet (HFD) or standard chow (SD) for 15, 30 or 45 weeks, after which they were evaluated by adiposity index, serum leptin levels, reproductive organ weights and sperm counts. In a second experiment, rats received HFD or SD only for 15 weeks, long enough to cause obesity. Sexual hormones and sexual behavior were evaluated in these animals, as well as fertility after natural mating. Another group of rats was submitted to motility analysis and fertility evaluation after in utero insemination. After 15, 30 or 45 weeks, HFD-fed animals presented significant increases in obesity index and serum leptin levels. Reproductive organ weights and sperm counts in the testis and epididymis were similar between the two groups at all timepoints studied. Sexual behavior was not altered by the diet regimen, and HFD fertility after natural mating was also similar to SD-fed animals. Intergroup testosterone levels were also comparable, but estradiol levels were increased in HFD rats. Furthermore, sperm quality was reduced in HFD animals as evidenced by their decreased percentage of sperm with progressive movement. This altered motility parameter was followed by a trend toward reduction in fertility potential after artificial in utero insemination. The results reported herein showed that obesity can affect sperm quality, by reducing sperm motility, without affecting other sperm parameters. The low sperm quality caused a slight reduction in fertility potential, showing that obesity may lead to impairment in male fertility.

Age and marital status at first birth and the pace of subsequent fertility.

Abstract: Taking care to minimize the truncation bias inherent in cross-sectional data and controlling for other variables, this paper demonstrates the strong effects of both age and marital status at first birth on the pace of subsequent fertility. These effects are particularly strong in the interval immediately following the first birth but persist even into the fourth interval. Important differences are found with respect to the experience of rapid fertility, rather than in the mean lengths of intervals. These results add to the growing attention to the social dimensions of age as a variable in fertility processes.