Fertility

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

Fertility treatments and multiple births in the United States.

Abstract: Background The advent of fertility treatments has led to an increase in the rate of multiple births in the United States. However, the trends in and magnitude of the contribution of fertility treatments to the increase are uncertain. Methods We derived the rates of multiple births after natural conception from data on distributions of all births from 1962 through 1966 (before fertility treatments were available). Publicly available data on births from 1971 through 2011 were used to determine national multiple birth rates, and data on in vitro fertilization (IVF) from 1997 through 2011 were used to estimate the annual proportion of multiple births that were attributable to IVF and to non-IVF fertility treatments, after adjustment for maternal age. Trends in multiple births were examined starting from 1998, the year when clinical practice guidelines for IVF were developed with an aim toward reducing the incidence of multiple births. Results We estimated that by 2011, a total of 36% of twin births and 77% of triplet and higher-order births resulted from conception assisted by fertility treatments. The observed incidence of twin births increased by a factor of 1.9 from 1971 to 2009. The incidence of triplet and higher-order births increased by a factor of 6.7 from 1971 to 1998 and decreased by 29% from 1998 to 2011. This decrease coincided with a 70% reduction in the transfer of three or more embryos during IVF (P<0.001) and a 33% decrease in the proportion of triplet and higher-order births attributable to IVF (P<0.001). Conclusions Over the past four decades, the increased use of fertility treatments in the United States has been associated with a substantial rise in the rate of multiple births. The rate of triplet and higher-order births has declined over the past decade in the context of a reduction in the transfer of three or more embryos during IVF. (Funded by the Centers for Disease Control and Prevention.)

Happiness: Before and After the Kids

Abstract: Understanding how the process of childbearing influences parental well-being has great potential to explain variation in fertility. However, most research on fertility and happiness uses cross-sectional data, hindering causal conclusions. We study trajectories of parental happiness before and after the birth of a child using British and German panel data and methods which control for unobserved parental characteristics. We find that happiness increases prior to and in the year of having a child and decreases thereafter, but not below before-child levels. This general pattern is modified by sociodemographic characteristics. Those who become parents at young ages have a downward happiness trajectory, while those becoming parents at older ages have a higher happiness level after the birth. The first child tends to increase happiness a lot, the second much less, and the third may decrease happiness. Socioeconomic resources are important for men, as those with low education gain little in happiness from the birth of a child. Women experience stronger pre-birth highs and post-birth drops than men. These results, which are similar in Britain and Germany, suggest that childbearing increases parental happiness most among those who postpone and have more resources. This recipe for happiness is highly consistent with the fertility behavior that emerged during the second demographic transition and provides new insights into the causes behind low and late fertility.

Pregnancy and Fertility Following Bariatric Surgery: A Systematic Review

Abstract: Context Use of bariatric surgery has increased dramatically during the past 10 years, particularly among women of reproductive age. Objectives To estimate bariatric surgery rates among women aged 18 to 45 years and to assess the published literature on pregnancy outcomes and fertility after surgery. Evidence Acquisition Search of the Nationwide Inpatient Sample (1998-2005) and multiple electronic databases (Medline, EMBASE, Controlled Clinical Trials Register Database, and the Cochrane Database of Reviews of Effectiveness) to identify articles published between 1985 and February 2008 on bariatric surgery among women of reproductive age. Search terms included bariatric procedures, fertility, contraception, pregnancy, and nutritional deficiencies. Information was abstracted about study design, fertility, and nutritional, neonatal, and pregnancy outcomes after surgery. Evidence Synthesis Of 260 screened articles, 75 were included. Women aged 18 to 45 years accounted for 49% of all patients undergoing bariatric surgery (>50 000 cases annually for the 3 most recent years). Three matched cohort studies showed lower maternal complication rates after bariatric surgery than in obese women without bariatric surgery, or rates approaching those of nonobese controls. In 1 matched cohort study that compared maternal complication rates in women after laparoscopic adjustable gastric band surgery with obese women without surgery, rates of gestational diabetes (0% vs 22.1%, P Conclusion Rates of many adverse maternal and neonatal outcomes may be lower in women who become pregnant after having had bariatric surgery compared with rates in pregnant women who are obese; however, further data are needed from rigorously designed studies.

Male factors and the likelihood of pregnancy in infertile couples. I. Study of sperm characteristics

Abstract: A prospective study of 394 infertile men was conducted over 3 years following a primary semen analysis. The cumulative pregnancy rate was 43 and 64% after 1 and 3 years, respectively. The pregnancy rate was significantly higher in the secondary infertile group. The study of various sperm factors and the occurrence of pregnancy showed that they were not of equal significance in predicting male fertility potential. The percentage of pregnancies decreased significantly only when the sperm concentration was less than 5 x 10(6)/ml. The pregnancy rate increased significantly with the percentage of motile sperm. The percentage of sperm with normal morphology was also found to be significantly higher when a pregnancy occurred than when the couple remained infertile (43.6% vs 37.7%). In a detailed morphological analysis of the sperm, six abnormalities (microcephaly, double head, amorphous head, cytoplasmic droplet, bent tail and coiled tail) were found to be significantly more frequent when a pregnancy did not occur. The most predictive value was given by the Multiple Anomalies Index (MAI), which is the mean number of abnormalities observed per abnormal sperm. The pregnancy rate was significantly lower after both 1 and 3 years when the MAI was greater than 1.6. Multivariate analysis showed that the best prognostic indicator of fertility was given by the percentage of motile sperm and the MAI, particularly in patients with primary infertility.