Disentangling causal paths between obesity and in vitro fertilization outcomes: an intractable problem?

The effect of maternal body condition on in vivo production of zygotes and behavior of delivered offspring in mice

“…This result suggests a strain-dependent effect. A decreased live birth rate was reported also in most human clinical studies [22,29]. As mentioned previously, if more donor dams were used in this study then some alterations in this parameter could have occurred.…”

The influence of body mass index on in vitro fertilization outcome

“…Recently, a series of editorials have challenged the contribution of obesity to poor reproductive outcome and dealt with the possible involvement of ovarian or extraovarian mechanisms [8][9][10]. In the present study, we added further information to this puzzle by showing an increased likelihood of poor responders among obese women, but a reasonable conception rate among nonobese poor responders-a rate similar to that found for nonobese patients or for normal responders in the 2 BMI subgroups.…”

“…While being obese increases risks associated with pregnancy and may reduce fertility [1], data regarding the impact of obesity on the outcome of in vitro fertilization (IVF) are controversial [2][3][4][5][6][7]. Several editorials have recently addressed the association of BMI and IVF outcome [8][9][10], all of which referring to the attempt by Bellver et al [11] to determine whether the mechanism for the observed decrease in reproductive outcome among obese women is ovarian.…”

Does Obesity Increase the Risk of Miscarriage in Spontaneous Conception: A Systematic Review

“…7,[9][10][11][12][13] There were 14 articles in which fertility drugs and/or IVF were used to assist conception, and therefore they were excluded. 8,[14][15][16][17][18][19][20][21][22][23][24][25][26] In one article, spontaneous conception data could be extracted, and this data subset was included. 27 Four articles were included from the initial search strategy.…”