Intercourse during an IVF cycle has the potential to improve pregnancy rates since exposure to semen is reported to promote embryo development and implantation in animals. Conversely, coitus-induced uterine contractions or introduction of infection may have a detrimental effect. A multicentre prospective randomized control trial was conducted to determine if intercourse during the peri-transfer period of an IVF cycle has any influence on pregnancy success. Participants undergoing thawed embryo transfer (Australian centre) or fresh embryo transfers (Spanish centres) were randomized either to abstain or to engage in vaginal intercourse around the time of embryo transfer. The transfer of 1343 embryos during 478 cycles of IVF resulted in 107 pregnancies (22.4%), with 125 viable embryos remaining by 6-8 weeks gestation. There was no significant difference between the intercourse and abstain groups in relation to the pregnancy rate (23.6 and 21.2% respectively), but the proportion of transferred embryos that were viable at 6-8 weeks was significantly higher in women exposed to semen compared to those who abstained (11.01 versus 7.69 viable embryos per 100 transferred embryos, P = 0.036, odds ratio 1.48, 95% confidence interval 1.01-2.19). Hence exposure to semen around the time of embryo transfer increases the likelihood of successful early embryo implantation and development.

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ObjectiveTo assess the links between structural and household determinants of household water insecurity and test three water insecurity measures against self-reported diarrhoea, dengue fever and perceived stress in the middle-income and low-income urban areas of Torreón, Mexico.DesignCross-sectional household survey conducted in two waves (rainy and dry seasons).Participants500 households selected via multistage cluster sample in selected communities. Socioeconomic status determined the selection of participant neighbourhoods; five were identified in low socioeconomic status neighbourhoods and five in low-medium socioeconomic status neighbourhoods. We examine how the context of urban water provision is related to a new cross-culturally valid Household Water Insecurity Experiences (HWISE) Scale.Primary outcome measuresThe HWISE Scale, self-reported diarrhoea, dengue fever and the Perceived Stress Scale.ResultsWater system intermittency (adjusted OR (AOR) 3.96, 95% CI 2.40 to 6.54, p<0.001), unpredictability (AOR 2.24, 95% CI 1.34 to 3.74, p=0.002) and the dry season (AOR 3.47, 95% CI 2.18 to 5.52, p<0.001) were structural correlates of the HWISE Scale. This study also found that the HWISE Scale was associated with two health outcomes, self-reported diarrhoea (AOR 1.09, 95% CI 1.03 to 1.15, p=0.002) and perceived stress (β=0.28, SE=0.07, t=4.30, p<0.001), but not self-reported dengue fever (AOR 1.02, 95% CI 0.98 to 1.06). A 3-item hygiene subscore and a 3-item water worry subscore were also both positively associated with self-reported diarrhoea and perceived stress.ConclusionShort-form screeners of water insecurity may be useful for assessing certain health risks by lay survey workers in settings with limited healthcare resources, particularly in lieu of more expensive microbiological tests that require specialised training and facilities.