An article has just been published this month in the prestigious European fertility journal Human Reproduction asking the surprising question if having sex in an IVF cycle around egg retrieval and embryo transfer increases pregnancy rates.
Crawfowd et al, the authors of the study, found seven randomized clinical trials that looked at the influence of sex on pregnancy rates in IVF cycles. Actually sex is the act but actually what the studies researched was the influence of seminal fluid. What is seminal fluid? It is the male ejaculate, which is made up of about 5% of sperm– the rest, is seminal plasma. The seminal plasma comes from the prostate and the seminal vesicle. Its mission is to protect the spermatozoa as they travel through the vagina, which is acidic. Another interesting property is that it is thought that it somehow prepares the endometrium by stimulating it to receive the embryos. Around ovulation tiny waves are produced below the endometrium to help the seminal fluid move through the cervix up into the uterus and to help the endometrium become more receptive. In these seven studies Crawford et al found a statistically significant increase in clinical pregnancy rates during IVF cycles.
The results from this study seem clear but as in life nothing is really black and white. Research has shown a very small risk of infection after having sex just after transfer. Another fact to look at before recommending sex after frozen cycles where ovulation is scheduled is that the oocyte that is ovulated can be fertilized and a multiple pregnancy achieved. Although this seems almost impossible, it happens and can be well documented when a single embryo transfer is performed and non-identical twins are born.
Only two of the seven studies reported the live birth rate and there was no significant difference in live birth rates between the groups who had had sex around egg retrieval and embryo transfer and those who did not. Further study will be needed to determine if this age-old method will indeed increase live birth rates.
This study goes to show that the human body has ways of preparing the uterus for receptivity that we as fertility specialists do not really take into account. Many times using so much sophisticated technology we forget that that pregnancy is an exquisitely complex occurrence and that every part plays an important role in achieving a healthy baby.
Crawford, G., Ray, A., Gudi, A., Shah, A., and Homburg, R. The role of seminal plasma for improved outcomes during in vitro fertilization treatment: review of the literature and meta-analysis. Hum.Reprod.Update. 21(2), 275-284.