Women with fertility issues have all sorts of solutions today to help them conceive in a variety of ways. One popular method is in vitro fertilization, where a woman’s egg is fertilized outside of the body and then planted in the woman’s uterus. When this method of fertility works, it can often result in multiple births. Unfortunately, a recent study has linked women who have had multiple births from IVF treatment with an increased risk of breast cancer.

However, Dutch investigators from the Omega study group say the reason may not be because multiple pregnancies actually cause cancer, but that a maternal trait related to a higher implantation potential and to breast cancer itself. Even though the results of the research were obtained from a nationwide cohort study, the researchers highlight that their results should be replicated in another study for further examination. Also, the research team says that the results don’t indicate that the general population should be screened any earlier than normal for breast cancer.

The study was present on July 9th at the annual meeting of ESHRE by Dr. Els Groeneveld from the VU University Medical Centre of Amsterdam, the Netherlands. The data from the Omega study included a nationwide cohort of near 20,000 women who had IVF or ICSI treatment between 1983 and 1995. Women who received the treatment between 1997 and 1999 were given a questionnaire about their treatment and about 12,500 women filled it out and sent it back. These women were then cross-references to the Netherlands cancer registry.

The analysis showed that after a median 16.7 years, 1,688 women birth multiples with IVF treatment, which is about 13% of the total number of women who filled out the questionnaire. 6,027 women gave birth to only one child, and 4,874 never gave birth at all. Out of these women, 317 were later diagnosed with breast cancer. 57 of the women diagnosed had multiple children at once because of IVF treatment. These statistics showed that women who gave birth to multiples were 44% more likely to later be diagnosed with breast cancer than women who only gave birth to a single child. Women who never gave birth at all were at no increased risk.

Dr. Groeneveld concluded the study by saying, " the main message of our study is that the increased breast cancer risk is not only a consequence of the multiple pregnancy itself because of high hormone levels, but that the risk of breast cancer may already be elevated prior to conception in women who have the potential -- the 'maternal trait' -- to develop a multiple pregnancy from all transferred embryos."

Source: European Society of Human Reproduction and Embryology (2013, July 9). Women who give birth to multiple babies after IVF are at higher risk of breast cancer. ScienceDaily.