The rate of women with pregnancy-associated cancer is on the rise, research suggests.
Yet the increase can only be “partially explained” by the growing number of older mothers.
The study, published in BJOG: An International Journal of Obstetrics and Gynaecology, looked at 781,907 births between 1994 and 2008 in New South Wales, Australia.
Out of the 781,907 births, there were over 1.3m pregnancies among the women studied.
A total of 1,798 pregnancy-associated cancers were identified, giving an incidence rate of 137.3 per 100,000 maternities.
The most common cancers developed by the women in the study were melanoma of skin, breast cancer, thyroid and other endocrine cancers, gynaecological and lymphohaematopoeitic cancers. The research found the incidence rate of pregnancy-associated cancer rose alongside the increase in maternal age.
During the study period, the rate grew from 112.3 to 191.5 per 100,000 maternities and the percentage of women aged 35 years and over increased from 13.2% to 23.6%.
Despite the findings, the research concluded only 14% of the increase in the incidence rate could be explained by increasing maternal age.
“The trend for women to postpone childbearing has raised concerns about the incidence of cancer in pregnancy increasing,” said Professor Christine Roberts, Clinical and Population Perinatal Health Research, Kolling Institute of Medical Research, University of Sydney, New South Wales and co-author of the research.
“Although maternal age was a strong risk factor for cancer, increasing maternal age explained only some of the increase in cancer incidence.
“Pregnancy increases women’s interaction with health services and the possibility for diagnosis is therefore increased. Furthermore, pregnancy may actually influence tumour growth.”
Improved diagnostic techniques, detection and increased interaction with health services during pregnancy were said to possibly contributed to the higher incidence rates of pregnancy-associated cancer.
Researchers also claimed the genetic and environmental origins of pregnancy-associated cancers are “likely” to pre-date a pregnancy, but that the hormones and growth factors necessary for fetal growth may accelerate tumour growth.
Are you seeing growing numbers of older mothers facing complications during or after their pregnancies?