Prenatal exposure to chemotherapy may not be detrimental to cognitive development in children
Exposure to chemotherapy during the second or third trimesters of pregnancy appears to have no impact on cognitive development in the children, according to a study presented at ESMO Asia 2017.
“[A]ll children [in the studies presented] who have been exposed to chemotherapy … looked very healthy and have good cognitive abilities and normal behaviour,” said Tineke Vandenbroucke, a researcher and clinical psychologist from the Department of Gynecological Oncology at KU Leuven, Leuven, Belgium.
In the INCIP* follow-up study, children whose mothers have been exposed to chemotherapy during pregnancy were initially evaluated at 18 months and then followed up at 3, 6, 9, 12, 15, and 18 years. Evaluation was carried out through a clinical neurological examination by a paediatrician, and health questionnaires were filled out by the parents of the children included in the study. The population was divided into a study group (prenatal exposure group) and a control group. Cognitive and language development was evaluated using the Bayley Scales of Infant and Toddler Development.
Results of the cognitive tests were within normal range in young children (aged 18 months) who underwent a Bayley test and older children (aged 5–18 years) who had an intelligence test. [Lancet 2012;13:256-264]
However, looking into cognitive outcomes in relation to pregnancy duration, full-term born children had better cognitive outcomes than preterm born children whose mothers underwent chemotherapy treatment during pregnancy, Vandenbroucke highlighted.
“This suggests that gestational age could influence cognitive development in children with prenatal exposure to chemotherapy,” she added. “[P]rematurity has an impact on the cognitive outcome independent of the cancer and cancer treatment during pregnancy … [and] may have adverse effects that are even bigger than those of chemotherapy and pregnancy. [Therefore], prematurity should be avoided if possible.”
In addition, Vandenbroucke stated that the placenta helps to protect the foetus from a prenatal exposure of chemotherapy given to mothers. However, there are significant differences between the several types of chemotherapy used.
A previous study reported that transplacental passage of chemotherapeutic agents such as paclitaxel was low at 1.4 percent, whereas docetaxel was not even detected in the foetal plasma, but a high transplacental passage of carboplatin was noted at 57 percent. [Int J Gynecol Cancer 2010;20:1456-1464]
Although prenatal exposure to chemotherapy does not seem to adversely affect cognitive abilities of the children based on tests used in the study, Vandenbroucke pointed out that “we have information from child and adult survivors who have been treated with chemotherapy [who] complained of cognitive deficits like attention and memory problems or [slower] information processing speeds.”
Longer term follow-up is warranted, as cognitive problems may be more apparent at school age, she added.
*INCIP: International Network on Cancer Infertility and Pregnancy