Disease remission at conception seems favourable for maintaining remission during pregnancy and child outcome; it is therefore part of preconception advice in females with inflammatory bowel disease. In this meta-analysis, the authors investigate the robustness of data justifying this advice and conclude that disease activity around conception increases the risk of disease activity during pregnancy.
We agree with the authors that most of the included studies are retrospective, thus have a high risk of bias, and heterogeneity between the studies is large and should therefore be interpreted with caution. However, we do not share their surprise in detecting no significant difference in effect estimate from the early 1950s until 2006. Despite the currently expanding number of patients on immunosuppressives (IS) and anti-TNF, all selected studies in this meta-analysis, including the most recent one, included females that were mostly treated with 5-ASA and/or steroids [Crohn's disease (CD) 66% and ulcerative colitis (UC) 83%], with only a minority treated with immunosuppressives (CD 22% and UC 10%) and almost none was treated with anti-TNF (0.5% CD and 0% UC). This might partly explain the similarity in effect estimate over the decades. Furthermore, disease activity seemed to be limited, as the number of patients on IS/anti-TNF was small and severe disease activity will negatively affect patients' sexual function and fertility, especially in those patients who underwent surgery.[4-6] This will inevitably lead to a universal selection of patients with relatively mild disease activity around conception.
In conclusion, this meta-analysis is an excellent first step in quantifying how disease activity around conception affects course during pregnancy, but shows the limitation of retrospective research that has been done in most of the pregnancy cohorts, and invites further prospective studies including more recent IBD treatments to bring the effect estimates into the 21st century.