Magnetic resonance imaging presentation of deep infiltrating endometriosis nodules before and after pregnancy: A case series

OBJECTIVE: To compare the magnetic resonance imaging (MRI) features of deep infiltrating endometriosis (DIE) lesions before and after pregnancy. DESIGN: Retrospective study. SETTING: A single French university tertiary referral hospital. PATIENTS: Twenty-one women without a prior history of surgery for endometriosis with a radiological diagnosis by MRI with two sets of examinations performed before and after pregnancy. INTERVENTIONS: The volumes of the lesions were compared using the same protocol before and after pregnancy based on MRI (1.5 T) examinations by a single experienced radiologist who is a referring practitioner for image-based diagnosis of endometriosis. MAIN OUTCOME MEASURE(S): The DIE lesion volume. MEASUREMENTS AND MAIN RESULTS: Between October 2012 and December 2016, a total of 21 patients (67 lesions) were included and compared before and after pregnancy. The mean time interval between the MRI before pregnancy and delivery was 19.6 ± 8.5 months (median: 17.6, IQR 13.5–25.2 months). The mean time interval between delivery and the MRI after pregnancy was 11.0 ± 6.4 months (median: 8.3, IQR 6–15.2 months). The mean overall DIE lesion volume by MRI was significantly higher before pregnancy compared to after pregnancy (2,552 ± 3,315 mm(3) vs. 1,708 ± 3,266 mm(3), respectively, p < 0.01). The mean volume by MRI of the largest lesion of each patient was significantly higher before pregnancy compared to after pregnancy (4,728 ± 4,776 mm3 vs. 3165 ± 5299 mm(3); p < 0.01). CONCLUSION: Our data indicate a favorable impact of pregnancy on DIE lesion volumes as measured by MRI.