Pregnant versus non-pregnant healthy subjects - a prospective longitudinal musculoskeletal ultrasound study concerning the spectrum of normality

Abstract

Pregnancy induces profound changes in the maternal body and the normality spectrum may differ compared to non-pregnant subjects. Aims: The main objective was to establish the presence, frequency and distribution of articular and peri-articular abnormal findings in healthy women, pregnant and non-pregnant, using clinical examination (CE) and musculoskeletal ultrasound (MSUS). Second objective was to identify which joint/tendon set would show fewer modifications in both groups of healthy subjects and would remain stable throughout pregnancy. Material and methods: A prospective cross-sectional and longitudinal study on healthy pregnant (case group, 5 evaluations - 1st, 2nd, and 3rd trimester of pregnancy and 2 postpartum visits) and non-pregnant female volunteers (control group, one evaluation), consisting in CE vs MSUS joint and tendon evaluation, was conducted. MSUS elementary lesions such as synovial hypertrophy, effusion, Power Doppler (PD) signal, erosions and osteophytes were quantified. Results: The case group (20 pregnant women) and 75 age- matched controls were evaluated on 46 joints and 24 tendon units. The highest frequency of grey scale pathologic-like imaging abnormalities was detected at metatarsophalangeal joints and wrist level in both groups. No pathologic-like abnormalities throughout pregnancy and postpartum were detected on flexor tendons (F1-F5), metacarpophalangeal joints (MCPj), extensor carpi ulnaris tendon (EUC) and large joints (glenohumeral, elbow, tibiotalar). Very low frequency of PD signal, erosions and osteophytes was identified in both groups. The highest longitudinal change was detected in the effusion on joint and tendon level only. Conclusion: MSUS inflammation-like abnormalities can be detected in healthy subjects and pregnancy may modify baseline findings. The identification of a joint/tendon set with less abnormalities (hand flexor tendons F1-F5, MCPj 2-5 and EUC) in healthy subjects would help in selecting target structures, important for identifying the disease onset and for further monitoring.