- In this study, 310 women completed the International Knee Documentation Committee questionnaire (IKDC) and the Pregnancy Physical Activity Questionnaire (PPAQ) at some point during pregnancy
- The overall average IKDC score was 84; scores significantly declined from the first to third trimester
- 26% of participants reported severe current knee dysfunction (IKDC <75), including 21% of the 234 women with no previous history of knee problems
- The average PPAQ score was 249 metabolic equivalent of tasks (MET)-h/wk (range, 41–806), with no significant difference across trimesters
- Severe current knee dysfunction was associated with BMI ≥30 kg/m2 (OR, 1.9; P=0.02), age <25 years (OR, 2.6; P=0.005), history of knee problems (OR, 2.7; P<0.001) and PPAQ ≥500 MET-h/wk (OR, 2.8; P=0.04)
Knee pain is common during pregnancy and is thought to be multifactorial. Weight gain, changes in mass distribution that lead to altered gait, postural adaptations and hormonal changes that increase ligamentous laxity have all been advanced as explanations.
However, few diagnostic and treatment pathways have been described for managing knee pain during pregnancy, as the fields of obstetrics and orthopedics do not often intersect. In fact, a common approach is to tell the woman to wait for the resolution of symptoms after childbirth.
Miho J. Tanaka, MD, director of the Women's Sports Medicine Program in the Department of Orthopaedics at Massachusetts General Hospital, and colleagues recently characterized the severity of knee pain and its associated risk factors during pregnancy. Their report in The Physician and Sportsmedicine presents their findings as a call for additional research and further collaborative efforts between specialists to address this problem.
Between 2017 and 2018, the researchers enrolled 310 women who presented for routine visits in two general obstetric clinic sites at Mass General. These volunteers completed the International Knee Documentation Committee (IKDC) questionnaire, which assesses knee symptoms and function, and the Pregnancy Physical Activity Questionnaire (PPAQ), which assesses hours spent on household/caregiving, occupational, sports/exercise, transportation and sedentary activities.
68, 111 and 131 patients were in their first, second and third trimesters, respectively, when they completed the questionnaires.
International Knee Documentation Committee Results
IKDC scores range from 0–100, with higher scores indicating better function. The averages in this study were:
- Overall: 84.4
- First trimester: 88.9
- Second trimester: 84.5 (P=0.05 vs. first trimester)
- Third trimester: 82.0 (P=0.003 vs. second trimester)
81 women (26%) had severe knee dysfunction (defined as IKDC <75), including 13%, 25% and 34% in the first, second and third trimesters, respectively.
76 women (25%) reported previous knee problems, injury or surgery. Even among those with no such history, 21% reported severe knee dysfunction, including 6% in the first trimester, 21% in the second and 29% in the third.
Pregnancy Physical Activity Questionnaire Results
The average PPAQ score was 249 metabolic equivalent of tasks (MET)-h/wk (range, 41–806). The trend was for scores to decline between trimesters, but there were no significant differences.
Poor Knee Function Risk Factors
In multivariable analysis, severe current knee dysfunction was associated with:
- BMI ≥30 kg/m2 (OR, 1.9; P=0.02)
- Age <25 years (OR, 2.6; P=0.005)
- History of knee problems (OR, 2.7; P<0.001)
- PPAQ ≥500 MET-h/wk (OR, 2.8; P=0.04)
The Need for Evidence
There is increasing emphasis on maintaining or initiating physical activity during pregnancy for overall health and pregnancy-related benefits. Yet little information is available regarding the need for orthopedic care in pregnant women who wish to continue fitness and athletic activities, particularly at a high level.
This study highlights the strong potential for knee dysfunction associated with pregnancy and emphasizes the need for better awareness and management through multidisciplinary care programs.
Learn more about the Women's Sports Medicine Program at Mass General
Refer a patient to the Mass General Department of Orthopaedics