Past studies, including “Ken Yokoi: Fundamental Investigation of Evaluating Method of Safety in Building During Childcare” (2011), and “Mai Kanto: A fundamental study on living environment preparation for the life difficulty of a pregnant woman” (2004), have reported regarding accidents that occur during pregnancy and the difficulty in performing activities of daily living (ADL) but have not examined the causes of accidents. We first identified the types of accidents that occur during pregnancy and then examined the difficulties in performing ADL. Furthermore, to identify physical changes in pregnant women, we examined abdominal circumference (AC) and body weight. We also evaluated the relationship between physical changes and domestic accidents, as well as ADL, to clarify where accidents occur inside and outside of the home and how accidents can be attributed to physical changes.<br> The survey included 490 women aged 20－44 years who were at 12 to 39 weeks' gestation. The women were categorized in seven groups at 4-week increments of pregnancy, with 70 women per group. Accidents experienced within 1 month of the survey date were considered.<br> The main survey items were subject attributes (age, week of pregnancy, body weight, and AC). Thirty items were regarding difficulty in performing ADL (21 items for ADL performed at home and 9 for ADL performed outside of the home) and 50 items were regarding accidents (37 items for accidents occurring at home and 13 for those occurring out-side of the home). Our survey results revealed the following five findings.<br><br> 1. The relationship among body weight changes, difficulty in performing ADL, and accidents experienced<br> Women who gained more weight compared with their pre-pregnancy weight experienced a higher number of accidents or events predictive of accidents. However, no relationship was observed between difficulty in performing ADL and accidents experienced.<br> 2. The relationship among AC change, difficulty in performing ADL, and accidents experienced<br> As AC increased with the duration of pregnancy, the difficulty in performing ADL increased. However, although the rates of accidents and events predictive of accidents were high when AC was 80－89 cm (20－32 weeks' gestation), the rate of accident somewhat decreased as AC further increased.<br> 3. Accident correlations<br> For pregnant women who experienced accidents while “open and close the entrance door,” and “ascending/descending the front step,” as well as events predictive of accidents, other accidents could be predicted based on the details of such experiences owing to a marked correlation found with other accidents within the home.<br> 4. Correlations with accidents according to changes in body weight and AC<br> Again, women who gained more weight during pregnancy compared with their pre-pregnancy weight experienced a higher number of accidents or events predictive of accidents. As AC increased from 70－79 cm to 80－89 cm with the progression of pregnancy, the number of accidents increased, showing a strong correlation. However, as AC increased from 80－89 cm to 90－ cm, the number of accidents decreased.<br> 5. Locations of accidents according to changes in body weight and AC<br> Accidents that tend to occur as AC increases include “<Collide> Kitchen: Cook” and “<Collide> Outside: Walk in a crowd.” Therefore, accidents commonly occur in places where the abdomen is more likely to bump into objects. Furthermore, the fact that a large number of women experienced events predictive of accidents indicates that accidents tend to occur when performing ADL while standing, such as “<Trip and fall down/Fall on the rear> Bathroom: Wash hair and body (while standing).”