Diagnostic Performance of Breast Imaging in Symptomatic Pregnant Patients

Author

Lu Mao

Published

April 6, 2026

Statistical analysis

Categorical variables were summarized using counts and percentages, while continuous variables were summarized using means and standard deviations. The diagnostic performance of breast imaging modalities was evaluated by calculating sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each cohort and imaging modality. Confidence intervals for these performance metrics were calculated using the exact binomial method. All analyses were performed using R (version 4.3.1).

Results

Demographics

Table 1: Demographic and clinical characteristics of the study population, stratified by cohort.
Characteristic Lactating
N = 5491		 Pregnant
N = 2161
Sex

    Female 549 (100%) 216 (100%)
Race

    White 467 (85%) 166 (77%)
    Asian 44 (8.0%) 13 (6.0%)
    Black or African American 22 (4.0%) 28 (13%)
    American Indian or Alaska Native 5 (0.9%) 1 (0.5%)
    Native Hawaiian or Other Pacific Islander 3 (0.5%) 1 (0.5%)
    Other 8 (1.5%) 7 (3.2%)
Ethnicity

    Hispanic or Latino 40 (7.3%) 30 (14%)
    Not Hispanic or Latino 508 (93%) 185 (86%)
    Unknown 1 1
BMI 25.3 (22.4, 29.1) 27.1 (23.6, 31.9)
Family history of breast cancer 232 (43%) 99 (47%)
    Unknown 15 7
Mammogram performed 353 (64%) 10 (4.6%)
Breast ultrasound performed

    Yes 549 (100%) 216 (100%)
1 n (%); Median (Q1, Q3)

Diagnostic performance of breast imaging

Table 2: Cross-tabulation of imaging results by cohort and imaging modality.
Characteristic Pregnant - Ultrasound alone
N = 2061		 Pregnant - Ultrasound + Mammogram
N = 101		 Lactating - Ultrasound alone
N = 1961		 Lactating - Ultrasound + Mammogram
N = 3531
Imaging result



    False Negative 0 (0%) 0 (0%) 1 (0.5%) 0 (0%)
    False Positive 40 (19%) 1 (10%) 21 (11%) 51 (14%)
    True Negative 166 (81%) 7 (70%) 174 (89%) 291 (82%)
    True Positive 0 (0%) 2 (20%) 0 (0%) 11 (3.1%)
1 n (%)
Table 3: Diagnostic performance of breast imaging modalities, stratified by cohort and imaging
cohort mod Sensitivity Specificity PPV NPV
Lactating Ultrasound alone 0.00 (0.00, 0.97) 0.89 (0.84, 0.93) 0.00 (0.00, 0.16) 0.99 (0.97, 1.00)
Lactating Ultrasound + Mammogram 1.00 (0.72, 1.00) 0.85 (0.81, 0.89) 0.18 (0.09, 0.30) 1.00 (0.99, 1.00)
Pregnant Ultrasound alone NA 0.81 (0.75, 0.86) 0.00 (0.00, 0.09) 1.00 (0.98, 1.00)
Pregnant Ultrasound + Mammogram 1.00 (0.16, 1.00) 0.88 (0.47, 1.00) 0.67 (0.09, 0.99) 1.00 (0.59, 1.00)