The impact of parity in primary breast augmentation: A clinical and cost-effective case control study.

Introduction: Breast augmentation is one of the most commonly performed aesthetic procedures in women. Despite the structural changes which occur during pregnancy and lactation have been extensively studied, there is no clarity in terms of the time required for the parenchymal angiogenic changes to regress or if these neovessels are preserved even years after the last lactating period. This study investigated whether these post-pregnancy structural changes on the breasts may influence the surgical efficiency, affect the rates of complications and have an impact on cost-effectiveness in primary breast augmentation.

Methods: This study encompasses a retrospective review of all patients who underwent implant-based bilateral primary breast augmentation, through inframammary fold (IMF) incision under general anaesthetic, by a single surgeon. The age, height, weight and parity (nulliparous or multiparous status), characteristics of implants used and clinical outcomes after a minimum of 6-month post-operative follow-up were recorded. A further prospective comparative trial investigated the effects of parity in the surgical efficiency and cost-effectiveness in primary breast augmentation. The surgical efficiency (total operative time) and the immediate complications of 85 consecutive cohort of patients were recorded by an independent observer. Statistical correlation investigated the relevance of parity as predictors of surgical efficiency and cost-effectiveness.

Results: A total of 894 patients were included with a minimum of 6-month follow-up following implants-based primary breast augmentation. There were 445 (49.8%) nulliparous and 449 (50.2%) patients had at least one child at the time of surgery. The average parity index was calculated to be 1.05. The average body mass index (BMI) was 20.8 kg/m (15.9-30.8). The mean implant volume used was 314 ml. Fifteen percent (n = 134) presented with post-operative complications, with an average follow-up period of 12.8 (6-116) months. The differences between parity and incidence of complications were not statistically significant (p = 0.82). Surgical efficiency parameters from 85 women (54 multiparous and 31 nulliparous) demonstrated total operative time difference; 35 ± 6.3 min for multiparous and 30.2 ± 5 min for nulliparous. There was a clinical average difference of 4.8 min, with a maximum difference of 16.1 min. These statistically significant difference account for an average increase of 13.7% in the operating time in multiparous versus nulliparous (p-value=0.0004, 95% CI = 2.2-7.4 min).

Conclusion: Primary breast augmentation in parous women faces parenchymal and vascular histological breast tissue transformations which may not fully revert to the pre-pregnant state. These changes encountered during pocket dissection seem to have an impact on the operating time, cost-effectiveness and can therefore affect negatively surgical efficiency. Nevertheless, when surgical technique is based on sharp, precise dissection and proactive haemostasis, parity does not show to have an impact on the rates of complications, despite longer operation times.