Introduction and hypothesisFirst vaginal delivery severely interferes with pelvic floor anatomy and function. This study determines maternal and pregnancy-related risk factors for pelvic floor dysfunction (PFD), including urinary incontinence (UI), urgency, anal incontinence (AI), pelvic organ prolapse (POP) and levator ani muscle (LAM) avulsion.MethodsThis is a single-centre prospective observational cohort study on healthy women in their first singleton pregnancy. All underwent clinical and 3D transperineal ultrasound examination at 6 weeks and 12 months postpartum. Objective outcomes were POP-Q and presence or absence of LAM trauma. Functional outcomes were measured by the ICIQ-SF and PISQ 12. Multivariate regression was performed to determine birth and maternal habitus-related risk factors for UI, urgency, AI, dyspareunia, LAM avulsion and ballooning.ResultsNine hundred eighty-seven women were included. Risk factors for UI were maternal age per year of age (OR: 1.09; 95% CI: 1.04–1.13; p = 0.0001) and BMI before pregnancy (OR: 1.08; 95% CI: 1.04–1.13; p = 0.001); for POP stage II+ maternal age (OR: 1.08; 95% CI: 1.08–1.14; p = 0.005). Avulsion was more likely after forceps (OR: 3.22; 95% CI:1.54–8.22; p = 0.015) but less likely after epidural analgesia (OR: 0.58; 95% CI: 0.37–0.90; p = 0.015) and grade I perineal rupture (OR: 0.50; 95% CI: 0.29–0.85; p = 0.012). Ballooning was more likely at increased maternal age (OR: 1.08; 95% CI: 1.02–1.13; p = 0.005), epidural (OR: 1.64; 95% CI: 1.06–2.55; p = 0.027) and grade I perineal rupture (OR: 1.79; 95% CI: 1.10–2.90; p = 0.018).ConclusionThough maternal characteristics at birth such as age or BMI increase the risk of PFD, labour and birth factors play a similarly important role. The most critical risk factor for MLA avulsion was forceps delivery, while an epidural had a protective effect.Electronic supplementary materialThe online version of this article (10.1007/s00192-019-04044-2) contains supplementary material, which is available to authorized users.

Objectives: To develop an MRI based model of the female pelvic floor to assess stress during vaginal delivery. Methods: Presented simulations are focused on levator ani muscle. Geometry of fetal head and female pelvic floor are based on live subject MRI data. Model was constructed from axial 3T MRI images. Initial 3D geometric model and the resulting geometry were constructed using 3D Slicer and HyperMesh software. Boundary conditions were considered to simulate real deformation levator ani. Von Mises analysis was used for the stress model. Analysis was performed for three different initial positions of fetal head. The first model represents normal presentation -left occipitoanterior position (LOA). The second -left occipitoposterior position (LOP). The third -left brow position (LB). Results: Simulated stress was calculated in different positions along the curve of Carus. The final stress distribution in levator ani muscle during fetal birth is shown in figure 1. The most problematic areas seem to be in the left muscle attachment, the arcus of muscle especially on the right side and in the middle of the muscle. Maximal stress varies between 0,013 -0,038 GPa. Conclusions: Highest muscle stress was found in LB presentation, the lowest in LOA presentation. The largest stress area was found in LOP presentation. While the peak muscle attachment stress was found at the end of simulation and lasted for a short time, the arcus peak stress lasted for a long period of time. Project is supported by PRVOUK P32 CHU UK.Supporting information can be found in the online version of this abstract Objectives: Training in ultrasonography is frequently done by hands-on teaching by an experienced sonographer. We developed a cervical length (CL) measurement e-learning module (CLEM) with the purpose to enhance the knowledge and skills of experienced sonographers. CLEM was designed especially for sonographers who perform ultrasound in general obstetrical practice, but who do not regularly perform CL measurements. We assessed the effect of the CLEM on the quality of CL measurements comparing CLEM trained and CLEM non-trained sonographers. Methods: The CLEM consists of 5 theoretical questions and 3 calliper placing tests to acquire the CL measurement technique. We offered CLEM to sonographers working in primary, secondary and tertiary care institutions. The quality of the CL measurements of CLEM participants were compared with images of non-participants (control group), by using a CL measurement image score (CIS) defined as the sum of six items assessing the quality of the image; each item was granted 1, 2 or 3 points, depending on a poor, moderate or good score ( fig. 1). Each CLEM participant submitted five CL images after completing the CLEM, the images of non CLEM trained sonographers were randomly selected from a sonography database. Results: The CIS of the sonographers who completed the CLEM (n = 61) was significantly higher than the CIS of sonographers who did not participate in the CLEM (n = 23, 164.8 vs. 155.4 respectively, p = ...