Record checklist.

(DOCX)</p

Outcomes following planned VBAC compared to ERCS.

Outcomes following planned VBAC compared to ERCS.</p

Outcomes following planned VBAC with and without labor induction compared to ERCS.

Outcomes following planned VBAC with and without labor induction compared to ERCS.</p

Characteristics of the study cohort by planned mode of birth after previous cesarean section.

Characteristics of the study cohort by planned mode of birth after previous cesarean section.</p

Outcomes following (A) planned VBAC compared to ERCS (B) planned VBAC without labor induction compared to ERCS (C) planned VBAC with labor inuction compared to ERCS (D) planned and actually had VBAC compared to ERCS, (E) planned VBAC but had in-labor non-elective repeat cesarean section compared to ERCS.

§Adjusted for year of birth and sociodemographic factors (maternal age, mother’s country of birth, marital status, and area deprivation) and maternal medical and obstetric-related factors (previous mode(s) of birth—categorized as cesarean section only/cesarean section and vaginal birth(s), parity, interpregnancy interval, diabetes, birth weight of child in pregnancy/birth in question treated as a continuous variable). CS, cesarean section; ERCS, elective repeat cesarean section; HR, hazard ratio; VBAC, vaginal birth after previous cesarean.</p

Supporting file.

Fig A. Schematic to explain time-varying exposure model that propose to use, allowing inclusion of more than 1 birth per woman in the study cohort. Text A. Extract from application to the Public Benefit and Privacy Panel for Health and Social Care Scotland, taken from application submitted in March 2018. Table A. Data sources. Table B. Data sources, codes, and database fields used to identify study population, exposures, outcomes, and covariates. Table C. Complete case analysis of outcomes following planned VBAC compared to ERCS. Table D. Complete case analysis of outcomes following planned VBAC with and without labor induction compared to ERCS. Table E. Complete case analysis of outcomes according to actual mode of birth—planned VBAC and had a VBAC and planned VBAC but had in-labor non-elective repeat cesarean section compared to ERCS. Table F. E-values for the observed associations between planned mode of birth after previous cesarean section (planned VBAC vs. ERCS) and pelvic floor outcomes. Table G. E-values for the observed associations between planned mode of birth after previous cesarean section (planned VBAC with and without labor induction vs. ERCS) and pelvic floor outcomes. Table H. E-values for the observed associations between actual mode of birth after previous cesarean section (planned VBAC and had a VBAC and planned VBAC but had in-labor non-elective repeat cesarean section compared vs. ERCS) and pelvic floor outcomes. Table I. Outcomes following planned VBAC compared to ERCS in women who had all their previous births in the SMR02. Table J. Outcomes following planned VBAC with and without labor induction compared to ERCS in women who had all their previous births in the SMR02. Table K. Outcomes according to actual mode of birth—planned VBAC and had a VBAC and planned VBAC but had in-labor non-elective repeat cesarean section compared to ERCS in women who had all their previous births in the SMR02. Table L. Rate and hazard ratio of any pelvic floor surgery by the exposures of interest in the subgroup of women who gave birth between 1 January 1983 and 31 December 1986. Table M. Outcomes following planned VBAC compared to ERCS, defining planned VBAC as birth vaginally or by non-electve cesarean section with a duration of labor of >4 hours (rather than ≥1 hour). (DOCX)</p

Flow diagram of cohort selection.

*Ineligible for planned VBAC or did not meet other eligibility criteria for study due to 1 or more of the following: non-cephalic presentation at delivery (n = 4,556); placenta praevia (n = 546); abdominal pregnancy (n = 1); known or suspected disproportion of maternal and/or fetal origin (n = 6,593); tumor of corpus uteri (n = 97); birth by pre-labor non-elective cesarean section (n = 2,632); antepartum stillbirth (n = 0); stillbirth missing time of death in relation to delivery (n = 147); pelvic floor surgery before birth (n = 28); missing information on mode of delivery (n = 24); delivered by non-elective cesarean section missing information about duration of labor (n = 927); number of previous cesarean sections greater than parity (n = 15). Reasons not mutually exclusive. aNumbers provided by ISD Scotland, now part of Public Health Scotland. CHI, community health index; ISD, Information Services Division; NRS, National Records of Scotland; SMR02, Scottish Morbidity Record Maternity Inpatient and Day Case dataset; VBAC, vaginal birth after previous cesarean.</p

Outcomes according to actual mode of birth—Planned VBAC and had a VBAC and planned VBAC but had in-labor non-elective repeat cesarean section compared to ERCS.

Outcomes according to actual mode of birth—Planned VBAC and had a VBAC and planned VBAC but had in-labor non-elective repeat cesarean section compared to ERCS.</p

Kaplan–Meier failure curve showing the cumulative probability of any pelvic floor surgery according to planned mode of birth after previous cesarean section.

Shaded areas denote 95% CIs. CI, confidence interval; ERCS, elective repeat cesarean section; VBAC, vaginal birth after previous cesarean.</p

Synthesis of boron nitride nanotubes by boron ink annealing

Ball-milling and annealing is one effective method for the mass production of boron nitride nanotubes (BNNTs). We report that the method has been modified to a boron (B) ink annealing method. In this new process, the nanosize ball-milled B particles are mixed with metal nitrate in ethanol to form an ink-like solution, and then the ink is annealed in nitrogen-containing gas to form nanotubes. The new method greatly enhances the yield of BNNTs, giving a higher density of nanotubes. These improvements are caused by the addition of metal nitrate and ethanol, both of which can strongly boost the nitriding reaction, as revealed by thermogravimetric analysis. The size and structure of BNNTs can be controlled by varying the annealing conditions. This high-yield production of BNNTs in large quantities enables the large-scale application of BNNTs