Antimicrobial and Chemoattractant Activity, Lipopolysaccharide Neutralization, Cytotoxicity, and Inhibition by Serum of Analogs of Human Cathelicidin LL-37.

Antimicrobial peptides have been evaluated in vitro and in vivo as alternatives to conventional antibiotics. Apart from being antimicrobial, the native human cathelicidin-derived peptide LL-37 (amino acids [aa] 104 to 140 of the human cathelicidin antimicrobial peptide) also binds and neutralizes bacterial lipopolysaccharide (LPS) and might therefore have beneficial effects in the treatment of septic shock. However, clinical trials have been hampered by indications of toxic effects of LL-37 on mammalian cells and evidence that its antimicrobial effects are inhibited by serum. For the present study, LL-37 was compared to two less hydrophobic fragments obtained by N-terminal truncation, named 106 (aa 106 to 140) and 110 (aa 110 to 140), and to a previously described more hydrophobic variant, the 18-mer LLKKK, concerning antimicrobial properties, lipopolysaccharide neutralization, toxicity against human erythrocytes and cultured vascular smooth muscle cells, chemotactic activity, and inhibition by serum. LL-37, fragments 106 and 110, and the 18-mer LLKKK inhibited the growth of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans in a radial diffusion assay, inhibited lipopolysaccharide-induced vascular nitric oxide production, and attracted neutrophil granulocytes similarly. While fragments 106 and 110 caused less hemolysis and DNA fragmentation in cultured cells than did LL-37, the 18-mer LLKKK induced severe hemolysis. The antibacterial effect of fragments 106 and 110 was not affected by serum, while the effect of LL-37 was reduced. We concluded that the removal of N-terminal hydrophobic amino acids from LL-37 decreases its cytotoxicity as well as its inhibition by serum without negatively affecting its antimicrobial or LPS-neutralizing action. Such LL-37-derived peptides may thus be beneficial for the treatment of patients with sepsis

Grindarbotnseinkenni eftir fæðingu og snemmíhlutun með sjúkraþjálfun

Markmið: Meginmarkmið þessa doktorsverkefnis var að kanna tíðni grindarbotnseinkenna og vanlíðunar sem þau valda frumbyrjum á fyrstu mánuðum eftir fæðingu, ásamt því að rannsaka hvort tengsl findust milli grindarbotnseinkennanna og fæðingartengdra þátta. Annað meginmarkmið var að kanna áhrif snemmbærrar grindarbotnsþjálfunar, sem stýrt var af sjúkraþjálfara, í hópi frumbyrja með einkenni frá grindarbotni. Þriðja markmið var að kanna áhrif íþróttaiðkunar fyrir fæðingu hjá afreksíþróttakonum á fæðingarútkomu fyrstu fæðingar. Þrjár vísindagreinar sem byggðar voru á þremur rannsóknum eru hluti af þessari ritgerð. Sértæk markmið voru: Rannsókn I: Að kanna tíðni grindarbotnseinkenna og vanlíðunar sem tengdist einkennunum hjá norður-evrópskum frumbyrjum 6-10 vikum eftir fæðingu og bera saman fæðingu um fæðingarveg og með keisaraskurði. Rannsókn II: Að kanna áhrif einstaklingsmiðaðrar grindarbotnsþjálfunar, sem sjúkraþjálfari leiðir á fyrstu mánuðum eftir fæðingu, á þvag- og endaþarmsleka og þá vanlíðan sem slík einkenni valda hjá frumbyrjum. Áhrif slíkrar þjálfunar á styrk og vöðvaúthald í grindarbotni var einnig metin. Rannsókn III: Að kanna fæðingarútkomu, þar á meðal tíðni bráðakeisaraskurða, lengdar fyrsta og annars stigs fæðingar og alvarlegra spangarrifa hjá frumbyrjum sem voru annaðhvort afreksíþróttakonur eða konur sem ekki æfðu íþróttir. Aðferðir: Rannsókn I var þversniðsrannsókn með 721 manns úrtaki frumbyrja sem fæddu einbura á höfuðborgarsvæðinu Reykjavík. Frá apríl 2015 til mars 2017 svöruðu þátttakendur rafrænum spurningalista heima 6-10 vikum eftir fæðingu. Upplýsingum um þvag- og endaþarmsleka, sig grindarholslíffæra og vandkvæðum tengd kynlífi ásamt tengdri vanlíðan var safnað og borið saman við gögn frá íslensku fæðingarskráningunni. Meginútkomubreytur voru framangreind grindarbotnseinkenni eftir fæðingu og tengd vanlíðan. Rannsókn II var slembi-samanburðarrannsókn til að kanna áhrif grindarbotnsþjálfunar, sem leidd var af sjúkraþjálfara, á tíðni þvag- og endaþarmsleka (aðal-útkomubreytur). Mæliaðilinn var blindaður á rannsóknahópana. Vanlíðan tengd raunverulegum einkennum, ásamt mati á styrk og úthaldi vöðva í grindarbotni voru flokkaðar sem aðrar útkomubreytur. Frá árinu 2016 til 2017 voru svör kvenna sem tóku þátt í Rannsókn I athuguð til að finna konur sem uppfylltu skilyrði til þátttöku. Þetta var gert um leið og konur skiluðu svörunum 6-10 vikum eftir fyrstu fæðingu. Níutíu og fimm konum sem töldust vera með þvagleka samkvæmt svörun spurningalistans var boðið að taka þátt. Af þeim þáðu 84 boðið. Samtals var 41 konu slembiraðað í íhlutunarhóp og 43 í samanburðarhóp. Þrjár og ein kona hættu þátttöku úr þessum tveim hópum. Íhlutunin, sem hófst um 9 vikum eftir fæðingu, samanstóð af 12 vikulegum tímum með sjúkraþjálfara. Eftir það voru útkomubreytur metnar ( 6 mánuðum eftir fæðingu). Viðbótar-eftirfylgni var framkvæmd um 12 mánuðum eftir fæðingu. Samanburðarhópurinn fékk engar sértækar leiðbeiningar eftir upphaflegu skoðunina. Rannsókn III var afturskyggn tilfella-viðmiðuð rannsókn þar sem fæðingarútkoma fyrstu fæðingar afreksíþróttakvenna var borin saman við útkomu kvenna sem ekki æfðu íþróttir. Íþróttakonurnar voru flokkaðar samkvæmt há-þungaberandi og lág-þungaberandi íþróttagreinum. Íþróttakonurnar höfði fyrir fyrstu fæðingu keppt með landsliðum eða tekið þátt í keppnum á alþjóðlegum vettvangi eða verið í sambærilegri stöðu í sinni íþróttagrein. Samtals tóku 248 konur þátt, 89 voru í há-þungaberandi og 41 í lág-þungaberandi íþróttum og 118 konur í samanburðahópi. Einennum kvenna sem skiptu máli fyrir rannsóknina ásamt svörum um tíðni íþróttaiðkunar í að minnsta kosti þrjú ár fyrir fyrstu meðgöngu og upplýsingum um almenna hreyfingu þeirra var safnað með spurningalista sem sendur var með tölvupósti. Upplýsingar fengust frá íslensku fæðingarskráningunni um tiltekin atriði varðandi fyrstu fæðingu allra þeirra kvenna sem tóku þátt í rannsóknunum. Niðurstöður: Í Rannsókn I var tíðni þvagleka 48% og tíðni endaþarmsleka 60%, auk þess sem 27% og 56% þátttakenda þjáðust af vanlíðan sökum þessa í viðkomandi hópum. Sigeinkenni grindarholslíffæra fundust hjá 29% kvenna og af öllum þátttakendum sögðust 13% glíma við vanlíðan vegna þess. Fimmtíu og fimm prósent kvennanna sögðust vera kynferðislega virkar, af þeim greindu 66% frá sársauka við samfarir. Af öllum þátttakendum sögðust 48% upplifa vanlíðan vegna kynlífstengdra atriða. Þvagleki með undirflokkum og sig á líffærum grindarhols var algengari hjá konum sem fæddu um fæðingarveg borið saman við keisaraskurð, en ekki fannst marktækur munur þegar um endaþarmsleka og sársauka við samfarir var að ræða. Að vera í offituflokki, borið saman við eðlilega þyngd (LÞS<25kg/m2) var tengt aukinni hættu á þvagleka hjá konum sem fæddu um fæðingarveg (LH 1.94; 95% ÖB 1.20-3.14). Fyrir konur sem fæddu um fæðingarveg var fæðingarþyngd yfir 50. hlutfallsmarki einnig áhættuþáttur fyrir bráðaþvagleka (LH 1.53; 95% ÖB; 1.05-2.21). Auk þess var spangarskurður tengdur auknum líkum á endaþarmsleka fyrir sama hóp kvenna (LH 2.19; 95% ÖB; 1.30-3.67). Engin tengsl fundust milli einkenna móður eða einstakra fæðingarbreyta við grindarbotnseinkenni hjá konum sem fæddu með keisaraskurði. Í Rannsókn II var þvagleki marktækt minni í lok meðferðar hjá íhlutunarhóp, með 21 konu (57%) enn með einkenni borið saman við 31 (82%) í samanburðarhópi (p=0,33). Einnig var þvagleka-tengd vanlíðan minni í íhlutunarhópnum, með 10 konur (27%) sem enn fundu fyrir slíku borið saman við 23 (60%) í samanburðarhópnum (p=0,005). Endaþarmsleki minnkaði ekki við grindarbotnsþjálfunina og var ekki marktækur munur á hópunum við lok meðferðar (p=0,33). Ekki fannst heldur munur á vanlíðan sem tengdist endaþarmsleka við lok meðferðar (p=0,82). Meðaltalsmunur hópanna á styrkbreytingum grindarbotnsvöðva var 5 hPa4 (95% ÖB 2-8; p=0,003), og varðandi úthaldsbreytingar var munurinn 50 hPa/sek (95% ÖB 23-77; p=0,001), hvort tveggja íhlutunarhópnum í vil. Meðaltalsmunur hópanna á styrkbreytingum hringvöðva endaþarms var 10 hPa (95% ÖB 2-18; p=0,01). Úthaldsbreytingin var 95 hPa/sek (95% ÖB 16-173; p=0,02), hvor tveggja íhlutunarhópnum í vil. Við eftirfylgni 12 mánuðum eftir fæðingu var ekki munur milli hópa á tíðni þvag- eða endaþarmsleka né tengdri vanlíðan. Styrkog úthaldsmunur bæði grindarbotnsvöðva og hringvöðva endaþarms íhlutunarhópnum í vil, var enn til staðar. Í Rannsókn III fannst enginn munur milli hópa á tíðni bráðakeisaraskurðar né lengdar á fyrsta og öðru stigi fæðingar. Tíðni þriðju og fjórðu gráðu spangarrifa var marktækt hærri (23,7%) hjá konum sem æfðu lág-þungaberandi íþróttir borið saman við háþungaberandi (5,1%, p=0,01). Enginn munur fannst þegar hvor íþróttahópurinn um sig var borinn saman við samanburðarhóp (12%, p=0,09 fyrir lág-þungaberandi og p=0,12 fyrir há-þungaberandi íþróttahópinn). Tíðni íþóttaiðkunar fyrir- og á meðgöngu, aldur móður eða LÞS fyrir fæðingu hafði ekki áhrif á útkomu og gang fæðingar. Ályktanir: Einkenni frá grindarbotni og vanlíðan sem tengdist þeim var algeng hjá frumbyrjum á fyrstu vikum eftir fæðingu. Ekki ætti að líta fram hjá þessu né þeim áhrifum sem grindarbotnsveikleiki hefur á konur. Hjá hópi kvenna með einkenni frá grindarbotni dró grindarbotnsþjálfun úr þvagleka og tengdri vanlíðan 6 mánuðum eftir fæðingu auk þess að bæta styrk og úthaldsgetu vöðva í grindarbotni. Endaþarmsleki minnkaði hins vegar ekki við íhlutunina. Þegar skoðaður var hópur kvenna með tilliti til líkamsþjálfunar fyrir fyrstu fæðingu, fannst ekkert samband mikillar íþróttaiðkunar á afreksstigi og verri útkomu fæðingar þegar metin var lengd fyrsta og annars stigs fæðingar, tíðni bráðakeisaraskurða og alvarlegar spangarrifur. Margar konur glíma við tiltölulega mild einkenni frá grindarbotni eftir fæðingu, einkenni sem eru líkleg til að minnka á fyrsta árinu eftir barnsburð. Bera þarf kennsl á þann hóp kvenna sem á við alvarleg grindarbotnseinkenni og vanlíðan að stríða þar sem þær eru líklegar til að hafa gagn af sérmiðaðri sjúkraþjálfun.University of Iceland Research Fund The Icelandic Physiotherapy Association Research Fund The Landspitali University Hospital Research Fund The Public Health Fund, Icelandic Directorate of Healt

Actions of Antimicrobial Peptides and Bacterial Components in Inflammation

Antimicrobial peptides are evolutionally ancient parts of the innate immune system and their primary role is to protect us from infections. The human cathelicidin-derived antimicrobial peptide, LL-37, not only possesses broad spectrum antimicrobial activities but is also able to bind and neutralize bacterial lipopolysaccharide (LPS), an important trigger of the widespread inflammatory response contributing to septic shock. LL-37 has been studied as an alternative to conventional antibiotics but clinical trials have been hampered by indications of its toxic effect on mammalian cells and evidence that its antimicrobial effects are inhibited by serum. It has been proposed that the cytotoxicity of LL-37 is due to hydrophobic amino acids. We were able, by removing hydrophobic amino acids from the N-terminal of LL-37, to generate less cytotoxic peptides with retained antimicrobial and LPS–neutralizing actions in serum. By using computer simulation we identified an active domain of LL-37, a 21 amino acid fragment, GKE, displaying similar antimicrobial and LPS-binding activity in vitro as native LL-37 but less toxic and therefore holding promise as a template for the development of peptide antibiotics for treating sepsis. Sepsis due to Gram-positive bacteria is becoming increasingly prevalent. The Gram-positive bacterium Streptococcus pyogenes, carrying a surface protein named M1 being fundamental for its virulence, is the major cause of severe streptococcal infections like streptococcal toxic shock syndrome and necrotizing fasciitis. We found that M1 protein is able to induce vascular nitric oxide (NO) production, which in turn relaxes smooth muscle cells and could thereby contribute to the severe hypotension seen in septic patients. This we confirmed by showing that M1 protein caused hyporesponsiveness to the vasoconstrictor, phenylephrine, in rat aorta. Bacterial compounds are able to activate Toll-like receptors generating an inflammatory response. Experiments using wild type and knockout mice revealed that M1 protein is able to attach to both TLR2 and TLR4 (TLR) in mice, only activating the latter. M1 protein only attached to TLR2 in human blood vessels. LL-37 possesses immunomodulatory effects. In order to explore potential modulatory effects of GKE on vascular nitric oxide production we used the well identified proinflammatory compounds interleukin-1β (IL-1β), M1 protein from Streptococcus pyogenes and lipoteichoic acid (LTA). All three induced vascular NO production in rat aorta. GKE at low concentration inhibited IL-1β-induced NO production, but synergistically increased it at higher concentrations. GKE did not affect the M1 protein induced NO production while GKE inhibited LTA induced NO production. Thus, GKE seems to have complex modulatory effects on vascular nitric oxide production depending on the inflammatory compound used

Tatiana Riabouchinska as the Serving Maid (left), Roman Jasinsky as the Shepherd (right), in Les dieux mendiants, Covent Garden Russian Ballet, Australian tour, His Majesty's Theatre, Melbourne, April 1939 [picture] /

From: Les dieux mendiants (The gods go a-begging) / pastorale by M. Sobeka ; music by George Frideric Handel, arranged by Sir Thomas Beecham.; Inscription: "G10".; Part of the collection: Hugh P. Hall collection of photographs, 1938-1940.; Performed October 1938 and April 1939.; Choreography by David Lichine ; scenery by Léon Bakst ; costumes by Juan Gris.; Also available in an electronic version via the internet at: http://nla.gov.au/nla.pic-vn4179104; Additional resources on the Ballets Russes and their Australasian tours are listed on the Ballets Russes Project resources page at http://www.nla.gov.au/balletsrusses/resources.html. One of a collection of photographs taken by Hugh P. Hall of 28 ballet productions performed by the Covent Garden Russian Ballet (toured Australia 1938-1939) and the Original Ballet Russe (toured Australia 1939-1940). These are the second and third of the three Ballets Russes companies which toured Australasia between 1936 and 1940. The photographs were taken from the auditorium during a live performance in His Majesty's Theatre, Melbourne and mounted on cardboard for display purposes. For conservation and storage, the photographs have been demounted. The original arrangement of the photographs has been recorded, and details are available from the Pictures Branch of the National Library

In silico identification and biological evaluation of antimicrobial peptides based on human cathelicidin LL-37.

Bacterial lipopolysaccharides (LPS) are important triggers of the widespread inflammatory response, which contributes to the development of multiple organ failure during sepsis. The helical 37-amino-acid-long human antimicrobial peptide LL-37 not only possesses a broad-spectrum antimicrobial activity but also binds and neutralizes LPS. However, the use of LL-37 in sepsis treatment is hampered by the fact that it is also cytotoxic. To find a less toxic analog of LL-37, we used in silico analysis to identify amphipathic helical regions of LL-37. A 21-amino-acid fragment (GKE) was synthesized, the biological actions of which were compared to those of two equally long peptides derived from the N and C termini of LL-37 as well as native LL-37. GKE displayed antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, and Candida parapsilosis that was similar to or even stronger than LL-37. GKE, as well as the equally long control peptides, attracted granulocytes in a fashion similar to that of LL-37, while only GKE was as potent as LL-37 in inhibiting LPS-induced vascular nitric oxide production. GKE caused less hemolysis and apoptosis in human cultured smooth muscle cells than LL-37. In summary, we have identified an active domain of LL-37, GKE, which displays antimicrobial activity in vitro and LPS-binding activity similar to those of LL-37 but is less toxic. GKE therefore holds promise as a template for the development of peptide antibiotics for the treatment of sepsis

M1 protein from Streptococcus pyogenes induces nitric oxidemediated vascular hyporesponsiveness to phenylephrine: Involvement of toll-like receptor activation.

Streptococcus pyogenes carrying M1 protein causes the severe and increasingly prevalent streptococcal toxic shock syndrome and necrotizing fasciitis. M1 protein is an important virulence factor of Streptococcus pyogenes and induces an inflammatory response in human monocytes. We wanted to investigate if purified M1 protein in solution could induce vascular nitric oxide (NO) production leading to vasopressor hyporesponsiveness. Rat aorta segments were incubated with M1 protein or lipopolysaccharide (LPS) in vitro. M1 protein (10 mug ml) and LPS (1 ng ml) to a similar extent induced NO production and hyporesponsiveness to the vasoconstrictor phenylephrine. Immuno-gold electron microscopy demonstrated that M1 protein binds to toll-like receptor (TLR) 2 as well as TLR4 in mouse aorta but only to TLR2 in human omental artery. Incubation with M1 protein caused a reduction in the contractile response to phenylephrine in aorta segments from wild type and TLR2 knockout but not from TLR4 knockout mice. In conclusion, M1 protein causes vascular NO production leading to hyporesponsiveness to vasopressors via a mechanism involving TLR but the subtypes may be species-dependent. M1 protein could contribute to the circulatory disturbances accompanying severe invasive streptococcal infections

Can postpartum pelvic floor muscle training reduce urinary and anal incontinence?: An assessor-blinded randomized controlled trial.

To access publisher's full text version of this article click on the hyperlink belowBackground: Pelvic floor dysfunction, including urinary and anal incontinence, is a common postpartum complaint and likely to reduce quality of life. Objective: To study the effects of individualized physical therapist-guided pelvic floor muscle training in the early postpartum period on urinary and anal incontinence and related bother, as well as pelvic floor muscle strength and endurance. Materials and methods: This was an assessor-blinded, parallel-group, randomized controlled trial evaluating effects of pelvic floor muscle training by a physical therapist on the rate of urinary and/or anal leakage (primary outcomes); related bother and muscle strength and endurance in the pelvic floor were secondary outcomes. Between 2016 and 2017, primiparous women giving birth at Landspitali University Hospital in Reykjavik, Iceland, were screened for eligibilty 6-10 weeks after childbirth. Of those identified as urinary incontinent, 95 were invited to participate, of whom 84 agreed. The intervention, starting at ∼9 weeks postpartum consisted of 12 weekly sessions with a physical therapist, after which the main outcomes were assessed (endpoint, ∼6 months postpartum). Additional follow-up was conducted at ∼12 months postpartum. The control group received no instructions after the initial assessment. The Fisher exact test was used to test differences in the proportion of women with urinary and anal incontinence between the intervention and control groups, and independent-sample t tests were used for mean differences in muscle strength and endurance. Significance levels were set as α = 0.05. Results: A total of 41 and 43 women were randomized to the intervention and control groups, respectively. Three participants and 1 participant withdrew from these respective groups. Measurement variables and main delivery outcomes were not different at recruitment. At the endpoint, urinary incontinence was less frequent in the intervention group, with 21 participants (57%) still symptomatic, compared to 31 controls (82%) (P = .03), as was bladder-related bother with 10 participants (27%) in the intervention vs 23 (60%) in the control group (P = .005). Anal incontinence was not influenced by pelvic floor muscle training (P = .33), nor was bowel-related bother (P = .82). The mean differences between groups in measured pelvic floor muscle strength changes at endpoint was 5 hPa (95% confidence interval, 2-8; P = .003), and for pelvic floor muscle endurance changes, 50 hPa/s (95% confidence interval, 23-77; P = .001), both in favor of the intervention group. The mean between-group differences for anal sphincter strength changes was 10 hPa (95% confidence interval, 2-18; P = .01) and for anal sphincter endurance changes 95 hPa/s (95% confidence interval, 16-173; P = .02), both in favor of the intervention. At the follow-up visit 12 months postpartum, no differences were observed between the groups regarding rates of urinary and anal incontinence and related bother. Pelvic floor- and anal muscle strength and endurance favoring the intervention group were maintained. Conclusion: Postpartum pelvic floor mucle training decreased the rate of urinary incontinence and related bother 6 months postpartum and increased muscle strength and endurance.University of Iceland Research Fund Public Health Fund, Icelandic Directorate of Health Icelandic Physiotherapy Association Science Fund Landspitali Science Fun

Cross-sectional study of early postpartum pelvic floor dysfunction and related bother in primiparous women 6-10 weeks postpartum.

To access publisher's full text version of this article click on the hyperlink belowIntroduction and hypothesis: To study the prevalence of pelvic floor dysfunction and related bother in primiparous women 6-10 weeks postpartum, comparing vaginal and cesarean delivery. Methods: Cross-sectional study of 721 mothers with singleton births in Reykjavik, Iceland, 2015 to 2017, using an electronic questionnaire. Information on urinary and anal incontinence, pelvic organ prolapse and sexual dysfunction with related bother (trouble, nuisance, worry, annoyance) was collected. Main outcome measures were prevalence of pelvic floor dysfunction and related bother. Results: The overall prevalence of urinary and anal incontinence was 48% and 60%, respectively. Bother regarding urinary symptoms was experienced by 27% and for anal symptoms by 56%. Pelvic organ prolapse was noted by 29%, with less than half finding this bothersome. Fifty-five percent were sexually active, of whom 66% reported coital pain. Of all the women, 48% considered sexual issues bothersome. Urinary incontinence and pelvic organ prolapse were more prevalent in women who delivered vaginally compared to cesarean section, but no differences were observed for anal incontinence and coital pain. Compared to women with BMI 50th percentile was predictive for urgency incontinence after vaginal delivery (OR 1.53; 95% CI 1.05-2.21). Episiotomy predicted more anal incontinence (OR 2.19; 95% CI 1.30-3.67). No associations between maternal and delivery characteristics were found for pelvic floor dysfunction after cesarean section. Conclusions: Bothersome pelvic floor dysfunction symptoms are prevalent among first-time mothers in the immediate postpartum period. Keywords: Anal incontinence; Childbirth; Coital pain; Pelvic organ prolapse; Primiparas; Urinary incontinence.University of Iceland Research Fund Public Health Fund, Icelandic Directorate of Health Icelandic Physiotherapy Association Science Fund Landspitali Science Fun

Do female elite athletes experience more complicated childbirth than non-athletes? A case-control study.

To access publisher's full text version of this article click on the hyperlink belowOBJECTIVE: Previous studies have suggested that female athletes might be at higher risk of experiencing complications such as caesarean sections and perineal tears during labour than non-athletes. Our aim was to study delivery outcomes, including emergency caesarean section rates, length of the first and second stages of labour and severe perineal tears, in first-time pregnant elite athletes compared with non-athletes. METHODS: This is a retrospective case-control study comparing birth outcomes of primiparous female elite athletes engaging in high-impact and low-impact sports compared with non-athletic controls. The athletes had prior to birth competed at a national team level or equivalent. Participant characteristics and frequency of training for at least 3 years before a first pregnancy were collected via a self-administered questionnaire. Information on delivery outcome was retrieved from the Icelandic Medical Birth Registry. RESULTS: In total, 248 participated, 118 controls, 41 low-impact and 89 high-impact elite athletes. No significant differences were found between the groups with regard to incidence of emergency caesarean section or length of the first and second stages of labour. The incidence of third-degree to fourth-degree perineal tears was significantly higher (23.7%) among low-impact athletes than in the high-impact group (5.1%, p=0.01), but no significant differences were seen when the athletes were compared with the controls (12%; p=0.09 for low-impact and p=0.12 for high-impact athletes). CONCLUSION: Participation in competitive sports at the elite level was not related to adverse delivery outcome, including length of labour, the need for caesarean section during delivery and severe perineal tears.University of Iceland Research Fund Public Health Fund Icelandic Directorate of Health Icelandic Physiotherapy Association Science Fund Landspitali University Hospital Iceland Science Fun