CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIzMiIgaGVpZ2h0PSIzMiIgZmlsbD0ibm9uZSI+PHBhdGggZmlsbD0iI0IyMEYwMyIgZD0iTTE2IDNhMTMgMTMgMCAxIDAgMTMgMTNBMTMuMDE1IDEzLjAxNSAwIDAgMCAxNiAzbTAgMjRhMTEgMTEgMCAxIDEgMTEtMTEgMTEuMDEgMTEuMDEgMCAwIDEtMTEgMTEiLz48cGF0aCBmaWxsPSIjQjIwRjAzIiBkPSJNMTcuMDM4IDE4LjYxNUgxNC44N0wxNC41NjMgOS41aDIuNzgzem0tMS4wODQgMS40MjdxLjY2IDAgMS4wNTcuMzg4LjQwNy4zODkuNDA3Ljk5NCAwIC41OTYtLjQwNy45ODQtLjM5Ny4zOS0xLjA1Ny4zODktLjY1IDAtMS4wNTYtLjM4OS0uMzk4LS4zODktLjM5OC0uOTg0IDAtLjU5Ny4zOTgtLjk4NS40MDYtLjM5NyAxLjA1Ni0uMzk3Ii8+PC9zdmc+);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="120"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "publications.waset.org",cType: 'non-interactive',cRay: '913509891a725f7b',cH: 'O6Z9_zePBfSm._BDo8DrFInMMQY3yH5rffzHfkeIXq8-1739787547-1.2.1.1-ksn8wuHWySo727awbvLUT6QyRTKlHnj6NSfCawY005U18h1aW19jCTNf6sTuElWW',cUPMDTk: "\/abstracts\/search?q=preterm&__cf_chl_tk=9TvnNF0rM0Wydul2MxybYeuKA3J2n_nQq7rkoBaz9eQ-1739787547-1.0.1.1-oklHvBK6ll5b3KxjHfTz4Z9368xLsAsgNPLJNj.J5aY",cFPWv: 'b',cITimeS: '1739787547',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/abstracts\/search?q=preterm&__cf_chl_f_tk=9TvnNF0rM0Wydul2MxybYeuKA3J2n_nQq7rkoBaz9eQ-1739787547-1.0.1.1-oklHvBK6ll5b3KxjHfTz4Z9368xLsAsgNPLJNj.J5aY",md: "sNbFK0Te1MGx.Xtog5gZkZ2tWmJXOPuZsl6AoczKorA-1739787547-1.2.1.1-AwVdkowaJ90IezCw05_KD1lTRBODADjyMQrYgV9MRm2tMMAJIyNVKf_G9w5Vf4m2v5hXO.NuFyin33kxAmuBNqFdoi086Sf.yzzjcU4ki6wWkw8HgilJKwuRNTQacCBVSI0LrgciEXLpDqi3ZH1rku3xs8qWPRVOouJ.bA3BKXTJQuy1aY85bh3eWACAi7.iAVonecRUE9gQw5YkgzBoL42yCLPEFZBvFxZ0VCUE45thuxr34qcpRIbwaSQnO01Ed7uMqtSpajlCkr1UG4FcpZGpXf58LDvG4WF53iYbItFSFQw6bcM57lXGJpORzigBJ6pfbH6o_JmJN5qRTLLjF_wMEaMCXmvLjjoa4RSQh9bQMf45CuKASZRiCs1q0qdAIBLAU_GpuPlZ1WGoWVRvVFhfNWsFzmkULDZYwf94A9sXIOp0T1qwMv8jEMbBfPhOCps4xZNnxysewmd7Zl5Dj9w4p6kGZDIwFFs8y1x4OWawBUIVO8UxiBK8DrdVZpk4smYFrEPR9A4wy5USCqtnh1uf4k19pyx0Ktr5Y0NZ4w7njSBft6AfUxRZ9NviP1FYIyANmTUoM7kQiO8IrgxrX8V4O1n1gSZRN3g.CPCaSyPNlJxe2iy7eTIJ7J9wZqElmYnAKRlPvT8ZHB3u36hufOLtTrQZIfHcTB6svdPsPNrYa2TCD9AeyR8VUyywIZvYGlDh4DM91lENGg6xiq9LG6YN7gC_8OdMEXYZEHy7JpAZ.O3EnadGh1opMb6o6gMcft2F3dg4T.FC6V9HeEmJcBopqMymVeXD0ZSygKQXlm_cTJ493zx.Ehpfnf2Y2hBRa0aFAieCqWmIhT6D3uZBzS6vgOFVrNt1QzLKQ9mbSnWn7HGk3eoMHMC1UYxiw3b8nOuFxoh3_Z3IH1x_JF43szD_6ipLd_VRimNjkb1FYiz1r2t82ym3S_u05Rpr5R9qC.MOCB9TkFqTKTouOvmvbBsO81vvIFvCEKASoiQBUtbSHWSpic99.1hN685w7IJwMesBAD.q6WIuS4rZdl6lISUCJ3PTfShmLP_eZcKqS7ZRaXxBozlOnn6hb43wne92ga5TQNhUvt4XOJMG9Y7stNQpFDgnCZE1SUo4Cwxjso8h3x1Z3D2SVAoueQRfk1iymYHRDwSQPtaM5p7JGFiRedwyku.wzURVaL7G5EgryeNh3Mz5X.yNUBFhETVsPDcs43gTLqbngSk_NuBbEobzjflw46im4JwNhvWurP2aeHl2.ABJjGElcjnRO5aBti7HZZc25540ZbkFSH5mTlx6mgw6IUvF1p8XxUNezsMsT4EfObuj_4EYJj1l0F0Z0N2dhSPAfyT7Avny6fH8oe8ng5ELLBc1GLG0EVnxYqpWMobiMBcTX49CY7NDaV3HRKI2fO8W34_fXTsRIktlvyDsfPFJ95MylgXq2y1VInHATubknYwjMgtJc8ETeLP64Dif7XIcUi8HeqygP74zDUPbVLs_kxtdCY9dHdJ2OjFbfBq93Cp3AIqGXzBwzdxtuclCAyEnmHooMWQzuJ0zjnhwFMw96g5gCBZ8ClKZ0KERQGd6SbNQF07TZl.SPwtnEVuh_00IvYS7oFX7G5RpKl.X2ICqf5l32mw.Fw941flHLuViG7h9_C3BRHm2EknT0j8.OyPdN9Wr1xz7QiXOEf.CQTOamwra9hvKKXZyvgQPdahBOoApYhhsMqec4ewApezJCA6AaZVGu6CW5uw6BZYDlaetVrxUPMbfkFD5gdUR.frztPHuQ8ZC2uFSMofYL06baxJCdI873NZUjHPu4oEgsYX0nRWuHXRDQtculqhhWxd66QKQVlruPM5B9NkENd0Nw3N_Fu23h.y4xroakYyvt2RmTUiXUHwI9PeJuoDbOcWH.9xMQb0GW3AHftlLgASVW2kzgRDt17fyGJsIhu5BbQ",mdrd: "BTEZZRpEFboFcaIqAr796nLbBXxsDAWbnQl_T69488s-1739787547-1.2.1.1-fldjp7O.IXSpudvIvDR0HDPZa.V0i8t56L6G0qLBTTRgPh3OYze19SCh50AxRUA.cFH6BF4WOctRVtDqyCZGz2XpMc3gfTswFaup0BXa8B.FiX2gGmOvqUHMPc1gxlEF2iQ2Lo_RfY0lcSpgG0YRsC4BS3hwQDjavA.nTvj9MVmQwEwVK3KjwyIRGt6zErqN7TMy1geCArrIwfdrk6AJ5y7iUocy8hEi6Dl058YmLt2OQ7BjA_0nDUr8jgCQxzjvk0.aXSufW65D.Li1yRwiwQ05ug8xQMUq0.Lrk_GX5bjx_zRZWnPx04E6DX0mZWAsbTMBI8RgCldXCRDYqN.t66Vsye02qCky4448TTSRr3ZsG3xnqVUza5CP_lj7IRyYZBGzmZ.Pp3GgVao_H.FklN5Jk6D6HjSJkRmBsyube94eky6LkEzvM4vUVm0WQBAYwZ.V.vT3ncEjgjj6PvSVhJFvbJAKzIK3FoSQ8658ssFXccQZm.MnYEzbud1KYUoWn1bTPE_M0FZOc6U6pKPTzWuXUWaGaTzlM3.Ci0wtWREGMWDtqbOIWmd1wmPtHSvyuXG1EjkkGuDtB1b6tDWvlKqmMsw2zDQ3vbH4twYBSjOZC5LYdu1e4Wc_PXEwNfzDUb2B1K8ucawEElvFwUtecbU8Y_K7lT1KTAZt_ooNFS4C7q6ahIMigkRwHv8As8GLcnTMh6KLSFijFGUnl6oaoQ.Jezqd6BSoPQIRUk0Bp98vKBPvCGudpuNYlcSvI6Uir8dX3JUilMuX6nY_Ut8a_kFiaozntzLuYFtQCmxQEKLjlTiZ00craqiXFLDfCbvZzv4JErKBAti1oFd5U4wGn7N5FZ8G89E1.ZR74VMNHb4EVUMMa15CrFAVzQX1Dq3oxWEWIU1duJHEvsCc9aqq02CkaEL_7.jcJ_N63ifx10BJhlC7.2xBAf3p3haWpHQKaeF0u6I9uETqTYNeOC8Y3lg5SqnqAANymXYSATg0fb24Df4sKLW8lwgttXrTSNqEVjhe.ww2TJ4L8JcVRaQ.GZuJUhIp5Ju_9Xo_RDKV2uSxVuDeZZycwTJIUlq7wujN3s5pIpC0yCXobLENJSjYyiOPYvHr0WEN97dTaxzQo4T4lRpDPujWx3IKYmSOT6Ol8zVfJF_XhFyrLb0GKUwoMNxYJ.w54keiba2KqmQ.LdRQghb1sf3wCfDg24KOnr9xJanmuz5KGiDWjdi3.PcUQUGpat_J5tMsuLeCjh3i8P8855HO1ASJAfpQkrk6xSqgQYRNqdm2SzvSgfPThc7vBr0JK_Ai3FRbX2gx.TASfE.kDQyxz0MkmWj96M5eoLnN.T3jIMuiEmUUSJy_uqqyBBuLOSKhaRW0ph_v6GdGfrlkSws9aIL1nrvEOPNfQrlq5R2rs_VZJb9V_rVGKXyI1z4AtWMLNDtrwvkQMLxC3N9BxHpWRIr47dA4jHSs.K8Sb08eL1qaQvXLySCAoISqtC5sx0j1honvLWNp25zo.jkra3CsXi89N726XEbirbMhXkr42xdOXGWjAnSqJenN6R1kV2UJXNYYqUpK7Ho94rmfL5Uo5P2kCZN84erBTTXoDrnjRz3h7hL1J.O3HlwuX0GfgANVOJyKur8J5Gsxg5xeDg6eRZg1R6PZDGXUCJNv0_zrHSefMHLAPRqFWs.9fG0fGi.yOATadatwBYSrgyy5jzcUzFK1Sk799AFFYI8BwBppWB5_FbXJirJFSZsUZ793zDBO8F5xTfrkZKc84mQ4oLk4bPmavvJoD2vGAf.3xMeVDF6rZkrZq0OmKNgaNHB.J139a5QUehVgeGJVgOTv0v5L46Hm..BO1KHdja8mL.DbGFmkX81RQtForI1e50pGoAirBKFSUWriOLDj2s9icz1E5FYTcGpOQLaIYiU4fo8.WDoQrO0T05SRNo2HbMCXwGgStBBob.COeMfM1XX5n59YqzB2ep8g6dL7qAjmVXPlyw_GtMQ_Y9XC7od8zjGriFaDMevlRZy6fWKbx1M"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=913509891a725f7b';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/abstracts\/search?q=preterm&__cf_chl_rt_tk=9TvnNF0rM0Wydul2MxybYeuKA3J2n_nQq7rkoBaz9eQ-1739787547-1.0.1.1-oklHvBK6ll5b3KxjHfTz4Z9368xLsAsgNPLJNj.J5aY" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>