{"id":6176,"date":"2026-10-19T09:48:36","date_gmt":"2026-10-19T09:48:36","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-laeknavisindum-harpa-vidarsdottir\/"},"modified":"2026-10-19T09:48:36","modified_gmt":"2026-10-19T09:48:36","slug":"doktorsvorn-i-laeknavisindum-harpa-vidarsdottir","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-laeknavisindum-harpa-vidarsdottir\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed l\u00e6knav\u00edsindum – Harpa Vi\u00f0arsd\u00f3ttir"},"content":{"rendered":"
\n
\n

F\u00f6studaginn 12. febr\u00faar ver Harpa Vi\u00f0arsd\u00f3ttir doktorsritger\u00f0 s\u00edna \u00ed l\u00e6knav\u00edsindum vi\u00f0 L\u00e6knadeild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0: Miklir \u00feungburar \u2013 fylgikvillar f\u00e6\u00f0ingar fyrir m\u00f3\u00f0ur og barn, og mynstur efnaskiptamerkja. Extreme macrosomia \u2013 birth outcome for mother and infant, and metabolomic profile.<\/strong><\/p>\n

V\u00f6rninni ver\u00f0ur streymt: <\/strong>https:\/\/livestream.com\/hi\/doktorsvornharpavidarsdottir<\/a><\/p>\n

Andm\u00e6lendur eru dr. Lars M\u00f6rkrid, pr\u00f3fessor vi\u00f0 H\u00e1sk\u00f3lann \u00ed \u00d3sl\u00f3, og dr. Hans T\u00f3mas Bj\u00f6rnsson, pr\u00f3fessor vi\u00f0 L\u00e6knadeild H\u00e1sk\u00f3la \u00cdslands.<\/p>\n

Umsj\u00f3narkennari var dr. Ragnar Bjarnason, pr\u00f3fessor, og lei\u00f0beinandi \u00de\u00f3r\u00f0ur \u00de\u00f3rkelsson, yfirl\u00e6knir. Auk \u00feeirra s\u00e1tu \u00ed doktorsnefnd dr. Reynir T. Geirsson, pr\u00f3fessor emeritus, dr. Unnur Anna Valdimarsd\u00f3ttir, pr\u00f3fessor og dr. \u00de\u00f3rhallur Ingi Halld\u00f3rsson, pr\u00f3fessor.<\/p>\n

Engilbert Sigur\u00f0sson, pr\u00f3fessor og forseti L\u00e6knadeildar H\u00e1sk\u00f3la \u00cdslands, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed H\u00e1t\u00ed\u00f0asal H\u00e1sk\u00f3la \u00cdslands og hefst kl. 13.00.<\/p>\n

Fj\u00f6ldatakm\u00f6rkun: Einungis 20 geta veri\u00f0 \u00ed salnum \u00e1 me\u00f0an \u00e1 doktorsv\u00f6rninni stendur.<\/strong><\/p>\n

\u00c1grip af ranns\u00f3kn<\/strong><\/p>\n

Markmi\u00f0:<\/strong> A\u00f0 kanna \u00e1h\u00e6ttu\u00fe\u00e6tti fyrir f\u00e6\u00f0ingu mikilla \u00feungbura (f\u00e6\u00f0ingar\u00feyngd \u22655000 g) og hugsanlegar aflei\u00f0ingar \u00feess fyrir m\u00f3\u00f0ur og barn (grein I). A\u00f0 sko\u00f0a mynstur efnaskiptamerkja mikilla \u00feungbura og bera saman vi\u00f0 b\u00f6rn me\u00f0 e\u00f0lilega f\u00e6\u00f0ingar\u00feyngd og b\u00f6rn me\u00f0 l\u00e1ga f\u00e6\u00f0ingar\u00feyngd (<2500 g) (grein II). A\u00f0 meta \u00e1hrif f\u00e6\u00f0ingarm\u00e1ta \u00e1 mynstur efnaskiptamerkja barna vi\u00f0 f\u00e6\u00f0ingu og vi\u00f0 n\u00fdburaskimun (grein III).<\/p>\n

A\u00f0fer\u00f0ir:<\/strong> Fyrsti hluti verkefnisins var ferilranns\u00f3kn me\u00f0 \u00f6llum f\u00e6\u00f0ingum mikilla \u00feungbura sem f\u00e6ddust \u00e1 \u00e1runum 1996-2005 \u00e1samt samanbur\u00f0ar\u00fe\u00fd\u00f0i sem h\u00f6f\u00f0u e\u00f0lilega f\u00e6\u00f0ingar\u00feyngd (10.-90.\u2030 \u00ed \u00edslensku \u00fe\u00fd\u00f0i). Annar hlutinn var gagnagrunnsranns\u00f3kn bygg\u00f0 \u00e1 ni\u00f0urst\u00f6\u00f0um \u00far \u00edslensku n\u00fdburaskimuninni me\u00f0 fullbur\u00f0a einburum f\u00e6ddum \u00e1 \u00cdslandi \u00e1 \u00e1runum 2009-2012. Miklir \u00feungburar voru bornir saman vi\u00f0 b\u00f6rn me\u00f0 e\u00f0lileg f\u00e6\u00f0ingar\u00feyngd og b\u00f6rn me\u00f0 l\u00e1ga f\u00e6\u00f0ingar\u00feyngd. \u00deri\u00f0ji hluti verkefnisins var framskyggn ranns\u00f3kn \u00e1 b\u00f6rnum f\u00e6dd me\u00f0 e\u00f0lilegri f\u00e6\u00f0ingu e\u00f0a valkeisaraskur\u00f0i og m\u00e6\u00f0rum \u00feeirra fr\u00e1 n\u00f3vember 2013 til apr\u00edl 2014. Bl\u00f3\u00f0 fr\u00e1 m\u00f3\u00f0ur fyrir f\u00e6\u00f0ingu, n\u00fdbura vi\u00f0 f\u00e6\u00f0ingu og ni\u00f0urst\u00f6\u00f0ur n\u00fdburaskimunar voru notu\u00f0 til a\u00f0 bera saman am\u00edn\u00f3s\u00fdrur og ac\u00fdlkarnit\u00edn milli f\u00e6\u00f0ingarm\u00e1ta.<\/p>\n

Ni\u00f0urst\u00f6\u00f0ur:<\/strong> 343 miklir \u00feungburar f\u00e6ddust \u00e1 \u00e1runum 1996-2005 e\u00f0a 0,9% allra einbura (grein I). M\u00e6\u00f0ur \u00feeirra voru l\u00edklegri til a\u00f0 vera me\u00f0 h\u00e6rri l\u00edkams\u00feyngdarstu\u00f0ul og \u00feyndaraukning \u00feeirra \u00e1 me\u00f0g\u00f6ngu var markt\u00e6kt h\u00e6rri en m\u00e6\u00f0ra barna me\u00f0 e\u00f0lilega f\u00e6\u00f0ingar\u00feyngd. \u00de\u00e1 voru miklir \u00feungburar l\u00edklegri til a\u00f0 lenda \u00ed axlarklemmu \u00ed f\u00e6\u00f0ingu, f\u00e6\u00f0ast me\u00f0 br\u00e1\u00f0akeisaraskur\u00f0i og a\u00f0 framk\u00f6llun f\u00e6\u00f0ingar mist\u00e6kist mi\u00f0a\u00f0 vi\u00f0 b\u00f6rn me\u00f0 e\u00f0lilega f\u00e6\u00f0ingar\u00feyngd.<\/p>\n

N\u00fdburar me\u00f0 l\u00e1ga f\u00e6\u00f0ingar\u00feyngd og miklir \u00feungburar h\u00f6f\u00f0u h\u00e6rri gildi af gl\u00fatam\u00edns\u00fdru en b\u00f6rn me\u00f0 e\u00f0lilega f\u00e6\u00f0ingar\u00feyngd (grein II). \u00de\u00e1 var \u00fere\u00f3n\u00edn h\u00e6rri hj\u00e1 b\u00f6rnum me\u00f0 l\u00e1ga f\u00e6\u00f0ingar\u00feyngd. Fr\u00edtt karnit\u00edn og sumar af me\u00f0al- og langrake\u00f0ju ac\u00fdlkarnit\u00ednum voru h\u00e6rri hj\u00e1 b\u00f6rnum me\u00f0 l\u00e1ga f\u00e6\u00f0ingar\u00feyngd. H\u00fddrox\u00fdb\u00fat\u00fdr\u00fdlkarnit\u00edn var l\u00e6gra hj\u00e1 b\u00f6rnum me\u00f0 l\u00e1ga f\u00e6\u00f0ingar\u00feyngd en h\u00e6rra hj\u00e1 miklum \u00feungburum. Acet\u00fdlkarnit\u00edn var h\u00e6rra hj\u00e1 b\u00f6rnum me\u00f0 l\u00e1ga f\u00e6\u00f0ingar\u00feyngd og hj\u00e1 miklum \u00feungburum.<\/p>\n

\u00cd samanbur\u00f0i vi\u00f0 n\u00fdbura sem f\u00e6ddir voru me\u00f0 valkeisaraskur\u00f0i (grein III) voru n\u00fdburar f\u00e6ddir \u00e1 e\u00f0lilegan m\u00e1ta me\u00f0 h\u00e6rri me\u00f0altalsmun fyrir sumar am\u00edn\u00f3s\u00fdrur og as\u00fdlkarnit\u00edna vi\u00f0 f\u00e6\u00f0ingu. Enginn markt\u00e6kur munur var \u00e1 am\u00edn\u00f3s\u00fdrum \u00ed bl\u00f3\u00f0s\u00fdni m\u00f3\u00f0ur og barns vi\u00f0 n\u00fdburaskimun eftir lei\u00f0r\u00e9ttingu fyrir fj\u00f6lda t\u00f6lfr\u00e6\u00f0ilegra pr\u00f3fana. Flestar am\u00edn\u00f3s\u00fdrur og minni stuttke\u00f0ju ac\u00fdlkarnit\u00edn voru, \u00f3h\u00e1\u00f0 f\u00e6\u00f0ingarm\u00e1ta, h\u00e6rri \u00ed naflastrengsbl\u00f3\u00f0i n\u00fdbura en bl\u00f3\u00f0i m\u00f3\u00f0ur. Sumar am\u00edn\u00f3s\u00fdrur og ac\u00fdlkarnit\u00edn voru h\u00e6rri vi\u00f0 n\u00fdburaskimun en \u00ed naflastrengss\u00fdnum \u00ed b\u00e1\u00f0um f\u00e6\u00f0ingarm\u00e1tah\u00f3pum.<\/p>\n

\u00c1lyktanir:<\/strong> H\u00e1r l\u00edkams\u00feyngdarstu\u00f0ull og of mikil \u00feyngdaraukning m\u00f3\u00f0ur \u00e1 me\u00f0g\u00f6ngu auka \u00e1h\u00e6ttu \u00e1 f\u00e6\u00f0ingu mikilla \u00feungbura. \u00cd sl\u00edkum tilfellum er aukin h\u00e6tta \u00e1 fylgikvillum \u00ed f\u00e6\u00f0ingu, b\u00e6\u00f0i hj\u00e1 m\u00f3\u00f0ur og barni. \u00dea\u00f0 vir\u00f0ist munur \u00e1 efnaskiptum mikilla \u00feungbura og barna me\u00f0 e\u00f0lilega f\u00e6\u00f0ingar\u00feyngd, sem er \u00f3l\u00edkur muninum milli barna me\u00f0 l\u00e1ga f\u00e6\u00f0ingar\u00feyngd og e\u00f0lilega. F\u00e6\u00f0ingarm\u00e1ti vir\u00f0ist tengjast mynstri efnaskiptamerkja \u00ed bl\u00f3\u00f0i barna vi\u00f0 f\u00e6\u00f0ingu en \u00ed n\u00fdburaskimuninni er \u00feessi munur l\u00edtill sem enginn.<\/p>\n

English abstract<\/strong><\/p>\n

Aims:<\/strong> To investigate risk factors for extreme macrosomia (birth weight \u22655000 g) and associated morbidities for both mother and neonate (paper I). To compare the metabolomic profile of extreme macrosomic babies to term babies born with a normal birth weight and low birth weight (<2500g) (paper II). To estimate the association between mode of delivery and metabolomic profile at birth and in newborn screening (paper III).<\/p>\n

Methods:<\/strong> Paper I was a cohort study including all births of extreme macrosomic babies in 1996-2005 (exposed) and comparison cohort with babies with birth weight in Icelandic population (non-exposed). Paper II was a register study based on the Icelandic Newborn Screening program and included full term singletons born in Iceland from 2009 to 2012. Extreme macrosomic neonates were compared to appropriate-for-gestational age neonates and babies born with low birth weight. Paper III was a prospective study including normal vaginal births and elective cesarean sections from November 2013 to April 2014 in Reykjavik, Iceland. Maternal blood samples before birth, neonatal samples at birth and newborn screening results were used to compare amino acids and acylcarnitines by delivery mode.<\/p>\n

Results:<\/strong> There were 343 macrosomic babies born in 1996-2005 or 0.9% of all singletons (paper I). Compared to non-exposed cohort, mothers of macrosomic newborns were more likely to have higher body-mass index and to have higher weight gain during pregnancy. Macromic babies were at increased odds of shoulder dystocia, emergency cesarean section and failed labour induction, compared to the normal birth weight cohort.<\/p>\n

Low birth weight and extreme macrosomic neonate were associated with higher levels of glutamic acid compared to the appropriate-for-gestational age (paper II) whereas threonine was increased in low birth weight neonates. Free carnitine and some medium- and long-chain acylcarnitines were higher in low birth weight infants. Hydroxybutyrylcarnitine was lower in low birth weight infants, but higher in extremely macrosomic neonates. Acetylcarnitine was higher in both low birth weight and extremely macrosomic neonates.<\/p>\n

Compared to neonates born with elective cesarean section, neonates born vaginally (paper III) had higher mean difference in some amino acids and acylcarnitines. Maternal blood samples and newborn screening results showed no differences after correction for multiple testing. For both delivery modes, most amino acids and smaller short-chain acylcarnitines were higher in cord blood compared to maternal blood. Some amino acids and some acylcarnitines were higher at the time of newborn screening compared to cord blood for both delivery modes.<\/p>\n

Conclusions:<\/strong> High maternal body-mass index and excess gestational weight gain increase the risk of extreme macrosomia. Macrosomia carries increased risk for birth complications, both for the mother and her offspring. There are distinctive differences in the metabolomic profile of extreme macrosomic neonates at birth compared to newborns with normal birth weight and those born at term with low birth weight. There are transient yet distinct differences in metabolic profile between newborns across delivery modes.<\/p>\n

Um doktorsefni\u00f0<\/strong><\/p>\n

Harpa Vi\u00f0arsd\u00f3ttir er f\u00e6dd 21. apr\u00edl 1985 og \u00f3lst upp \u00ed Reykjav\u00edk. H\u00fan lauk kand\u00eddatspr\u00f3fi fr\u00e1 H\u00e1sk\u00f3la \u00cdslands \u00ed j\u00fan\u00ed 2010 og f\u00e9kk l\u00e6kningaleyfi \u00ed okt\u00f3ber 2011 og starfa\u00f0i \u00fe\u00e1 sem deildarl\u00e6knir \u00e1 Barnasp\u00edtala Hringsins vi\u00f0 Landsp\u00edtala. \u00cd jan\u00faar 2014 h\u00f3f Harpa st\u00f6rf sem s\u00e9rn\u00e1msl\u00e6knir \u00ed barnal\u00e6kningum vi\u00f0 Astrid Lindgren barnasj\u00fakrah\u00fasi\u00f0, Karolinska sj\u00fakrah\u00fasinu \u00ed Stokkh\u00f3lmi, \u00a0og hefur sinnt \u00fev\u00ed samhli\u00f0a doktorsn\u00e1minu. Harpa var\u00f0 s\u00e9rfr\u00e6\u00f0ingur \u00ed barnal\u00e6kningum \u00ed jan\u00faar 2020. H\u00fan stundar n\u00fa s\u00e9rn\u00e1m \u00ed barnahjartal\u00e6kningum vi\u00f0 Mi\u00f0st\u00f6\u00f0 barnahjartal\u00e6kninga \u00ed Stokkh\u00f3lmi-Upps\u00f6lum, vi\u00f0 Astrid Lindgren Barnasj\u00fakrah\u00fasi\u00f0 \u00ed Stokkh\u00f3lmi. Harpa hefur sinnt kennslu sem hluta af s\u00e9rn\u00e1mi s\u00ednu \u00ed barnal\u00e6kningum \u00e1samt stundakennslu vi\u00f0 Heilbrig\u00f0isv\u00edsindasvi\u00f0 H\u00cd og H\u00e1sk\u00f3la unga f\u00f3lksins samhli\u00f0a doktorsn\u00e1minu. Foreldrar H\u00f6rpu eru Vi\u00f0ar M\u00e1r Matth\u00edasson l\u00f6gfr\u00e6\u00f0ingur og Gu\u00f0r\u00fan Angant\u00fdsd\u00f3ttir kennari. Harpa er gift Degi Inga J\u00f3nssyni, s\u00e9rfr\u00e6\u00f0ingi \u00ed taugal\u00e6kningum, og b\u00faa \u00feau \u00ed Stokkh\u00f3lmi. \u00deau eiga \u00ferj\u00fa b\u00f6rn, Trausta M\u00e1, Hei\u00f0d\u00edsi Eddu og Frosta \u00de\u00f3r.<\/p>\n<\/div><\/div>","protected":false},"featured_media":4933,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2021-02-12T13:00:00+00:00","_phd_date_end":"2021-02-12T16:00:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0asalur","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Miklir \u00feungburar \u2013 fylgikvillar f\u00e6\u00f0ingar fyrir m\u00f3\u00f0ur og barn, og mynstur efnaskiptamerkja. Extreme macrosomia \u2013 birth outcome for mother and infant, and metabolomic profile","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_laeknavisindum_harpa_vidarsdottir","_phd_source_node_id":"372731","_phd_source_type":"vidburdir","_phd_member_id":694,"footnotes":""},"phd_school":[60,67],"phd_discipline":[69],"class_list":["post-6176","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-heilbrigdisvisindasvid","phd_school-laeknadeild","phd_discipline-phd-i-laeknavisindum"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6176","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6176\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/4933"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6176"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6176"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6176"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}