Academic article

• Miriam Gjerdevik; Hans Ivar Hanevik; Siri Eldevik Håberg et al. (2026). Gestational age determination in pregnancies conceived via assisted reproductive technology. (external link)
• Jon Bohlin; Yunsung Lee; Ida Henriette Caspersen et al. (2026). Longitudinal study of genome-wide DNA methylation in individuals with and without post-acute symptoms following SARS-CoV-2 infection. (external link)
• Yunsung Lee; Håkon Kristian Gjessing; Christian Magnus Page et al. (2025). Methylation differences between assisted reproductive technology-conceived and naturally conceived children near BRCA1 and NBR2. (external link)
• Hsi Hsuan Yang; Claire Baldauf; Trevor A. Pickering et al. (2025). Maternal and Fetal SERPINA3 Polymorphisms and Risk of Preeclampsia: A Dyad and Triad Based Case-Control Study. (external link)
• Siri Nærland Skodvin; Miriam Gjerdevik; Julia Romanowska et al. (2025). Statistical methods to disentangle genetic effects influencing infertility and early fetal viability with a genome-wide application. (external link)
• William Robert Paul Denault; Håkon K. Gjessing; Julius Juodakis et al. (2021). Wavelet Screening: a novel approach to analyzing GWAS data. (external link)
• Stein Atle Lie; Lars B. Engesæter; Leif Ivar Havelin et al. (2004). Dependency issues in survival analyses of 55 782 primary hip replacements from 47 355 patients. (external link)
• Stein Emil Vollset; Aage Tverdal; Håkon K. Gjessing (2006). Smoking and deaths between 40 and 70 years of age in women and men. (external link)
• Maria Christine Magnus; Anne K. Örtqvist; Stine Kjaer Urhoj et al. (2023). Infection with SARS-CoV-2 during pregnancy and risk of stillbirth: a Scandinavian registry study. (external link)
• Richard Pierce; Håkon K. Gjessing (1994). A stochastic model for the presence/absence of readings in Nidrstigningar Saga. (external link)
• S.A. Lie; L.B. Engesæter; L.I. Havelin et al. (2000). Mortality after total hip replacement - 0-10-year follow-up of 39,543 patients in the Norwegian Arthroplasty Register. (external link)
• Harleen M. S. Grewal; Tom Hemming Karlsen; Helene Vetvik et al. (2000). Measurement of specific IgA in faecal extracts and intestinal lavage fluid for monitoring of mucosal immune responses. (external link)
• K.K. Melve; Håkon K Gjessing; Rolv Skjærven et al. (2000). Infants' length at birth: an independent effect on perinatal mortality. (external link)
• Astanand Jugessur; Min Shi; Håkon K Gjessing et al. (2009). Genetic determinants of facial clefting: analysis of 357 candidate genes using two national cleft studies from Scandinavia. (external link)
• Kristine Løkås Haftorn; Yunsung Lee; William Robert Paul Denault et al. (2021). An EPIC predictor of gestational age and its application to newborns conceived by assisted reproductive technologies. (external link)
• Stein Emil Vollset; Helge Refsum; Lorentz M. Irgens et al. (2000). Plasma total homocysteine, pregnancy complications, and adverse pregnancy outcomes: the Hordaland Homocysteine Study. (external link)
• Rolv Skjærven; Håkon K Gjessing; Leif S. Bakketeig (2000). Birthweight by gestational age in Norway. (external link)
• Rolv Skjærven; Håkon K Gjessing; Leif S. Bakketeig (2000). New standards for birth weight by gestational age using family data. (external link)
• K.K. Melve; Rolv Skjærven; Håkon K Gjessing et al. (1999). Recurrence of gestational age in sibships: Implications for perinatal mortality. (external link)
• Roy Miodini Nilsen; Anne Lise Bjørke Monsen; Øivind Midttun et al. (2012). Maternal tryptophan and kynurenine pathway metabolites and risk of preeclampsia. (external link)
• Tor A. Strand; D.E. Briles; Håkon K Gjessing et al. (2001). Pneumococcal pulmonary infection, septicaemia and survival in young zinc-depleted mice. (external link)
• Roy M Nilsen; Stein Emil Vollset; Håkon K. Gjessing et al. (2006). Patterns and predictors of folic acid supplement use among pregnant women: the Norwegian Mother and Child Cohort Study. (external link)
• Cornelius A. Rietveld; SE Medland; J Derringer et al. (2013). GWAS of 126,559 Individuals Identifies Genetic Variants Associated with Educational Attainment. (external link)
• Nina Gunnes; Håkon K. Gjessing; Inger Johanne Landsjøåsen Bakken et al. (2020). Seasonal and pandemic influenza during pregnancy and risk of fetal death: A Norwegian registry‑based cohort study. (external link)
• Julia Romanowska; Øystein Ariansen Haaland; Astanand Jugessur et al. (2020). Gene-methylation interactions: Discovering region-wise DNA methylation levels that modify SNP-associated disease risk. (external link)
• H.W. Block; T.H. Savits; L.E. Eberly et al. (2001). Understanding the shape of the hazard rate: A process point of view - Comments and rejoinder. (external link)
• Aase Serine Devold Pay; Frederik Frøen; Anne Cathrine Staff et al. (2016). Prediction of small-for-gestational-age status by symphysis–fundus height: a registry-based population cohort study. (external link)
• Per Magnus; Håkon K Gjessing; Anders Skrondal et al. (2001). Paternal contribution to birth weight. (external link)
• Jon Bohlin; Siri Eldevik Håberg; Per Minor Magnus et al. (2024). MinLinMo: a minimalist approach to variable selection and linear model prediction. (external link)
• Roy M Nilsen; Stein Emil Vollset; Håkon K. Gjessing et al. (2009). Self-selection and bias in a large prospective pregnancy cohort in Norway. (external link)
• Halvor Sommerfelt; Hans Steinsland; Lize van der Merwe et al. (2012). Case/Control studies with follow-up: constructing the source population to estimate effects of risk factors on development, disease, and survival. (external link)
• Astanand Jugessur; Øivind Skare; Rolv T. Lie et al. (2012). X-Linked Genes and Risk of Orofacial Clefts: Evidence from Two Population-Based Studies in Scandinavia. (external link)
• Tor A Strand; Pushpa R Sharma; Håkon K. Gjessing et al. (2012). Risk factors for extended duration of acute diarrhea in young children. (external link)
• Inger Økland; Tore Bjåstad; Tonni Franke Johansen et al. (2011). Narrowed beam width in newer ultrasound machines shortens measurements in the lateral direction: fetal measurement charts may be obsolete. (external link)
• Astanand Jugessur; Øivind Skare; Jennifer Harris et al. (2012). Using offspring-parent triads to study complex traits : a tutorial based on orofacial clefts. (external link)
• Stein Emil Vollset; Håkon K Gjessing; Anne Tandberg et al. (2005). Folate supplementation and twin pregnancies. (external link)
• Øystein Ariansen Haaland; Rolv T. Lie; Julia Romanowska et al. (2018). A genome-wide search for gene-environment effects in isolated cleft lip with or without cleft palate triads points to an interaction between maternal periconceptional vitamin use and variants in ESRRG. (external link)
• Håkon K. Gjessing; Per Grøttum; Inger Økland et al. (2016). Fetal size monitoring and birth-weight prediction: a new population-based approach. (external link)
• Astanand Jugessur; Fedik Rahimov; Rolv Terje Lie et al. (2008). Genetic variants in IRF6 and the risk of facial clefts: Single-marker and haplotype-based analyses in a population-based case-control study of facial clefts in Norway. (external link)
• Øivind Skare; Rolv T. Lie; Øystein Ariansen Haaland et al. (2018). Analysis of parent-of-origin effects on the X chromosome in asian and european orofacial cleft triads identifies associations with DMD, FGF13, EGFL6, and additional loci at Xp22.2. (external link)
• Rolv Terje Lie; Allen J Wilcox; Jack Taylor et al. (2008). Maternal smoking and oral clefts - The role of detoxification pathway genes. (external link)
• Håkon K. Gjessing (2017). Svangerskapsdatering. (external link)
• Maria Christine Magnus; Allen J. Wilcox; Elin Anita Fadum et al. (2021). Growth in children conceived by ART. (external link)
• SE Hiby; R Apps; O Chazara et al. (2014). Maternal KIR in combination with paternal HLA-C2 regulate human birth weight. (external link)
• Tron Anders Moger; Odd Olai Aalen; K Heimdal et al. (2004). Analysis of testicular cancer data using a frailty model with familial dependence. (external link)
• Miriam Gjerdevik; Håkon K. Gjessing; Julia Romanowska et al. (2020). Design efficiency in genetic association studies. (external link)
• Miriam Gjerdevik; Astanand Jugessur; Øystein Ariansen Haaland et al. (2019). Haplin power analysis: a software module for power and sample size calculations in genetic association analyses of family triads and unrelated controls. (external link)
• Siri Nærland Skodvin; Håkon Kristian Gjessing; Astanand Jugessur et al. (2023). Statistical methods to detect mother-father genetic interaction effects on risk of infertility: A genome-wide approach. (external link)
• Aase Serine Devold Pay; Frederik Frøen; Anne Cathrine Staff et al. (2013). A new population-based reference curve for symphysis-fundus height. (external link)
• Inger Økland; Håkon Gjessing; Per Grøttum et al. (2010). Biases of traditional term prediction models: results from different sample-based models evaluated on 41 343 ultrasound examinations. (external link)
• Harleen M. S. Grewal; Tom Hemming Karlsen; Helene Vetvik et al. (2000). Measurement of specific IgA in faecal extracts and intestinal lavage fluid for monitoring of mucosal immune responses. (external link)
• Maria Teresa Grønning Dale; Per Magnus; Elisabeth Leirgul et al. (2019). Intake of sucrose‑sweetened soft beverages during pregnancy and risk of congenital heart defects (CHD) in offspring: A Norwegian pregnancy cohort study. (external link)
• Michelle M. Clark; Olympe Chazara; Eric M. Sobel et al. (2017). Human birth weight and reproductive immunology: testing for interactions between maternal and offspring KIR and HLA-C genes. (external link)
• Ralph McGinnis; Valgerdur Steinthorsdottir; Nicholas O. Williams et al. (2017). Variants in the fetal genome near FLT1 are associated with risk of preeclampsia. (external link)
• Yunsung Lee; Miriam Gjerdevik; Astanand Jugessur et al. (2025). Parent-of-Origin Effects in Childhood Asthma at Seven Years of Age. (external link)
• Hans Steinsland; Palle Valentiner-Branth; Håkon K Gjessing et al. (2004). Protection from natural infections with enterotoxigenic Escherichia coli: longitudinal study. (external link)
• Solveig Myking; Heather A Boyd; Ronny Myhre et al. (2013). X-chromosomal maternal and fetal SNPs and the risk of spontaneous preterm delivery in a Danish/Norwegian genome-wide association study. (external link)
• Hans Steinsland; Palle Valentiner-Branth; Håkon K Gjessing et al. (2003). Protection from natural infections with enterotoxigenic Escherichia coli: longitudinal study. (external link)
• Hege Vefring; Line L. Wee; Astanand Jugessur et al. (2010). Maternal angiotensinogen (AGT) haplotypes, fetal renin (REN) haplotypes and risk of preeclampsia; estimation of gene-gene interaction from family-triad data. (external link)
• Miriam Gjerdevik; Øystein Ariansen Haaland; Julia Romanowska et al. (2017). Parent-of-origin-environment interactions in case-parent triads with or without independent controls. (external link)
• Fred Espen Benth; Håkon K Gjessing (2000). A nonlinear parabolic equation with noise. A reduction method. (external link)
• Ida Laake; Siri Nærland Skodvin; Kristine Blix et al. (2022). Effectiveness of mRNA booster vaccination against mild, moderate, and severe COVID-19 caused by the Omicron variant in a large, population-based, Norwegian cohort. (external link)
• Harleen M. S. Grewal; Tom Hemming Karlsen; H Vetvik et al. (2000). Measurement of specific IgA in faecal extracts and intestinal lavage fluid for monitoring of mucosal immune responses. (external link)
• FE Benth; Håkon K Gjessing (2000). A nonlinear parabolic equation with noise - A reduction method. (external link)
• Rolv Skjærven; Håkon K Gjessing; LS Bakketeig (2000). Birthweight by gestational age in Norway. (external link)
• Stein A Lie; Lars B. Engesæter; Leif Ivar Havelin et al. (2000). Mortality after total hip replacement: 0-10-year follow-up of 39,543 patients in the Norwegian Arthroplasty Register. (external link)
• Kari Klungsøyr Melve; Håkon K Gjessing; Rolv Skjærven et al. (2000). Infant's length at birth: an independent effect on perinatal mortality. (external link)
• Maria Christine Magnus; Laura L. Oakley; Håkon K. Gjessing et al. (2021). Pregnancy and risk of COVID-19: a Norwegian registry-linkage study. (external link)
• Stein Emil Vollset; Helga Refsum; Lorentz Irgens et al. (2000). Plasma total homocysteine, pregnancy complications, and adverse pregnancy outcomes: the Hordaland Homocysteine Study. (external link)
• Torbjørn Moe Eggebø; Olav-Andre Klefstad; Inger Økland et al. (2016). Estimation of fetal weight in pregnancies past term. (external link)
• Rolv Skjærven; Håkon K Gjessing; LS Bakketeig (2000). New standards for birth weight by gestational age using family data. (external link)
• Øivind Skare; Håkon K. Gjessing; Miriam Gjerdevik et al. (2017). A new approach to chromosome-wide analysis of X-linked markers identifies new associations in Asian and European case-parent triads of orofacial clefts. (external link)
• Solveig Myking; Ronny Myhre; Håkon Gjessing et al. (2011). Candidate gene analysis of spontaneous preterm delivery: New insights from re-analysis of a case-control study using case-parent triads and control-mother dyads. (external link)
• Øystein Ariansen Haaland; Astanand Jugessur; Miriam Gjerdevik et al. (2017). Genome-wide analysis of parent-of-origin interaction effects with environmental exposure (PoOxE): An application to European and Asian cleft palate trios. (external link)
• Øystein Ariansen Haaland; Julia Romanowska; Miriam Gjerdevik et al. (2019). A genome-wide scan of cleft lip triads identifies parent-of-origin interaction effects between ANK3 and maternal smoking, and between ARHGEF10 and alcohol consumption. (external link)
• Astanand Jugessur; Min Shi; Håkon K. Gjessing et al. (2010). Maternal genes and facial clefts in offspring: a comprehensive search for genetic associations in two population-based cleft studies from Scandinavia. (external link)
• L M Moreno Uribe; Tatiana Fomina; R G Munger et al. (2017). A Population-Based Study of Effects of Genetic Loci on Orofacial Clefts. (external link)
• Odd Olai Aalen; Håkon K Gjessing (2001). Understanding the shape of the hazard rate: a process point of view. (external link)
• Håkon K. Gjessing; Kjetil Røysland; Odd O. Aalen et al. (2010). Recurrent events and the exploding Cox model. (external link)
• Clara G. Gjesdal; Stein Emil Vollset; Per Magne Ueland et al. (2006). Plasma total homocysteine level and bone mineral density - The Hordaland homocysteine study. (external link)
• Per Magnus; Oddbjørn Brubakk; Oddbjørn Brubakk et al. (2009). Vaccination as teenagers against meningococcal disease and the risk of the chronic fatigue syndrome. (external link)
• Astanand Jugessur; Min Shi; Håkon Gjessing et al. (2011). Fetal genetic risk of isolated cleft lip only versus isolated cleft lip and palate: a subphenotype analysis using two population-based studies of orofacial clefts in Scandinavia. (external link)
• William Robert Paul Denault; Julia Romanowska; Øystein Ariansen Haaland et al. (2021). Wavelet Screening identifies regions highly enriched for differentially methylated loci for orofacial clefts. (external link)
• Gidske Leknæs Andersen; Knut Krzywinski; Håkon K. Gjessing et al. (2016). Seed viability and germination success of Acacia tortilis along land-use and aridity gradients in the Eastern Sahara. (external link)
• Siri Eldevik Håberg; Christian Magnus Page; Yunsung Lee et al. (2022). DNA methylation in newborns conceived by assisted reproductive technology. (external link)
• Elisabet Witsø; Ondrej Cinek; German Tapia et al. (2015). Genetic determinants of enterovirus infections: Polymorphisms in type 1 diabetes and innate immune genes in the MIDIA study. (external link)
• Aase Serine Devold Pay; Frederik Frøen; Anne Cathrine Staff et al. (2017). Symfyse-fundus-mål – prediktiv verdi av ny referansekurve. (external link)
• Li Ding; Matthew J. Blitz; Deborah A. Wing et al. (2020). PHLDA2 gene polymorphisms and risk of HELLP syndrome and severe preeclampsia. (external link)
• Kari Klungsøyr. Melve; Rolv Skjærven; Håkon K. Gjessing et al. (1999). Recurrence of gestational age in sibships: Implications for perinatal mortality. (external link)
• Yunsung Lee; Kristine Løkås Jacobsen; William Robert Paul Denault et al. (2020). Blood-based epigenetic estimators of chronological age in human adults using DNA methylation data from the Illumina MethylationEPIC array. (external link)
• Tron Anders Moger; Marion Haugen; Benjamin H. K. Yip et al. (2011). A hierarchical frailty model applied to two-generation melanoma data. (external link)
• Inger Økland; Håkon Gjessing; Per Grøttum et al. (2011). A new population-based term prediction model vs. two traditional sample-based models: validation on 9046 ultrasound examinations. (external link)
• Håkon K. Gjessing; Per Grøttum; Johan Morten Dreier et al. (2024). Biparietal diameter vs crown–rump length as standard parameter for late first-trimester pregnancy dating. (external link)
• Geir Drage Berentsen; Francesca Azzolini; Hans J. Skaug et al. (2020). Heritability curves: A local measure of heritability in family models. (external link)
• Håkon K. Gjessing; Rolv Terje Lie (2006). Case-parent triads: Estimating single- and double-dose effects of fetal and maternal disease gene haplotypes. (external link)
• Sophia Rabe-Hesketh; Anders Skrondal; Håkon K. Gjessing (2008). Biometrical modeling of twin and family data using standard mixed model software. (external link)
• Huiling Li; Isabelle Romieu; Juan-Jose Sienra-Monge et al. (2006). Genetic polymorphisms in arginase I and II and childhood asthma and atopy. (external link)
• Maria Teresa Grønning Dale; Alexander Nissen; Mona Berthelsen et al. (2021). Psychosocial work factors and sick leave risk after a terrorist bomb attack: a survey and registry-based longitudinal study of governmental employees in Norway. (external link)
• Karoline Hansen Skåra; Yunsung Lee; Astanand Jugessur et al. (2024). Telomere length in relation to fecundability and use of assisted reproductive technologies: the Norwegian Mother, Father, and Child Cohort Study. (external link)
• Maria Christine Magnus; Anne K. Örtqvist; Elisabeth Dahlqwist et al. (2022). Association of SARS-CoV-2 Vaccination during Pregnancy with Pregnancy Outcomes. (external link)
• Palle Valentiner-Brandt; Hans Steinsland; Håkon K Gjessing et al. (1999). Community-based randomized controlled trial of reduced osmolarity oral rehydration solution in acute childhood diarrhea. (external link)
• Håkon K. Gjessing; Rolv Terje Lie (2008). Biometrical modelling in genetics: are complex traits too complex?. (external link)
• Astrid Lunde; Kari Klungsøyr Melve; Håkon K. Gjessing et al. (2007). Genetic and environmental influences on birth weight, birth length, head circumference and gestational age using population based parent-offspring data. (external link)
• Annica Dominicus; Anders Skrondal; Håkon K. Gjessing et al. (2006). Likelihood ratio tests in behavioral genetics: Problems and solutions. (external link)
• William Robert Paul Denault; Julia Romanowska; Øyvind Helgeland et al. (2021). A fast wavelet-based functional association analysis replicates several susceptibility loci for birth weight in a Norwegian population. (external link)
• Håkon K Gjessing; Rolv Terje Lie (2005). Case-parent triads: Estimating single- and double-dose effects of fetal and maternal disease gene haplotypes. (external link)
• Inger Økland; Ole Jakob Nakling; Håkon K. Gjessing et al. (2012). Advantages of the population-based approach to pregnancy dating: results from 23 020 ultrasound examinations. (external link)
• Jannicke Igland; Stein Emil Vollset; Ottar Nygård et al. (2012). Relative importance of risk factors for coronary heart disease - The Hordaland Homocysteine Study. (external link)
• Håkon Gjessing; Jostein Paulsen (1997). Present value distributions with applications to ruin theory and stochastic equations. (external link)
• Jostein Paulsen; Håkon Gjessing (1997). Optimal choice of dividend barriers for a risk process with stochastic return on investments. (external link)
• Abee L. Boyles; Allen J. Wilcox; Jack A. Taylor et al. (2009). Oral facial clefts and gene polymorphisms in metabolism of folate/one-carbon and vitamin A: a pathway-wide association study. (external link)
• Siri Eldevik Håberg; Lill Trogstad; Nina Gunnes et al. (2013). Risk of Fetal Death after Pandemic Influenza Virus Infection or Vaccination. (external link)
• Håkon Gjessing; Jostein Paulsen (1997). Present value distributions with applications to ruin theory and stochastic equations. (external link)
• Jostein Paulsen; Håkon Gjessing (1997). Ruin theory with stochastic return on investments. (external link)
• Jon Bohlin; Siri Eldevik Håberg; Per Magnus et al. (2016). Prediction of gestational age based on genome-wide differentially methylated regions. (external link)
• Øivind Skare; Astanand Jugessur; Rolv T. Lie et al. (2012). Application of a Novel Hybrid Study Design to Explore Gene-Environment Interactions in Orofacial Clefts. (external link)
• Astanand Jugessur; Håkon K. Gjessing; Allen J Wilcox et al. (2012). Assessing the impact of nicotine dependence genes on the risk of facial clefts: An example of the use of national registry and biobank data. (external link)
• Lydia E. Farrel; Susan E. Hiby; Richard Apps et al. (2014). KIR and HLA-C: Immunogenetic regulation of human birth weight. (external link)
• Siri Nærland Skodvin; Håkon K. Gjessing; Astanand Jugessur et al. (2025). Genome-Wide Association Analyses in Family Triads and Dyads Following Assisted Reproductive Technology. (external link)
• Jostein Paulsen; Håkon Gjessing (1997). Optimal choice of dividend barriers for a risk process with stochastic return on investments. (external link)
• Jostein Paulsen; Håkon Gjessing (1997). Ruin theory with stochastic return on investments. (external link)
• Hans Steinsland; Palle Valentiner-Branth; Håkon K Gjessing et al. (2003). Protection from natural infections with enterotoxigenic Escherichia coli: longitudinal study. (external link)
• Rolv Terje Lie; Svein Rasmussen; H. Brunborg et al. (1997). Fetal and maternal contributions to risk of pre-eclampsia: population based study. (external link)
• Ingunn Størksen; Espen Røysamb; Håkon K Gjessing et al. (2007). Marriages and psychological distress among adult offspring of divorce: A Norwegian study. (external link)
• Rolv T. Lie; Maria Christine Magnus; Håkon K. Gjessing et al. (2024). Daily snuff use during pregnancy, gestational length and birth weight; register-based study. (external link)
• Dana Kristjansson; Yunsung Lee; Christian Magnus Page et al. (2024). Sex differences in DNA methylation variations according to ART conception-evidence from the Norwegian mother, father, and child cohort study. (external link)
• Claire Baldauf; Chen Wei; Trevor A. Pickering et al. (2025). Hypoxia-Inducible Factor 1-Alpha Gene Polymorphisms Impact Risk of Severespectrum Hypertensive Disorders of Pregnancy: A Case-Control Study. (external link)
• Stein Emil Vollset; Jannicke Igland; Mazda Jenab et al. (2007). The association of gastric cancer risk with plasma folate, cobalamin, and Methylenetetrahydrofolate reductase polymorphisms in the European prospective investigation into cancer and nutrition. (external link)
• Yunsung Lee; Astanand Jugessur; Håkon K. Gjessing et al. (2024). Effect of polygenic scores of telomere length alleles on telomere length in newborns and parents. (external link)
• Vidar Hjellvik; Randi Selmer; Håkon K. Gjessing et al. (2013). Body mass index, smoking, and risk of death between 40 and 70 years of age in a Norwegian cohort of 32,727 women and 33,475 men. (external link)
• Tor A Strand; Sunita Taneja; Nita Bhandari et al. (2007). Folate, but not vitamin B-12 status, predicts respiratory morbidity in north Indian children. (external link)
• Kristina Gervin; Martin Hammerø; Hanne Elisabeth Akselsen et al. (2011). Extensive variation and low heritability of DNA methylation identified in a twin study. (external link)
• Julia Romanowska; Haakon Egdetveit Nustad; Christian Magnus Page et al. (2023). The X-factor in ART: does the use of assisted reproductive technologies influence DNA methylation on the X chromosome?. (external link)
• Rolv Terje Lie; S. Rasmussen; H. Brunborg et al. (1998). Fetal and maternal contributions to risk of pre-eclampsia: population based study. (external link)
• Yunsung Lee; Sanaa Choufani; Rosanna Weksberg et al. (2019). Placental epigenetic clocks: estimating gestational age using placental DNA methylation levels. (external link)
• Håkon K Gjessing; Odd Olai Aalen; Nils Lid Hjort (2003). Frailty models based on L{\'e}vy processes. (external link)
• Huiling Li; Isabelle Romieu; Hao Wu et al. (2007). Genetic polymorphisms in transforming growth factor beta-1 (TGFB1) and childhood asthma and atopy. (external link)
• Håkon K. Gjessing; Per Grøttum; P Grottum et al. (2007). A direct method for ultrasound prediction of day of delivery: a new, population-based approach. (external link)
• Odd Olai Aalen; Håkon K. Gjessing (2004). Survival models based on the Ornstein-Uhlenbeck process. (external link)
• Ronny Myhre; Anne Lise Brantsæter; Solveig Myking et al. (2011). Intake of probiotic food and risk of spontaneous preterm delivery. (external link)
• Jonas Minet Kinge; Jørgen Heibø Modalsli; Simon Nygaard Øverland et al. (2019). Association of Household Income with Life Expectancy and Cause-Specific Mortality in Norway, 2005-2015. (external link)

Doctoral thesis (PhD)

• Siri Nærland Skodvin; Håkon K. Gjessing; Miriam Gjerdevik et al. (2025). Family-based statistical modeling of genetic effects on infertility and early fetal viability. (external link)
• Håkon Gjessing (1995). Anticipating calculus and wick products. (external link)

Research report

• Håkon K. Gjessing; Odd O. Aalen; Nils Lid Hjort (2003). Frailty models based on Lévy processes. (external link)
• Håkon K. Gjessing (1994). Integral conditions for Skorod stochastical differential equations. (external link)
• Håkon K. Gjessing (1993). A note on the Wick product. Report No.23 March 1993. (external link)
• Stein Emil Vollset; randi selmer; Aage Tverdal et al. (2006). Hvor dødelig er røyking? Rapport om dødsfall og tapte leveår som skyldes røyking. (external link)
• Stein Emil Vollset; Randi Marie Selmer; Aage Tverdal et al. (2006). Hvor dødelig er røyking? Rapport om dødsfall og tapte leveår som skyldes røyking. (external link)

Lecture

• Håkon Gjessing (1997). Blødninger tidlig i svangerskapet; farligere enn tidligere antatt?. (external link)

Conference abstract

• Ingrid Økland; Håkon K. Gjessing; Per Grøttum et al. (2012). Advantages of the population-based approch to pregnancy dating demonstrated with results from 73,400 second-trimester ultrasound examinations. (external link)
• Inger Økland; Håkon K. Gjessing; Per Grøttum et al. (2012). OP32.01: The importance of standardizing pregnancy dating models. (external link)
• Bo Jacobsson; Anne Lise Brantsæter; Håkon Gjessing et al. (2012). Intake of food with antimicrobial diet components and risk of spontaneous preterm delivery. (external link)
• Rolv T. Lie; Håkon K Gjessing; Jack Taylor et al. (2007). Haplotype relative risk estimation in epidemiological studies; New methodology applied to a study of smoking, relevant detoxification genes and oral clefts in Norway. (external link)
• Torbjørn Moe Eggebø; Olav-Andre Klefstad; Inger Økland et al. (2016). Prenatal detection of low birthweight in pregnancies past term. (external link)
• Sturla Eik-Nes; HG Blaas; Per Grøttum et al. (2007). Predicting remaining time of pregnancy - a new population-based approach for the prediction of day of delivery based on Femur length. (external link)
• Inger Økland; Håkon K. Gjessing; Per Grøttum et al. (2007). A new population-based term prediction method-evaluation of the FL-based predictions. (external link)
• Inger Økland; Håkon K. Gjessing; Per Grøttum et al. (2007). A new population-based term prediction method-evaluation of the BPD-based predictions. (external link)
• Rolv Terje Lie; Håkon K. Gjessing; J Taylor et al. (2007). Haplotype relative risk estimation in epidemiological studies; New methodology applied to a study of smoking, relevant detoxification genes and oral clefts in Norway. (external link)
• Siri Eldevik Håberg; Lill Trogstad; Nina Gunnes et al. (2012). The 2009 Influenza Pandemic, Vaccination during Pregnancy and Fetal Death: A National Registry-Based Study in Norway. (external link)
• Bo Jacobsson; Øivind Skare; Verena Sengpiel et al. (2012). Genetic variants in gene-environment interaction analysis of probiotic intake in spontaneous preterm delivery. (external link)
• Torbjørn Moe Eggebø; Olav-Andre Klefstad; Inger Økland et al. (2016). Estimation of fetal weight in pregnancies past term. (external link)
• Torbjørn Moe Eggebø; Olav-Andre Klefstad; Inger Økland et al. (2016). Prenatal detection of macrosomia in pregnancies past term. (external link)
• Aase Serine Devold Pay; Håkon K. Gjessing; Anne Cathrine Staff et al. (2012). A population-based reference chart for fundal height measures. (external link)

Conference lecture

• Kari Klungsøyr. Melve; Håkon Gjessing; Rolv Skjærven (1998). Perinatal mortality and infants' length at birth. (external link)
• Rolv Terje Lie; Håkon Gjessing (1998). Distinguishing maternal and fetal contributions to birth weight using half-sib data. (external link)
• Torbjørn Moe Eggebø; Olav-Andre Klefstad; Inger Økland et al. (2016). Prenatal detection of low birthweight in pregnancies past term. (external link)
• Rolv Terje Lie; Svein Rasmussen; H. Brunborg et al. (1997). Føtalt og maternelt bidrag til risiko for preeklampsi. (external link)
• Rolv Terje Lie; Svein Rasmussen; H. Brunborg et al. (1997). Føtalt og maternelt bidrag til risiko for preeklampsi. (external link)
• Rolv Skjærven; Håkon Gjessing; Gunnar Dalseth et al. (1997). New standards for birth weight by gestational age using family data. (external link)
• Håkon Gjessing; R. Skjærven; Allen J. Wilcox (1997). Svangerskapsvarigheter og fødselsvekter, noe for en statistiker?. (external link)
• Håkon Gjessing; R. Skjærven; Allen J. Wilcox (1997). Svangerskapsvarigheter og fødselsvekter, noe for en statistiker?. (external link)
• Håkon Gjessing; R. Skjærven; Allen J. Wilcox (1997). Errors in gestational age. A somewhat different analysis of errors in computed length of gestation, using birth weight as reference. (external link)
• Håkon Gjessing; R. Skjærven; Allen J. Wilcox (1997). Errors in gestational age. A somewhat different analysis of errors in computed length of gestation, using birth weight as reference. (external link)
• Stein Atle Lie; LB Engesæter; LI Havelin et al. (1999). Patient mortality after total hip replacement - follow-up of 35938 patients in the Norwegian Arthroplasty Register. (external link)
• Håkon K Gjessing (2001). Frailty as a stochastic process. (external link)
• Torbjørn Moe Eggebø; Olav-Andre Klefstad; Inger Økland et al. (2016). Estimation of fetal weight in pregnancies past term. (external link)
• Torbjørn Moe Eggebø; Olav-Andre Klefstad; Inger Økland et al. (2016). Prenatal detection of macrosomia in pregnancies past term. (external link)
• SA Lie; LB Engesæter; LI Havelin et al. (1999). Mortality after total hip replacement. 10 years follow-up of 39453 patients in the Norwegian Arthroplasty Register. (external link)
• Håkon Gjessing; R. Skjærven; Allen J. Wilcox (1997). Errors in gestational age. A somewhat different analysis of errors in computed length of gestation, using birth weight as reference. (external link)
• Håkon Gjessing; R. Skjærven; Allen J. Wilcox (1997). Svangerskapsvarigheter og fødselsvekter, noe for en statistiker?. (external link)
• Rolv Terje Lie; Svein Rasmussen; H. Brunborg et al. (1997). Føtalt og maternelt bidrag til risiko for preeklampsi. (external link)
• Tor A Strand; Sunita Taneja; Nita Bhandari et al. (2005). Folate, but not cobalamin status predicts respiratory morbidity in north Indian children. (external link)
• Håkon Gjessing (1996). A variation of parameters solution of a quasi-linear Skorohod stochastic differential equations using the Wick product. (external link)

Popular science article

• Håkon K. Gjessing; Christine Steiro; Georg Becher et al. (2006). Redusert analytisk tilgjengelighet for PCB i humusfarget vann. (external link)

Editorial/Leader article

• Siri Eldevik Håberg; Lill Trogstad; Nina Gunnes et al. (2013). Risk of Fetal Death After Pandemic Influenza Virus Infection or Vaccination EDITORIAL COMMENT. (external link)
• Håkon K. Gjessing; Hans J. Skaug (2019). Editorial. (external link)
• Ørnulf Borgan; Håkon K. Gjessing (2019). Special issue dedicated to Odd O. Aalen. (external link)

Letter to the editor

• Sturla Eik-Nes; Per Grøttum; Håkon K. Gjessing (2006). Regarding "Term prediction with ultrasound: evaluation of a new dating curve for biparietal diameter". (external link)
• Maria Christine Magnus; Håkon K. Gjessing; Helena Niemi Eide et al. (2021). Covid-19 vaccination during pregnancy and first-trimester miscarriage. (external link)
• Håkon K Gjessing; Per Grøttum; Sturla H Eik-Nes (2008). Re: A direct method for ultrasound prediction of day of delivery: a new, population-based approach. Problems of accounting for a retrospective selection - Reply. (external link)
• Håkon K Gjessing; Per Grøttum; Inger Økland et al. (2009). Comment and reply on: Prediction of the date of delivery based on first trimester ultrasound measurements: an independent method from estimated date of conception. (external link)
• Håkon K. Gjessing; Per Grøttum (2007). Accuracy of second trimester fetal head circumference and biparietal diameter for predicting the time of spontaneous birth. (external link)
• Sturla Eik-Nes; Per Grøttum; Håkon K. Gjessing (2006). Regarding "Term prediction with ultrasound: evaluation of a new dating curve for biparietal diameter". (external link)
• Håkon K. Gjessing; Per Grøttum; Inger Økland et al. (2010). Comment and reply on: Prediction of the date of delivery based on first trimester ultrasound measurements: an independent method from estimated date of conception. (external link)

Conference poster

• Dinka Smajlagic; Stella Tsotsi; Miriam Gjerdevik et al. (2022). Parent-of-origin effects in childhood aggression. (external link)
• Yunsung Lee; Miriam Gjerdevik; Astanand Jugessur et al. (2023). Parent-of-origin effects on childhood asthma. (external link)
• Håkon Kristian Gjessing; Miriam Gjerdevik; Julia Romanowska et al. (2023). Family-based methods to identify genes implicated in infertility and fetal viability. (external link)
• Jannicke Igland; Stein Emil Vollset; Ottar Nygård et al. (2010). Relative importance of risk factors for cardiovascular disease incidence and mortality: a prospective cohort study. (external link)
• Julia Romanowska; Håkon K. Gjessing; Inge Jonassen et al. (2015). Haplin — a powerful tool for studying gene-environment interactions. (external link)

Academic book chapter

• Odd Olai Aalen; Håkon K Gjessing (2003). A look behind survival data: Underlying processes and quasi-stationarity. (external link)

Academic monograph

• Odd O. Aalen; Ørnulf Borgan; Håkon K. Gjessing (2008). Survival and Event History Analysis: A Process Point of View. (external link)
• Odd O. Aalen; Ørnulf Borgan; Håkon K Gjessing (2008). Event history analysis: A process point of view. (external link)
• Odd O. Aalen; Ørnulf Borgan; Håkon K. Gjessing (2008). Survival and event history analysis: a process point of view. (external link)

Master’s thesis

• Håkon Gjessing (1990). Some convergence results for ITO diffusions and optimal stopping. (external link)

See a complete overview of publications in NVA.