Olga Basso, who had been a guest researcher in 2001-2002, returned to the Epidemiology Branch in 2004 as a research fellow. She currently works with Allen Wilcox, M.D., Ph.D., on birth weight, mortality and pre-eclampsia, a disorder of pregnancy characterized by hypertension and proteinuria that may have serious consequences for both the mother and the baby. Her first interest in epidemiology was in methodology, especially concerning the potential for bias in non-experimental studies. She participated—as database administrator, interviewer and data analyst—in the Italian study on asthma and atopy, part of the European Respiratory Health Survey. She became interested in reproductive epidemiology in 1995 and she has since worked in that area. After moving to the Danish Epidemiology Science Centre, she took advantage of the rich data sources available in Denmark to carry out registry-based studies.
The recurrence risk of a number of adverse pregnancy outcomes has been the focus of several studies. Studying changes in putative determinants in couples who had experienced a given outcome provides a powerful basis for etiologic studies, albeit at a relatively crude level. Focusing upon women who had changed partners between two pregnancies permitted investigation of possible contributions of the paternal genotype to risk. One case in which a paternal effect was considered important involved pre-eclampsia, a relatively common complication of pregnancy of unknown etiology. The "primipaternity" hypothesis, formulated by Robillard et al. (1993, 1994) postulated that a woman's immune reaction to her partner's sperm may be a cause of pre-eclampsia. Unlike the previous studies examining this aspect, Basso, in collaboration with Jorn Olsen and Kaare Christensen, speculated that time itself, or a close correlate, may be responsible for the increased risk. This hypothesis appeared to be the case (Basso et al., 2001) and was corroborated in an independent study based on Norwegian data (Skiærven et al., 2002).
In collaboration with Donna Baird, Ph.D., Clarice Weinberg, Ph.D. and Allen Wilcox, M.D., Ph.D., she has extended her studies on pre-eclampsia to examining new risk factors, such as subfecundity or difficulty to conceive a clinically recognized pregnancy and mother's height (Basso et al., 2003; Basso et al., 2004). She has also been interested in the methodological aspects of subfecundity investigations and studies using time to pregnancy (TTP), the amount of time between when couples begin trying to have a child to when conception occurs. She has paid special attention to the outcome of pregnancy in couples taking over a year to conceive. That subfecundity per se may be associated with a higher risk of adverse pregnancy outcome has merited relatively little attention compared to the amount of research devoted to studying pregnancy outcome in couples receiving treatment. The importance of establishing whether subfecundity is a risk factor, independent of treatment, has clinical relevance as well as methodological implications, because most studies examining the effect of treatment use, as comparison, a population with relatively high fecundity, instead of a population of infertile women not receiving treatment. An increased risk of preterm delivery and neonatal death was seen in couples taking longer than 12 months to conceive among those participating in the Danish National Birth Cohort (Basso and Baird, 2003; Basso and Olsen, 2005; Zhu et al, 2006).
Studies
Planning a longitudinal study on pre-eclampsia among women at high risk
Selected Publications
Basso O, Olsen J, Bisanti L, Juul S, Boldsen J and The European Study Group of Infertility and Subfecundity: Is seasonal preferences in pregnancy planning a source of bias in studies of seasonal variation in reproductive outcomes? Epidemiology 6:520-24, 1995. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8562629)
Basso O, Olsen J, Knudsen L, Christensen K. Low birthweight and preterm birth after short interpregnancy intervals. Am J Obstet Gynecol 178:259-63, 1998. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9500484)
Basso O, Christensen K, Olsen J. Higher risk of pre-eclampsia after change of partner. An effect of longer interpregnancy intervals? Epidemiology 12:624-9, 2001. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11679788)[Full Text](http://gateway.ut.ovid.com/gw2/ovidweb.cgi?QS=T9HJnZDcSFrOY4GK%2fiEqO1FujU1VEwqcNK3bJMhWXNFkRUFnKt0MFex%2fl98VCnIXIsCP4R5ImAxTchNEtM%2bhKtEeELqgD1HDXtUWrjeNFL1x09ql29G6Fc32c2nRVGmg1WOoHVXynWNL3j1g%2fkjzQWWQ%2fa3eeBEQ_gzpMetcwjmXybx9g)[download the PDF](http://gateway.ut.ovid.com/gw2/ovidweb.cgi?WebLinkFrameset=1&S=FPDDNCGJJCBJMK00D&returnUrl=ovidweb.cgi%3f%26Full%2bText%3dL%257cS.sh.15.16%257c0%257c00001648-200111000-00008%26S%3dFPDDNCGJJCBJMK00D&directlink=http%3a%2f%2fgraphics.tx.ovid.com%2fovftpdfs%2fFPDDNCGJJCBJMK00D%2ffs033%2fovft%2flive%2fgv017%2f00001648%2f00001648-200111000-00008.pdf)
Basso O, Baird DD. Infertility and preterm delivery, birthweight, and Caesarean section: a study within the Danish National Birth Cohort. Human Reprod. 18:2478-84, 2003. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&list_uids=14585905&dopt=Abstract)[Full Text](http://humrep.oupjournals.org/cgi/content/full/18/11/2478)[downlaod the PDF](http://humrep.oupjournals.org/cgi/reprint/18/11/2478)
Basso O, Olsen J. Subfecundity and neonatal mortality. A longitudinal study within the Danish National Birth Cohort. BMJ. 330:393-4, 2005. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15695499)[Full Text](http://bmj.bmjjournals.com/cgi/content/full/330/7488/393)[download the PDF](http://bmj.bmjjournals.com/cgi/reprint/330/7488/393)
Basso O, Wilcox AJ, Weinberg CR. Birth weight and mortality: causality or confounding? Am J Epidemiol. 2006;164:303-11. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16847040&query_hl=1&itool=pubmed_docsum)
Basso O, Rasmussen S, Weinberg CR, Wilcox AJ, Irgens LM, Skjaerven R. Trends in fetal and infant survival following preeclampsia. JAMA 296:1357-62, 2006. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16985227&query_hl=4&itool=pubmed_docsum)
Zhu JL, Basso O, Obel C, Bille C, Olsen J. Infertility, infertility treatment, and congenital malformations: Danish national birth cohort. BMJ 333:679, 2006. Epub Aug 7, 2006. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16893903&query_hl=4&itool=pubmed_docsum)
Chen A, Basso O. Does low maternal blood pressure during pregnancy increase the risk of perinatal death?. Epidemiology (Cambridge, Mass.) 5:619-622, 2007. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=17879438)
Zhu JL , Obel C , Bech BH , Olsen J , Basso O. Infertility, infertility treatment and fetal growth restriction. Obstetrics and gynecology 110(6):1326-1334, 2007. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=18055728)
Pedersen CB, Sun Y, Vestergaard M, Olsen J, Basso O. Assessing fetal growth impairments based on family data as a tool for identifying high-risk babies. An example with neonatal mortality. BMC pregnancy and childbirth 7:28, 2007. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=18045458)
Basso O. Birth weight is forever. Epidemiology (Cambridge, Mass.) 2008 19(2):204-205. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=18277158)
Sun Y, Vestergaard M , Pedersen CB , Christensen J , Basso O , Olsen J. Gestational age, birth weight, and intrauterine growth and risk of epilepsy. American journal of epidemiology 2008 167(3):262-270. [Abstract](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=18042672)