title: Infertility, infertility treatment and psychomotor development: the Danish National Birth Cohort.
abstract: Babies born of infertile couples, regardless of treatment, have a higher risk of preterm birth and low birthweight, conditions associated with delayed development. We examined developmental milestones in singletons as a function of parental infertility [time to pregnancy (TTP) > 12 months] and infertility treatment. From the Danish National Birth Cohort (1997-2003), we identified 37 897 singletons born of fertile couples (TTP < or = 12 months), 4351 born of infertile couples conceiving naturally (TTP > 12 months), and 3309 born after infertility treatment. When the children were about 18 months old, mothers reported 12 developmental milestones by responding to structured questions. We defined a failure to achieve the assessed milestone or the minimal numbers of milestones in a summary (motor, or cognitive/language skills) as delay. Naturally conceived children born of infertile couples had a pattern of psychomotor development similar to that of children born of fertile couples, but increasing TTP correlated with a modest delay. When the analysis was restricted to infertile couples (treated and untreated), children born after treatment showed a slight delay in cognitive/language development (odds ratio 1.24, [95% confidence interval 1.01, 1.53]) for not meeting at least three out of six cognitive/language milestones); children born after intracytoplasmic sperm injection (ICSI) had the highest estimated relative risk of delay for most milestones, especially motor milestones. These results suggest that a long TTP may be associated with a modest developmental delay. Infertility treatment, especially ICSI, may be associated with a slight delay for some of these early milestones.
authors.affiliation: The Danish Epidemiology Science Centre, University of Aarhus, Aarhus, Denmark. zjl@soci.au.dk
authors.forename: Jin Liang
authors.initials: JL
authors.lastname: Zhu
authors.forename: Olga
authors.initials: O
authors.lastname: Basso
authors.forename: Carsten
authors.initials: C
authors.lastname: Obel
authors.forename: Dorte
authors.initials: D
authors.lastname: Hvidtjørn
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
mesh_terms: D000293:Adolescent; D000328:Adult; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000502:physiology*; D007246:Infertility / Q000628:therapy; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D027724:Reproductive Techniques, Assisted; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult