Infertility, infertility treatment and psychomotor development: the Danish National Birth Cohort

Parental infertility and developmental coordination disorder in children

BACKGROUND

It has previously been reported that children born after infertility treatment had a slight delay in early motor milestones. In this study, we examined whether children of infertile couples with or without infertility treatment had a higher risk of developmental coordination disorder (DCD).

METHODS

We used data on parental infertility and DCD among 23 167 singletons from the Danish National Birth Cohort (1996-2002). Data on time to pregnancy (TTP) and infertility treatment were collected early in pregnancy. Data on DCD in children were collected using the Developmental Coordination Disorder Questionnaire, filled in by the mothers during follow-up when the children were 7 years old. We used the recommended cut-off for the age group to classify children.

RESULTS

Compared with children born of fertile couples, children conceived after a waiting TTP of longer than 12 months had a slightly higher risk of DCD [odds ratio (OR) 1.35, 95% confidence interval (CI) 1.03-1.77], but the estimated OR was not significant in children born after infertility treatment (OR 1.19, 95% CI 0.86-1.66). None of the individual treatment procedures was significantly associated with a higher risk of DCD. Children of parents who had not planned their pregnancy showed no elevated risk.

CONCLUSIONS

Our findings are overall reassuring, although it is possible that low fecundity may be associated with a modestly increased risk of DCD.

Infant outcome of 957 singletons born after frozen embryo replacement: the Danish National Cohort Study 1995-2006

OBJECTIVE

To examine infant outcome of singletons born after cryopreservation of embryos (Cryo).

DESIGN

National population-based controlled follow-up study.

SETTING

Denmark, 1995-2007.

PATIENT(S)

The study population was 957 Cryo singletons (Cryo-IVF, n=660; Cryo-ICSI, n=244; Cryo-IVF/-ICSI, n=53). The first control group was all singletons born after fresh IVF or intracytoplasmic sperm injection (ICSI) during the same period (IVF, n=6904; ICSI, n=3425). The second control group comprised a random sample of non-assisted reproductive technology (ART) singletons (n=4800).

INTERVENTION(S)

All observations were obtained from national registers.

MAIN OUTCOME MEASURE(S)

Low birth weight (LBW; <2500 g), preterm birth (PTB; <37 weeks), congenital malformations, mortality, and morbidity.

RESULT(S)

Birth weight was higher in Cryo (mean=3578 g, SD=625) versus fresh (mean=3373 g, SD=648) and in Cryo versus non-ART (mean=3537 g, SD=572), and this was also the case for first birth only. Lower adjusted risk of LBW (odds ratio [OR]=0.63; 95% confidence interval [CI], 0.45-0.87) and PTB (OR=0.70; 95% CI, 0.53-0.92) was observed in Cryo versus fresh. Similar LBW and PTB rates were observed when comparing Cryo with non-ART, but the perinatal mortality rate was doubled in Cryo (1.6%) compared with non-ART (0.8%) singletons, and the adjusted risks of very preterm birth (<34 weeks) and neonatal admittance were also significantly increased. No significant differences in the prevalence rates of birth defects, neurological sequelae, malignancies, and imprinting-related diseases were observed between the Cryo and the two control groups. However higher malformation and cerebral palsy rates were observed in the total Fresh vs. non-ART group.

CONCLUSION(S)

Cryo singletons have better neonatal outcome than offspring after fresh ET but poorer compared with non-ART singletons.