Threatened abortion in utero carries heightened risk of cerebral palsy

Children affected by threatened abortion (TAB) in utero are at risk of having cerebral palsy (CP) but not epilepsy or attention-deficit/hyperactivity disorder (ADHD), a study has found.

The study population comprised 1,864,221 singletons live-born in Denmark, among whom 59,134 were affected by TAB. Outcomes such as epilepsy, CP, and ADHD were assessed and compared using Cox regression. Birth year, birth order, parental age, morbidity, medication use, and maternal socioeconomic factors were included as confounding factors.

During follow-up (1979–2010 through 2016), the respective cumulative incidences among the TAB-affected and -unaffected children were 2.2 percent and 1.6 percent for epilepsy, 0.4 percent and 0.2 percent for CP, and 5.5 percent and 4.2 percent for ADHD.

The hazard estimate was significant for CP (hazard ratio [HR], 1.42, 95 percent confidence interval [CI], 1.20–1.68) but not for epilepsy (HR, 1.25, 95 percent CI, 1.16–1.34) and ADHD (HR, 1.21, 95 percent CI, 1.14–1.29).

In the sibling analyses, performed to remove time-invariant family-shared confounding, the estimates were unity for epilepsy (full siblings: HR, 0.96, 95 percent CI, 0.82–1.12; maternal: HR, 1.04, 95 percent CI, 0.90–1.20; paternal: HR, 1.08, 95 percent CI 0.93–1.25) and ADHD (full: HR, 1.08, 95 percent CI, 0.92–1.27; maternal: HR, 1.04, 95 percent CI, 0.90–1.20; paternal: HR, 1.08, 95 percent CI, 0.93–1.25).

For CP, the estimates shifted away from unity among sibling pairs (full: HR, 2.92, 95 percent CI, 1.33–6.39; maternal: HR, 2.03, 95 percent CI, 1.15–3.57; paternal: HR, 3.28, 95 percent CI, 1.36–7.91).