Design: Systematic review and Bayesian aggregated case series
Population: 216 pregnant patients given thrombolytics (85 for ischaemic stroke) from 123 studies
Primary outcome: Maternal and fetal safety outcomes
Effect: Symptomatic ICH risk difference −0.4% (−0.8 to 2.7) vs non-pregnant; 6 of 32 fetal deaths likely treatment-related

A systematic review and aggregated case series in Neurology, published on 30 October, gathered 216 pregnant patients given thrombolytics, 85 for ischaemic stroke and the rest for pulmonary embolism, valve thrombosis or deep vein thrombosis.

Symptomatic intracerebral haemorrhage was similar to that in young non-pregnant patients given thrombolysis. Of 32 fetal deaths, six were judged likely related to treatment, three of them after stroke thrombolysis. Miscarriage and stillbirth were more common than in the general pregnant population, though the disease itself probably contributed.

Pregnancy is often treated as a reason not to thrombolyse, and many pregnant women with disabling stroke miss treatment. This analysis suggests the maternal risk is not higher, and the fetal risk, while real, is small relative to the harm of a disabling maternal stroke.

The evidence comes from published cases, which favour unusual and successful outcomes. It supports individual decisions made jointly with obstetrics, not a blanket rule.

Consider thrombolysis for disabling ischaemic stroke in pregnancy rather than excluding it on pregnancy alone.
Involve obstetrics urgently, but do not let that delay the decision past the treatment window.
Counsel about a small risk of fetal loss linked to treatment.
Check eligibility in the usual way; pregnancy does not change the other contraindications.
Consider thrombectomy where large-vessel occlusion is present.

Why it matters

It challenges the reflex to withhold thrombolysis because a patient is pregnant.

The statistics, in plain English

The miscarriage risk was 12.4 percentage points higher than in the general pregnant population (95% credible interval 2.6 to 23.2), and stillbirth 5.9 points higher (1.6 to 12.7). Credible intervals are the Bayesian equivalent of confidence intervals. Comparing a case series with population rates cannot separate the effect of the drug from that of the illness.