Methods

Randomised controlled trial. Open label.
Study type: multicenter study (34 hospitals). National: The Netherlands.
Study phase: III.
Study design: parallel.
Phase of perinatal period at entry: pregnancy (< 36 weeks' gestation).
Randomisation: by computer‐generated table of random numbers allocation. It was conducted before 36 weeks' gestation.
Allocation concealment: not described.
Blinding: pediatricians who assessed the babies were not masked to the treatment.

Analysis results: per‐protocol analysis.
Follow‐up period: from "day 259 of pregnancy till delivery".

Lost post‐randomisation: 13 (32%) (not included the final analysis).

• Betamethosone group: 6.

• Control (no treatment): 7.

• Reasons: secondary thrombocytopenia (7), lost to follow up (3), attending physician altered treatment (2), preterm delivery before treatment started (1).

Participants

Recruited participants: 59 women (64 pregnancies).

Number randomised: 38 women (41 pregnancies).

Number analysed: 26 women (28 pregnancies).
Mean (SD) age of experimental group (n = 14): 29 (5) years.

Mean (SD) age of experimental group (n = 14): 29 (6) years.

Inclusion criteria: pregnant women with idiopathic thrombocytopenic purpura (thrombocytopenia (maternal platelet count < 150 x 10⁹/l) on more than 1 occasion, the presence of a normal or increased number of megakaryocytes in bone marrow, and the absence of other diseases, of splenomegaly, of antinuclear antibodies and of the use of drugs known to induce thrombocytopenia).

Exclusion criteria: pregnant women already using corticosteroids.

Interventions

Bethametasone: 0.5 mg thrice/day (1.5 mg/day) by the first 2 weeks and 0.5 mg twice/day/ during the third week.

Control: no treatment.

Outcomes

Primary:

1. neonatal thrombocytopenia;

2. neonatal bleeding complications.

Notes

Funding/support: no special funding required.

8 pregnant women were included with normal platelet counts with diagnosis of ITP made before the current pregnancy and who had had a splenectomy.

Trial period: March 1984 to March 1987.

Reasons for non‐admitted participants during recruitment period: use of corticosteroids (10 participants), concomitant disease (7 participants) and refused to participate (6 participants).

Risk of bias

Bias

Authors' judgement

Support for judgement

Adequate sequence generation?

Low risk

Adequate: quote: "...according to a computer‐generated table of random numbers".

Allocation concealment?

Unclear risk

Insufficient information to permit judgement of ‘yes’ or ‘no’.

Blinding?
Blinding of patients

Unclear risk

Insufficient information to permit judgement of ‘yes’ or ‘no’.

Blinding?
Blinding of outcome assessors

High risk

Inadequate.

Comment: treatment received by mother were known by paediatricians who assessed newborns.

Blinding?
Blinding of caregivers

Unclear risk

Insufficient information to permit judgement of ‘yes’ or ‘no’.

Incomplete outcome data addressed?
All outcomes

High risk

Inadequate.

Comment: study excluded 13 pregnancies (32%).

Free of selective reporting?

Unclear risk

Unclear.
Comments: study reported data on the planned outcomes. However, this RCT did not include relevant clinical outcome: maternal death, perinatal mortality, postpartum haemorrhage and intracranial haemorrhage neonatal.

Free of other bias?

High risk

Inadequate.

There is a chance of bias due to inadequate sample size for estimating a real effect. This trial may be affected by early stopping bias:

Free of baseline imbalance?

Unclear risk

Inadequate.

Comments: it only shows the baseline characteristics of the analysed participants.

Free of academic bias?

Low risk

Adequate.
No previous published RCTs of the same intervention.

No previous published RCTs of the same medical condition.

This RCT reports a retrospective study which used prednisone and suggested a beneficial effect on the neonatal platelet count.

Free of attrition bias?

High risk

Inadequate.

Comment: there were 32% (13/41) post‐randomisation drop‐outs.