Not Helpful

The authors’ one-sided description of available options for anticoagulation in pregnancy is not helpful.

• None of the cited articles allows the conclusion that <3 mg phenprocoumon/day is unproblematic; this has never been studied.
• In the cited study by Schaefer et al, actual embryopathies were reported—particularly in association with phenprocoumon, the most commonly used anticoagulant in Germany.
• The Schaefer et al study reported a miscarriage rate of 42% with coumarins; Regitz-Zagrosek et al did not mention this at all.
• Chan et al reported a rate of warfarin related embryopathies of 6.4%, a rate of spontaneous abortions of 24.8%, and a rate of fetal losses and neonatal deaths of 26.5% (1).
• Another study showed that in the long term, coumarin during pregnancy results in lowered intelligence in the ensuing children.

Women planning to become pregnant should be switched to a therapeutic dose of low-molecular weight heparin in good time before conception. This is safe, according to the current literature, and is not associated with an increased risk of thromboembolism if the appropriate dosage is selected (2× daily, adapted to weight, 100 anti-Xa-units per kg body weight) (2).

The 2008 American College of Chest Physicians (ACCP) guideline (3) recommends 2× daily, dose-adjusted treatment with low molecular weight heparins in patients with valve dysfunction in first place, equivalent to the option to restart patients on warfarin from the 13th week of gestation.

DOI: 10.3238/arztebl.2011.0621a

Dr. med. Hannelore Rott

Duisburg

Hannelore.Rott@gzrr.de

Conflict of interest statement
The author declares that no conflict of interest exists.