Pregnancy outcome after exposure to ranitidine and other H2-blockers. A collaborative study of the European Network of Teratology Information Services.
BACKGROUND
Published data on pregnancy outcome after exposure to H2-blockers is scarce. The aim of the present study was to evaluate the data collected by the memberships of the European Network of Teratology Information Services (ENTIS).


METHODS
The patients were pregnant women who or whose doctor or midwife did contact a Teratology Information Service for risk assessment after the use of a H2-blocker in pregnancy. The data were prospectively collected, i.e. before the outcome of pregnancy was known. Standardized procedures for data collection were used by each centre. The data of the exposed women were compared to those of a control group exposed to non-teratogenic substances.


RESULTS
Data on the outcome of 553 pregnancies with exposure to an H2-blocker were evaluated (ranitidine n=335; cimetidine n=113, famotidine n=75; nizatidine n=15, roxatidine n=15). Most of them had been exposed at least in the first trimester. The incidence of premature deliveries was higher in the exposed group compared to the control group. There was no increase in the incidence of major malformations. Two pregnancies with maternal use of famotidine in early pregnancy were terminated after the prenatal diagnosis of a neural tube defect.


CONCLUSIONS
There is no indication for an increased risk of major malformations after the use of H2-blockers during pregnancy.
Garbis
Hanneke
H
Teratology Information Service, National Institute of Public Health and Environment, P.O. Box 1, 3720 BA Bilthoven, The Netherlands. hanneke.garbis@rivm.nl
Elefant
Elisabeth
E
Diav-Citrin
Orna
O
Mastroiacovo
Pierpaolo
P
Schaefer
Christof
C
Vial
Thierry
T
Clementi
Maurizio
M
Valti
Electra
E
McElhatton
Patricia
P
Smorlesi
Carlo
C
Rodriguez
Elvira Pinilla
EP
Robert-Gnansia
Elisabeth
E
Merlob
Paul
P
Peiker
Gertrud
G
Pexieder
Tomas
T
Schueler
Lavinia
L
Ritvanen
Annukka
A
Mathieu-Nolf
Monique
M
D000014:Abnormalities, Drug-Induced / Q000453:epidemiology / Q000209:etiology*; D000328:Adult; D016022:Case-Control Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006635:Histamine H2 Antagonists / Q000009:adverse effects*; D006801:Humans; D007231:Infant, Newborn; D007391:International Cooperation; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D011297:Prenatal Exposure Delayed Effects; D011446:Prospective Studies; D011899:Ranitidine / Q000009:adverse effects*; D018570:Risk Assessment
D006635:Histamine H2 Antagonists; D011899:Ranitidine