Antithrombotic therapy for improving maternal or infant health outcomes in women considered at risk of placental dysfunction.
BACKGROUND
Pregnancy complications such as pre-eclampsia and eclampsia, intrauterine growth restriction and placental abruption are thought to have a common origin related to abnormalities in the development and function of the placenta.


OBJECTIVE
To compare, using the best available evidence, the benefits and harms of antenatal antithrombotic therapy to improve maternal or infant health outcomes in women considered at risk of placental dysfunction, when compared with other treatments, placebo or no treatment.


METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (March 2010).


METHODS
Randomised controlled trials comparing antenatal antithrombotic therapy (either alone or in combination with other agents) with placebo or no treatment, or any other treatment in the antenatal period to improve maternal or infant health outcomes in women considered at risk of placental dysfunction.


METHODS
Two review authors evaluated trials under consideration for appropriateness for inclusion and methodological quality without consideration of their results according to the prestated eligibility criteria. We used a fixed-effect meta-analysis for combining study data if the trials were judged to be sufficiently similar. We investigated heterogeneity by calculating I(2) statistic, and if this indicated a high level of heterogeneity among the trials included we used a random-effects model.


RESULTS
Our search strategy identified 14 reports of 10 studies for consideration, of which five met the inclusion criteria, involving 484 women. Four studies compared heparin (alone or in combination with dipyridamole) with no treatment; and one compared trapidil (triazolopyrimidine). While there were no statistically significant differences identified for the primary outcomes following heparin treatment, it was associated with a reduction in the risk of pre-eclampsia, eclampsia, and infant birthweight less than the 10th centile for gestational age.


CONCLUSIONS
The review identified no significant differences for the primary outcomes perinatal mortality, preterm birth less than 34 weeks' gestation, and childhood neurodevelopmental handicap, although the number of studies and participants was small. While treatment with heparin appears promising with a reduction in pre-eclampsia, eclampsia, and infant birthweight less than the 10th centile for gestational age, the number of studies and participants included was small, and to date important information about serious adverse infant and long-term childhood outcomes is unavailable. Further research is required.
Dodd
Jodie M
JM
School of Paediatrics and Reproductive Health, Discipline of Obstetrics and Gynaecology, The University of Adelaide, Women's and Children's Hospital, 72 King William Road, Adelaide, South Australia, Australia, 5006.
McLeod
Anne
A
Windrim
Rory C
RC
Kingdom
John
J
D004176:Dipyridamole / Q000627:therapeutic use; D004461:Eclampsia / Q000517:prevention & control; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D007223:Infant; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D010922:Placenta Diseases / Q000517:prevention & control*; D011225:Pre-Eclampsia / Q000188:drug therapy / Q000517:prevention & control; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic; D013927:Thrombosis / Q000517:prevention & control*; D014192:Trapidil / Q000627:therapeutic use; D016896:Treatment Outcome
D005343:Fibrinolytic Agents; D004176:Dipyridamole; D006493:Heparin; D014192:Trapidil