 If the fetus is vertex (head down), the two horns may not contract in coordination, or the horn that does not contain the pregnancy may interfere with contractions and descent of the fetus, causing obstructed labor.Usage of intrauterine device (IUD) with copper requires one IUD in each horn to be effective in case of bicornuate uterus.The same practice is generally applied when using IUD with progestogen due to lack of evidence of efficacy with only one IUD.