依赖于障碍性避孕方法如隔膜及配偶使用避孕套的妇女比使用其他方法的妇女发生先兆子痫的危险性增加一倍多,预先接触精子对妊娠期发育的胎儿具有保护性免疫作用。这种接触被障碍性方法阻止就意味着阻止活精子进入子宫,但非障碍性避孕工具如计划生育药片、 Women who rely on obstructive contraception, such as diaphragms and spouses, more than double the risk of pre-eclampsia compared to women who use other methods, pre-exposure to sperm has protective immunity against developing fetuses during pregnancy. Blocking such contacts by obstructive means means stopping live sperm from entering the womb, but non-stop contraceptives such as family planning pills,