Many of the predisposing factors are chronic, and in these cases, placental abruption has a high recurrence rate. Pritchard and associates (1970) identiied a recurrence rate of 12 percentand half of these caused another fetal death. Furuhashi and colleagues (2002) reported a 22-percent recurrence rate-half recurred at a gestational age 1 to 3 weeks earlier than the first abruption. In the Dutch study mentioned previously, Ruiter and coworkers (2015) cited a recurrence risk of 5.8 percent. Looked at a second way, Tikkanen and associates (2006) found that of 114 parous women who experienced an abruption, 9 percent had a prior abruption. A third perspective is provided by a population-based study of 767,000 pregnancies reported by Rasmussen and Irgens (2009). They found a 6.5-fold higher risk for recurrence of a "mild" abruption and 11.5-fold risk for a "severe" abruption. For women who had two severe abruptions, the risk for a third was increased 50-fold.
Management of a pregnancy subsequent to an abruption is diicult because another separation may suddenly occur, even remote from term. In many of these recurrences, fetal wellbeing is almost always reassuring beforehand. hus, antepartum fetal testing is usually not predictive. Because term abruptions tend to be recurrent, Ruiter and coworkers (2015) recommend labor induction at 37 weeks. Our practice at Parkland Hospital is to induce labor at 38 weeks if other complications do not develop beforehand.
Cigarette smoking is linked to an elevated risk for abruption (vIisra, 1999; Naeye, 1980). Results of a metaanalysis of 1.6 million pregnancies included a twofold risk for abruption in smokers (Ananth, 1999b). This risk was five-to eightfold if smokers had chronic hypertension, severe preeclampsia, or both. Similar findings are reported by others (Hogberg, 2007; Kaminsky, 2007). Antepartum Vitamin C and E were reported to be protective for abruption in smokers (Abramovici, 2015).
Cocaine abuse is linked with an alarming frequency of placental abruption (Addis, 2001; Cressman, 2014). Bingol and colleagues (1987) described 50 women who abused cocaine during pregnancy-eight had a stillbirth caused by placental abruption.
Uterine leiomyomas, especially if located near the mucosal surface behind the placental implantation site, can predispose to placental abruption. This was reviewed recently by Ezzedine and Norwitz (2016).
Isolated single umbiical artey is associated with a 3.4-fold increased risk for placental abruption (Gutvirtz, 2016). Twins resulting from infertility treatments also carry greater risk (Okby, 2017). Subclinical hypothyroidism or high levels of antithyroid antibodies have been associated with a two-to threefold higher risk for abruption (Abbassi-Ghanavati, 2010; Casey, 2014; Maraka, 2016).
Women afected by some of the thrombophilias have higher associated rates of thromboembolic disorders during pregnancy. However, the link with placental abruption is less clear (American College of Obstetricians and Gynecologists, 2017 a,b). Lupus anticoagulant is associated with maternal floor infarction of the placenta but is less so with typical abruptions. No convincing evidence supports a role for thrombophilias and placental abruption.