Indexed on: 01 Jul '12Published on: 01 Jul '12Published in: Pregnancy Hypertension
Gestational hypertension/preeclampsia (GH) is clearly a heterogeneous condition of which the pathogenesis could be different in women with various risk factors. Nulliparity is a known risk factor for GH, however a previous abortion (spontaneous or induced) may be associated with a lower risk of GH.To examine the effect of abortion history on rates of GH and spontaneous preterm delivery (SPTD) and in nulliparous women.Nulliparous women with an initial prenatal screening at <13 weeks' gestation and a current singleton gestation delivering between 6/2006 and 6/2011 that voluntarily enrolled for risk assessment-case management services were identified from a database of clinical information. Excluded were women reporting a history of both spontaneous (SAB) and induced (IAB) abortions, or with a priori diagnosis of diabetes. Rates of SPTD and GH were compared between women with SAB or IAB history (AB group) and a reference group of primigravid women using Pearson's chi-square, Student's t, Kruskal-Wallis H, and Mann-Whitney U statistics.Of the 75,487 women studied, 5.7% (n=4288) reported a history of IAB and 24.3% (n=18,328) reported a history of SAB. Overall, 301 women (0.4%) experienced a SAB at <20 weeks in the index pregnancy. Of those 75,186 with delivery ⩾20 weeks, the incidence of SPTD was 6.1% in controls vs. 6.0% in the IAB/SAB group (p=0.550). Rates of GH were 10.2% in controls vs. 8.0% (p<0.001) in the AB group despite the AB group having significantly (p<0.001) higher rates of women of African-American race (8.5% vs. 5.5%); age >34years (23.9% vs. 10.0%); and obesity (19.6% vs. 16.6%). For women with >2 AB's significant differences were observed in rates of SPTD vs. controls (8.2% vs. 6.0%, p<0.001), but rates of GH were similar (9.2% vs. 10.2%, p=0.188). (1)p<0.001 vs. 0 AB group.In nulliparous women, prior AB is associated with a reduction in risk for GH. Risk for SPTD increases only in those with >2 prior AB's.