Placental previa in relation to induced and spontaneous abortion: a population-based study.
OBJECTIVE
To evaluate the impact of induced abortion and spontaneous abortion on the occurrence of placenta previa in later pregnancies.


METHODS
A population-based, case-control study was conducted using 1984-1987 Washington state birth certificate data. The study population included 486 white women with a pregnancy complicated by placenta previa and 1598 randomly selected controls without placenta previa. Unconditional logistic regression was used to estimate odds ratios and 95% confidence intervals (CIs).


RESULTS
After adjustment for confounding variables, the odds ratio in association with one or more induced abortions was 1.28 (95% CI 1.00-1.63). For one or more spontaneous abortions, the odds ratio was 1.30 (95% CI 1.01-1.66).


CONCLUSIONS
Women who report one or more induced or spontaneous abortions are 30% more likely to have a subsequent pregnancy complicated by placenta previa than women without such a history. The results should not be generalized to areas where suction curettage is not the preferred method of induced abortion.
Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
V M
VM
Taylor
M D
MD
Kramer
T L
TL
Vaughan
S
S
Peacock
D000028:Abortion, Induced / Q000009:adverse effects*; D000022:Abortion, Spontaneous / Q000150:complications*; D000328:Adult; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008423:Maternal Age; D016017:Odds Ratio; D010298:Parity; D010923:Placenta Previa / Q000209:etiology*; D011247:Pregnancy; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects