Listeriosis: a previously unreported medical complication in women with multiple gestations.

OBJECTIVE

Our purpose was to determine whether women pregnant with multiple gestations are at greater risk for perinatal listeriosis than are women pregnant with singletons.

STUDY

DESIGN

Active surveillance for perinatal listeriosis was carried out in Los Angeles County, California, medical records were reviewed, and rates of listeriosis were calculated from live birth and fetal death data.

RESULTS

From January 1985 through December 1992, 12 (4.0%) of 301 perinatal listeriosis cases occurred in pregnant women with multiple gestations, almost four times the overall multiple gestation rate in Los Angeles County. Rates of listeriosis in pregnant women per 100,000 live births and fetal deaths were 19.8 for singleton and 74.9 for multiple gestations (risk ratio 3.8, 95% confidence interval 2.1 to 6.8). Compared with singleton pregnancies, greater risk of listeriosis was observed in pregnancies with triplet gestations (risk ratio 38.4, 95% confidence interval 9.6 to 153.3) than in those with twin gestations (risk ratio 3.2, 95% confidence interval 1.7 to 6.0). Increased risk of listeriosis during multiple-gestation pregnancies was most notable among women > or = 35 years (risk ratio 13.6, 95% confidence interval 5.2 to 35.5) and Hispanic women (risk ratio 5.3, 95% confidence interval 2.8 to 10.0).

CONCLUSIONS

To reduce the risk of listeriosis, obstetricians should incorporate dietary recommendations into routine prenatal nutritional counseling for all pregnant women and should especially counsel women pregnant with multiple gestations of their greater risk.