Severe Vomiting During Pregnancy Causes Serious Risk to Mothers, Infants

February 18, 2005

Eurona Earl Tilley

Feb. 18, 2005 (Washington) — The risk of premature delivery, a low-birth-weight neonate, as well as prenatal and postnatal complications are increased among mothers hospitalized for hyperemesis gravidarum compared with pregnant women not hospitalized for this condition. Michele A. Soltis, MD, from the Madigan Army Medical Center in Tacoma, Washington, and Emily K. Brunson, from the University of Washington in Seattle, presented these findings here at Preventive Medicine 2005, the annual meeting of the American College of Preventive Medicine.

The two researchers explained in their poster presentation that hyperemesis gravidarum, or severe vomiting during pregnancy, often requires hospitalization. These women suffer from volume depletion, metabolic disturbance, and weight loss. It is believed that this condition affects between 0.1% and 2.0% of all pregnant women and may be a result of hormonal aberrations, autonomic irregularities, or mechanical impingement.

Due to the nutritional deprivation associated with hyperemesis gravidarum, Dr. Soltis and Ms. Brunson hypothesized that it may be responsible for placental pathologies, premature delivery, low birth weights among infants, and increased fetal anomalies. To assess the affects of hyperemesis gravidarum on pregnancy difficulties, delivery complications, and adverse infant outcomes, they developed a population-based, retrospective cohort study of singleton, live-born pregnancies.

Birth certificate data and hospitalization records from Washington state between 1987 and 2002 were analyzed. The researchers identified 4,808 pregnant women hospitalized at nonfederal institutions with hyperemesis gravidarum. The records of these women were compared with those of 9,616 randomly selected mothers not hospitalized for hyperemesis gravidarum. The two groups were further analyzed by year of delivery. Exclusion criteria were a pregnancy ending with fetal demise, a multiple-birth pregnancy, or a delivery at a federal institution. Stratified analysis using relative risk estimates was used to determine the effects of hyperemesis gravidarum on pregnancy, delivery, and infant outcome.

Results of the analysis showed that women hospitalized with hyperemesis gravidarum had an increased risk of preeclampsia compared with those not hospitalized for the condition. Of the women with hyperemesis gravidarum, 5.7% suffered from preeclampsia compared with 4.3% of the women without hyperemesis gravidarum (relative risk [RR], 1.3; 95% confidence interval [CI], 1.1 - 1.6).

In addition, women with hyperemesis gravidarum required extended hospital stays after both vaginal and cesarean delivery. Among the vaginal deliveries within the two groups of women, 7.0% of the hyperemesis gravidarum group required a hospital stay longer than three days compared with 4.0% of the control group (RR, 1.8; 95% CI, 1.5 - 2.1). Likewise, among the cesarean deliveries, 12.0% of the hyperemesis gravidarum group required a hospital stay longer than five days compared with 6.4% of the control group (RR, 2.0; 95% CI, 1.5 - 2.7).

Infants born to the group of women with hyperemesis gravidarum were also more likely to weigh less than 2500 g (6.4% of infants born to women with hyperemesis gravidarum vs 4.7% of infants born to women without hyperemesis gravidarum; RR, 1.3; 95% CI, 1.2 - 1.6). Furthermore, premature deliveries (before 28 weeks' gestational age) occurred in 0.6% of the pregnancies of women with hyperemesis gravidarum compared with 0.3% of the women without hyperemesis gravidarum (RR, 2.1; 95% CI, 1.2 - 4.0).

In evaluating the strengths and weaknesses of their research, Dr. Soltis and Ms. Brunson explained in their poster presentation that "since data is population based, results will prove to be generalized to the obstetric patient population at large." The researchers recognize, though, that there are variations in the diagnostic criteria of hyperemesis gravidarum among providers and healthcare systems.

Dr. Soltis and Ms. Brunson concluded in their poster presentation that "this study may inform physicians and expectant mothers of the complications that may occur secondary to hyperemesis gravidarum. Awareness of this condition and its potentially deleterious consequences may influence the implementation of better treatment modalities and affect the prevention of such adverse maternal and infant outcomes."

ACPM 2005: Poster 6. Presented Feb. 17, 2005.

Reviewed by Gary D. Vogin, MD

Eurona Earl Tilley is a freelance writer for Medscape.


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