Carbon Monoxide Poisoning


It is known that CO poisoning during pregnancy can lead to stillbirths and birth defects. Most studies have focused on fetal brain damage; in this report, malformations of the infant are strongly suspected to be a result of mild, chronic CO exposure of the mother.

The baby was carried to term and weighed 6.5 pounds (2950 grams) at birth. He had a cleft lip and palate, low-set ears, underdeveloped external genitalia, and visual and hearing defects. He also had multiple heart defects, which were rapidly fatal.

Upon interviewing the mother, they discovered that 10 weeks into the pregnancy, she had complained of dizziness and headache. Her 16-month old daughter had suffered an episode of unconsciousness at about that same time. They suspected that the gas water heater was faulty but didn't have it repaired. The daughter was found comatose during the seventh month of pregnancy; upon admission to the emergency room her COHb was 27.5% and the mother's was 14%. Both were treated with hyperbaric oxygen and released.

Upon investigation of the water heater, after 2 minutes of use the CO levels in the bathroom and kitchen were 100 and 120 parts per million, respectively. Normal levels are less than 5 ppm.

From: Hennequin, Y., Blum, D., Vamos, E., Steppe, M., Goedseels, J., Cavatorta, E. (1993) In-utero carbon monoxide poisoning and multiple fetal abnormalities. Lancet, 341: 240.

What this study shows:

last changed 07/08/02

Back to Case Study Index