May 19 2022

Classification of the active ingredient acetylsalicylic acid


Risk level in pregnancy: This medicine is classified as Category category C for the first quarter and D during the 2nd and 3rd..

A case-control study, based on telephone interviews to 141 mothers of children with congenital heart defects could not find any relationship between these diseases and taking aspirin during pregnancy of these children.

No there is evidence that moderate doses of salicylates are teratogenic in humans. However, the infants of mothers who have taken prolonged salicylates have more often low birth weight. When the drug is administered during the third quarter increased perinatal mortality, risk of anemia, antepartum and postpartum hemorrhage, prolonged gestation, and complicated deliveries, so that its use in this period should be avoided.

In animal studies, early use of salicylates during pregnancy causes various malformations, including facial defects, nervous system, eyes, visceral malformations and skeletal abnormalities. Experimental studies seem to show a mutagenic effect of aspirin on fibroblast cell cultures. However, controlled studies in humans have not shown teratogenicity.

In the last weeks of pregnancy, high doses of salicylate for large periods may extend the period of gestation, increase the risk of postmaturity and neonatal bleeding. In theory, the use of salicylates in the later stage of gestation constriction can cause premature closure of the ductus arteriosus. However, there has been an increase in stillborn or underweight newborns with therapeutic doses of salicylates

Salicylates have been shown to reduce the mean birth weight in animals and also in human study. In the third quarter the effects of salicylates are mediated by antiprostaglandins properties of these substances, including prolongation of pregnancy and labor, increased blood loss during delivery and increased perinatal mortality. A classic study in The Lancet (1975) showed a reduction in birth weight and increased perinatal mortality but not congenital anomalies. Bleeding and withdrawal symptoms in newborns are associated with elevated levels of salicylate in the fetal blood, which must be determined in the neonate when it is known or suspected ingestion of salicylates by the mother beyond sensible range.

A baby, otherwise healthy, from a patient who took 6.5 grams of aspirin per day throughout the entire pregnancy, reported a salicylate plasma at birth of 25 mg / 100 ml, equivalent to 75 mg / kg body weight. The drug was removed during the five days after delivery, faster than in the case of infants whose mothers had taken a modest dose of aspirin, although more slowly than an adult, because of the immaturity of mechanism of renal elimination and hepatic metabolization. presented

newborn metabolic acidosis, tachypnea, and hypoglycemia after ingestion by the mother of a high dose of salicylates. The case was initially interpreted as a possible case of neonatal sepsis. The detailed history revealed that the mother had ingested aspirin during pregnancy.

pregnant teenager aged 17, who confessed during the last month ingested 50 aspirin tablets daily for suicide was admitted and treated with success of his intoxication, but the fetus was dead at the time of admission, presenting at autopsy petechial spots by various organs. The authors conclude that salicylic poisoning affects more to the fetus than the mother. Data calculated from other observations,suggest that 20 hours is the limit of survival period of a fetus whose mother had taken an overdose of salicylates.

pregnant 19 years 38 weeks pregnant, ingested for suicide 16.25 grams of aspirin, posing on one salicilemia admission 31.7 mg / dL. Fetal monitoring and fetal distress revealed bradycardia (60 bpm), so who underwent cesarean section.

before intervention, maternal salicilemia had dropped to 14 mg / dL, while the first determination to be made to the neonate was 35.2 mg / dL. Subsequent measurements showed 26.4 mg / dL at 28 hours and 8.1 mg / dL to 101 hours after birth. It should be noted in this case high levels of salicylate in the neonate compared to the mother's breast and few symptoms compared with that of the fetus and newborn, who suffered a severe metabolic alkalosis .

Update 18.07.2009

Meaning of category D

There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.