In summary, it may be desirable to discontinue aspirin one to two weeks prior to term to avoid aspirin-induced bleeding problems. If high dose aspirin is used during the second half of pregnancy, amniotic fluid volume and patency of foetal ductus arteriosus should be monitored by foetal cardiac ultrasound . Due to their effects on prostaglandins, they may cause premature closure of the ductus arteriosus , oligohydroamnion and bleeding complications. They are effective as tocolytic agents and have been used for the treatment of premature labour. They should be used with caution near term and careful follow-up for amniotic fluid volume and the patency of the ductus are mandatory.
Codeine is a widely used narcotic analgesic and antitussive.
Many cold preparations and over-the counter medications contain codeine. It is not associated with a higher risk of congenital malformations in animals. Use of codeine near term may cause a narcotic withdrawal syndrome in the newborn, manifested as tremor, jitteriness, diarrhoea and poor feeding. During labour, neonatal respiratory depression can occur to the same magnitude as other narcotics. Meperidine is not associated with increased incidence of birth defects .