Pregnancy & Lactation : הריון/הנקה

4.6   Fertility, pregnancy and lactation
Pregnancy:
Inhibition of prostaglandin synthesis may adversely affect pregnancy and/or embryo-foetal development. Data from epidemiological studies have raised concern about an increased risk of miscarriage and malformations after the use of a prostaglandin synthesis inhibitors in early pregnancy. The risk is believed to increase with dose and duration of therapy.
Available epidemiological data for acetylsalicylic acid indicate an increased risk of gastroschisis.
Animal studies have shown reproductive toxicity (see section 5.3).
From the 20th week of pregnancy onward, use of Aspirin may cause oligohydramnios resulting from foetal renal dysfunction. This can occur shortly after the start of treatment and is generally reversible after discontinuation of treatment. These adverse outcomes are seen, on average, after days to weeks of treatment, although oligohydramnios has been infrequently reported as soon as 48 hours after NSAID initiation. There have also been reports of constriction of the ductus arteriosus after treatment in the second trimester of pregnancy, although this regressed after discontinuation of treatment in most cases.
Aspirin should therefore not be administered during the first and second trimester of pregnancy unless this is absolutely necessary. If Aspirin is used by a woman attempting to conceive, or during the first and second trimester of pregnancy, the dose should be kept as low as possible and the duration of treatment as short as possible. After Aspirin has been taken for several days from the 20th week of pregnancy, antenatal monitoring for oligohydramnios and constriction of the ductus arteriosus should be considered. Aspirin should be discontinued if oligohydramnios or constriction of the ductus arteriosus is found.

During the third trimester of pregnancy, all prostaglandin synthesis inhibitors may: expose the fetus to:
• cardiopulmonary toxicity (with premature constriction/closure of the ductus arteriosus and pulmonary hypertension)
• impaired kidney function (see above) expose the mother and neonate, at the end of pregnancy, to:
• possible prolongation of bleeding time, a platelet aggregation-inhibiting effect that can occur even at very low doses;
• inhibition of uterine contractions, which can lead to delayed labor or prolonged parturition.

Consequently, acetylsalicylic acid is contraindicated during the third trimester of pregnancy (see sections 4.3 and 5.3).

Fertility:
There is evidence that drugs that inhibit cyclooxygenase/prostaglandin synthesis may impair female fertility through an effect on ovulation. This effect is reversible on discontinuation of treatment.

Lactation:
Acetylsalicylic acid and its metabolites pass into breast milk in small quantities. Adverse effects on infants have not been reported to date. It is therefore not necessary to interrupt breast-feeding due to occasional use at the recommended dosage. Nonetheless, in the case of use for extended periods or consumption of high doses, breastfeeding should be stopped.