Does Slynd (drospirenone‑only oral contraceptive) cause fetal harm if a woman becomes pregnant while taking it?

Does Slynd Cause Fetal Harm?

Slynd (drospirenone-only oral contraceptive) does not cause fetal harm based on available evidence, and inadvertent exposure during early pregnancy does not increase the risk of birth defects or miscarriage above background rates. 1

Evidence from Pregnancy Exposure Data

The FDA drug label for drospirenone-containing products provides the most direct evidence regarding fetal safety:

• A large retrospective database study in Norway examined 44,734 pregnancies, including 368 women who inadvertently took drospirenone/ethinyl estradiol during the first trimester. This study found no adverse effects on pre-term birth, small for gestational age infants, or birth weight Z-scores. 1

• Post-marketing surveillance data on drospirenone and ethinyl estradiol use in pregnant women shows that frequencies of miscarriage and congenital anomalies were not higher than the estimated background risk in the general population. 1

• The U.S. background risk of major birth defects in clinically recognized pregnancies is 2-4%, and the miscarriage risk is 15-20%. Drospirenone exposure does not increase these baseline rates. 1

Epidemiologic Evidence on Combined Hormonal Contraceptives

While Slynd contains only drospirenone (without estrogen), broader evidence on hormonal contraceptives is reassuring:

• Epidemiologic studies and meta-analyses have not found an increased risk of genital or non-genital birth defects (including cardiac anomalies and limb-reduction defects) following exposure to combined hormonal contraceptives before conception or during early pregnancy. 1

• Safety data from multiple studies indicate that drospirenone-containing products have no negative impact on birth defect risk. 2

Clinical Management Algorithm

If pregnancy is discovered while taking Slynd:

1. Discontinue Slynd immediately – there is no use for contraception during pregnancy. 1

2. Reassure the patient that available evidence shows no increased risk of fetal harm from inadvertent first-trimester exposure. 1

3. Provide routine prenatal care without additional fetal monitoring beyond standard obstetric protocols, as no specific teratogenic effects have been identified. 1

4. Document the exposure but recognize that no special interventions are warranted based on current evidence. 1

Important Caveats

Pregnancy testing before initiation: While Slynd does not harm the fetus if pregnancy occurs, clinicians should ensure reasonable certainty that patients are not pregnant before starting the medication, using the criteria outlined in CDC guidelines. 3

Lactation considerations: Drospirenone is present in breast milk at very low levels (approximately 0.1% of maternal dose reaches the infant), and while there is limited information on effects, the developmental benefits of breastfeeding should be weighed against the mother's need for contraception. 1

Distinction from other medications: This safety profile for drospirenone contrasts sharply with truly teratogenic medications like mycophenolate products, which are contraindicated in pregnancy due to high risks of miscarriage and birth defects. 3