The term “steroids” covers two classes: corticosteroids and Anabolic Androgenic Steroids (AAS). Corticosteroids, such as prednisone, are prescription medications that mimic adrenal hormones to reduce inflammation and suppress the immune system. AAS are synthetic derivatives of testosterone, often misused for performance enhancement and muscle building. Understanding the type of steroid is necessary to assess potential effects on having a baby, from fertility to fetal development.
Anabolic Steroids and Reproductive Health
Anabolic Androgenic Steroids severely disrupt the body’s natural hormone production, affecting the ability to conceive in both males and females. The reproductive system is governed by the hypothalamic-pituitary-gonadal (HPG) axis. When synthetic androgens are introduced, the brain perceives an excess of sex hormones and signals the body to stop its own production.
In males, HPG suppression reduces the release of Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) from the pituitary gland. Since FSH is necessary for sperm production and LH stimulates testosterone production, the testes become inactive. This quickly leads to oligospermia (low sperm count) or azoospermia (absence of sperm), causing temporary infertility. Testicular atrophy (shrinkage) may also occur. While these effects are often reversible after cessation, the recovery time can range from several months to a year or more, and sometimes the HPG axis does not fully return to its pre-steroid function.
For females, AAS misuse disrupts the hypothalamic-pituitary-ovarian (HPO) axis, leading to hyperandrogenism (excess male hormones). High levels of androgens inhibit proper signaling, disrupting the release of LH and FSH necessary for ovulation. This hormonal imbalance causes significant menstrual irregularities, including amenorrhea and anovulation, leading directly to infertility. Androgenic effects can also cause physical changes, known as virilization, such as male-pattern hair growth, deepening of the voice, and breast atrophy.
Corticosteroid Use During Pregnancy
Corticosteroids are commonly prescribed for maternal conditions like asthma, autoimmune disorders, and severe allergies. Physicians weigh the benefit of treating the mother’s illness against potential risks, as uncontrolled maternal illness poses a greater threat to the pregnancy than the medication.
For systemic use, drugs like prednisone and prednisolone are preferred because they are sensitive to a placental enzyme (11-beta-hydroxysteroid dehydrogenase type 2). This enzyme converts the drugs into inactive forms, limiting the amount of active drug that crosses the placental barrier and reaches the fetus.
Treatment aims to use the lowest effective dose for the shortest duration. Inhaled or topical corticosteroids, such as those for asthma, are safest because they result in minimal systemic absorption. Appropriate medical supervision allows for necessary management of maternal health without significant fetal exposure.
Fetal Development and Neonatal Health Risks
The use of either AAS or corticosteroids during pregnancy carries distinct risks for the developing fetus and the newborn infant.
Risks of Anabolic Steroids (AAS)
Exposure of a female fetus to high levels of synthetic androgens can cause virilization, resulting in the development of male-like characteristics in the external genitalia. This occurs because the androgens cross the placenta and act directly on the developing fetal tissues. Maternal AAS use is associated with an increased risk of preterm birth and low birth weight. If the mother’s illicit use was high, the infant may experience adrenal suppression or a form of withdrawal due to the sudden cessation of steroid effects after birth. Exposure to high levels of androgens in utero can also be a risk factor for certain childhood cancers like hepatoblastoma.
Risks and Benefits of Corticosteroids
Prescribed corticosteroids have a specific beneficial application: accelerating fetal lung maturity. If preterm birth is anticipated between 24 and 34 weeks of gestation, a course of corticosteroids (usually betamethasone or dexamethasone) is administered to the mother. This treatment enhances the development of pneumocytes, the cells that produce surfactant, which coats the lungs and prevents the air sacs from collapsing. This single course reduces the risk of respiratory distress syndrome, intraventricular hemorrhage, and neonatal death in premature infants.
However, prolonged use of systemic corticosteroids by the mother, especially at high doses, can pose a risk of transient neonatal adrenal suppression. The infant’s adrenal glands, suppressed by the high levels of placental-transferred steroid, may not produce enough cortisol immediately after birth. This is usually a temporary condition, but it requires close monitoring of the newborn for signs of insufficient adrenal function, such as hypoglycemia. While older studies suggested a slight increase in the risk of oral clefts, most current human data do not support a strong association.
Steroid Transfer During Breastfeeding
The safety of breastfeeding while taking steroids depends on the type and dose. Most common corticosteroids, such as prednisone, transfer into breast milk at very low levels. For mothers taking up to 40 mg of prednisone daily, the amount ingested by the infant is minimal and not expected to cause adverse effects.
For higher doses, timing the dose immediately after a feeding and waiting four hours before the next feeding is sometimes recommended. However, this maneuver is often considered unnecessary due to the low levels in the milk. The benefit of breastfeeding outweighs the negligible risk of corticosteroid exposure, especially with inhaled or topical varieties.
Anabolic Androgenic Steroids (AAS) are contraindicated during breastfeeding. AAS are lipid-soluble and transfer into breast milk, exposing the infant to synthetic androgens. This exposure risks disrupting the infant’s hormonal balance. Hormonal side effects, including virilization in a female infant or premature closure of growth plates, make AAS use incompatible with nursing.