Everything you need to know about TMS and Pregnancy: Safety Data, Considerations, and Treatment Options — how it works, what it costs, and how to find a provider who actually knows what they're doing.

Perinatal depression — depression occurring during pregnancy or in the postpartum period — affects roughly 10-15% of pregnant people. It is undertreated, in part because many standard antidepressant medications carry concerns about first-trimester exposure and breastfeeding compatibility.

TMS presents itself as an attractive option for this population: localized to the brain, non-systemic, with no systemic medication exposure to the patient or fetus. The safety data, while not as extensive as for medications with decades of pregnancy registries, is increasingly reassuring.

What You’ll Learn

• Current FDA pregnancy category classification for TMS and what it means
• Safety evidence from pregnancy registries and observational studies
• ACOG and Clinical TMS Society guidelines on TMS during pregnancy
• How TMS compares to antidepressants for pregnant patients with depression
• Postpartum considerations including breastfeeding compatibility

What We Know About TMS Safety in Pregnancy

TMS is classified as pregnancy category B by the FDA — the same classification as most SSRIs — meaning that animal studies have shown no fetal risk, but adequate human studies have not been conducted. This is not unique to TMS; virtually no psychiatric treatment has robust pregnancy safety data from randomized trials (for obvious ethical reasons).

The available evidence comes from three sources:

Pregnancy registries and observational studies have followed women who received TMS during pregnancy. To date, no study has found an increased risk of adverse pregnancy outcomes — miscarriage, preterm birth, fetal growth restriction, or major congenital malformations — associated with TMS exposure.

Case series have documented successful TMS treatment in pregnant patients with severe depression, with no reported fetal complications. These are not controlled data, but they add to the safety picture.

Mechanistic reasoning. TMS produces localized effects in the brain with essentially no systemic absorption. The magnetic field dissipates rapidly and does not penetrate to abdominal structures. There is no plausible mechanism by which TMS could affect a fetus in the womb.

The theoretical concern most often raised is the potential for induced uterine contractions from the magnetic field. This concern has not been substantiated in practice — no study has reported increased uterine activity or preterm labor in patients receiving TMS during pregnancy.

Clinical Practice Guidelines

The FDA labeling for TMS does not include pregnancy as a contraindication, though it notes that adequate data in pregnant women is lacking. Major professional organizations have taken the following positions:

The American College of Obstetricians and Gynecologists (ACOG) notes that TMS is a reasonable option for pregnant patients with depression who have not responded to psychotherapy, acknowledging the limitations of antidepressant medication during pregnancy.

The Clinical TMS Society recommends that TMS be considered a first-line option for treatment-resistant depression in pregnant patients, given its safety profile and absence of systemic exposure.

The Postpartum Support International guidelines for perinatal depression list TMS as an evidence-based option for patients who cannot take medications or have not responded to other treatments.

Practical Considerations During Pregnancy

If you are pregnant and considering TMS, discuss the following with your treatment team:

Timing of sessions. Some clinicians prefer to delay elective TMS until after the first trimester when major organogenesis is complete. Others proceed without delay, given the lack of mechanistic risk. Discuss your preferences with your doctor.

Positioning. As pregnancy progresses, lying flat on your stomach (even with a coil access opening) becomes less comfortable and may be contraindicated for some patients in later pregnancy due to vena cava compression. Most TMS clinics can accommodate pregnancy with modified positioning after the first trimester.

Anxiety reduction. Pregnancy often brings anxiety about every exposure, medication, and activity. It is normal and reasonable to have questions. Ask your TMS clinician to walk you through their specific experience with pregnant patients and their approach to safety questions.

Concurrent therapy. Most pregnant patients receiving TMS also participate in psychotherapy — particularly interpersonal therapy or cognitive behavioral therapy, which have good evidence in perinatal depression. TMS can complement therapy without replacing it.

TMS vs. Medication During Pregnancy

The risk-benefit calculation for antidepressants during pregnancy is genuinely complex. SSRIs, particularly paroxetine, carry some increased risk. The absolute risks in most studies are small, but they are real. For patients with severe depression who need treatment, this creates genuine tension.

TMS offers a way to treat depression without these concerns. For pregnant patients who have failed psychotherapy alone, TMS is a reasonable escalation option.

That said, TMS during pregnancy is not trivial. It requires daily clinic visits for weeks. For patients in the third trimester, logistical challenges increase as pregnancy progresses. Some patients choose to defer TMS until after delivery if the depression is not severe enough to warrant treatment during pregnancy.

Postpartum Considerations

Postpartum depression is common and often severe. TMS is increasingly used in the postpartum period, including in breastfeeding patients. Because TMS is not a medication, there is no concern about drug exposure through breast milk. This is a meaningful advantage over antidepressant medications, which require careful evaluation of breastfeeding compatibility.

Postpartum TMS often involves scheduling that accommodates infant care — early morning sessions before the baby wakes, or scheduling around feeding times. Many clinics are flexible with postpartum patients.

What to Discuss With Your OB/GYN

Before starting TMS during pregnancy, have a conversation with your obstetrician. Key points to cover:

• Your current depression severity and treatment history
• Whether you are already on medications (which may be continued or tapered depending on the situation)
• Any obstetric risk factors that might affect the decision
• The TMS clinic’s experience with pregnant patients
• Your preferences and concerns

Most obstetricians will support TMS for a pregnant patient with treatment-resistant depression, but they should be informed and on board. Good care is coordinated care.

The Bottom Line

TMS is considered one of the safest options for treating depression during pregnancy. The mechanistic rationale for safety is strong, and the observational data available to date has not shown harm.

For pregnant patients with moderate to severe depression who have not responded to psychotherapy and are considering medication, TMS is a reasonable option to discuss with your treatment team. The absence of systemic exposure is a genuine advantage when carrying a pregnancy.

The decision should be made individually, weighing the severity of depression, the patient’s preferences, and the clinical context. But TMS should be on the table — not as experimental, but as one of the more evidence-based options available.