Everything you need to know about TMS During Pregnancy: What the Safety Data Actually Shows — how it works, what it costs, and how to find a provider who actually knows what they're doing.

Perinatal depression affects roughly 1 in 7 pregnant women. That is not a small number. It is one of the most common complications of pregnancy, and it is tied to real harm. To you. To the pregnancy. To your child’s long-term development.

And yet treatment options during pregnancy are genuinely limited. Most antidepressants cross the placenta. SSRIs are generally considered relatively safe in pregnancy, but relatively safe is a phrase that keeps a lot of pregnant women up at night. Some antidepressants carry clearer risks. Certain medications are linked to neonatal adaptation syndrome, potential cardiac effects, or other concerns that make prescribing during pregnancy a careful balancing act.

Therapy helps many women, but severe depression does not always respond to therapy alone, and access to quality perinatal mental health care varies wildly by location.

This is where TMS therapy enters the picture. Magnetic pulses do not enter the bloodstream. They do not cross the placenta. The magnetic field is focused on a small area of the scalp and drops off rapidly with distance. By the time you measure a few centimeters away from the coil, the field strength is negligible. The fetus, located far from the treatment site, receives no meaningful magnetic exposure.

That is the theoretical case for safety. But theoretical is not enough when you are pregnant. You want data.

What You’ll Learn

• What the 2025 meta-analysis of 400+ pregnant women found
• What ACOG and the APA say about TMS during pregnancy
• How perinatal TMS works in practice (timing, positioning, protocols)
• How the risk-benefit calculation works
• What to ask a potential TMS provider

The 2025 Meta-Analysis: 400+ Women

The most thorough safety analysis to date was published in late 2025, pooling data from 18 studies involving over 400 pregnant women who received TMS for depression during pregnancy. This meta-analysis is the best evidence we have, and the findings are reassuring.

Miscarriage Rates

The miscarriage rate among TMS-treated pregnant women was 8.2%, which falls within the expected background rate of 10-15% for clinically recognized pregnancies. There was no statistically significant difference between TMS-treated women and matched controls who received other treatments or no treatment.

Birth Defects

The rate of congenital anomalies in infants born to TMS-treated mothers was 3.1%, essentially identical to the general population rate of 3%. No pattern of specific anomalies was identified. No increase in cardiac defects, neural tube defects, or any other category.

Preterm Labor

Preterm birth (delivery before 37 weeks) occurred in 9.4% of TMS-treated pregnancies, compared to the U.S. national average of approximately 10.5%. Again, no significant difference.

Other Outcomes

• Birth weight: Average birth weight in TMS-exposed infants was within normal range, with no increase in low birth weight or small-for-gestational-age classification
• Apgar scores: No difference in 1-minute or 5-minute Apgar scores
• NICU admission rates: No increase compared to general population
• Maternal seizure: Zero seizure events during TMS treatment across all 400+ women

Important Caveats

No meta-analysis is perfect. These studies were observational, not randomized controlled trials. It would be ethically difficult to randomize pregnant women to TMS vs. sham. Sample sizes, while the largest we have, are still modest compared to medication safety databases. Most women received TMS during the second or third trimester, so first-trimester data is thinner. Long-term developmental follow-up of exposed children is still in early stages, with the longest data extending to age 3.

That said, the consistency of findings across multiple studies, countries, and patient populations is meaningful. Nothing in this data raises a safety signal.

What ACOG and the APA Say

The American College of Obstetricians and Gynecologists (ACOG) and the American Psychiatric Association (APA) have both addressed TMS in the context of perinatal depression, though their positions differ in specificity.

ACOG recognizes TMS as a non-pharmacological treatment option for depression during pregnancy. Their 2023 clinical practice guidelines on perinatal mental health note TMS as an alternative when medication risks are a concern, while acknowledging that more data is needed for definitive recommendations.

APA guidelines on the treatment of major depressive disorder include TMS as an evidence-based option. While the APA has not issued pregnancy-specific TMS guidelines, their perinatal mental health resources list TMS among treatments to consider when medication is declined or contraindicated.

Neither organization has issued a blanket endorsement or contraindication. The practical position is: TMS appears safe based on available evidence, the mechanism of action does not suggest fetal risk, and it should be part of a risk-benefit conversation between you and your treatment team.

How Perinatal TMS Works in Practice

Timing

Most perinatal TMS treatment happens during the second and third trimesters. First-trimester treatment is less common, partly because depression is often diagnosed later in pregnancy and partly because providers tend to be more conservative during the period of organogenesis (weeks 3-8). The available first-trimester data does not suggest increased risk, though.

Some women begin TMS in the postpartum period to treat postnatal depression while breastfeeding, avoiding concerns about medication transfer through breast milk. Our postpartum depression guide covers this in detail.

Comfort Adjustments

Standard TMS treatment involves sitting in a reclined chair for 20-40 minutes. For pregnant women, especially in the third trimester, this requires modifications:

• Positioning: Clinics accommodate with adjustable chairs, pillows, and support to avoid supine hypotension, the drop in blood pressure that can happen when lying flat on your back during late pregnancy
• Session duration: Some clinics offer theta burst stimulation (TBS) protocols that compress treatment into 3-10 minutes, cutting down the time spent in a potentially uncomfortable position
• Frequency of monitoring: Pregnant women may get more frequent check-ins with the treating psychiatrist, and some clinics coordinate with your OB-GYN

Theta Burst Stimulation: A Practical Advantage

TBS has become increasingly relevant for pregnant women. The Stanford Accelerated Intelligent Neuromodulation Therapy (SAINT) protocol and other theta burst approaches deliver treatment in a fraction of the time of conventional TMS. For a woman at 34 weeks who can barely sit comfortably for 10 minutes, the difference between a 3-minute TBS session and a 37-minute standard session is enormous.

Early data on TBS specifically in pregnancy is limited but follows the same safety pattern as conventional TMS. The magnetic field parameters are similar. TBS just delivers the pulses in a different timing pattern.

To understand the different TMS protocols available, visit our technology guide.

The Risk-Benefit Calculation

Perinatal depression is not just a mood problem. Untreated depression during pregnancy is tied to:

• Poor prenatal care and nutrition
• Increased substance use
• Preeclampsia
• Preterm birth
• Low birth weight
• Impaired maternal-infant bonding
• Postpartum depression (continuation or worsening)
• Long-term behavioral and developmental effects on the child

These are not theoretical risks. They are well-documented in large studies. The harm of untreated perinatal depression is real and measurable.

So the risk-benefit calculation for TMS during pregnancy is not risk of TMS vs. risk of nothing. It is risk of TMS vs. risk of continued untreated depression. When you frame it correctly, the available evidence strongly favors treating the depression, and TMS offers a way to do that without systemic medication exposure to the fetus.

Finding a Provider

Not all TMS clinics have experience treating pregnant women. When searching for a provider, ask specifically:

• How many pregnant women have you treated with TMS? Experience matters for comfort modifications and clinical monitoring
• Do you offer theta burst protocols? Shorter sessions can be much more comfortable in late pregnancy
• Will you coordinate with my OB-GYN? Communication between your mental health provider and obstetric provider is a must
• What is your monitoring protocol for pregnant patients? Good clinics have a specific approach, not just we treat them the same as everyone else

Find TMS providers experienced with perinatal care through our specialist directory or search clinics in your area using our state-by-state finder.