Climate Change and Pregnancy: The Maternal Health Crisis We Keep Underestimating

How rising heat, toxic air, and unstable environments reshape pregnancy risks and demand a new clinical responsibility.

The American Journal of Obstetrics & Gyecology (AJOG) article “Accelerating Climate Action to Promote Reproductive Health” reviews extensive evidence that climate change affects every dimension of reproductive health: fertility, pregnancy outcomes, fetal development, infectious disease risks, and gynecologic cancer. It emphasizes that pregnant women and their fetuses are particularly vulnerable to extreme heat, air pollution, and climate-driven disasters. The authors argue that ObGyn clinicians are uniquely positioned to lead climate action because the health care sector itself contributes substantially to greenhouse gas emissions. They outline practical interventions at the individual, departmental, and health-system levels to reduce environmental harm while protecting patients. The call is clear: climate change is a reproductive health crisis requiring immediate, coordinated clinical and institutional leadership.

Pregnancy is a physiological stress test. Climate change is making that test harder every year.

We now have robust evidence linking rising temperatures, worsening air quality, and climate-driven disasters with higher rates of miscarriage, preterm birth, stillbirth, fetal anomalies, infections, and long-term child developmental challenges. These are not distant projections. They are happening now, in every community, and the mechanisms are disturbingly straightforward. Heat destabilizes maternal cardiovascular balance. Fine particulate pollution reaches the placenta. Floods and fires interrupt prenatal care, increase infections, and reduce food stability. Climate change has become one of the most powerful, under-addressed determinants of perinatal outcomes.

The Evidence Pregnant Women Cannot Escape

Large epidemiologic studies now link air pollution and ambient heat exposure to spontaneous and medically indicated preterm birth, fetal growth restriction, stillbirth, placental abruption, and congenital anomalies.

Infants exposed in utero to wildfire smoke or particulate matter show higher NICU admission rates and later risks of asthma, impaired cognition, and altered stress reactivity. Even fertility is affected. Heat and pollution reduce ovarian reserve and impair sperm parameters, with downstream effects on IVF success and early pregnancy viability. These findings consistently replicate across settings and populations. The most sobering pattern is disproportionate impact on structurally disadvantaged groups. Climate change magnifies preexisting inequities. Lower-income neighborhoods experience more heat, more pollution, and less access to cooling, clean air, or timely prenatal care. This is environmental injustice translated directly into adverse pregnancy outcomes.

A New Clinical Obligation

Obstetricians have always practiced in a system shaped by biology and society. Climate change adds a new, escalating layer. We cannot counsel a patient on preterm birth prevention and ignore the reality that heat waves alone increase preterm birth risk. We cannot address fetal growth restriction without acknowledging that air pollution is a modifiable driver. We cannot advocate for reproductive justice while ignoring that climate instability disproportionately harms those already bearing the weight of health inequities.

Our ethical obligation is not political. It is clinical. Reproductive health professionals provide care to those most vulnerable to climate-related harm: pregnant women and developing fetuses. That makes climate action part of our professional duty of beneficence.

The Health Care Paradox: We Are Also Part of the Problem

Hospitals account for nearly 10 percent of U.S. commercial energy use. Operating rooms alone account for 30 percent of hospital energy consumption and produce enormous volumes of waste, including single-use devices that generate greenhouse gases across their life cycle. Cesarean delivery has a much larger environmental footprint than vaginal birth. Nitrous oxide used for labor analgesia is nearly 300 times more potent as a greenhouse gas than CO₂. This is the uncomfortable truth: the system tasked with protecting maternal and newborn health simultaneously contributes to environmental conditions that undermine it. This does not mean abandoning essential care. It means redesigning care to reduce avoidable harm.

What Clinicians Can Do Now

The AJOG article outlines micro, mezzo, and macro strategies, and several are immediately actionable.

• Replace disposable specula with metal ones (back to the future).

• Optimize delivery packs to eliminate unused materials.

• Encourage telehealth for appropriate prenatal visits. (add AI!)

• Reduce unnecessary cesareans. (Absolutely!)

• Avoid nitrous oxide where alternatives exist.

• Collaborate with anesthesia colleagues to minimize high-impact agents.

• Educate patients about heat exposure risks during pregnancy and help vulnerable families develop disaster plans.

Individual actions matter, not because they solve the crisis but because they model responsibility and reduce cumulative harm. Every avoided emission protects pregnancies not yet conceived.

The Broader Systems We Must Build

Departments should publicly identify sustainability as part of patient safety. Residency programs must educate trainees on climate-health science. Hospitals must conduct waste audits, invest in energy-efficient infrastructure, and evaluate new technologies through a climate-impact lens. National organizations—including ACOG, ACNM, ASA, AAP, and FIGO—have begun this work, but momentum is uneven and often symbolic. What obstetrics needs now is implementation. Climate preparedness is perinatal preparedness. Health systems that respond early will protect more pregnancies than any single therapeutic invention could.

Reflection

Climate change is not an adjacent issue to obstetrics. It is a defining one. The maternal-fetal dyad is exquisitely sensitive to environmental stressors that are increasing in frequency and intensity. The question for our field is simple. Will we lead, or will we continue to treat climate change as someone else’s domain while our patients absorb the consequences? In an era when reproductive rights and maternal health are already under strain, failing to address climate risk is a choice. The next generation will interpret that choice clearly.