If you’re pregnant and feel like mosquitoes have declared open season on you, you’re not imagining it. The direct answer to do mosquitoes bite pregnant women more is yes: a landmark study published in The Lancet in 2000 found that pregnant women attracted roughly twice as many malaria mosquitoes as non-pregnant women — and newer research continues to support the connection between pregnancy, body chemistry, and mosquito attraction.
That matters beyond itchiness. Mosquito-borne illnesses like Zika and West Nile virus carry real risks during pregnancy, so understanding why you’re a bigger target — and how to protect yourself — is genuinely useful. This article walks through the research, the biological reasons, and practical protection strategies. One important note up front: this article gives general information only and no product dosing recommendations — always talk to your doctor first about which repellents are right for your pregnancy.
The Landmark Finding: Twice as Many Bites
The study most people cite comes from researcher Steve Lindsay and colleagues, working in Gambia and published in The Lancet in 2000. They compared how many mosquitoes from the Anopheles gambiae complex — the mosquitoes that spread malaria in Africa — were attracted to pregnant versus non-pregnant women. The result: pregnant women drew about twice the number of mosquitoes.
Two physiological differences explained most of the effect. First, women in late pregnancy exhaled about 21% more air volume than non-pregnant women, and mosquitoes are exquisitely tuned to carbon dioxide — it’s one of the primary signals they use to locate a host from a distance. Second, pregnant women’s abdomens ran about 0.7°C warmer than normal, and warmer skin releases more of the volatile compounds (like lactic acid) that mosquitoes find attractive.
This wasn’t a one-off curiosity. The finding has been referenced and built upon for over two decades, and it carries particular weight for public health: in regions where mosquitoes spread malaria, pregnant women are already a high-risk group, and doubled bite exposure compounds that risk. In the US, where Zika and West Nile are the headline concerns, the takeaway is the same — pregnancy appears to genuinely increase your mosquito appeal.
New Research: Hormones, Odor, and the Menstrual Cycle
A 2026 study from the Swedish University of Agricultural Sciences, published in the journal iScience, added a new layer. Researchers exposed yellow fever mosquitoes (Aedes aegypti) to odor samples from 42 women and analyzed which chemical compounds the mosquitoes’ antennae responded to. The results showed mosquito attraction was influenced both by where the women were in their menstrual cycle and by pregnancy — and one compound stood out: octenol (sometimes called “mushroom alcohol”), found at higher levels in people mosquitoes preferred.
This fits a growing picture: human attractiveness to mosquitoes isn’t fixed — it shifts with physiology. A separate line of research on the menstrual cycle has found that mosquito landing rates and repellent protection times vary across cycle phases, with higher attraction during ovulation when estrogen peaks. The proposed mechanisms overlap with pregnancy: fluctuating hormones change body odor, skin chemistry, and body temperature, all of which feed into the scent signature mosquitoes read.
Taken together, the research story is coherent: pregnancy changes how much CO2 you exhale, how warm your skin runs, and the chemical profile of your odor — and mosquitoes, which hunt primarily by smell and heat, notice all three. No single study is the final word, but the direction of the evidence has been consistent for 25 years.
It is also worth noting what the research does not say. Blood type, often cited in popular articles, has shown mixed results across studies and is a much weaker factor than the pregnancy-related changes above. And “sweet blood” is a myth — mosquitoes are tracking exhaled gases, heat, and specific odor molecules, not sugar content. Focusing on the proven drivers (CO2, warmth, odor chemistry) is more useful than chasing folk explanations.
Why Pregnancy Makes You a Mosquito Magnet
Pulling the mechanisms together, here is what researchers believe is happening:
More carbon dioxide. Mosquitoes detect CO2 from dozens of feet away and use it as a long-range homing beacon. Late-pregnancy physiology increases breathing volume substantially — the frequently cited figure is about 21% more exhaled air — giving mosquitoes a stronger signal to follow.
Warmer skin. The roughly 0.7°C increase in abdominal temperature (about 1.26°F) may sound trivial, but mosquitoes are sensitive heat-seekers at close range. Warmer skin also volatilizes more skin chemicals, amplifying the odor signal.
Changed body odor. Pregnancy shifts hormones dramatically, and hormones influence the volatile compounds released through skin and sweat — lactic acid, octenol, and hundreds of other compounds that make up your personal scent signature. The 2026 Swedish study’s identification of octenol as a key attractant is one piece of this puzzle.
More exposed skin and outdoor time. This one is behavioral, not biological: warmer months, maternity clothing, and simply spending more time resting outdoors can all increase bite opportunities. It doesn’t explain the lab findings, but it matters in real life.
None of this means you’re doing anything wrong — it’s physiology, not hygiene or habits. But it does mean protection deserves extra attention during pregnancy.
Why It Matters More During Pregnancy
For most adults, a mosquito bite is an itchy nuisance. During pregnancy, the stakes include mosquito-borne diseases with documented pregnancy risks:
- Zika virus is the most serious concern: infection during pregnancy can cause microcephaly and other severe birth defects. Zika transmission in the continental US has been limited, but travel to affected regions makes this a real consideration — discuss travel plans with your doctor.
- West Nile virus circulates in the US every summer. Most infections are mild, but severe cases occur, and pregnancy warrants extra caution.
- Dengue and chikungunya are concerns primarily with travel, but their ranges are expanding.
The practical implication: bite prevention during pregnancy isn’t cosmetic — it’s a genuine health measure. That framing is also why repellent choice deserves a conversation with your clinician rather than a guess at the pharmacy shelf.
Protection Strategies During Pregnancy
General, evidence-aligned strategies — with the standing caveat to talk to your doctor first about specific products:
- Use an EPA-registered repellent. Public health agencies, including the CDC, have stated that EPA-registered repellents — including those with DEET, picaridin, IR3535, and oil of lemon eucalyptus — are considered appropriate for use during pregnancy when used as directed. Which one suits your pregnancy is a question for your clinician, not this article.
- Dress defensively. Long sleeves, long pants, and light-colored clothing (mosquitoes are drawn to dark colors) reduce exposed skin. Treating clothing per label directions adds another layer.
- Mind timing and place. Mosquitoes are most active at dusk and dawn and breed in standing water, so source reduction around your home pays off.
- Use screens and nets. Keep windows screened, repair tears, and consider a bed net when traveling in high-risk areas.
- Add a fan outdoors. Mosquitoes are weak fliers; a breeze across your seating area genuinely reduces landings.
What to skip: unproven “natural” hacks as your primary defense. If you’re curious about the viral coffee-grounds trend: the smoke — not coffee — is doing the work, and it’s a weak strategy when the stakes are higher.
For treating bites that do happen during pregnancy, see our guide on insect repellent safety for children and during pregnancy.
When to See a Doctor for a Bug Bite
During pregnancy, be quicker to call your clinician than you otherwise would:
- Fever, headache, body aches, or rash in the days after mosquito bites — mention the bite exposure explicitly, especially after travel.
- Any bite that shows infection signs: spreading redness, increasing pain or warmth after 48 hours, pus, or red streaks. See our guide on bug-bite infection, cellulitis, and antibiotics.
- Signs of allergic reaction: large swelling, hives, trouble breathing — call 911 for breathing difficulty.
- If you’ve traveled to a Zika-affected area, discuss testing and monitoring with your doctor even without symptoms.
Frequently Asked Questions
Do mosquitoes really bite pregnant women more?
Yes — the best-known study (The Lancet, 2000, Gambia) found pregnant women attracted about twice as many malaria mosquitoes as non-pregnant women, likely due to ~21% more exhaled CO2 and ~0.7°C warmer abdominal skin. A 2026 Swedish study in iScience further linked pregnancy and menstrual-cycle phase to mosquito attraction via body-odor chemistry.
Why are mosquitoes more attracted to pregnant women?
The leading explanations: more exhaled carbon dioxide (mosquitoes’ long-range homing signal), slightly warmer skin (a close-range attractant that also releases more odor compounds), and hormone-driven changes in body odor, including compounds like octenol identified in recent research.
Is it safe to use mosquito repellent while pregnant?
Public health agencies consider EPA-registered repellents appropriate during pregnancy when used as directed — but which product is right for your specific pregnancy is a decision to make with your doctor. This article doesn’t recommend doses or specific products; bring the question to your next prenatal visit.
Does the increased attraction apply to all mosquito species?
The landmark 2x finding involved Anopheles malaria mosquitoes in Africa. The 2026 Swedish study used Aedes aegypti (yellow fever mosquitoes). Different species use slightly different cues, so the magnitude may vary — but the overall pattern of increased attraction during pregnancy has held across studies.
I’m pregnant and got bitten a lot — should I worry?
Most bites are just itchy. But during pregnancy, it’s worth mentioning heavy bite exposure to your clinician — especially if you develop fever, headache, body aches, or rash afterward, or if you’ve traveled to areas with Zika, dengue, or chikungunya. When in doubt, call.
I’m pregnant — should I avoid travel to areas with Zika or dengue?
Talk to your doctor before booking. Public health agencies advise pregnant people to weigh travel to Zika-affected areas carefully and take strict bite-prevention measures if travel is unavoidable. If you’ve already traveled somewhere with Zika, dengue, or chikungunya, tell your prenatal provider even if you feel fine — testing and monitoring decisions are individualized, so bring the question to a clinician rather than guessing.
Medically reviewed by Dr. Sarah Jones, MD.
This article is for informational purposes only and isn’t medical advice. If you’re worried about a bite or sting, talk to a healthcare professional.
