Swimming: Pools and Open Water
Verdict: Go swim. Pool and ocean swimming has no negative effect on fertility for either partner. Chlorine at standard pool concentrations does not affect sperm, eggs, or hormones. Saltwater is equally fine. Swimming is actually one of the best exercises for TTC — low-impact, cardiovascular, and stress-reducing.
The only real concern is pool chemicals for people with very sensitive skin or vaginal flora — prolonged time in heavily chlorinated water can occasionally disrupt vaginal pH and trigger yeast infections. The fix: rinse off after swimming and change out of wet swimsuits promptly.
Hot Tubs: The One Real Concern
For him: Avoid prolonged use. Hot tubs (typically 100–104°F) raise scrotal temperature well above the 93–95°F range that spermatogenesis requires. A 2007 UC San Francisco study found that men who used hot tubs for 30+ minutes weekly had measurably lower sperm counts and motility. The damage was reversible — sperm parameters recovered within 3–6 months of stopping.
For her: Low concern. The uterus and ovaries are insulated by the body, and brief hot tub exposure doesn’t raise core temperature enough to affect egg quality or implantation. The concern during early pregnancy (post-implantation) is that sustained core temperature elevation above 101°F may increase neural tube defect risk — but this applies to prolonged exposure, not a quick dip.
Him: Skip hot tubs entirely, or limit to brief dips (under 10 minutes, not submerging the groin area). Her: Fine in moderation (15–20 minutes). During the TWW, err on the side of caution — warm baths over hot tubs. Both: Stay hydrated. The combination of heat + dehydration is worse than either alone.
Saunas and Steam Rooms
For him: Same concern as hot tubs. Dry saunas at 170–190°F raise scrotal temperature significantly. Finnish studies (where sauna use is nearly universal) show temporary sperm quality reduction with frequent use. Limit sessions and take cold showers between rounds. For her: Brief sauna use (10–15 minutes) is generally considered safe during TTC. Avoid during the TWW if you’re being cautious.
Water Parks and Lazy Rivers
No concerns at all. These are chlorinated pools at normal temperatures. Enjoy them without a second thought. The biggest risk is sunburn — use mineral sunscreen and reapply after swimming.
Lake and River Swimming
No fertility concerns. The water temperature in natural bodies of water is well below the threshold for sperm damage. If anything, cooler water may provide a minor benefit. Just follow standard safety: avoid swallowing water in areas with known contamination, and be aware of current conditions.
The Sunscreen Question
Spending time in the sun means wearing sunscreen — but not all sunscreens are created equal for TTC. Chemical sunscreens containing oxybenzone, octinoxate, and homosalate are established endocrine disruptors. Mineral sunscreens (zinc oxide and/or titanium dioxide) provide the same UV protection without hormonal concerns.
Our full guide: Sunscreen and Fertility: Are Endocrine Disruptors in Your SPF?
Summer Gear for TTC
- Mineral sunscreen (zinc oxide) →
- Loose-fit swim trunks for him → (better thermal regulation than compression-fit)
- Insulated water bottle → (stay hydrated in the heat)
The Full Summer TTC Guide
Our checklist covers every summer-specific consideration for TTC — from sunscreen to supplements to seasonal nutrition.
Summer TTC Checklist →