Does COVID-19 change sperm shape? The evidence suggests the share of normal-shaped sperm dropped during the pandemic years, but this study does not show that COVID-19 infection itself caused it. A 2026 study of 90,125 men at one reproductive medicine center in Chongqing, China, found that the share with at least 4% normal-shaped sperm fell from 88.9% before the pandemic to 55.1% in 2024.
Normal sperm shape dropped in every period after the pandemic began
The study is a Basic and Clinical Andrology paper, published 26 March 2026. It looked at infertility clinic patients from 2017 through 2024, split into a pre-pandemic period, a pandemic period, and two post-pandemic periods. Each drop in the table was statistically significant at p < 0.001.
| Period | Share with at least 4% normal forms |
|---|---|
| 2017 to 2019, before the pandemic | 88.9% |
| January 1, 2020 to December 7, 2022, during the pandemic | 72.7% |
| December 8, 2022 to 2023, first post-pandemic phase | 62.4% |
| 2024, second post-pandemic phase | 55.1% |
The typical result did not move. The median stayed at 4% in every period. What changed is the spread. The middle half of results narrowed from 4 to 6% before the pandemic to 3 to 4% in the later periods, and more results sat below the line. By 2024, 44.9% fell below 4%, up from 11.1% before the pandemic.
A 4% normal-shape result is the cutoff on a semen analysis
On a semen analysis, sperm shape is called morphology. The MedlinePlus semen analysis page says over 4% of your sperm should have a normal shape, and that sperm with abnormal shapes may not be able to fertilize an egg. The study counts a result at or above 4% as meeting the cutoff.
MedlinePlus also says that if your results aren’t all normal, it doesn’t mean you’re permanently infertile.
The shape drop is large, and testosterone moved only a little
The authors cite earlier longitudinal studies that link each one-percentage-point drop in normal forms to a 5 to 10% lower rate of natural conception. This study did not measure conception.
Hormones moved too:
- Testosterone (a male sex hormone) had a median of 4.46 ng/mL before the pandemic and 4.19 ng/mL in 2024, a 6.1% drop (p = 0.006).
- In 2022 to 2023, the median was 4.31 ng/mL (p = 0.011). The change between before the pandemic and during it was not significant (p = 0.591).
- LH (luteinizing hormone) declined, and FSH (follicle-stimulating hormone) stayed stable.
- The median stayed above 3.0 ng/mL, the usual line for biochemical hypogonadism (low testosterone).
This study does not prove COVID-19 caused the change
The study compared time periods, not infected and uninfected men. The authors say that design cannot separate the direct effects of infection from stress, lifestyle changes or disrupted health care. Keep these limits in mind:
- It describes men already attending an infertility clinic. It does not describe men in general.
- It comes from one regional center in China, so it may not apply to fertile men or to other places.
- It did not record individual infection status, vaccination history or fever severity.
- Trained staff judge sperm shape, and the authors note variation between observers. The same two technicians did the morphology work throughout.
- It did not measure sperm DNA fragmentation.
Earlier studies of COVID-19 and sperm point in different directions
A 2023 review in the Journal of Assisted Reproduction and Genetics said it is still controversial whether COVID-19-induced fever adversely affects sperm parameters.
A Scientific Reports study reported by EMJ in November 2025 followed 74 men who had pre-infection data and at least three post-recovery tests. Sperm concentration and progressive motility fell one month after infection. Gradual improvement followed at two and three months, but quality had not fully returned to baseline after six months. Statistical modelling estimated median recovery of about five months for concentration and about three months for progressive motility. EMJ’s headline calls the effect temporary, and says most men recover within three to five months.
A repeat semen analysis and a clinician visit are the next steps
Sperm count and quality can vary from day to day, so MedlinePlus notes you may need two or more samples within a week or two. Before the sample, you’ll usually avoid sexual activity that ends in ejaculation for 2 to 7 days. Our semen analysis basics guide explains the test.
See a clinician if you and your partner have been trying to conceive for at least 12 months without success, and ask about a semen analysis. Bring any earlier semen results, the timing and severity of any COVID-19 infection, and a list of medicines and supplements you take.
If your concern is watery semen, the watery sperm and pregnancy guide covers that question.
By ReproductiveHealthCtr.com Health Education Team