At three months after a caesarean, one study found 64.3% of women had a hypertrophic scar. Raised, firm, often itchy or tender.
That number sounds alarming until you follow the same women forward. At six months it was 56.6%. At one year it was 35.3%.
So roughly two thirds of the scars that look bad at three months are no longer classified that way by twelve. The scar you are looking at eight weeks post-op is not the scar you will have, and a great many women make expensive decisions during a window when the tissue was going to settle on its own.
About one in three does not settle. That is who the rest of this is for.
What Hypertrophic, And How It Differs From a Keloid
Hypertrophic scar: raised, firm, sometimes red or itchy, but it stays within the boundaries of the original incision.
Keloid: grows beyond the original wound edges into surrounding skin, and behaves more like a benign growth than a scar.
Caesarean scars go hypertrophic far more often than they go keloid. In the study above, following that whole cohort for a year, no keloids were seen at all.
That distinction matters because the treatments diverge. Hypertrophic scars respond to pressure, moisture and time. Keloids frequently need steroid injection or specialist input, and they recur.
The Incision Type is The Single Biggest Risk Factor, By An Enormous Margin
This is the finding that dwarfs everything else in the literature.
A midline vertical incision carries an odds ratio of 20.53 for hypertrophic scarring compared with a transverse incision, with a confidence interval running from 4.18 to 100.92.
Twenty times the odds. Not twenty percent higher.
Most planned caesareans use a low transverse incision, partly for this reason among several others. Vertical incisions are generally reserved for emergencies, certain placental positions, or specific surgical circumstances, which means the women at highest risk are often the ones who had the least say in it.
If you had a vertical incision, you are in a different risk category and it is worth saying so to whoever is managing your follow-up.
Other Factors That Turned Up in The Same Cohort
Slightly counterintuitive, some of these.
- Patients whose skin tans easily showed more hypertrophic scarring.
- Non-smokers showed more than smokers.
- Patients with allergies showed more.
That smoking finding is genuinely odd and I would not read anything actionable into it. Smoking impairs wound healing on nearly every other measure, and one cohort showing less hypertrophic scarring is not a reason to do anything differently.
What The Dressing Trials Show, Honestly
Here is where I have to be careful, because this area is full of confident marketing sitting on top of mediocre evidence.
Hydrocolloid dressings, caesarean-specific. A study applying hydrocolloid dressings to caesarean wounds found a relative risk of 0.623 for hypertrophic scarring, with a confidence interval of 0.417 to 0.930. The authors concluded that hydrocolloid dressings reduce the risk. Applied to a baseline around 35%, that lands you somewhere near 22%.
Silicone gel sheeting. More studied, and the picture is messier than the marketing suggests. A pooled analysis of ten trials found a relative risk of 0.70, confidence interval 0.49 to 0.99, statistically significant at P = 0.04. In people specifically prone to scarring, Cochrane found RR 0.46, confidence interval 0.21 to 0.98.
Individual trials swing widely. Signorini reported RR 0.25. De Giorgi reported 0.50. Cruz-Korchin reported 0.45. And Niessen reported a result favouring the control group at RR 2.71.
Paper tape. Atkinson randomised 70 patients to three months of tape fixation or no treatment, working on the theory that reducing tension across the incision reduces the fibrotic response.
The Caveat The Product Pages Leave Out
Cochrane’s own conclusion on silicone gel sheeting reads: weak evidence of benefit as prevention in high-risk individuals, with the poor quality of the research meaning a great deal of uncertainty prevails.
The pooled analysis had heterogeneity of I² = 88%, which is very high. It means the trials disagree with each other substantially, and a pooled average across studies that disagree that much should be held loosely.
So the honest summary is that these dressings probably help, the effect is real but modest, the confidence intervals brush against 1.0 in several analyses, and anyone quoting you a precise percentage reduction is quoting one trial rather than the body of evidence.
That is still a reasonable basis for using them. Silicone sheeting is cheap, non-invasive, and the main downside in the trials was skin irritation. It is just not the guaranteed intervention it gets sold as.
Practical Points That Matter More Than Product Choice
Wait for the wound to close completely. Silicone goes on intact, healed skin. Not on an open or weeping incision.
Consistency beats product. The trials that show benefit run these dressings for months, not weeks, often 12 hours a day or more. A packet used sporadically for a fortnight is not what was tested.
Protect it from sun. UV exposure on new scar tissue drives hyperpigmentation, and a caesarean scar sits exactly where a swimsuit line does not always cover it.
Reduce tension where you can. The theory behind taping is mechanical, and it is also why heavy lifting restrictions after surgery are about more than pain.
Give it a year before deciding. That 64% to 35% curve is the whole argument for patience. Laser, steroid injection and revision are all options that remain available in twelve months and are much harder to undo.
When To Get it Look at Rather Than Waiting
Some things are not scar maturation.
Increasing pain rather than decreasing. Redness spreading outward, warmth, or any discharge, which points at infection rather than scarring. A scar growing beyond the original incision line, which suggests keloid rather than hypertrophic and needs different management. Or a scar that is genuinely restricting movement.
Also worth mentioning to your GP or obstetric team if the appearance is affecting you psychologically. That is a legitimate reason to be referred, it is common after caesarean, and it gets dismissed more often than it should.
A note on the numbers in this article. The 64.3%, 56.6% and 35.3% figures and the vertical incision odds ratio come from a single cohort study and should be read as one dataset rather than a settled consensus. The dressing figures come from separate trials with differing populations and follow-up periods. I could not locate a trial reporting a reduction to precisely 13%, and I would treat any single headline percentage in this field with caution given how much the underlying studies disagree.
Sources
- Cochrane, Silicone gel sheeting for preventing and treating hypertrophic and keloid scars: https://pubmed.ncbi.nlm.nih.gov/24030657/
- Tsai et al., Review of Silicone Gel Sheeting and Silicone Gel for the Prevention of Hypertrophic Scars and Keloids: https://pubmed.ncbi.nlm.nih.gov/28570253/
- Hydrocolloid dressings and hypertrophic scarring after caesarean section, with incision type risk data: https://www.researchgate.net/publication/256845940_Silicon_gel_sheeting_for_preventing_and_treating_hypertrophic_and_keloid_scars
- Cochrane data tables, prevention outcomes by risk group: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD003826.pub3/information
