The newborn check is the moment a lot of parents first hear that something might be off. The midwife or doctor mentions that one testis isn't where it should be, says it'll be looked at again in six weeks, and you're left holding a baby and a slightly worrying piece of information. The honest reassurance: most of these have sorted themselves out by the next check. The honest caution: the ones that haven't need a clear plan, and the timing of that plan really does matter.
Healthbooq (healthbooq.com) covers what gets looked for at the newborn check and what happens if anything is flagged.
What's Actually Happening
In utero, the testes start life up near the kidneys and migrate down through the abdomen, into the inguinal canal, and finally into the scrotum in the last few weeks of pregnancy. That migration is the bit that doesn't always finish.
In term boys, around 2 to 5% have at least one undescended testis at birth. In premature babies, the figure climbs sharply — around 30% in boys born at 30 weeks or earlier, simply because the migration hasn't had time to complete.
After birth, there's a small natural testosterone surge in the first three months that finishes the descent in many of those babies. That's why the 6- to 8-week check matters: it's a real opportunity for the situation to have resolved on its own, without anyone doing anything.
Retractile Is Not Undescended
This distinction is the source of an enormous amount of unnecessary worry, so it's worth spelling out:
- A retractile testis has fully descended at some point, but a normal reflex (the cremasteric reflex) pulls it up into the groin when the baby is cold, anxious, or being examined. Warm the baby up, get him in a warm bath, and the testis sits where it should. A clinician can also gently coax it down without resistance, where it stays — at least for a moment — before springing back up.
- A truly undescended testis can't be brought into the scrotum at all on examination, no matter how warm and relaxed the baby is.
Retractile testes are common, harmless, and almost always settle by puberty as the testes grow bigger and the cremasteric reflex eases off. They don't need surgery, don't reduce fertility, and don't increase cancer risk. If your GP says "retractile, no action needed, recheck at his next routine appointment," that is the right answer.
The Timeline
This is the timeline to keep an eye on:
- Birth (NIPE): both testes documented as in scrotum, or one/both flagged as undescended.
- 6 to 8 weeks: repeat check. Many flagged at birth have descended by now.
- 6 to 9 months: if a testis still isn't down, this is when the referral to paediatric surgery or paediatric urology should be made. Beyond about 6 months, spontaneous descent essentially stops.
- 6 to 18 months: the operation, if needed, ideally happens here.
If you reach 9 months and a testis is still undescended without anyone making the referral, ask. Politely, but ask. The window matters.
Why the Window Matters
Two reasons, both important enough to justify operating on a baby:
Fertility. Sperm production depends on the testis being a couple of degrees cooler than core body temperature, which is why the scrotum hangs where it does. A testis stuck in the inguinal canal or abdomen sits at body temperature and the cells responsible for sperm production gradually lose function. The longer it stays warm, the bigger the hit. Operating before 18 months gives the best preserved fertility outcome; operating at 3, 4, or 5 years gives meaningfully worse numbers.
Cancer risk. Men with a history of cryptorchidism have around three to five times the lifetime risk of testicular cancer compared with men whose testes descended normally. Bringing the testis down doesn't fully erase the increased risk, but it lowers it — and it makes self-examination from adolescence onward actually possible, because the testis is in a place you can feel. That is why every man with this history is taught to check his testes regularly from his teens.
The Operation
Orchidopexy is straightforward in surgical terms: a general anaesthetic, an incision in the groin, the testis is found, gently freed up, and stitched into a small pouch in the scrotum. Day case, 30 to 45 minutes, dissolvable stitches, home the same afternoon. Most babies are back to bouncing around within a week. Pain relief for the first day or two is paracetamol and ibuprofen alternated.
If the testis is intra-abdominal — sitting up inside, not just in the canal — the surgery is laparoscopic and may need two stages a few months apart, because the blood supply has to be coaxed down with the testis.
Occasionally the surgeon finds nothing — a "vanishing testis," which happens when the blood supply twists and dies during fetal development. No further treatment is needed; a silicone prosthesis can be discussed in adolescence if your son ever wants one for cosmetic reasons.
What to Watch For Later
A few things every parent of a boy with cryptorchidism (treated or not) should know:
- Testicular torsion — sudden, severe pain in the groin or scrotum, sometimes with vomiting — is a same-hour emergency in any boy and slightly more common in this group. Straight to A&E, not the GP.
- Hernias in the same groin are slightly more common, both before and after orchidopexy.
- Self-examination from puberty onward. Once a month, in the shower, feel for any new lump or change. Most lumps are not cancer, but the only way to catch the rare ones early is to know what normal feels like.
When to Ask Questions
- Your baby's notes don't make it clear whether both testes were in the scrotum at the newborn check.
- The 6- to 8-week check happened but you weren't told what was found.
- A testis was undescended at the 6- to 8-week check and the 6- to 9-month review hasn't been booked.
- The 9-month review came and went and no surgical referral has been mentioned.
In all of those, a phone call to the GP is the right move — and asking specifically about referral to paediatric surgery is fair game.
Key Takeaways
Around 1 in 25 boys born at term has at least one testis that hasn't reached the scrotum at birth, and the figure is much higher in babies born early. Most descend on their own in the first three months. By six months, what hasn't moved isn't going to — that's when the referral for surgery should start. The aim is to operate between 6 and 18 months because earlier treatment protects fertility and lowers the future cancer risk. Retractile testes — the ones that pop up into the groin when you change a nappy and slide back down when warm — are a different, harmless thing that does not need surgery.
