The nerve!

Pregnant women are typically advised that they might experience fatigue, morning sickness, heartburn and aches during their 40-week journey.

There’s also a stealth side effect that can sneak up on expecting moms, leaving them with searing pain in their hands, tingling fingertips and weakness in their wrists.

Roughly 31% to 62% of pregnant women suffer from carpal tunnel syndrome. Compare that to the 4% to 5% of the general adult population who develop it.

“Hormonal changes during pregnancy cause increased swelling and inflammation in the tissues around the wrist, which causes compression of the median nerve, causing carpal tunnel symptoms,” Dr. Christopher G. Larsen, an orthopedic surgeon who specializes in hand and upper extremity surgery at Good Samaritan University Hospital, told The Post.

Wrist assured, relief is possible! Two physicians reveal the best strategies for combating carpal tunnel in pregnancy — and the potential risks that can persist even after giving birth.

Inside carpal tunnel syndrome

The median nerve runs from the neck, down the arm, through the forearm and wrist to the hand. The condition occurs when the nerve becomes compressed through the carpal tunnel, the narrow passageway at the base of the wrist.

In pregnancy, increased blood volume, fluid retention and hormones cause swelling that puts pressure on the median nerve.

Carpal tunnel can develop at any point in pregnancy, but it tends to become apparent in the second or third trimester. Some women are shocked when they get it, especially if they didn’t have it in prior pregnancies.

“Some risk factors for pregnancy-related [carpal tunnel] include older maternal age, generalized hand swelling during pregnancy, obesity, gestational diabetes or other pre-existing conditions like hypothyroidism or diabetes,” Dr. Stephen Miranda, director of Peripheral Nerve for the Department of Neurosurgery at the Icahn School of Medicine at Mount Sinai, told The Post.

Beware these classic carpal tunnel symptoms

“Carpal tunnel syndrome typically presents with numbness in the fingers, usually the thumb, index and middle fingers, that is worse at night and can sometimes cause burning pain in the hand that will wake you from sleep,” Larsen said.

Hands down, persistent finger numbness and tingling that resemble pins and needles are key signs of carpal tunnel.

Larsen noted that De Quervain’s tenosynovitis — aka “Mommy thumb” — triggers pain over the thumb side of the wrist that can radiate up the forearm. It doesn’t typically cause numbness.

With carpal tunnel, patients may have difficulty opening jars, turning doorknobs, buttoning their clothes, using their phone or gripping objects.

Symptoms tend to worsen at night because many people bend their wrists as they curl up to sleep.

“Bending the wrist decreases the space in the carpal tunnel for the median nerve, which provokes symptoms,” Larsen explained.

“Also, when you lie down at night, fluid shifts throughout the body,” he added. “Fluid that would normally be in your legs during the day while sitting or standing gets redistributed throughout the body, which tends to increase swelling in the arms compared to during the day.”

And of course, the burning pain and numbness often intensify as pregnancy progresses, especially after 32 weeks.

Larsen suggests seeking medical help if the numbness becomes more prevalent in the daytime.

“Eventually, if the symptoms become severe enough, permanent nerve damage can occur,” he warned.

Carpal diem! Ways to find relief

It’s important to be hands-on with carpal tunnel treatment.

Most anti-inflammatory medications aren’t recommended during pregnancy — they can cause kidney problems in the fetus — so Larsen advises wearing wrist braces at night.

“This is just a brace that keeps the wrist straight to prevent bending it while sleeping,” he said. “The brace should be on just tight enough to not bend the wrist, but putting it on too tight can actually make the symptoms worse.”

Next up, nerve glide exercises. These movements involve making a fist, straightening the fingers while keeping the thumb pressed to the hand, bending the wrist back, extending the thumb outward, rotating the forearm and gently stretching the thumb backward. You can do them with an occupational therapist or at home.

If neither treatment works, you may want to consider steroid shots into the carpal tunnel.

“Local steroid injections are known to be safe during pregnancy because only a small amount of steroid gets absorbed systemically,” Larsen said. “Not only can injections be great for symptom relief, but they can help prevent further progression of the symptoms.”

A light at the end of the tunnel

The good news is that carpal tunnel symptoms often improve dramatically or resolve completely with childbirth.

But severe, prolonged nerve compression that goes untreated can sometimes lead to lasting muscle and hand weakness and persistent numbness.

If symptoms fail to improve with non-surgical treatments, carpal tunnel release may be an option during or after pregnancy.

At Mount Sinai, Miranda performs Thread carpal tunnel release, a minimally invasive, incisionless procedure that involves looping a special surgical thread around the transverse carpal ligament via tiny needle punctures.

The ligament gets divided, easing pressure on the median nerve. At the end of the 10- to 15-minute procedure, the thread is removed and two small bandages are placed over the puncture points.

“The good thing is that there is minimal downtime, without the recovery time needed for incisional healing, so even postpartum, that would be helpful for new mothers,” Miranda said.

“And the procedure can be done with local anesthetic, so sedation or other anesthesia can be avoided, if it needs to be done during pregnancy.”