Overview of Dilation and Curettage
Dilation and curettage (D&C) is a common procedure done in the United States, often performed for either diagnosis or treatment reasons. Sometimes, the process can start as a diagnostic one but end up as a treatment. This surgery might be suggested to women considering an elective termination or those experiencing a missed, incomplete, or unavoidable abortion in the first phase of pregnancy that is less than 14 weeks along. There’s another procedure similar to a D&C, called dilation and evacuation, but that’s usually done when the pregnancy is more than 14 weeks along.
Statistics show that by 45 years of age, about 30% of women will have an abortion, mostly outpatients. In 2013, the most common way to have an abortion was using a method called first-trimester aspiration, which made up 74% of all abortions. However, more recent numbers show that medical abortions now make up about half of all abortions in high-income countries, and about 90% of all abortions are done before 13 weeks of gestation.
A D&C can also be used when evaluating abnormal uterine bleeding. Previously, D&C was the first step in checking this condition, but with technology advancements and new tools, it’s rarely the first course of action now. However, a D&C might still be used if medication isn’t enough to manage irregular uterine bleeding.
The D&C procedure comprises two parts – dilation or opening of the cervix, and curettage, which is the scraping of the endometrial cavity, or the inside of the womb. The tools used in this procedure haven’t changed much from when they were first used in the early 19th century. The first tool to dilate the cervix came out at that time, and the first curette, resembling a small scoop or spoon on a long handle, was invented by Recamier in 1843.
Anatomy and Physiology of Dilation and Curettage
A D&C, or dilation and curettage, is a procedure where tissue is removed from inside the uterus. This is typically done in order to analyze the tissue under a microscope to look for any abnormalities. There is a special type of endometrial sampling, which involves using a small camera to see inside the uterus, but a D&C can also be done if the necessary equipment isn’t available.
To help you understand the procedure, let’s take a quick look at female anatomy. The cervix, which is the lower part of the uterus, can be seen during a medical examination. This part extends into a canal that leads into the uterus. Usually, this canal needs to be widened a bit during a D&C to allow for medical instruments to pass through.
If you’re not pregnant, there are two layers to the inner lining of your uterus. During a D&C, the top layer is removed for analysis. This procedure doesn’t affect ovulation or your menstrual cycle.
If you’re pregnant, the inner lining of your uterus changes into a tissue called decidua. It has three layers of its own. If a D&C is done because of a miscarriage, the doctors need to be careful to only remove the top two layers. If the bottom layer is affected, it could lead to potential complications. The procedure aims to avoid creating any adhesions, which are bands of scar tissue that can cause organs to stick together.
Why do People Need Dilation and Curettage
A D&C, or dilation and curettage, is a medical procedure where doctors dilate the cervix to gain access to the uterus, and then scrape or suction tissue from its lining. This procedure is done for different diagnostic or therapeutic reasons, depending on whether the patient is pregnant or not.
For pregnant women, a D&C might be necessary in several situations. These include: ending a pregnancy voluntarily, resolving an early pregnancy that has failed, treating a molar pregnancy (an abnormal form of pregnancy), or removing leftover tissue after a miscarriage. D&C can also be used to check pregnancy tissues in the uterus if the location of the pregnancy is unknown. The procedure is usually done through manual or electric vacuum aspiration, which sucks out the contents of the uterus.
When a woman is not pregnant, a D&C might be done for several diagnostic reasons. However, many of these have been replaced with a simpler office-based procedure called endometrial biopsy (EMB), which is taking a small sample of tissue from the lining of the uterus. Both procedures can detect cancer equally well, but in some cases, an EMB is not enough. For example, if a patient can’t tolerate an EMB, or if the sample taken isn’t enough for a diagnosis, a D&C may be needed. D&C might also be necessary if the woman has a tight cervix, unusual bleeding that continues, or if she’s bleeding after menopause even though an EMB showed that the uterus is healthy. A D&C can also help rule out uterine cancer if a patient has a precancerous condition of the uterus detected through an EMB.
Therapeutically, a D&C can be useful in nonpregnant women with heavy vaginal bleeding that can’t be controlled with medicines or if the patient’s vital signs are unstable due to severe bleeding. In these situations, a D&C may not fully diagnose the problem with the uterus, but it can reduce the bleeding temporarily.
When a Person Should Avoid Dilation and Curettage
The only reason why a D&C (a procedure to remove tissue from inside your uterus) should be absolutely avoided is if a woman wants to keep her pregnancy.
There are situations that should be considered when deciding if the D&C can be done safely, and whether it should happen in a doctor’s office or a hospital. For instance, patients who have a tendency to bleed excessively, or are taking blood-thinning medication, may require extra attention.
It’s generally safe for a patient taking blood-thinners to have an early abortion, and they’re not likely to bleed any more than if they weren’t taking the medication. However, a doctor must carefully balance the risks of stopping the blood-thinning medication against the possible complications of it.
For those with a deficiency in a protein that helps blood clotting (coagulation factor), they should receive that protein before the procedure.
For patients who are suspected to have a molar pregnancy (a rare condition where the tissue that should become a fetus turns into an abnormal growth in the uterus), the D&C should be performed in a hospital due to risks of complications from anesthesia and heavy bleeding. A planned D&C should be postponed in a patient with a pelvic infection. However, if a patient has an infection in the uterus (septic abortion or endometritis) with possible tissue left in the womb from a pregnancy, the surgeon should empty the uterus immediately.
Equipment used for Dilation and Curettage
Doctors need special tools such as cervical dilators, curettes, and an instrument that creates suction to perform medical procedures on the neck of the womb (cervix).
Dilators
There are 3 main types of dilator tools used by doctors: Pratt dilators, Hank dilators, and Hegar dilators. Each of these tools are used to open up or widen a body part, in this case, the cervix.
Pratt dilators have long, tapered tips to help the doctor use minimal force. Each Pratt dilator is measured in a unit called ‘French’. This unit is equivalent to the diameter of the dilator in millimeters. The French unit divided by roughly 3 (an approximation of Pi) yields the size of the dilator in millimeters.
Hank dilators are very much like Pratt dilators, but they have cuffs. The tip of a Hank dilator is more sharply pointed. Doctors often use the cuff of the Hank dilator to prevent the dilator from going in too far, which could puncture the uterus by accident.
Hegar dilators have blunt ends and are shorter. They come in different sizes, and their sizes increase quickly with each size up. The shortness makes Hegar dilators riskier to use because they require more force. This can potentially puncture the uterus. Patients who are overweight or have a long vagina might not be suitable for the use of the Hegar dilator.
Curettes
Curettes, another type of tool used by doctors, can be made of metal or plastic. A diagnostic procedure called D&C (dilation and curettage) is usually performed using a sharp metal curette. Metal curettes have a long, flexible handle with a tear-drop shaped opening at the tip. These tools are available in many sizes. Sometimes a curette with teeth is used for tougher tissue sampling from the lining of the uterus in postmenopausal patients.
Plastic curettes, also known as cannulas, are used more frequently in pregnant patients. These tools can be straight or curved, rigid or flexible. During an abortion procedure in the first three months of pregnancy, a cannula between 7 and 12 millimeters is usually enough. Rigid plastic cannulas can be a bit more difficult to place. For example, if the doctor is using a Pratt dilator alongside an 8 mm cannula, they should enlarge the cervical canal just enough to fit the cannula comfortably.
Aspirators
The aspirators used by doctors are either electric or manual vacuum aspirators. The electric aspirators work by creating a suction force to quickly and efficiently clear the uterus and decrease bleeding. However, these machines can be noisy, which could potentially cause anxiety in the patient. The manual vacuum aspirator on the other hand is a handheld device with a large attached syringe to create suction. While these can be very effective when used in the clinic, they tend to prolong the duration of the procedure as multiple attempts may be needed.
Who is needed to perform Dilation and Curettage?
A simple procedure like using a manual or electric vacuum aspiration can be done by an experienced professional with the help of one assistant. The assistant’s job could be gathering the materials vacuumed out or help with the ultrasound, if needed. Even though a skilled professional can do this on their own, it’s still important for another person to be present to oversee everything due to the examination’s nature.
If the patient needs to be put to sleep (general anesthetic) or have intravenous (IV) sedation (medicine given through a vein to help you relax or sleep), then a specialist in anesthesia (the medicine that prevents pain during surgery) will be needed.
Preparing for Dilation and Curettage
There are fewer strict rules about preparing the cervix before a D&C, which is a procedure to clear out the uterus, compared to other operations like a D&E. Two common steps that doctors might take to prepare the cervix include using osmotic dilators or chemical ripening agents.
Osmotic dilators, like laminaria and Dilapan-S, gradually expand the cervix by absorbing moisture from it. These need to be placed inside the cervix the day before the operation. On the other hand, chemical ripening agents make the cervix softer or more ready for the procedure. A common medicine used for this is Misoprostol, which is placed in the vagina. It can be given on the same day as the procedure and is a safe and efficient method of preparing the cervix. Another medication called mifepristone is just as effective, but it is often not used because of its high cost and limited availability.
The Society of Family Planning suggests that first-trimester abortions don’t usually require any steps to prepare the cervix, unless there’s an increased risk of complications like cuts in the cervix, inadequate cervix dilation, or damage to the uterus. However, preparing the cervix might be considered for abortions performed between 12 and 14 weeks, or in patients where it may be difficult to dilate the cervix, such as young people or those with a history of cervical conization, which is a surgical treatment where a piece of the cervix is removed.
In order to lower chances of infection after an abortion, the vagina is generally prepared with a disinfectant solution. While there’s some lack of clarity about which solution is the best, there is data showing that using a solution called chlorhexidine can reduce the amount of bacteria in the vagina. However, more research needs to be done to determine if this directly leads to fewer infections.
Administering antibiotics before the procedure has been shown to lower the risk of infection in pregnant patients. However, there’s no evidence that they help in non-pregnant patients, so they’re generally not given to those getting a D&C unless an abortion is being performed. When antibiotics are used, Doxycycline is a safe and effective option.
How is Dilation and Curettage performed
The procedure begins with the patient in a position similar to that of a routine check-up, with feet in stirrups known as the dorsal lithotomy position. The doctor will do a hands-on check (bimanual examination) to determine the size and position of the uterus – the organ where a baby grows in a pregnant woman.
Next, a device is placed in the vagina to allow access. If the patient is getting local anesthesia, then the lower section of the uterus and the cervix (the lower part of the uterus that opens into the vagina) will be numbed, commonly with a 1% lidocaine injection. The doctor uses an instrument to hold onto the front part of the cervix and pulls it towards the lower part of the birth canal. This keeps the uterus still and reduces the risk of puncturing it accidentally.
The doctor then starts dilating, or opening, the cervix using the smallest possible dilator – a medical instrument used for this purpose. The size of the dilator is then increased step by step. The doctor will know when the dilator is correctly positioned by a change in resistance under gentle pressure. The doctor uses the minimum force necessary to move the dilator to minimize risk. The size of the opening required depends on the amount of tissue to be removed and the size of another instrument called a curette.
After the cervix is adequately dilated, the curette – either metal or plastic is inserted into the uterus. Care is taken to avoid any cervical damage during this process. Using the curette, the doctor removes or samples tissues lining the uterus while taking care not to cause damage to the cervix. This is done by moving the curette from the top of the uterus to the bottom, rotating the curette as needed to reach all areas of the uterus.
Successful completion of the procedure is indicated by a gritty texture on the curette, showing that all the necessary tissue or pregnancy has been removed. In cases where bleeding does not appropriately decrease, the doctor may provide treatment with additional procedures such as massaging the uterus with their hands, or by checking with an ultrasound to see if there’s any remaining tissue or injury. Using ultrasound during the procedure is not necessary but can be helpful in certain cases to ensure safety.
Possible Complications of Dilation and Curettage
Undergoing a D&C (Dilation and Curettage), which is a type of procedure mainly used to diagnose and treat certain uterine conditions, overall has a low risk of serious problems or death. This can be compared to the risk of giving birth, which is 14 times higher. Still, the further along a pregnancy is, the higher the chances are of complications occurring.
Issues that could happen after going through a D&C include infection, bleeding, injuries to the cervix, holes in the womb (uterine perforation), and postoperative uterine adhesions. But, these are uncommon. The chances of infection occurring after a D&C are low – between 1% to 2%. To lower this risk further, doctors usually provide pregnant patients with preventative antibiotics. However, they generally don’t recommend giving these to non-pregnant patients as their risk of infection is even lower.
The most common immediate problem after a D&C procedure is a hole forming in the womb. This is more likely to happen at the top of the womb, and certain factors can increase this risk. These include having given birth recently, being of non-childbearing age, giving birth for the first time, and having a tilted womb. The chances of this complication increase as a pregnancy progresses. If this happens, doctors may need to carry out the procedure using a small camera to see directly into the womb. This approach is especially needed if there is heavy bleeding or suspicion of injury to the side wall of the womb.
Injury to the cervix can take place if too much force is applied during the procedure. These injuries can usually be managed using pressure, specific medical applications, or stitching, if necessary. There are also methods to manage any injuries to the inner lining of the cervix. If these methods don’t work, other more specific interventions could be considered.
Heavy bleeding is extremely rare in non-pregnant patients having a D&C. If this happens, it’s most likely because of a tear in the womb or cervix, and it will be managed accordingly. In pregnant patients, heavy bleeding is more common, especially as the pregnancy progresses or just after giving birth. Leftover tissue from pregnancy, a loss of muscle tone in the womb after birth, abnormal placement of the placenta, or injuries can potentially cause heavy bleeding. These will be managed depending on the specific cause.
Last, in very rare cases, adhesions, or scar-like tissues, can form inside the womb after a D&C. This is more likely to happen after a septic (infection-related) abortion. These patients might have symptoms such as fertility problems, menstrual cycle changes or painful periods. For definitive diagnosis, doctors look directly into the womb with a hysteroscope. Depending on the severity of the condition, treatment can be complex.
What Else Should I Know About Dilation and Curettage?
Dilation and curettage (D&C) is a type of surgery that may be an option for both pregnant and non-pregnant persons. If you’re pregnant and want to end the pregnancy, either by choice or necessity, there are both medicine-based and surgical methods available, which are chosen based on how far along the pregnancy is. In such cases, a D&C could be a good option because it can often more quickly and effectively manage bleeding and discomfort compared to medication-induced abortion. While the results of either approach may be similar, the risks versus benefits will depend on each person’s individual health profile and personal wishes.
If you’re not pregnant, a D&C can also be an option, or you may have a procedure called an endometrial biopsy (EMB) alongside an ultrasound, which can help check the lining of the uterus and collect tissue for laboratory examination. The risks and benefits of each method should be discussed with your healthcare provider to decide on the best plan.