Overview of Dilation and Curettage
A dilation and curettage, or D&C for short, is a common medical procedure done in the United States. It may be performed on a woman who’s pregnant or not pregnant, and can have the goal of either diagnosing a medical condition or treating one. In some cases, what starts out as a procedure to diagnose an issue may turn into one that treats a problem. An example of this is when a woman chooses to end her pregnancy or when there’s a problem with the pregnancy in the first trimester – that is within the first 14 weeks of pregnancy. This patient may opt for a D&C or they may go for medical management.
The latter option becomes a treatment given when the pregnancy is beyond 14 weeks. It’s important to note that roughly 30% of women will have an abortion by the time they are 45 years old; the majority of these procedures are carried out in an outpatient setting.
As of 2013, aspiration procedures, such as a D&C, were the most common treatment used in abortions, accounting for 74% of all cases. This means that D&Cs were used in nearly three out of four abortions during that year. Nonetheless, recent data hints that medical abortions are now equally common in rich countries, and about 90% of all abortions are performed before 13 weeks into the pregnancy.
Besides ending a pregnancy, a D&C may also be done when there’s abnormal bleeding from the uterus. As technology has progressed and new equipment introduced, D&Cs are no longer the first choice for diagnosing this issue. However, the D&C can still be used to treat this type of bleeding when medication isn’t effective.
A D&C procedure involves two steps: first, the cervix is dilated or opened; second, the lining of the uterus, called the endometrial cavity, is scraped or removed. The dilators used to open up the cervix were first introduced in the early 1800s, while the first curette, a tool resembling a small scoop or spoon with a long handle, was invented in 1843 by Recamier. Over the years, the tools used in a D&C have essentially remained the same as the original dilators and curettes.
Anatomy and Physiology of Dilation and Curettage
A D&C, or dilation and curettage, is a procedure where tissue is removed from the lining of the uterus. This procedure usually happens when the patient is not pregnant and the tissue is taken out for examining under a microscope. There are certain procedures preferred for sampling the tissue such as a hysteroscopy. However, in some cases, where certain equipment or resources are not available, a basic D&C might be done to collect tissue for examination.
The cervix, which is the lower part of the uterus that opens into the vagina, can be seen during a speculum examination. There is an opening in the cervix, called the cervical os, that leads into a canal extending to another opening at the top of the cervix. This canal is directly connected to the cavity of the uterus. The openings at both ends of the canal are usually narrower so these may need to be dilated, or expanded, to fit the medical tools used in a D&C.
When a woman is not pregnant, the lining of her uterus, or endometrium, has two layers. The D&C aims to remove one of these layers, known as the stratum functionalis. The removal of this layer doesn’t interfere with the hormones that control the menstrual cycle and doesn’t impact ovulation or future menstrual periods.
On the other hand, during pregnancy, the lining of the uterus transforms into a special tissue called the decidua, which is made up three layers. The implantation of the fertilized egg happens in the decidua basalis and forms what is called the basal plate. When a D&C is done on a pregnant woman to remove the remains of a pregnancy from the uterus, care must be taken to avoid removing tissue deeper than the decidua basalis layer. If any of that particular layer is removed, it could lead to the formation of adhesions, which are bands of scar tissue.
Why do People Need Dilation and Curettage
A Dilation and Curettage (D&C) is a medical procedure that is used for different reasons in pregnant and nonpregnant patients. A D&C involves dilating, or opening, the cervix, and then removing tissue from the uterine lining or womb.
For pregnant patients, D&C might be carried out for elective termination of pregnancy, the failure of an early pregnancy, clearing out of an abnormal type of pregnancy called a molar pregnancy, or if there’s suspicion of retention of pregnancy tissues after a miscarriage. Sometimes, a D&C is also performed to study pregnancy tissues in a scenario where the location of the pregnancy is unknown. This is usually done with vacuum aspiration where a manual or electric pump is used to gently suction out the tissue.
Nonpregnant patients may require D&C for various diagnostic reasons. However, a procedure called endometrial biopsy has replaced many of these uses. An endometrial biopsy involves taking a sample of tissue from the womb’s lining. D&C and endometrial biopsy are both effective in detecting conditions like cancer. However, there are situations where an endometrial biopsy may not be sufficient. A hysteroscope, which is a thin, lighted tube, might be used to examine the womb and followed by D&C although this step isn’t always necessary.
If the patient can’t tolerate an endometrial biopsy or if the biopsy fails to provide a tissue sample suitable for accurate diagnosis, a D&C might be needed. Similarly, patients with a narrow cervix, unresolved abnormal bleeding, or postmenopausal bleeding even after a benign endometrial biopsy might also require a D&C. In patients diagnosed with a non-cancerous condition in the womb lining called endometrial intraepithelial neoplasia, a D&C might be needed to rule out cancer.
D&C can also perform a therapeutic role in nonpregnant patients. For example, in situations where patients experience excessive uterine bleeding that doesn’t improve with medications or causes instability in blood pressure and heart rates, D&C may be performed. While D&C alone might not completely evaluate the issue with the womb in these instances, it usually helps in reducing bleeding temporarily.
When a Person Should Avoid Dilation and Curettage
The only time a D&C (dilation and curettage, a surgical procedure to remove tissue from the uterus) cannot be done is if a woman wants to keep her pregnancy.
There are other conditions that make a D&C less safe, and the doctors will need to decide if the procedure can be done at a regular doctor’s office or should be performed in a surgery center. For example, if a patient has a tendency to bleed excessively or is taking blood-thinning medications it can pose a problem if they are treated outside a surgery center.
Generally, having an abortion in the first three months of pregnancy is considered safe for someone taking blood-thinners and they bleed about as much as non-blood-thinner takers. But, doctors need to balance the risks of stopping these blood thinners against the seriousness of the patient’s condition. Patients with a disease that affects the ability of their blood to clot should have treatment to correct this before the procedure.
If it is suspected that a woman has a molar pregnancy (a rare condition where an abnormal growth forms in the uterus), the D&C should be done in a surgery center so the doctor can better manage potential complications, such as a bad reaction to anesthesia and excessive bleeding. If a woman has an active infection in her pelvic area, it’s safer to delay the D&C unless she has an infected abortion or inflammation of the uterus lining with possibly left-over pregnancy tissue. In that case, the doctor should go on with the evacuation of the uterus.
Equipment used for Dilation and Curettage
Healthcare providers need tools like cervical dilators, curettes, and a manual or machine-based suction device to perform certain procedures.
Dilators
There are 3 common types of dilators: Pratt dilators, Hank dilators, and Hegar dilators. All of these dilators serve a similar purpose but are slightly different in design.
Pratt dilators feature long, gradually slimming tips. This shape allows the doctor to use less force when making an opening. These dilators come in sizes from 9 to 79 French, a measurement related to the diameter of the dilator in millimeters. If you divide the French unit by 3 (an approximate measurement of the mathematical constant Pi), you can get the diameter of the dilator in millimeters.
Hank dilators are similar to Pratt dilators but with a cuff. The tip’s angle of increase is sharper than that of the Pratt dilator. But, there could be a risk of puncturing the uterus with the Pratt dilators. To prevent this, many doctors use the cuff to stop the dilator from going in too far. It’s important to remember that every person’s body is unique, so what works for one may not work for another.
Hegar dilators are short with a blunt end. They come in millimeter sizes and increase in size pretty fast, requiring more force to use. This can lead to a higher risk of puncturing the uterus. Also, for patients who are obese or have a long vagina, Hegar dilators might not work as they may be too short to create an opening in the inner cervical canal.
Curettes
Curettes can be made out of metal or plastic. Doctors usually use a sharp-edged metal curette for a biopsy (cell sample collection). These come in various sizes, depending on the width at the tip. Sometimes, a toothed curette might be used on patients after menopause for thorough tissue sampling from the uterus lining.
For pregnant patients, plastic curettes or tubes (cannulas) are often used. These come in many forms: straight or angled, stiff or bendable. These tubes are sized in millimeters and for first-trimester abortion, tubes between 7 mm and 12 mm are usually enough. If the doctor is using a Pratt dilator, they will dilate only slightly larger than the chosen tube size.
Aspirators
Aspirators can be either electric or hand-held vacuum aspirators. Electric suction devices quickly and efficiently empty the uterus to decrease bleeding. But these machines can be noisy and potentially increase patient anxiety. Hand-held aspirators use a large attached syringe to create suction. They can be very effective in-office, but they might take more time as multiple attempts may be needed.
Who is needed to perform Dilation and Curettage?
For a medical procedure that uses an electric or hand-held suction device, only a skilled medical professional and an assistant are needed. The assistant may collect the material removed by the suction device, or help with ultrasound guidance if the medical professional needs it. Even though one skilled professional can carry out this procedure, another person must always be present to monitor the situation, which is necessary for this type of exam.
If the patient needs to be put to sleep through a drip (IV sedation) or needs a general anesthetic (that puts them in a state of controlled unconsciousness), then a professional specialized in giving anesthesia will be needed.
Preparing for Dilation and Curettage
Preparing the Cervix
For a certain type of womb operation called D&E (Dilation and Evacuation), doctors suggest preparing the cervix, which is the lower part of the womb, in advance. However, for a D&C (Dilation and Curettage), this isn’t always necessary. The cervix can be prepared using either osmotic dilators or chemical agents.
Osmotic dilators, such as laminaria and Dilapan-S, are used to gradually widen the cervix. These are inserted into the cervix and grow bigger as they soak up moisture, gently opening up the cervix. This method requires them to be inserted the day before the procedure.
Chemical agents, also known as prostaglandin analogs or progesterone antagonists, soften the cervix. Misoprostol is a common chemical agent that can be inserted into the vagina on the same day as the procedure. Though mifepristone is just as effective, it is not often used due to its high cost and complexity in obtaining it. Not all patients need to prepare their cervix, especially if they’re undergoing an abortion in the first three months of their pregnancy. Such preparation can be time-consuming and may cause discomfort. However, it may be necessary for patients who may face difficulties, such as teenagers or those who’ve previously had a certain surgical procedure on their cervix.
Preventing Infection
Cleaning the vagina with an antiseptic solution is usually done to lower the risk of getting an infection after an abortion. Although there’s limited evidence to suggest that chlorhexidine or povidone-iodine solutions are much better than saline alone, some studies show that chlorohexidine can reduce the level of bacteria in the vagina.
Taking antibiotics before the surgery can reduce the risk of infection following a surgical abortion in pregnant patients. However, this hasn’t been proven effective in non-pregnant patients undergoing a D&C procedure. Antibiotics are typically not recommended for standard procedures like endometrial biopsies and hysteroscopy performed on non-pregnant patients. Doxycycline, an antibiotic, is considered safe and efficient for preventing infections following surgical abortions and can be used as a single dose or a short course around the time of the surgery.
How is Dilation and Curettage performed
The first step in the procedure involves positioning the patient with their back and legs up, like in childbirth. After this, the doctor checks the size and position of the uterus by performing an examination with both hands.
Once the patient is in the correct position, the doctor will use an instrument, either a bivalve or a weighted speculum, to open up the vagina. If the procedure is being done using local anesthesia, it is then injected into the cervix and bottom part of the uterus. A commonly used anesthesia is 1% lidocaine. The doctor then affixes a device called a tenaculum to the front lip of the cervix to carefully pull it towards the vaginal entrance. This is done to steady the uterus and make it less likely to punch through it during the procedure.
Next, the doctor will use an instrument called a dilator to gently open up the cervix. They start with the smallest size that fits, then move up to larger sizes as needed. The dilator should only be held with two fingers to make sure no harmful pressure is applied. The actual size the dilator needs to be will depend on how much tissue needs to be removed and the chosen size of the curette, a scoop-like instrument.
After the cervix has been sufficiently opened, the curette is inserted into the endocervical canal, which leads into the uterus itself, and then to the top. Once there, a manual or electric vacuum is used to suction the walls of the uterus. The curette is then rotated all the way around while repeating this sweeping motion. The procedure is usually complete when the uterus feels gritty, indicating that all needed tissue has been removed.
If no bleeding is observed despite the gritty texture, it is a sign that the procedure has been successful. But if there is bleeding, other techniques like a bimanual massage might be required. An ultrasound can be used to guide the procedure though it’s not a necessity, especially for patients with irregular uterine shapes or when it’s challenging to dilate the cervix.
Possible Complications of Dilation and Curettage
Dilation and curettage, or D&C, is a procedure that has a low death rate overall. To clarify, for every 100,000 abortions performed by a professional, only about 0.6 people die. This is a lot lower than the risk of dying from giving birth, which is approximately 14 times higher. However, it’s important to note that risks may increase as a pregnancy progresses.
Some complications from a D&C, whether the person is pregnant or not, can include infections, bleeding, tears in the cervix, holes in the uterus, and making the uterus stick together after surgery. However, infections are rare, affecting only about 1-2% of cases. Doctors often suggest using antibiotics in patients who are pregnant to prevent this. In people who aren’t pregnant, infections are even less common and antibiotics aren’t typically necessary.
The most common immediate problem after a D&C is a hole or puncture in the uterus. This is more likely to happen at the top of the uterus, and those at a higher risk may have just given birth, gone through menopause, never been pregnant, or have a tilted uterus. The risk for this is also higher in pregnant patients as the pregnancy progresses. Depending on when it happens during the procedure, it may need to be managed by a laparoscopy. This is where a small camera is inserted to look inside the uterus, especially if there is heavy bleeding or there might be a hole in the uterus wall.
Injuries or tears in the cervix usually happen when too much force is applied during the D&C. Most of these injuries can be treated with pressure, using silver nitrate or ferric subsulfate, or occasionally, tying off the injury with a stitch. If the canal within the cervix is injured, doctors will try to stop the bleeding with pressure or a stitch. If the bleeding doesn’t stop, more advanced procedures like using a balloon to add pressure or blocking the blood flow to the uterus may be necessary, along with further assessment for internal or retroperitoneal (the space at the back of the abdomen) bleeding.
In non-pregnant patients, heavy bleeding after a D&C is very rare. If it does happen, it’s usually due to a puncture in the uterus, or an injury to the cervix which should be treated appropriately. Bleeding is more common in pregnant patients after a D&C, and the risk increases as the pregnancy progresses and after giving birth. Causes for significant bleeding in pregnant or post-birth patients can involve retained tissue, a soft uterus that doesn’t contract properly, abnormal placental attachment, and injuries to the cervix or uterus. Each of these should be managed according to its specific cause.
Over-sticking of the uterus, known as Asherman syndrome, is a very rare complication that can occur after a D&C, especially if a patient has a septic or infection-related abortion. Patients might realise this has happened if they find they struggle to conceive, experience changes in their menstrual cycle, or have painful periods. Such adhesions can be identified through hysteroscopy, a procedure that allows a doctor to look at the uterus. The treatment can be complex, depending on the severity of the condition.
What Else Should I Know About Dilation and Curettage?
Dilation and Curettage, often referred to as D&C, is a type of surgery that can be a suitable option for women who are pregnant and those who are not. For those who are pregnant and wish to have an abortion, whether elective or for any other reason, there are both medical and surgical options available, and the right choice will depend on how far along the pregnancy is. D&C has the advantage of being able to manage bleeding and pain effectively, and it works quicker than a medical abortion. The outcomes are usually similar, but the best choice will depend on the individual woman’s situation and her own wishes.
For women who aren’t pregnant, a D&C can be done, or they can undergo an Endometrial Biopsy, known as an EMB, along with an ultrasound. This helps the doctor examine the inside of the womb and take a small tissue sample for further testing. Each method has its own risks and benefits, and it’s important for the patient to fully understand these. The doctor will discuss all these factors to help the woman decide on the best treatment option for her.
