Pelvic pain is common during early pregnancy and may accompany serious or minor disorders. Some conditions causing pelvic pain also cause vaginal bleeding. In some of these disorders (eg, ruptured ectopic pregnancy, ruptured hemorrhagic corpus luteum cyst), bleeding may be severe, sometimes leading to hemorrhagic shock.
Causes of upper and generalized abdominal pain are similar to those in nonpregnant patients.
Etiology
Causes of pelvic pain during early pregnancy (see table Some Causes of Pelvic Pain) may be
Obstetric
Gynecologic
Nongynecologic
Sometimes no particular etiology is identified.
The most common obstetric causes of pelvic pain during early pregnancy are
Normal changes of pregnancy
Spontaneous abortion (threatened, inevitable, incomplete, complete, missed, or septic)
The most common serious obstetric cause is
Ruptured ectopic pregnancy
Gynecologic causes include adnexal torsion, which is more common during pregnancy because the corpus luteum causes the ovaries to enlarge, increasing the risk of the ovary twisting around its pedicle.
Common nongynecologic causes include various common gastrointestinal and genitourinary disorders:
Viral gastroenteritis
During late pregnancy, pelvic pain may result from labor, obstetric complication, or one of the many nonobstetric causes of pelvic pain.
Some Causes of Pelvic Pain During Early Pregnancy
Cause | Suggestive Findings | Diagnostic Approach* |
|---|---|---|
Obstetric disorders | ||
Normal changes of pregnancy, including those due to stretching and growth of the uterus and surrounding connective tissues | Crampy sensation or pressure in the lower abdomen, pelvis, lower back, or a combination Sometimes, with movement, sudden sharp pain (round ligament pain) | Routine prenatal evaluation with maternal vital signs, abdominal examination, sometimes pelvic examination, and fetal heart rate auscultation (depending on gestational age) Sometimes, pelvic ultrasonography Evaluation for ectopic pregnancy or other conditions, if suspected |
Abdominal or pelvic pain, which is often sudden, localized, and constant (not crampy), usually with vaginal bleeding Closed cervical os No fetal heart sounds Possibly hemodynamic instability if ectopic pregnancy has ruptured Sometimes, a palpable adnexal mass | Quantitative beta-hCG measurement, repeated every 2 days if diagnosis is uncertain Complete blood count Pelvic ultrasonography Sometimes, endometrial sampling Laparoscopy or, if the patient is hemodynamically unstable, laparotomy | |
Spontaneous abortion (threatened, inevitable, incomplete, complete, missed) | Crampy, diffuse, lower abdominal pain, often with vaginal bleeding Open or closed cervical os depending on the type of abortion (see table Some Causes of Vaginal Bleeding) | Fetal heart rate auscultation Quantitative beta-hCG measurement, repeated every 2 days if diagnosis is uncertain Complete blood count Pelvic ultrasonography |
Usually, history of recent induced or spontaneous abortion (risk is higher if induced abortion is performed without appropriately trained clinicians and equipment or if self-induced) Fever, chills, constant abdominal or pelvic pain Vaginal bleeding and/or purulent vaginal discharge Uterine tenderness Open cervical os | Evaluation as for spontaneous abortion plus evaluation for STIs and vaginitis | |
Gynecologic disorders | ||
Uterine fibroid degeneration | Sudden onset of pelvic pain, dull or sharp, usually severe, often with nausea, vomiting, and fever Sometimes, vaginal bleeding Uterine tenderness | Ultrasonography MRI (used only if diagnosis is uncertain) |
Sudden onset of localized pelvic pain, which may be severe and intermittent (if torsion spontaneously resolves) Often, nausea, vomiting | Doppler ultrasonography | |
Ruptured corpus luteum cyst | Localized abdominal or pelvic pain Sometimes, vaginal bleeding Usually, sudden onset | Ultrasonography Complete blood count |
Pelvic inflammatory disease (uncommon during pregnancy) | Purulent cervicovaginal discharge Significant cervical motion, uterine, and/or adnexal tenderness Often, fever and/or abnormal vaginal bleeding | Evaluation for STIs and vaginitis White blood cell count |
Benign or malignant ovarian tumor | Dull abdominal pain or pressure Sometimes, weight loss Sometimes, abdominal distension and ascites Sometimes, ovarian cancer risk factors | Ultrasonography Tumor markers Sometimes, diagnostic laparoscopy |
Ovarian hyperstimulation syndrome | Use of fertility medications for current pregnancy Dull abdominal pain or pressure If moderate or severe, weight gain, abdominal distension and ascites, acute kidney disease, pleural effusion, or disseminated intravascular coagulation | Ultrasonography Complete blood count Comprehensive metabolic panel |
Nongynecologic disorders | ||
Usually, continuous diffuse or localized abdominal pain, tenderness Possibly atypical location (eg, right upper quadrant) or qualities (milder, crampy, no peritoneal signs) compared with pain in nonpregnant patients; appendix may be in a different position due to enlarged uterus Sometimes, peritoneal signs Sometimes, nausea, vomiting, or loss of appetite | Pelvic/abdominal ultrasonography, followed by MRI if ultrasonography is inconclusive; consideration of CT if MRI is not readily available White blood cell count or C-reactive protein | |
Suprapubic discomfort, often with bladder symptoms (eg, burning, frequency, urgency) Sometimes, fever, chills, and/or flank pain (risk of pyelonephritis is increased in pregnancy) | Urinalysis and culture | |
Variable pains (crampy or constant) in no consistent location, often with diarrhea and sometimes with mucus or blood Sometimes, fever Usually, a known history of IBD | Sometimes, fecal calprotectin Sometimes, endoscopy | |
Acute nausea and vomiting, usually in patients who have had abdominal surgery, have an intraabdominal malignancy, or sometimes an incarcerated hernia detected during examination Colicky pain, vomiting, no bowel movements or flatus Distended, tympanitic abdomen Usually, history of abdominal surgery (causing adhesions), have an intraadominal malignancy, or sometimes an incarcerated hernia detected during examination May be caused by or occur in patients with appendicitis | Evaluation as for ectopic pregnancy Abdominal imaging with flat and upright x-rays, ultrasonography, and possibly CT (if x-ray and ultrasonography results are equivocal) | |
Usually, vomiting, diarrhea No peritoneal signs | Sometimes, stool tests (if bacterial or parasitic infection is suspected) | |
Beta-hCG = beta subunit of human chorionic gonadotropin; STIs = sexually transmitted infections. | ||
* Evaluation of concerning symptoms in all pregnant patients should include assessment of maternal vital signs, physical examination, and evaluation of fetal status with fetal heart rate monitoring or ultrasonography. | ||
Evaluation
Evaluation of patients with pelvic pain during early pregnancy should exclude potentially serious treatable causes (eg, ruptured or unruptured ectopic pregnancy, septic abortion, appendicitis).
History
History of present illness should include the estimated due date (and whether this is based on last menstrual period or ultrasonography), any risk factors for obstetric complications, and prior testing or complications during the current pregnancy. It should include any events associated with the onset of the pain (eg, physical trauma) and characteristics of the pain: onset (sudden or gradual), location (localized or diffuse), character (crampy, colicky, or sharp), pattern (constant or intermittent), and effect of movement. Any fever, chills, or vaginal bleeding or discharge should be noted. A history of self-induced or illegal termination of pregnancy suggests septic abortion, but absence of this history does not exclude this diagnosis.
Review of systems should include genitourinary and gastrointestinal symptoms that suggest a cause.
Important genitourinary symptoms and suggested etiologies include
Vaginal bleeding: Ectopic pregnancy or abortion
Syncope or near syncope: Ectopic pregnancy
Urinary frequency, urgency, or dysuria: Urinary tract infection
Vaginal discharge with fever: Pelvic inflammatory disease
Important gastrointestinal symptoms and suggested etiologies include
Diarrhea: Gastroenteritis, inflammatory bowel disease, or irritable bowel syndrome
Vomiting: Due to many disorders, including gastroenteritis and bowel obstruction
Constipation or obstipation: Bowel obstruction, irritable bowel, or a functional disorder
Past medical history should include gravidity (number of confirmed pregnancies), parity (number of term and preterm deliveries) and number of abortions (spontaneous or induced), and questions relevant to disorders known to cause pelvic pain (eg, inflammatory bowel disease, irritable bowel syndrome, nephrolithiasis, ectopic pregnancy, spontaneous abortion). Risk factors for these disorders should be identified.
The most significant risk factors for ectopic pregnancy include
Previous ectopic pregnancy (the most important)
Previous abdominal surgery (especially tubal surgery, eg, tubal ligation)
Tubal abnormalities (eg, hydrosalpinx)
Current use of intrauterine device
In vitro fertilization in current pregnancy
Additional risk factors for ectopic pregnancy include history of sexually transmitted infection or pelvic inflammatory disease, current use of estrogen/progestin oral contraceptives, cigarette smoking, infertility, and prior spontaneous or induced abortion.
Risk factors for spontaneous abortion include
Age > 35
History of spontaneous abortion
Cigarette smoking
Uterine abnormalities (eg, leiomyoma, adhesions)
Risk factors for bowel obstruction include
Previous abdominal surgery
Hernia
Intraabdominal malignancy
Physical examination
Evaluation of patients during pregnancy should include routine prenatal evaluation to assess maternal and fetal status, including
Assessment of maternal vital signs
Abdominal examination for fundal height
Sometimes, pelvic examination
Evaluation of fetal status with fetal heart rate auscultation
Sometimes pelvic ultrasonography (depending on symptoms and gestational age)
Physical examination directed at evaluating pelvic pain includes noting whether vital signs indicate fever and signs of hypovolemia (hypotension, tachycardia).
The abdomen is palpated for tenderness, peritoneal signs (rebound, rigidity, guarding), and uterine size and is percussed for tympany.
Pelvic examination includes inspection of the cervix for discharge, dilation, and bleeding. Vaginal or cervical discharge, if present, should be sampled and tested for infection, if vaginitis or cervicitis is suspected.
Bimanual examination should check for cervical motion tenderness, adnexal masses or tenderness, and uterine size. If ectopic pregnancy is suspected, pelvic examination should be done carefully without placing excess pressure on the adnexa, which could cause rupture of a tubal pregnancy.
Red flags
The following findings are of particular concern:
Hemodynamic instability (hypotension, tachycardia, or both)
Syncope or near syncope
Peritoneal signs (rebound, rigidity, guarding)
Fever, chills, and/or purulent vaginal discharge
Interpretation of findings
Certain findings suggest causes of pelvic pain but are not always diagnostic (see table Some Causes of Pelvic Pain).
For all women who present with pelvic pain during early pregnancy, the most serious cause—ectopic pregnancy—must be excluded, regardless of any other findings. Nonobstetric causes of pelvic pain (eg, acute appendicitis) must always be considered and investigated as in nonpregnant women.
As in any patient, findings of peritoneal irritation (eg, focal tenderness, guarding, rebound, rigidity) are a concern. Common causes include appendicitis, ruptured ectopic pregnancy, and, less often, ruptured ovarian cyst. However, absence of peritoneal irritation does not rule out such disorders, and index of suspicion must be high.
Findings that suggest a cause include
Vaginal bleeding accompanying the pain: Spontaneous abortion or ectopic pregnancy
An open cervical os or tissue passed through the cervix or vagina: Generally, an inevitable, incomplete, or complete abortion
Presence of fever, chills, and a purulent vaginal discharge: Septic abortion (particularly in patients with a history of instrumentation of the uterus or illicitly attempted termination of pregnancy)
Pelvic inflammatory disease is rare during pregnancy but may occur.
Testing
If an obstetric cause of pelvic pain is suspected, quantitative measurement of beta-hCG and complete blood count should be done,
If the patient also has vaginal bleeding or suspected internal bleeding, blood type and Rh typing are done. If there is hemodynamic instability (with hypotension, persistent tachycardia, or both), blood should be cross-matched, and fibrinogen level, fibrin split products, and prothrombin time/partial thromboplastin time (PT/PTT) are determined.
Pelvic ultrasonography is done to confirm an intrauterine pregnancy and to evaluate for
Fetal heartbeat, size, and movement
Uterine pathology
Fallopian tube or ovarian mass or other abnormalities
Free fluid in the pelvis
Both transabdominal and transvaginal ultrasonography should be used as necessary. If the uterus is empty and the patient has not noted passage of tissue from the vagina, ectopic pregnancy is suspected. If Doppler ultrasonography shows that blood flow to the adnexa is absent or decreased, adnexal (ovarian) torsion is suspected. However, this finding is not always present because spontaneous detorsion can occur.
However, ultrasonography can and should be deferred, as needed, to expedite surgical treatment in the hemodynamically unstable patient with a positive pregnancy test, given the very high likelihood of either ectopic pregnancy or spontaneous abortion with hemorrhage.
Laparoscopy can be used to diagnose pain that remains significant and undiagnosed after the usual evaluation.
Treatment
Treatment of pelvic pain during early pregnancy is directed at the cause.
Treatment of spontaneous abortion
Women who have an Rh-negative blood type and have vaginal bleeding or an ectopic pregnancy should be given Rho(D) immune globulin to prevent alloimmunization.
Ruptured corpus luteum cysts and degeneration of a uterine fibroid are treated conservatively with oral analgesics.
Treatment of adnexal torsion is surgical:
If the ovary is viable: Manual detorsion
If the ovary is infarcted and nonviable: Oophorectomy or salpingectomy
Key Points
Pelvic pain in early pregnancy should always raise concern for ectopic pregnancy.
Consider nonobstetric etiologies as a cause of acute abdomen during pregnancy.
If no clear nonobstetric cause is identified, ultrasonography is usually necessary.
Suspect a septic abortion when there is a history of recent uterine instrumentation or induced abortion.
Determine blood type and Rh status for all women during early pregnancy; if heavy vaginal bleeding or ectopic pregnancy occurs, all women with Rh-negative blood should be given Rho(D) immune globulin.
