Pelvic Pain During Early Pregnancy

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

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.

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

• Vaginal bleeding

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.

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.