Author:
Patricia DeMelo Panakos
IvetteMotola
Description
- Pregnancy is not a disease process but rather a physiologic state
- It involves severe metabolic stresses on the mother to facilitate the growth and development of the fetus
- All women of reproductive age with abdominal pain are considered pregnant until proven otherwise (even those with history of sterilization)
- The changes in pregnancy occur from the production of large amounts of placental hormones:
Pediatric Considerations |
- Range for menarche in the U.S. is 11-15 yr old
- Pregnant adolescents who present to the ED may be either unaware of the pregnancy or reluctant to admit it:
- Always consider pregnancy in adolescents, regardless of the chief complaint
- Pediatric pregnancies have an increased risk of shoulder dystocia
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Etiology
- Preceding signs and symptoms can be explained by elevations in various hormone levels or changes in anatomy that are a function of the progression of the pregnancy
- Placental human chorionic gonadotropin (hCG):
- Prevents the normal involution of the corpus luteum at the end of the menstrual cycle
- Causes the corpus luteum to secrete even larger quantities of estrogen and progesterone
- Elevated hCG levels are responsible for nausea and vomiting
- Placental progesterone:
- Causes decidual cells in the endometrium to develop and provide nutrition for the early embryo
- Decreases contractility of the gravid uterus and risk of spontaneous abortion
- Helps estrogen prepare the breasts for lactation
- Placental estrogen:
- Responsible for enlargement of uterus, breasts, and mammary ducts
- Enlargement of female external genitalia, relaxation of pelvic ligaments, symphysis pubis, and sacroiliac joints
The diagnosis of pregnancy and some of its potential complications focus on 3 diagnostic tools:
- History and physical exam
- Hormonal assays
- US
Signs and Symptoms
- Amenorrhea accompanied by nausea and vomiting in a sexually active woman
- Amenorrhea:
- Most common cause of secondary amenorrhea in a woman of reproductive age is pregnancy
- Nausea and vomiting (morning sickness)
- Breast tenderness (mastodynia)
- Urinary frequency
- Headache
- Low back pain
- Pica
- Edema of feet and ankles
- Weight gain
- Easy fatigability, generalized malaise
- Increase in abdominal girth
- Constipation
- Heartburn
- Excessive eructation
- Skin darkening
History
- Prior obstetric and gynecologic history, including the course of prior pregnancies
- Determine first day of last menstrual period (FDLMP)
- 40% of women cannot accurately remember their FDLMP
Physical Exam
- Estimate expected date of delivery by determining uterine fundal height
- Centimeters from pubic bone to top of uterus approximates gestational age after 16 wk
- Detect abnormal pelvic pain or masses
Diagnostic Tests & Interpretation
Lab
- Pregnancy tests:
- β-subunit of hCG
- Quantitative hCG normally doubles every 2 days until 6-7 wk gestation
- Progesterone
- Measurement of β-hCG:
- Most urine pregnancy tests have sensitivity at 25 mIU/mL:
- False-negative tests can occur with dilute urine and high vitamin C intake
- Home pregnancy tests are not that accurate:
- Detect pregnancy 9-12 d post conception
- Positive home pregnancy tests should be confirmed by serum hCG levels
- Serum level of hCG:
- Detectable 8-11 d post conception
- hCG levels may remain detectable up to 60 d after an abortion
- Serum progesterone level is an indicator of the viability of the pregnancy and may be used to predict the outcome of the pregnancy:
- A serum progesterone level of <5 ng/mL is indicative of a nonviable pregnancy (spontaneous abortion or ectopic pregnancy)
- Progesterone level 25 ng/mL denotes a viable pregnancy
Imaging
- US is used to confirm pregnancy in the setting of abdominal pain, vaginal bleeding, or some other potential obstetric complication:
- Can estimate gestational age
- Confirm intrauterine or ectopic pregnancy
- Evaluate fetal viability
- Identify fetal abnormalities
- Transabdominal US vs. transvaginal US:
- Transvaginal US is more sensitive but more difficult to perform
- Intrauterine pregnancy seen at 4-5 wk in transvaginal US
- Gestational sac seen at 5.5-6 wk in transabdominal US
- Transvaginal US is contraindicated in the setting of premature rupture of membranes and third-trimester bleeding
- When used in combination with hCG levels, US is a very helpful tool in detecting abnormal/problem pregnancy
- MRI: No significant side effects have been documented:
- Often the study of choice to evaluate for appendicitis in pregnancy
- Plain radiography and CT:
- Dose-dependent teratogen
- Slight increase in risk of childhood cancer
- Goal is to not exceed 5,000 mrad fetal dose of radiation:
- CXR with abdominal shield: <1 mrad
- Abdominal plain film: 240 mrad
- Chest CT: <10 mrad
- Head CT: < 10 mrad
- Abdominal CT with and without contrast: 2,000 and 1,000 mrad
- Cardiac catheterization: 1,300 mrad
- VQ scan: <50 mrad
Differential Diagnosis
Any woman who is of the age to be sexually active who presents to the ED should be assumed to be pregnant until proven otherwise
Prehospital
- Assume the patient is pregnant
- Administer medications only when necessary to avoid teratogenic side effects or placental-fetal compromise (e.g., epinephrine)
- If >24 wk gestation, transport in left lateral recumbent position or manually displace the uterus to the left
Initial Stabilization/Therapy
- Advanced cardiac life support/advanced trauma life support measures as needed: Oxygen, cardiac monitor, IV access, and fluids:
- First objective is to resuscitate mother
- If >24 wk gestation, place in the left lateral recumbent position
ED Treatment/Procedures
The goal is to optimize maternal condition to improve fetal condition
Medication
- First trimester is when organogenesis is occurring
- Fetal malformation continues beyond the first trimester
- Before using any drug, refer to its Food and Drug Administration safety classification in pregnancy:
- This classification system categorizes drugs as A, B, C, D, and X, with category A being the safest and category X being the most toxic
- FDA pregnancy categories (A, B, C, D, and X) have been supplanted and are replaced by a “narrative risk summary” based on available data
- This change has not been fully implemented at the time of publishing
- Analgesics: Acetaminophen is the preferred OTC analgesic
- Aspirin and NSAIDs are not teratogenic but are best used in consultation with an obstetrician
- Oxycodone, codeine, hydrocodone, meperidine, and morphine have no known teratogenic affect and can be used for the control of severe pain in pregnancy for short periods of time (3-4 d)
- Antibiotics: Selecting the right antibiotic in a gravid female depends on 3 factors:
- Maternal drug allergies
- Gestational age
- Type of infections and associated pathogens
- Consider placing patient on prenatal vitamins
- Pain control:
- Acetaminophen: 500 mg PO q6h; do not exceed 4 g/d
- Antiemetic:
Disposition
Admission Criteria
- Pregnant women with the following obstetric complications should be admitted to the hospital:
- Hyperemesis gravidarum with inability to tolerate oral fluids
- Complicated UTI
- Ectopic or molar pregnancy
- Septic abortion
- Preterm labor
- Premature rupture of membranes
- Preeclampsia/eclampsia
- Severe pregnancy-induced HTN
- Pregnant women with medical conditions that would warrant admission in a nongravid female
Discharge Criteria
Women without the above conditions may be discharged from the ED
Follow-up Recommendations
Need OB follow-up for prenatal care by 6-8 wk gestation
- Committee on Practice Bulletins-Obstetrics. ACOG Practice Bulletin No. 189: Nausea and vomiting of pregnancy . Obstet Gynecol. 2018;131:e15-e30.
- CrochetJR, BastianLA, ChireauMV. Does this woman have an ectopic pregnancy?: The rational clinical examination systematic review . JAMA. 2013;309(16):1722-1729.
- DoubiletPM. Ultrasound evaluation of the first trimester . Radiol Clin North Am. 2014;52(6):1191-1199.
- KilfoyleKA, VreesR, RakerCA, et al. Nonurgent and urgent emergency department use during pregnancy: An observational study . Am J Obstet Gynecol. 2017;216:181.e1-181.e7.
- WallsRM, HockbergerRS, Gausche-HillM, et al. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed.Philadelphia, PA: Elsevier; 2017.
The authors gratefully acknowledge Jonathan B. Walker for his contribution to the previous edition of this chapter.