Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 19-01: Diagnosis of Pregnancy For further information, see CMDT Part 19-02: Essentials of Prenatal Care For further information, see CMDT Part 19-03: Nutrition in Pregnancy + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Amenorrhea, weight gain, nausea and vomiting, and breast changes Positive pregnancy test +++ General Considerations ++ Prompt diagnosis of pregnancy allows early prenatal care and avoidance of harmful activities or exposures In the event of an unwanted pregnancy, early diagnosis allows for counseling regarding options + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Amenorrhea, weight gain Nausea and vomiting Breast tenderness and tingling Urinary frequency and urgency "Quickening" (perception of the first fetal movement) is noted at about 18 weeks' gestation Signs Breast changes, abdominal enlargement, and cyanosis of the vagina and cervical portio (week 7) Softening of the cervix (week 7) Generalized enlargement and softening of the corpus (post-week 8) Uterine fundus is palpable above the pubic symphysis by 12–15 weeks from last menstrual period Fundus reaches the umbilicus by 20–22 weeks Fetal heart tones heard by Doppler at 10–12 weeks +++ Differential Diagnosis ++ Myomas can be confused with a gravid uterus A midline ovarian tumor may displace a nonpregnant uterus Ectopic pregnancies may show lower levels of human chorionic gonadotropin (hCG) that level off or fall Premature menopause + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests +++ DIAGNOSTIC TESTS ++ All urine or blood pregnancy tests rely on detection of placental hCG and are accurate at the time of a missed period or shortly after it Laboratory and home assays use monoclonal antibodies specific for hCG hCG levels increase shortly after implantation, double every 48 h (this rise can range from 30% to 100% in normal pregnancies), peak at 50–75 days, and fall in second and third trimesters +++ SCREENING AT THE TIME OF DIAGNOSIS ++ The following are recommended Urinalysis; culture of a mid-stream urine sample Complete blood count (CBC) Random blood glucose Serologic test for syphilis Rubella antibody titer History of varicella Blood group and Rh type Antibody screening Hepatitis B surface antigen testing HIV testing should be encouraged Women at increased risk for infection should be tested for Chlamydia trachomatis and Neisseria gonorrhoeae using a nucleic acid amplification test (NAAT) of a vaginal or/endocervical swab or first-catch urine Testing for abnormal hemoglobins should be done in patients at risk for sickle cell or thalassemia traits Tuberculosis skin testing is recommended for high-risk groups Screening for Tay-Sachs, Canavan disease, and familial dysautonomia should be offered to Jewish women with Jewish partners (especially those of Ashkenazi descent) Couples of French-Canadian or Cajun ancestry Hepatitis C screening should be offered to mothers at high risk +++ SCREENING DURING PREGNANCY ++ In the first and second trimesters, aneuploidy screening should be offered to all women, ideally before 20 weeks gestation Noninvasive first trimester screening for Down syndrome includes ultrasonographic nuchal translucency and serum levels of PAPP-A (pregnancy-associated plasma protein A) and the free beta subunit of hCG In the second trimester, a "quad screen" blood test can be performed; it measures serum alpha-fetoprotein (msAFP), hCG, unconjugated estriol, and inhibin A Noninvasive testing with cell free fetal DNA from maternal plasma screens only for trisomy 13, 18, and 21 Screening for gestational diabetes by checking glucose 1 h post a 50-g glucose load (26–28 weeks) 3-h glucose tolerance test follows up an abnormal 1-h glucose load test Repeat Rh testing for negative patients (28 weeks, though result is not required before Rho(D) Ig is given) CBC to evaluate for anemia of pregnancy (28–32 weeks) Repeat tests for syphilis, HIV, and cervical cultures in at-risk patients (36 weeks to delivery) Screening for group B streptococcal (GBS) colonization can be done by rectovaginal culture at 35–37 weeks If negative, no prophylaxis is given Intrapartum prophylaxis with penicillin or clindamycin is given if screening cultures are positive and organism is sensitive Patients with risk factors for GBS or who deliver at < 37 weeks receive intrapartum prophylaxis Patients without a culture at 35–37 weeks receive prophylaxis only for a history of GBS bacteriuria or prior GBS disease in an infant, intrapartum fevers, or membrane rupture > 18 h +++ Imaging Studies ++ Radiographs should be avoided unless essential and approved by a physician and utilize shielding Fetal ultrasound for accurate dating and to evaluate fetal anatomy is usually done at 18–22 weeks' gestation In multiple pregnancies, ultrasound is repeated every 2–6 weeks to identify discordant growth + Treatment Download Section PDF Listen +++ +++ Medications ++ Prenatal vitamins with iron and folic acid are indicated Medications should not be taken unless prescribed or authorized by the patient's provider (Table 19–1) For prophylaxis of group B streptococcal infection, Penicillin G, 5 million units intravenously as a loading dose and then 2.5–3 million units intravenously every 4 hours until delivery In penicillin-allergic patients not at high risk for anaphylaxis, 2 g of cefazolin intravenously as an initial dose and then 1 g intravenously every 8 hours until delivery In patients at high risk for anaphylaxis, use vancomycin 1 g intravenously every 12 hours until delivery After confirmed susceptibility testing of group B streptococcal isolate, clindamycin 900 mg intravenously every 8 hours until delivery ++Table Graphic Jump LocationTable 19–1.Common drugs that are teratogenic or fetotoxic.1View Table||Download (.pdf) Table 19–1. Common drugs that are teratogenic or fetotoxic.1 ACE inhibitors Alcohol Androgens Angiotensin-II receptor blockers Antiepileptics (phenytoin, valproic acid, carbamazepine) Benzodiazepines Cyclophosphamide Diazoxide Diethylstilbestrol Disulfiram Ergotamine Estrogens Griseofulvin Isotretinoin Lithium Methotrexate Misoprostol NSAIDs (third trimester) Opioids (prolonged use) Radioiodine (antithyroid) Reserpine Ribavirin Sulfonamides (second and third trimesters) Tetracycline (third trimester) Thalidomide Tobacco smoking Warfarin and other coumarin anticoagulants 1Many other drugs are also contraindicated during pregnancy. Evaluate any drug for its need versus its potential adverse effects. Further information can be obtained from the manufacturer or from any of several teratogenic registries around the country.Go to https://www.fda.gov/ScienceResearch/SpecialTopics/WomensHealthResearch/ucm134848.htm for more information.ACE, angiotensin-converting enzyme; NSAIDs, nonsteroidal anti-inflammatory drugs. +++ Therapeutic Procedures ++ Genetic counseling with the option of chorionic villous sampling or amniocentesis should be offered to women 35 or older at delivery, a family history of congenital abnormalities, or previous child with a metabolic disease, chromosomal abnormality, or neural tube defect + Outcome Download Section PDF Listen +++ +++ Follow-Up ++ Prenatal visits should be scheduled Every 4 weeks from 4–28 weeks Every 2 weeks from 28–36 weeks Weekly from 36 weeks to delivery +++ Complications ++ Fetal alcohol syndrome: no safe level of alcohol intake has been established for pregnancy Cigarette smoking increases risk of abruptio placentae, placenta previa, and premature rupture of the membranes Premature delivery and lower birth weights are more common in children born to smokers Maternal cocaine, amphetamine, and opioid use in pregnancy is associated with numerous complications +++ Prevention ++ Decrease caffeine intake Avoid ingestion of raw meat, all tobacco, alcohol, and recreational drugs, exposure to environmental tobacco smoke, excessive heat, hot tubs, and saunas, and handling of cat feces or litter Regular exercise can be continued at a mild to moderate level Exercises that require a great deal of balance should be met with caution + References Download Section PDF Listen +++ + +ACOG Committee on Genetics. Committee Opinion No. 691: Carrier screening for genetic conditions. Obstet Gynecol. 2017 Mar;129(3):e41–55. [PubMed: 28225426] + +ACOG Committee on Genetics. Committee Opinion No. 442: Preconception and prenatal carrier screening for genetic diseases in individuals of Eastern European Jewish descent. Obstet Gynecol. 2009 Oct;114(4):950–3. [Reaffirmed 2014] [PubMed: 19888064] + +American College of Obstetricians and Gynecologists. ACOG Committee Opinion No. 548: Weight gain during pregnancy. Obstet Gynecol. 2013 Jan;121(1):210–2. [Reaffirmed 2015] [PubMed: 23262962] + +Bobdiwala S et al. Factors to consider in pregnancy of unknown location. Womens Health (Lond). 2017 Aug;13(2):27–33. [PubMed: 28660799] + +Carlson LM et al. Prenatal diagnosis: screening and diagnostic tools. Obstet Gynecol Clin North Am. 2017 Jun;44(2):245–56. [PubMed: 28499534] + +Kilpatrick SJ et al Guidelines for Perinatal Care, 8th ed. American Academy of Pediatrics, 2017.