Introduction
Antepartum care, also referred to as prenatal care, consists of the all-encompassing management of patients throughout their pregnancy course. Antepartum care has become the most frequently utilized healthcare service within the United States, averaging greater than 50 million visits annually. After the first positive pregnancy test, care is typically sought by patients and begun after confirmed sonographic intrauterine pregnancy. The average number of visits ranges between twelve to seventeen visits, depending on the complexity of the pregnancy course.
The prenatal course is typically separated into trimesters, for which each of the three trimesters serves a specific purpose for maternal/fetal monitoring, gestation-specific examinations and laboratory work, and screening for potential pregnancy abnormalities. Traditionally, prenatal visit frequencies are typically scheduled at 4-week intervals until 28 weeks of gestation, at which time visits are scheduled every 2 weeks until 36 weeks of gestation, followed by weekly visits until delivery. Visits may be adjusted to more frequent follow-ups when high-risk pregnancy complications are present, when pertinent lab values must be reviewed, or if patients require closer monitoring for risk factors.[1][2][3]
With the increasing focus beginning in the early 1990s on preventing maternal and fetal morbidity and mortality, great efforts have been made to improve access to quality antepartum care to low socio-economic and minority populations. Although still prevalent despite efforts, the growing disparities between minority populations (specifically among Hispanics and African Americans) are rooted in lack of access and complex obstetric and medical risk factors leading to poor obstetric outcomes. Thus, an adequate evaluation of a patient’s medical history, related risk factors, and potential obstacles to healthcare must be attained, followed by a patient-centered discussion regarding the potential prenatal plan of care.[1][2][3]
Function
First Trimester Antepartum Care (0-14 6/7 weeks)
First trimester antepartum care most commonly begins with an initial prenatal visit, after the development of symptoms, a positive pregnancy test, and confirmed intrauterine gestation via sonography. Patients with early pregnancies may present with any combination of signs and symptoms or might be completely asymptomatic. The most common presenting complaint of patients is an abrupt cessation of the menstrual cycle in previously healthy women of reproductive age with regular menstrual cycles. Although this is a common presenting complaint, menstrual cycle variation among women of varying ages or underlying gynecologic conditions also means amenorrhea cannot reliably be utilized as the only method of diagnosis of pregnancy. Patients may also present with complaints of breast pain or swelling, often less commonly reported by multiparous patients.
Sonography, specifically transvaginal sonography, plays an essential role in identifying and establishing gestational age and confirms the location of the pregnancy. Intrauterine pregnancies are confirmed by the presence of a gestation sac within the endometrial cavity, typically identified at 4 to 5 weeks gestation, along with a visualization of a yolk sac, typically seen by 5 weeks gestation. With this confirmation, and at about 6 weeks gestation, cardiac activity may be noted.
Several major tasks must be accomplished during this initial visit, including establishing the baseline medical condition of the patient and fetus, proper gestational age and dating, and planning the intended course of obstetric care with the patient. Within the first visit, a complete history should be taken, including a detailed history of past medical problems that may be of concern during pregnancy, previous surgeries, and detailed past obstetric and gynecologic history for foreseeable complications. Current issues and complaints should also be addressed.
A complete physical examination should also be performed, including complete vital signs, maternal weight, and pelvic/cervical examination, fundal height, and fetal heart rate. Laboratory tests should also be collected and completed during this first visit. These include a complete blood count (CBC), complete metabolic panel (CMP), blood type and Rh factor testing with antibody screen, urine analysis, urine culture, pap smear screening, rubella serology, syphilis serology, gonorrhea, and chlamydia screening, Hepatitis B serology, and HIV serology. These results should be followed up promptly so as to begin necessary adjustments to prenatal care, repeat laboratory testing, or initiate treatment or a higher level of care. During the first trimester, fetal nuchal translucency sonography and fetal aneuploidy screening may be performed between 11 and 14 weeks gestation and again during the second trimester depending on the modality of fetal aneuploidy testing utilized.[4][5][6][7][8]
Second Trimester Antepartum Care (15 0/7 - 28 6/7 weeks)
In the second trimester, antepartum care consists of updated histories with each visit, including reviewing current pregnancy-related issues and a review of newly occurring issues. This includes assessing possible symptoms such as headaches, altered vision, abdominal pain, nausea or vomiting, vaginal bleeding, leakage of fluid, or dysuria. During early second trimester gestations, patients may begin to endorse the perception of fetal movement. This is typically found at around 16 to 18 weeks gestation, or even up to 20 weeks gestation, in primigravida patients and varies in the detection based on maternal factors such as body habitus.
Care also includes repeat blood pressure recordings, maternal weight, fundal height, and fetal heart rate. Fetal heart rates can be detected via Doppler ultrasound, in nonobese patients, at as early as 10 weeks gestation. Because the second trimester encompasses a vast majority of the rapid fetal growth period, several essential screening and laboratory tests are collected during this trimester. Earlier in the second trimester, the second portion of combined-trimester fetal aneuploidy testing or single-test quadruple maternal screening is collected between 16 to 20 weeks gestation. In addition to this, fetal sonography for the anatomic survey is performed during 18 to 20 weeks gestation.
Gestational diabetic screening is also an essential component of second-trimester testing via a 50-gram glucose tolerance test. This is typically collected between 24 to 28 weeks of gestation. Tdap vaccinations are also routinely administered during this timeframe. If patients have a known Rh-negative status, Rhogam is administered at 28 weeks. Patients during this trimester are also counseled at around 28 weeks gestation to begin self-monitoring of fetal movements equating to 10 movements within 2 hours, also known as “fetal kick counts.”[9][10][11]
Third Trimester Antepartum Care (29 0/7- 41 6/7 weeks)
The third trimester of antepartum care consists of the final preparations, screenings, necessary treatments, and counseling to facilitate safe and timely delivery and improved maternal and fetal outcomes. As with second-trimester visits, antepartum care in the third trimester consists of updated histories with each visit, reviewing current pregnancy-related issues and reviewing newly occurring issues. Review of new symptoms such as headaches, altered vision, abdominal pain, nausea or vomiting, vaginal bleeding, leakage of fluid, or dysuria should be discussed. If present, appropriate physical examination or laboratory testing should be completed. And, as performed in other visits, blood pressure recordings, maternal weight, fundal height, and fetal heart rate should be obtained.
Between 36 to 37 weeks gestation, third-trimester laboratory testing is typically collected in uncomplicated prenatal care. These include repeat complete blood count to address and correct anemia or thrombocytopenia prior to delivery, Hepatitis B surface antigen testing, gonorrhea and chlamydia screening, HIV screening, and Group B Streptococcal screening. During late third trimester visits, patients typically return for weekly visits to assess for signs of early labor, fetal distress, or maternal complaints.
Patients may also require a physical examination, including cervical examination, sonography to assess for estimated fetal weight and amniotic fluid index, or nonstress tests to examine fetal status. If there are abnormalities, other pregnancy-related, or maternal-related medical conditions present, patients may require induction of labor or imminent delivery depending on the circumstance and severity.[12][13]
Issues of Concern
Several issues of concern may arise during the course of antepartum care. While serious medical conditions pose a risk and concern to prenatal management (discussed in other articles), most areas of concern in day-to-day pregnancy issues also comprise a significant amount of patient complaints. Therefore, recognition of these concerns and timely intervention is an essential contributor to adequate antepartum care.
Nausea and Vomiting
Nausea and vomiting are among the most common complaints of pregnant patients within the first trimester of pregnancy, and is thought to be multifactorial and more directly caused by rapidly increasing level of pregnancy-related hormones such as beta HCG, estrogen, progesterone, placental growth hormone, leptin, and several others. Patients may experience varying degrees of nausea or vomiting throughout the antepartum course. Severe cases may require hospitalization and workup for more serious causes, such as hyperemesis gravidarum, identified by severe dehydration, accompanied by acid-base and electrolyte abnormalities. Patients typically state symptoms present prominently after the first missed menstrual cycle and may continue up to 16 weeks of gestation and up to 22 weeks gestation in rare cases. Symptoms are typically perceived to be more severe during early waking hours. Patients experiencing these issues may receive relief from several different interventions. First, patients may attempt to portion smaller, more frequent meals, ginger into their diets, or supplement medications. Patients may require Vitamin B6 supplementation with Doxylamine or antiemetics such as H1-receptor antagonists.[14][15]
Musculoskeletal Back Pain
Patients during the antepartum course may also have significant complaints of back and lower lumbar pain, most commonly in the third trimester of pregnancy and caused by the increasing size of the gravid uterus and alignment distortion. This is typically worsened by walking significant distances, intense bending forward, or lifting moderately weighted objects. Severe cases of back pain may warrant orthopedic evaluation. Management of back pain includes rest, heating pads, back braces, and analgesics.[16][17][18]
Weight Gain
Weight gain during pregnancy should be discussed with patients and assessed based on pre-pregnancy BMI and individual risk factors, with an increased focus on obesity. Obesity’s association with fetal macrosomia, gestational diabetes, gestational hypertension, preeclampsia, rate of cesarean sections, and other pregnancy complications requires early intervention and counseling of patients beginning in early antepartum care. Pre-pregnancy BMI categories allow for stratification of the total weight gain throughout pregnancy recommendation for underweight patients (BMI <18.5) to be a 28 to 40 lb (12.7 18.1 kg) to total weight gain, normal weight (BMI: 18.5 to 24.9) to be a 25 to 35 lb (11.3 to 15.9 kg) total weight gain, overweight (BMI: 25.0 to 29.9) to be a 15 to 25 lb (6.8 to 11.3 kg) total weight gain, and obese (BMI great or equal to 30.0) to be an 11 to 20 lb (5 to 9 kg) total weight gain. The emphasis during antepartum care and weight gain is currently focused on the obese population, given the significantly increased risk for gestational diabetes, macrosomia, gestational hypertension, preeclampsia, and cesarean delivery, and other antepartum and intrapartum complications.[19][20][21]
Smoking, Alcohol, and Illicit Drugs Use
Although the overall prevalence of cigarette smoking during pregnancy has decreased significantly throughout the United States, there continues to be a prevalence of twelve to thirteen percent of women who endorse cigarette use during the antepartum period. These patients typically tend to be younger in age, have completed fewer years of education, and are of lower socioeconomic status. During the antepartum course, it is essential to identify patients who endorse smoking, counsel patients extensively regarding risk factors associated with cigarette use during pregnancy, and implement a quitting plan with the identification of foreseeable roadblocks and obstacles to doing so. Cigarette smoke is fetotoxic due to the vasoactive effects leading to its substances leading to a marked reduction in oxygen levels. Effects of decreased oxygen levels may lead to cardiac anomalies, gastroschisis, hydrocephaly, microcephaly, omphalocele, cleft lip, and palate, or limb anomalies. These effects are noted to be dose-dependent. Risks associated with cigarette smoke use and exposure in the antepartum period also include spontaneous abortions, fetal growth reduction, preterm delivery, and placental abnormalities, like placental abruption or placenta previa.[22]
Like tobacco, alcohol use during pregnancy, while decreasing in prevalence, is still prevalent amongst eight to thirty percent of pregnancies in the United States. Alcohol exposure in-utero has been established as the leading cause of non-genetically linked mental retardation, along with a constellation of presenting defects that together are referred to as Fetal Alcohol Syndrome. These include notable central nervous system abnormalities (neurologic, functional, and structural dysfunction), growth restriction, notable dysmorphic facial features (short palpebral fissures, smooth philtrum, and thinned vermilion border), and other anomalies (cardiac, skeletal, renal, auditory, ophthalmologic, etc.). While the dose-effect correlation between alcohol use in pregnancy and fetal defects is unknown, several studies show an increased risk among those exposed to excessive binge-drinking behavior.[23][24]
Illicit drug use during pregnancy is also of major concern to both maternal and fetal outcomes. With exposure rates as high as ten percent, assessing patients using recreational drugs must be completed in all pregnant patients. The use of drugs poses a unique risk when considering outcomes and fetal effects, given the multiple variables typically associated with those using drugs. These include younger patient populations, low socioeconomic status, polysubstance abuse, mental health issues, infectious diseases, and other social issues, which may complicate the picture of diagnosis and management. The greatest risk of illicit drug use in pregnancy also lies with the toxic and teratogenic effects of additives and impurities found in several street drugs. Effects of recreational drug use include, but are not limited to, fetal growth restriction, facial defects, cardiovascular, renal, and urinary abnormalities, behavioral abnormalities, and complications of fetal withdrawal (i.e., seizures, central nervous system defects).[25][26]
Work & Employment
With more than half of pregnant women working from conception until delivery, employment during the antepartum course is another common area of concern for patients. According to the Family and Medical Leave Act, pregnant employees must be granted at least twelve weeks of unpaid leave from employment for delivery and newborn care. As per the American College of Obstetrics and Gynecology, pregnant women may continue employment until labor begins in the absence of obstetric complications.
Despite these recommendations, some work may increase the risk of complications to pregnant patients, including employment that requires strenuous heavy lifting and long work hours. These demanding conditions may place additional stress on the patient as well as the pregnancy course, leading to complications such as gestational hypertension with an increased risk of the development of preeclampsia, preterm premature rupture of membranes, preterm labor and delivery, and fetal growth restrictions. It is acceptable to counsel patients with significant obstetric histories of these complications on the added risk of strenuous workplaces on the antepartum course.[27][28][29]
Exercise
With the emphasis on promoting healthy lifestyles during antepartum care, patients may have specific concerns regarding exercise safety during pregnancy. The American College of Obstetrics and Gynecology recommends that after thorough clinical evaluation and with no contraindications, pregnant women should be encouraged to participate in regular, moderate-intensity physical activity in regular, moderate-intensity physical activity for at least thirty minutes or greater per day. Relative contraindications are noted as follows: heavy smoking, poorly controlled disorders such as seizure disorder, hyperthyroidism, Type 1 diabetes, or hypertension, extreme weights including morbid obesity or underweight, intrauterine growth restriction, chronic bronchitis, unevaluated maternal cardiac arrhythmia, history of severely sedentary lifestyle, symptomatic or severe anemia, or heavy smoking.
Absolute contraindications as as follows: incompetent cervix or cerclage, multifetal gestation pregnancy with risk of preterm labor, persistent second or third trimester vaginal bleeding, preterm labor during in the pregnancy, placenta previa present after 26 weeks of gestation, rupture of membranes, preeclampsia or pregnancy-induced hypertension, significant heart disease, or restrictive lung disease. Specific physical activities and intensity of those activities should be reviewed. Those activities in which the risk of trauma to the abdomen or falls are increased should be discouraged.[30][31][32]
Travel
The American College of Obstetrics and Gynecology states that pregnant women may safely travel until 36 weeks of gestation provided there are no complications. Modern, adequately pressurized aircraft pose no harm to pregnant patients or fetuses. Patients are advised to ambulate every hour while on long flights to prevent thromboembolism and wear seat belts throughout the flight. Seat belt safety in regards to automobile travel should be discussed with all pregnant patients during antepartum care. Specifically, correct placement of seatbelts via three-point restraints where the shoulder portion of the strap should be firmly positioned between the breasts and bottom portion should safely be positioning under the abdomen and across the upper portion of the thigh. Both should be positioned across the body tightly, and airbags should always be present in vehicles and utilized in the event of a high-impact accident.[33][34][35]
Clinical Significance
The totality of antepartum care is an intricate balance of maternal and fetal management aimed to prevent significant maternal and fetal morbidity and mortality and provide support throughout the prenatal course. Close follow-up with timely review of new complaints or issues, significant physical exam, sonography, and laboratory findings facilitate the necessary interventions. These may include escalation of care to more frequent antepartum care visits, close follow-up by maternal-fetal medicine specialists, or potential early delivery depending on the gestational age, clinical picture, and potential improvement of outcomes.
While all of these interventions can be implemented with relative ease, major obstacles do exist to achieving this. The main concern for practitioners is patient compliance with visits, specifically in low socioeconomic or minority populations. Obstacles, such as access to prenatal facilities, transportation, or proper understanding of risk factors, all play a role in delayed intervention. Because of this, it is essential for the antepartum care team to identify these obstacles early in the prenatal course so as to preemptively find solutions to potential obstacles.[1][2][3]
Enhancing Healthcare Team Outcomes
During the antepartum course, the care and management of patients serve significant challenges and obstacles, given the complexity of caring for both the patient and fetus. Because of this dual perspective, a team-directed approach of care by physicians, nurses, pharmacists, and healthcare aids is essential for improving maternal and fetal outcomes. This begins with adequate antepartum or prenatal care to ensure patients feel supported and informed. This also includes early detection and acknowledgments of patient complaints, signs, and symptoms of early disease processes, vital signs, laboratory values, and antepartum and prenatal care goals.
Antepartum Care