Globally, there are more than 200 million pregnancies each year. Of these pregnancies, more than 40% are unintended. Unintended does not imply unwanted. Every couple must have the opportunity to plan for pregnancy and choose when they are ready for pregnancy. Of the 40% of unintended pregnancies, early prenatal care is important to prevent poor perinatal outcomes and complications. Opportunities for diagnosing pregnancy and preventing unwanted and unplanned pregnancies exists during routine visits, sports exams, well-woman exams, emergencies, and during acute visits. Taking these opportunities for a pregnancy test can play a major role in getting women to early prenatal care. All women of reproductive age should receive folate at 400 mcg to 800 mcg to prevent neural tube defects. This is a Grade A recommendation by the United States Preventive Task Force (USPTF) and The American College of Obstetrics and Gynecology (ACOG) since most women present after the critical part of organogenesis.[1] The key determinants to a healthy pregnancy and reproductive life are preventing, identifying, and addressing preconception health issues, pregnancy readiness, early prenatal care, and minimizing risks during perinatal and the inter-conception period. [2] [3]

Prenatal Diagnosis

Many women will come in for interim visits with complaints of abdominal pain, abnormal uterine bleeding, and irregular menses. Women with a functioning reproductive system must have a pregnancy test to rule out pregnancy. The gold standard for pregnancy testing is the quantitative beta HCG radioimmunoassay. Most providers in the emergency, ambulatory, or episodic care environments use the urine HCG tests for the initial screen. The quantitative HCG is usually done in conjunction with examination and ultrasound to confirm a normal versus abnormal pregnancy, to correlate gestational age with last normal menstrual period, or to guide in the management of a potential miscarriage. Once a woman has a confirmed pregnancy, she should be scheduled for the first prenatal visit that includes a full review of the pertinent history.

The prenatal intake should include a thorough history and physical to identify potential risks and to assist in referral to appropriate services. Components include:

• Medical history
• Surgical history (especially history of any uterine or abdominal incisions, salpingectomies, and cesareans)
• Family history (especially history of diabetes, genetic disorders, and hemoglobinopathies)
• Obstetric history including last normal menstrual period, previous pregnancy complications, preterm births, and previous pregnancy losses
• Gynecologic history 
• Mental health history

Risk Assessment should include the following:

• Diabetes (Assessment for undiagnosed type 2 diabetes using risk factor criteria as set by the American Diabetic Association)
• Infection
• Genetic[4]
• Occupational and Environmental
• Psychosocial
• Substance and Drug Use
• Tobacco Use
• Financial
• Nutrition
• Other risks that might impact pregnancy such as medications, exposures, and known teratogens.

Every couple should have the opportunity to review and decide on readiness for parenting. Family planning options must be discussed including abstinence, natural family planning, oral contraceptives, condoms, implants, injections, intrauterine devices, and sterilization options. Family planning education and counseling should be noncoercive including full disclosure of risks and benefits. For couples who have recently completed a pregnancy, education must include risks associated with short interval pregnancy. Couples should receive information about contraceptive options before, during, and after pregnancy.

First Trimester Testing and Education

First-trimester testing includes the following:

• Complete blood count
• Screening for hemoglobinopathy in at-risk populations. 

African Americans and women of African descent are at risk for sickle cell trait or disease, i.e., AS or SS and Hemoglobin C. Women of Southeast Asian descent are at risk for Hemoglobin E disease, usually associated with mild hemolytic anemia. Hemoglobin E-beta thalassemia is associated with more severe disease. Women of Mediterranean descent are at risk for sickle-beta thalassemia disease. The severity of the disease varies depending on the amount of hemoglobin A present.

• Screening for tuberculosis in women who are at risk
• Blood type and Rh with antibody screen (Grade A Recommendation, USPTF)
• Hepatitis B surface antigen (Grade A Recommendation, USPTF)

Women at high risk for hepatitis B should receive hepatitis B vaccination. Risk factors for hepatitis include unprotected sex with multiple sexual partners with known risk for hepatitis B, living with someone with hepatitis B, men having sex with men, intravenous (IV) drug use, an infant born to a mother with hepatitis B, working in the healthcare setting with exposure to body fluids, and travel to a country that is high-risk for hepatitis B. [5][6]

• HIV screening using an opt-out approach (Grade A Recommendation, USPTF).

Women who are HIV-positive should present for early prenatal care. Treatment and management of HIV during pregnancy and childbirth reduce transmission of disease from mother to newborn. 

• Screening for other infectious diseases like chlamydia, gonorrhea, and syphilis (Grade A Recommendation, USPTF). 

The USPTF does not recommend screening low risk asymptomatic pregnant women for bacterial vaginosis. The USPTF reports insufficient evidence for screening asymptomatic women at high risk for preterm labor for bacterial vaginosis.

• TSH for women with known thyroid disease 
• Urine Culture (Grade A Recommendation, USPTF)

Screening for asymptomatic bacteriuria is recommended between 12 to 16 weeks gestation or first prenatal visit if it occurs later. Women with sickle cell trait are at increased risk for asymptomatic bacteriuria. They should have a urine culture at intake and each trimester until delivered.

• Varicella titer
• First-trimester genetic screening for chromosomal abnormalities done between 10 and 13 weeks (cell-free DNA testing that determines risk for aneuploidy) and ultrasound evaluation of the nuchal fold of the fetus. For women at high risk, chorionic villus sampling is a diagnostic test that can confirm genetic disorders before birth. Women who are of advanced maternal age, greater than 35 years old, and with a history of having a previous child with a genetic disorder can consider this screening and diagnostic tests to evaluate genetic risks. Providers must discuss testing and risks with women during the appropriate period. [7]
• Other health maintenance items are updated at the initial visit such as the Hepatitis B vaccine for women at risk and tetanus vaccine. Women older than 21 years of age who are due for pap smears should have those at the first visit along with other STD screening as listed above for high-risk groups.

First-trimester education includes general information about hyperemesis, constipation, early discomforts such as fatigue and dizziness, and emotional stressors. First trimester visits are usually every four weeks for low-risk women. However, women who are high risk may require additional visits with the primary obstetric provider, high-risk specialists, social services, and case managers. The first visit must include visit plans, an overview of routine testing, medications safety in pregnancy, and expectations for weight gain through the pregnancy.

Second Trimester: Evaluation, Testing, and Education

Second-trimester prenatal visits include a targeted examination and limited testing. During each visit, the prenatal provider evaluates the history and updates records for any issues occurring since the last visit. The examination includes routine vitals, evaluation of maternal well-being and fetal growth, fetal heart tones, and targeted questions about changes and symptoms common during the second trimester. Ultrasounds are performed between 16 to 20 weeks for fetal anatomy and dating.  During the second trimester, women are offered additional genetic screening (quad screen) and amniocentesis if offered for women greater than 35 years old and women with a prior history of a child with a birth defect. The complete blood count may be repeated for those women with a history of anemia or at risk for anemia. Women are referred for visits with social services and specialists based on risk factors identified during the first trimester.

Women at risk for hepatitis B receive the second dose of the hepatitis B vaccine. Influenza vaccination is recommended during the flu season. 

Second-trimester education includes discussion about quickening that occurs around 21 weeks gestation. General education includes discussion about physiologic changes in pregnancy, heartburn, skin changes, bleeding gums, nose bleeds, breastfeeding, edema, and fetal growth. 

Low dose aspirin is recommended for women at risk for preeclampsia after 12 weeks gestation. (Grade B Recommendation, USPTF)

Third Trimester: Evaluation, Testing, and Education

Third-trimester prenatal visits include targeted examination and specific third-trimester screening. During each visit, the provider will inquire about common complaints during pregnancy such as nausea and vomiting, cramping, contractions, bleeding, headaches, back pain, vaginal discharge, swelling, hemorrhoids, weight gain, and urinary symptoms. During the third trimester weeks 24 to 28, women are offered to screen for diabetes. This screening is beneficial for both low resource and high resource populations.[8]The United States Preventive Task Force recommends screening for asymptomatic pregnant women after 24 weeks gestation. (Grade B recommendation, USPTF) The American Diabetic Association recommended initial screening using the two-hour 75 g glucose tolerance test (one-step test) or the one hour 50 g oral glucose solution followed by the 100 g glucose tolerance test for abnormal values (more than 140mg/dl) on the initial screen (two-step test). Confirming the diagnosis with the one-step testing is fasting glucose of greater than 92 mg/dl, one-hour greater than 180 mg/dl, and two-hour greater than 153 mg/dl. The confirmation of the diagnosis on step two of the two-step testing is a fasting glucose of greater than 95 mg/dl or 105 mg/dl, a one-hour of greater than 180 mg/dl or 190 mg/dl, and a two-hour of greater than 155 mg/dl or 165 mg/dl, or three-hour of greater than 140 mg/dl or 145 mg/dl. Women diagnosed with gestational diabetes should be referred to the dietician and appropriate support and specialty services. Recent literature suggests insulin as the first line of therapy but does not rule out sulfonylureas and metformin as options.[9] Additional third-trimester testing includes repeating the screening for syphilis and other sexually transmitted infections for high-risk women. RH-negative women should receive repeat RH antibody testing between 24 to 28 weeks gestation. (Grade B recommendation, USPTF) Group B Strep screening is recommended between 35 to 37 weeks gestation. Women with positive results are given an intrapartum prophylactic antibiotic. The antibiotic of choice is penicillin to prevent early-onset newborn infection. Alternative treatment for women allergic to penicillin is erythromycin or vancomycin.

Women with a negative blood type should receive Rhogam in the third trimester. Third-trimester vaccination includes influenza vaccination during flu season for women who have not previously received the vaccination, dose three of hepatitis B vaccine, and Tdap vaccination to prevent pertussis in the newborn. 

Third-trimester education includes information to help the woman distinguish between discomforts of pregnancy and more concerning issues such as intrauterine fetal demise, preterm labor, and preeclampsia. Common discussion during the visit include signs and symptoms of preterm labor (less than 37 weeks) and labor (more than 37 weeks), kick counts, family planning, childbirth classes, breastfeeding, pain management during labor and delivery, expectations in labor and delivery, postpartum care, and newborn care. Additional education must include planned antenatal testing for pregnancies that continue past the expected due date.

Prenatal Care after 40 weeks

Perinatal complications and mortality increase as pregnancy approaches 42 weeks of gestation. The rate of stillbirth and neonatal death doubles. In the United States, women who are not delivered at 40 weeks will most likely deliver before 42 weeks gestation. Labor induction at 41 weeks is recommended to decrease perinatal complications. (Grade A recommendation). At 41 weeks gestation, providers schedule a nonstress test and check the amniotic fluid index for assessing the well-being of the fetus. At the prenatal visit, the physician must review induction plans and indications including setting a date. Women who are greater than 35 years of age have a higher risk of stillbirth after 41 weeks gestation.

Prenatal Care is essential to improving perinatal outcomes. General education about content and visit schedules are standard recommendations based on the United States Preventive Task Force, the American College of Obstetrics and Gynecology, and evidence-based practices. The overall goal of prenatal care is to provide access to quality care based on recommended standards during the pregnancy to result in good maternal and newborn outcomes.

The United States Preventive Task Force recommends that clinicians provide or refer pregnant and postpartum patients at risk for depression for counseling and intervention. (Grade B Recommendation, USPTF)