What are the recommended assessments and interventions for a prenatal check-up at 27 weeks of gestation?

From the Guidelines

At 27 weeks gestation, a comprehensive prenatal check-up should include blood pressure measurement, weight assessment, fundal height measurement, fetal heart rate monitoring, and screening for gestational diabetes if not already completed, as recommended by recent guidelines 1. The healthcare provider should assess for signs of preeclampsia by checking blood pressure (target below 140/90 mmHg) and testing urine for protein. Fundal height should measure approximately 27 cm, corresponding to gestational age. Fetal movement should be evaluated, with patients typically feeling at least 10 movements within a 2-hour period. Some key points to consider during this visit include:

• Laboratory tests should include a complete blood count to check for anemia (hemoglobin should be above 10.5 g/dL), and if the patient is Rh-negative and not sensitized, Rho(D) immune globulin (RhoGAM) 300 mcg should be administered at this visit.
• Nutritional counseling should address appropriate weight gain (approximately 1 pound per week during the second and third trimesters) and adequate intake of iron, calcium, and folic acid.
• Patients should be educated about preterm labor warning signs, including regular contractions, pelvic pressure, low back pain, and increased vaginal discharge.
• This visit is also an appropriate time to discuss birth plans, breastfeeding options, and to answer any questions about the third trimester. According to the most recent guidelines, all pregnant women not previously known to have diabetes should be evaluated for gestational diabetes mellitus (GDM) at 24 to 28 weeks of gestation 1. Additionally, the International Association of Diabetes and Pregnancy Study Groups (IADPSG) recommends “outcome based” criteria for the classification of glucose concentrations in pregnancy, which can help identify women at risk for GDM 1. It is also important to note that the Society for Maternal-Fetal Medicine recommends that fetal growth restriction be defined as an ultrasonographic estimated fetal weight or abdominal circumference below the 10th percentile for gestational age, and that a detailed obstetrical ultrasound examination be performed with early-onset fetal growth restriction (<32 weeks of gestation) 1. The American College of Obstetricians and Gynecologists (ACOG) and the Royal College of Obstetricians and Gynecologists agree that the risk of perinatal morbidity and mortality increases once the estimated fetal weight or the abdominal circumference < 10th centile, and that amniotic fluid an important diagnostic and prognostic parameter in fetuses with intrauterine growth restriction 1. Overall, these assessments and interventions are crucial as the pregnancy transitions to the third trimester, when monitoring for complications becomes increasingly important.

From the Research

Prenatal Check-up at 27 Weeks

At 27 weeks of gestation, the following assessments and interventions are recommended:

• Screening for gestational diabetes between 24 and 28 weeks is recommended for all patients 2
• Fetal heart rate monitoring and other antepartum fetal surveillance techniques may be used to assess fetal well-being, especially in high-risk pregnancies 3, 4
• Ultrasound may be used to assess fetal anatomy and detect any potential issues 4
• Fetal movement analysis may be used as a method of assessing fetal wellbeing, particularly in high-risk cohorts with fetal growth restriction 5

Risk Factors and Interventions

Pregnant individuals with certain risk factors, such as advanced maternal age (35 years or older), may require additional assessments and interventions, including:

• Ancestry-based genetic risk stratification using family history to inform genetic screening 2
• Rho(D) immune globulin to decrease alloimmunization risk in RhD-negative individuals carrying an RhD-positive fetus 2
• Treatment of iron deficiency anemia to decrease the risk of preterm delivery, intrauterine growth restriction, and perinatal depression 2

General Prenatal Care

General prenatal care recommendations include:

• Folic acid supplementation (400 to 800 mcg daily) to decrease the risk of neural tube defects 2
• Screening for asymptomatic bacteriuria, sexually transmitted infections, and immunity against rubella and varicella 2
• Administration of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap), influenza, and COVID-19 vaccines as recommended 2