Large for Gestational Age (LGA) - Notes

Initial Patient Assessment

  • Patient: 28-year-old female, 20 weeks pregnant.

  • History: Unplanned pregnancy, history of irregular periods, hasn't had antenatal screening/checkup.

  • Examination: Fundal height 30 cm.

Differential Diagnosis for Large for Gestational Age (LGA)

  • Wrong Dates: Discrepancy between estimated gestational age and actual fetal size.

  • Macrosomia: Fetus is larger than normal for gestational age.

  • Diabetes: Maternal diabetes (gestational or pre-existing) can lead to increased fetal growth.

  • Genetic Malformations: Certain genetic conditions can affect fetal size.

  • Polyhydramnios: Excessive amniotic fluid.

  • Multiple Pregnancies: Presence of twins or higher-order multiples.

  • Fibroid: Uterine fibroids can increase the size of the uterus.

  • Torch Infections: Infections during pregnancy (Toxoplasmosis, Other, Rubella, Cytomegalovirus, Herpes simplex) can affect fetal growth.

  • Chorioangioma of Placenta: A non-trophoblastic tumor of the placenta, a rare benign vascular tumor of the placenta.

History Taking - Key Questions

Obstetric History

  • Previous tests: "Have you had any blood tests or dating scans done early in the pregnancy?"

  • Down syndrome screening: "Have you had Down syndrome screening?"

  • 18-20 week ultrasound: "Have you had an ultrasound at 18-20 weeks to check fluid and baby?"

  • Preeclampsia symptoms: "Any headaches, blurred vision, nausea, vomiting, or leg swelling?"

Differential Diagnosis Questions

Incorrect Dates

  • Last menstrual period: "When was your last menstrual period?"

  • Period regularity: "Are your periods regular or irregular?"

  • Cycle length: "How long do your cycles usually last?"

Diabetes

  • Previous/family history: "Any previous or family history of high blood sugar/diabetes?"

  • Polyuria: "Have you been passing more urine lately?"

  • Thirst: "Are you feeling more thirsty lately?"

  • Tiredness: "Any complaints of tiredness?"

Multiple Pregnancy

  • Dating/morphology scan: "Have you had a dating scan and morphology scan done?"

  • Morning sickness: "Did you have severe morning sickness early in the pregnancy?"

  • Assisted pregnancy: "Was this an assisted pregnancy?"

  • Family history: "Any family history of twins/multiple pregnancies?"

Fibroids

  • Previous diagnosis: "Have you been told you have fibroids?"

  • Menstrual bleeding: "Did you have heavy bleeding during your periods?"

Torch Infections

  • Symptoms: "Any fever or rashes during your pregnancy?"

  • Contact with sick: "Have you had contact with sick people?"

  • Animal contact: "Do you have contact with animals?"

  • Raw meat: "Do you usually eat raw meat?"

Macrosomia

  • Family history: "Do you have a family history of delivering large babies?"

  • Weight monitoring: "Have you been checking your weight since you became pregnant?"

  • Rapid weight gain: "Was there any rapid increase in your weight?"

Social History

  • Smoking: "Do you smoke?"

  • Alcohol: "Do you drink alcohol?"

  • Drugs: "Do you use any drugs?"

  • Medications: "Are you on any regular medications?"

  • Allergies: "Do you have any allergies?"

  • Past medical history: "Any other relevant past medical history I should know about?"

  • Family history: "Any family history I should know about?"

Diagnosis Explanation

  • Large for Gestational Age (LGA): Womb is larger than expected for gestational age.

  • Polyhydramnios: Increased amniotic fluid.

  • Macrosomia: Baby is larger than usual.

  • Incorrect Dates: Due to irregular periods and lack of dating scan.

  • Torch Infection: Potential infection.

  • Genetic Malformations: Possible genetic issues.

  • Diabetes: Maternal diabetes.

  • Fibroids: Uterine fibroids.

  • Multiple Pregnancies: Potential for twins or higher-order multiples.

Further Investigations

  • Ultrasound:

    • Number of babies

    • Amniotic fluid amount

    • Genetic malformations

  • CTG (Cardiotocography): Fetal heart rate monitoring.

  • Oral Glucose Tolerance Test (OGTT): Assess for gestational diabetes.

  • Torch Serology: Check for TORCH infections.

  • Kidney Function Test: Urea, electrolytes, creatinine.

  • Liver Function Test

  • Full Blood Examination

Physical Examination Findings

  • General Appearance:

    • Alertness, pallor, rashes.

  • Vital Signs:

    • Blood pressure, pulse rate, temperature.

  • Abdomen:

    • Tenderness on uterus.

    • Leopold's maneuver.

    • Fundal height measurement (from symphysis pubis to highest point of uterus).

  • Fetal Assessment:

    • Fetal lie, presentation, and height via Leopold's maneuvers.

    • Fetal heart rate.

  • Pelvic Examination (with consent):

    • Inspection for rashes, bleeding, discharge.

    • Speculum examination: Cervix (bleeding, tissue, swelling), vaginal walls (abnormalities).

    • Uterus cervical motion tenderness, size, tenderness, irregularities.

    • Adnexa: Masses or tenderness.

  • Office Tests:

    • Urine dipstick, blood sugar level.