A critical component of Antenatal care (ANC) is a detailed trimester-wise history of the current pregnancy. Recording this history helps clinicians anticipate complications, guide investigations, and implement timely interventions.
These 3 blog explains what to ask in each trimester, why it matters, and how national guidelines in India inform our practice.
This particular blogs deals with the common questions during the FIRST TRIMESTER.
Case-wise More history may be needed depending upon individual cases.
First Trimester: Early Clues and Risk Identification
Purpose of First-Trimester History
The first trimester is a crucial phase of pregnancy because most fetal organs develop during this period. The aim of first-trimester history taking is to identify risks early and ensure a safe course for both mother and fetus.
Key objectives include:
• Confirming and dating the pregnancy to establish accurate gestational age and viability.
• Detecting early complications such as ectopic pregnancy, miscarriage, molar pregnancy, or severe vomiting.
• Identifying teratogenic exposures like unsafe medications, infections (rubella, varicella), alcohol, smoking, or radiation.
• Screening for chronic medical conditions (diabetes, hypertension, thyroid disorders, epilepsy, renal disease) that may worsen during pregnancy.
• Assessing past obstetric history to recognize women at higher risk of recurrence of earlier complications.
• Initiating essential preventive care including folic acid supplementation and early screening tests recommended in India.
In short, first-trimester history helps detect danger early, guide timely interventions, and set the foundation for comprehensive antenatal care.
Key Areas of History in First Trimester
1. Hyperemesis Gravidarum: This condition involves severe, persistent vomiting leading to dehydration and malnutrition.
• Commonly seen in primigravidas, it may also be associated with molar or multiple pregnancies.
• A history of hyperemesis in prior pregnancies or strong family history raises suspicion.
• It is important to consider even non-obstetric causes:
o Medical: UTI, Hepatitis, Peptic Ulcer, Diabetic Ketoacidosis
o Surgical: appendicitis, cholecystitis,
o Gynecological: Twisted ovarian cysts, red degeneration of fibroid.
2. Bleeding Per Vaginum:
First-trimester bleeding is taken seriously because it may indicate miscarriage, ectopic pregnancy, molar pregnancy, or other complications that affect maternal safety and fetal viability.
Early evaluation ensures timely diagnosis and prevents severe outcomes.
• Ask amount, pain, LMP reliability, tissue passage.
o Possible causes:
o Implantation bleeding
o Impending abortion,
o Ectopic pregnancy,
o Molar pregnancy,
o Cervical lesions (polyp, erosion, carcinoma).
3. Fever and Rash: High-grade fever accompanied by rash is concerning for infections with teratogenic potential such as
• Rubella,
• Chickenpox (varicella), and
• Measles.
Such infections may lead to miscarriage, fetal death, or congenital anomalies.
4. Exposure to Radiation:
Ask about any X-ray exposure and its timing.
• Cumulative radiation above 5 rad is teratogenic. Nevertheless, even low-dose radiation (<5 rad) during the first trimester can increase risks of fetal malformations and childhood cancers.
• Prefer USG/MRI: Common indications for radiation exposure should be critically reviewed, favoring alternatives such as ultrasound or MRI when possible
5. Drug History and Teratogenicity:
It is crucial to document all drugs taken, including over-the-counter and traditional medications.
• Folic acid supplementation (500 mcg daily) before conception and during early pregnancy reduces neural tube defects.
• Drugs are classified by the FDA into categories based on fetal risk—from safe (category A) to contraindicated (category X)—which guides counseling and prescriptions.
• Check for intake of known teratogenic drugs:
o Anti-epileptics – phenytoin and valproate
o Antihyprtensives – ACE inhibitors (captopril, enalapril)
o Anticoagulants – warfarin
o Antibiotics – tetracycline and chloramphenicol (some safe antibiotics in pregnancy are penicillins, cephalosporins, and erythromycin)
o Chemotherapy drugs
References:
• Dutta DC. Textbook of Obstetrics. 9th ed. Jaypee Brothers; 2023.
• Padubidri VG, Daftary SN. Shaw’s Textbook of Gynaecology. 18th ed. Elsevier; 2022.
• Park K. Park’s Textbook of Preventive and Social Medicine. 28th ed. Bhanot; 2025.
• Babu SA. Clinical Obstetrics and Gynecology. 2nd ed. Wolters Kluwer; 2025.
Trimester-wise History Taking in Antenatal Care: SECOND Trimester
Trimester-wise History Taking in Antenatal Case: THIRD Trimester