Trimester-wise Antenatal History: First, Second & Third Trimester Guide | ihatepsm.com
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.
This blog explains what to ask in each trimester, why it matters, and how national guidelines in India inform our practice.
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
Trimester-wise History in ANC: Second Trimester
The main focus in this period is fetal well-being and growth, screening for early complications, and ensuring vaccination is up-to-date.
1. Ask about Antenatal Visits: How many ANC visits in this trimester?
• Helps assess if antenatal care has been adequate and timely
2. Vaccination– Td (Tetanus & Diphtheria): If received any tetanus injections during this trimester? Ask about Td vaccine timing
If vaccination status is unknown, there may be a need to give 2 doses 4 weeks apart.
If completely vaccinated in last 3 years, only 1 booster is needed.
3. Quickening: (Fetal Movement Felt by the Mother for the FIRST time in current pregnancy)
Ask when did the mother first perceive fetal movements:
Typically, a Primigravida feels at 18–20 weeks and a Multigravida at 16–18 weeks
Clinical importance:
• Confirms a live fetus at that time.
• Helps estimate gestational age, especially if LMP is uncertain or cycles were irregular.
• Estimating EDD using quickening:
o Primigravida: Date of quickening + 20 weeks
o Multigravida: Date of quickening + 22 weeks
Note: These methods are approximate and used only when LMP/early scan is unreliable.
4. Iron and Calcium Supplementation: Ask about compliance with supplements
1. Iron–Folic Acid (IFA): under ‘Anemia Mukt Bharat’:
• Prophylactic: One tablet (60 mg elemental iron + 500 mcg folic acid) daily from 2nd trimester for at least 180 days and to continue for 180 days after delivery.
• Therapeutic IFA (if anemia is diagnosed): One tablet TWICE daily for the same period
2. Calcium: One tablet (500 mg calcium +250 IU Vitamin D3), Twice a day, From second trimester (14 weeks) onwards throughout pregnancy for 6 months (360 tablets) and continued for 6 months after delivery (360 tablets) taken in between meals
• Iron folic acid tablet and calcium tablets should not be taken together at the same time.
• There should be a gap of at least 2 hours between IFA and calcium for better absorption of both.
• Calcium should not be taken immediately after a meal.
5. Ask for Symptoms Suggestive of Preeclampsia
• Headache
• Blurred vision
• Epigastric pain
• Decreased urine output
• Sudden or excessive weight gain
• Swelling of face/hands/feet
Physiological edema of feet may occur in late second trimester; still the possibility of pre-eclampsia must be ruled out
• If edema feet disappears after rest, it is likely to be physiological;
• Nevertheless, you must question about headache, visual disturbance and oliguria, to rule out pre-eclampsia
Normal weight gain: 10–12 kg during pregnancy; about 5 kg in the 2nd trimester.
7. Screening for Gestational Diabetes Mellitus (GDM): Ask whether GDM screening has been done.
Universal screening is done at the first visit and a repeat screening at 24–28 weeks.
8. Ask if the Second Trimester Anomaly Scan has been done at 18–22 weeks for detecting major structural anomalies
9. Ask about Maternal Comfort and Sleep
Though there is individual variation, the usual advice is: 10 hours rest (8 hours at night + 2 hours during the day).
• In late pregnancy, left lateral position—improves comfort and uteroplacental blood flow.
10. Any Bleeding per vaginum
Third Trimester: Preparing for Delivery and Complication Surveillance
In the third trimester (28 weeks until delivery), the focus shifts to delivery planning and monitoring for potential maternal or fetal complications.
History Elements to Prioritize
Antenatal Visits: Ongoing assessment of booking and care continuity.
Fetal Movement Monitoring: Patient should report perception of fetal movements
• Reduced or absent movements may indicate fetal distress.
Bleeding Per Vaginum:
Causes include
• Physiological show with labor onset,
• Placenta previa,
• Abruption placentae,
• Scar rupture (common in previous cesarean sections), and
• Cervical lesions.
Prompt history helps distinguish between these and initiate appropriate referral.
Drug Compliance: Continued iron and calcium supplementation adherence should be emphasized.
Symptoms of Preeclampsia or Eclampsia:
• Persistent headache,
• Visual changes,
• Abdominal pain,
• Swelling, and
• Decreased urine output
If present, require urgent attention.
Pain Abdomen: Causes in late pregnancy include
• Labor Pain,
• Abruption,
• Uterine Rupture (Scarred Uterus), But Also
Non-Obstetric Causes Like
• Urinary Tract Infections Or
• Appendicitis Etc.
Leaking Per Vaginum: Assess for rupture of membranes (ROM)—
• Prelabor rupture of membranes (PROM) if term,
• Preterm premature rupture of membranes (PPROM) if before 37 weeks.
Diagnosis includes history, clinical exam with speculum, and tests for leakage of amniotic fluid.
Birth preparedness and Complication Readiness (BPCR) — preferred place and mode of delivery, plans for labor and other components of BPCR
Psychosocial aspects — support system, stress, mental health, and counseling needs.
Signs of labor or complications — premature rupture of membranes, contractions, bleeding.
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.
• Care During Pregnancy and Childbirth: Training Manual for Community Health Officers. Ministry of Health and Family Welfare, Government of India; 2019. Available from: https://nhsrcindia.org/sites/default/files/2021-12/Care%20During%20Pregn... (Accessed 2025 Nov 17).