Which Hadlock formula is used for Expected Fetal Weight (EFW) in India?

The Hadlock 1985 formula is standard in Indian obstetric practice. The 4-parameter formula (BPD+HC+AC+FL) is preferred for accuracy; the 3-parameter formula (BPD+AC+FL) is used when head circumference (HC) is unavailable. EFW results have ±15% variability.

What is a good Bishop score for induction of labour?

A Bishop score ≥9 is highly favourable — direct oxytocin induction of labour is appropriate. Score 6–8 is favourable. Score below 6 requires cervical ripening with prostaglandins (PGE2) or mechanical methods (Foley balloon) before induction.

What is the DIPSI protocol for GDM screening in India?

DIPSI (Diabetes in Pregnancy Study Group India) recommends a 75g oral glucose tolerance test (non-fasting). Blood glucose ≥140 mg/dL at 2 hours is diagnostic for gestational diabetes mellitus (GDM). FOGSI recommends universal screening at first antenatal visit and at 24–28 weeks for all Indian pregnant women.

How is PPH risk stratified in obstetrics?

PPH risk is assessed using weighted risk factors per RCOG/FOGSI guidelines. Risk categories: Low (score 0), Moderate (score 1-2), High (score 3-4), Very High (score ≥5). Management escalates with risk level — from standard AMTSL (low risk) to MDT involvement and cell salvage (very high risk).

← All Calculators

GA by LMP / Scan EFW Hadlock Bishop Score Apgar Score GDM Screening VBAC Eligibility PPH Risk

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Gestational Age Calculators

GA by LMP · GA by Ultrasound Scan · GA on Any Date · LMP from EDD

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Gestational Age by LMP (Naegele's Rule)

Calculate gestational age and expected due date (EDD) from the last menstrual period (LMP), adjusted for menstrual cycle length.

Last Menstrual Period (LMP)

Cycle Length (days)

Gestational Age by Ultrasound Scan

Back-calculate expected due date (EDD) and LMP from ultrasound dating. Most accurate in first trimester (CRL measurement).

Scan Date

GA at Scan — Weeks

GA at Scan — Days

Gestational Age on Any Given Date

Find exact gestational age (weeks and days) on a specific date — useful for operation notes, discharge summaries, or referral letters.

LMP Date

Calculate GA on

Cycle Length

LMP from EDD (Reverse Calculator)

Calculate the last menstrual period (LMP) and approximate conception date when only the estimated due date (EDD) is known.

Estimated Due Date (EDD)

Cycle Length

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Fetal Assessment

Expected Fetal Weight (Hadlock Formula) · Apgar Score Calculator

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Expected Fetal Weight (EFW) — Hadlock 1985 Formula

Calculate estimated fetal weight using Hadlock formula with biometric measurements. 4-parameter (BPD+HC+AC+FL) preferred; 3-parameter (BPD+AC+FL) if HC unavailable. Measurements in millimeters.

BPD (mm)

HC (mm, optional)

AC (mm)

FL (mm)

GA at Scan (weeks)

💡 Note: Head circumference (HC) is optional. If not available, the 3-parameter formula (BPD+AC+FL) will be used automatically. All EFW results have ±15% variability — use for trend monitoring.

Apgar Score Calculator (Newborn Assessment)

Score all 5 criteria (A-P-G-A-R) from 0–2 each. Assessment typically at 1 minute and 5 minutes after birth.

A — Appearance (Colour)

P — Pulse (Heart Rate)

G — Grimace (Reflex Irritability)

A — Activity (Muscle Tone)

R — Respiration (Breathing Effort)

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Obstetric Scoring & Risk Assessment

Bishop Score · VBAC Eligibility · PPH Risk Assessment

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Bishop Score — Cervical Favorability Assessment for Induction of Labour

Score all 5 cervical parameters to assess favorability before labor induction. Score ≥9 favourable for oxytocin; <6 requires cervical ripening.

Cervical Dilation (cm)

Cervical Effacement (%)

Fetal Head Station

Cervical Consistency

Cervical Position

VBAC/TOLAC Eligibility Assessment — FOGSI & ACOG Guidelines

Assess suitability for trial of labor after cesarean (TOLAC) or vaginal birth after cesarean (VBAC). Answer all 8 questions per FOGSI/ACOG criteria.

Uterine Scar Type

Number of Previous Cesarean Sections

Previous Vaginal Delivery

Indication of Previous Cesarean Section

Interpregnancy Interval

Current Fetal Presentation

Estimated Fetal Weight

Uterine Scar Thickness on Ultrasound

Postpartum Hemorrhage (PPH) Risk Assessment

Select all applicable risk factors. Risk score calculated per RCOG and FOGSI guidelines. PPH defined as blood loss ≥500ml (vaginal) or ≥1000ml (cesarean).

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Maternal Screening

GDM Screening Dates — DIPSI & FOGSI Protocol

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Gestational Diabetes Mellitus (GDM) Screening Schedule — DIPSI / FOGSI

Calculate personalized GDM screening dates based on DIPSI protocol and risk factors. High-risk women receive early and more frequent screening per FOGSI guidelines.

Last Menstrual Period (LMP)

Select all applicable risk factors

ObsCalc India — Free Obstetric Calculator Suite for Doctors

ObsCalc is a comprehensive, free obstetric calculator platform designed for Indian obstetricians and gynecologists. It provides instant, evidence-based calculations for all common bedside obstetric assessments — gestational age, fetal weight, cervical scoring, newborn assessment, GDM screening, VBAC eligibility, and postpartum hemorrhage risk. All calculators follow FOGSI, ACOG, RCOG, and WHO guidelines.

Gestational Age Calculators

GA by LMP (Naegele's Rule): Calculate gestational age and expected due date (EDD) from the last menstrual period (LMP), adjusted for menstrual cycle length. Displays current trimester, weeks/days, and EDD with calendar integration.

GA by Ultrasound Scan: Back-calculate EDD and LMP from ultrasound-dated gestational age. Most accurate in the first trimester using crown-rump length (CRL) measurement; accuracy decreases in second and third trimesters.

GA on Any Given Date: Calculate the exact gestational age (weeks and days) on any specified date — essential for operation notes, discharge summaries, and referral letters.

LMP from EDD (Reverse Calculator): Reverse-calculate the last menstrual period (LMP) and approximate conception date when only the estimated due date (EDD) is known.

Fetal Assessment Tools

Expected Fetal Weight (EFW) — Hadlock 1985 Formula: Gold-standard biometric formula used in Indian obstetric practice. Accepts 4-parameter (BPD+HC+AC+FL) for maximum accuracy, or 3-parameter (BPD+AC+FL) when head circumference is unavailable. Results include ±15% confidence interval and small-for-gestational-age (SGA), appropriate-for-gestational-age (AGA), and large-for-gestational-age (LGA) classification.

Apgar Score Calculator: Calculate newborn Apgar score (0–10) from five clinical criteria assessed at 1 minute and 5 minutes post-birth. Categorizes as normal (7–10), moderately depressed (4–6), or severely depressed (0–3) with corresponding management recommendations.

Obstetric Scoring & Risk Assessment

Bishop Score (Cervical Favorability): Assess cervical favorability for labor induction by scoring five parameters: dilation, effacement, station, consistency, and position. Score ≥9 highly favourable (direct oxytocin); scores 6–8 favourable; <6 requires cervical ripening with prostaglandins or mechanical methods.

VBAC/TOLAC Eligibility Assessment: Comprehensive 8-point checklist per FOGSI and ACOG guidelines. Evaluates uterine scar type, number of previous cesarean sections, previous vaginal delivery, indication for prior CS, interpregnancy interval, current presentation, estimated fetal weight, and uterine scar thickness on ultrasound. Provides absolute contraindications, relative risks, and eligibility verdict.

Postpartum Hemorrhage (PPH) Risk Assessment: Weighted risk factor calculator based on RCOG and FOGSI guidelines (15 factors). Stratifies risk as Low/Moderate/High/Very High with specific management protocols including AMTSL, IV access, blood crossmatch, and MDT involvement as risk escalates.

GDM Screening Schedule — DIPSI & FOGSI Protocol

The DIPSI (Diabetes in Pregnancy Study Group India) protocol recommends universal gestational diabetes screening for all pregnant women in India using a single-step 75g oral glucose tolerance test (non-fasting). Blood glucose ≥140 mg/dL at 2 hours is diagnostic for GDM. FOGSI guidelines recommend screening at booking (first antenatal visit) and at 24–28 weeks. High-risk women (obesity, previous GDM, family history of diabetes, PCOS) receive an additional screen at 32–34 weeks for comprehensive coverage.

Why Use ObsCalc?

Accurate & Evidence-Based: All calculators follow FOGSI, ACOG, RCOG, and WHO standards.

Instant Results: No registration, login, or delays — calculate immediately.

Mobile-Friendly: Works seamlessly on phones, tablets, and desktops.

Comprehensive: 10+ tools cover prenatal, intrapartum, and immediate postpartum assessments.

Clinical Workflow Integrated: Share results via WhatsApp, print for medical records, save as images, add to calendar.

Frequently Asked Questions

How is gestational age calculated from LMP?

Using Naegele's Rule, gestational age is calculated by adding 280 days to the first day of the last menstrual period (LMP). Adjustment is made for non-standard menstrual cycles: add or subtract the difference from 28 days. For example, a 30-day cycle gets +2 days added to the standard 280-day calculation.

Which Hadlock formula should be used for EFW in India?

The Hadlock 1985 formula is the gold standard in Indian obstetric practice. The 4-parameter formula (BPD+HC+AC+FL) is most accurate; the 3-parameter formula (BPD+AC+FL) is used when head circumference (HC) is not available. All EFW estimates have ±15% variability and should be combined with clinical findings — never used in isolation for clinical decisions.

What Bishop score indicates favorable cervix for induction?

Bishop score ≥9 indicates highly favorable cervix — direct oxytocin induction of labor is appropriate. Score 6–8 is favorable — induction likely to succeed. Score <6 is unfavorable — cervical ripening with prostaglandins (PGE2) or mechanical methods (Foley catheter balloon) is recommended before induction.

What is the DIPSI GDM screening protocol in India?

DIPSI recommends a single-step, non-fasting 75g oral glucose tolerance test (OGTT). Blood glucose ≥140 mg/dL at 2 hours post-glucose load is diagnostic for gestational diabetes mellitus (GDM). FOGSI recommends universal screening for all pregnant women at first antenatal visit and at 24–28 weeks, with additional screening at 32–34 weeks for high-risk women.

What are the VBAC eligibility criteria per FOGSI and ACOG?

FOGSI and ACOG criteria for VBAC/TOLAC: (1) Single previous low transverse lower segment cesarean section (LSCS), (2) cephalic presentation, (3) uterine scar thickness ≥3.5mm on ultrasound, (4) no recurring indication for cesarean (e.g., not CPD if vertex delivery possible), (5) interpregnancy interval ≥18 months. Trial of labor after cesarean (TOLAC) requires emergency cesarean capability and continuous cardiotocography (CTG) monitoring.

What is a normal Apgar score for a newborn?

Apgar score 7–10 is normal — routine newborn care is sufficient. Score 4–6 is moderately depressed — oxygen therapy, tactile stimulation, and possible bag-mask ventilation required. Score 0–3 is severely depressed — immediate full resuscitation including positive pressure ventilation (PPV), chest compressions if needed, medication, and resuscitation team activation.

What are the common causes of postpartum hemorrhage?

Postpartum hemorrhage (PPH) is most commonly caused by uterine atony (the '4 Ts': Tone, Trauma, Tissue, Thrombin). PPH is defined as blood loss ≥500ml after vaginal delivery or ≥1000ml after cesarean section. FOGSI and RCOG recommend active management of the third stage of labor (AMTSL) for all women to prevent PPH — oxytocin 10 IU intramuscularly at delivery of the anterior shoulder, controlled cord traction, and fundal massage.

What is macrosomia in pregnancy?

Macrosomia refers to a fetus with estimated weight ≥4 kg (some definitions use ≥4.5 kg). Risks include cephalopelvic disproportion (CPD), prolonged labor, maternal perineal trauma, and neonatal hypoglycemia, shoulder dystocia, and brachial plexus injury. Maternal gestational diabetes mellitus (GDM), obesity, and maternal age ≥35 are key risk factors for fetal macrosomia.

Related Clinical Tools

⚠️ For clinical use by qualified healthcare professionals only. Results are clinical decision aids — always apply clinical judgment, combine with physical examination findings, and refer to current FOGSI, ACOG, RCOG, and WHO guidelines for individual patient management decisions. This tool does not replace professional medical advice.