18.2 Obstetrics & Antenatal Care
Key Takeaways
- Dating uses LMP (Naegele’s rule: add 7 days, subtract 3 months, add 1 year) and early ultrasound; ANC schedules intensify surveillance in the third trimester
- Physiological anaemia of pregnancy reflects plasma-volume expansion; true iron-deficiency anaemia needs confirmation and treatment to reduce maternal–fetal risk
- PIH spectrum ranges from gestational hypertension to preeclampsia–eclampsia; proteinuria and end-organ features distinguish preeclampsia
- APH is bleeding from the genital tract after 28 weeks (or ≥20 weeks in some definitions) before delivery—placenta previa and abruption are the classic pair
- PPH is excessive blood loss after delivery (≥500 mL vaginal / ≥1000 mL caesarean commonly cited); the 4 Ts (tone, trauma, tissue, thrombin) organise causes
18.2 Obstetrics & Antenatal Care
Quick Answer: Date the pregnancy (Naegele + early USG), then triage three red-flag families—anaemia severity, hypertension after 20 weeks with proteinuria/end-organ signs, and bleeding (painless previa vs painful abruption). PPH uses the 4 Ts; Homoeopathic haemorrhage remedies never replace resuscitation language in emergency stems.
AIAPGET obstetrics stems test whether you can recognise physiological adaptation versus pathology, time events by gestational age, and triage bleeding and hypertension. Homoeopathic prescribing in pregnancy still rests on accurate obstetric triage—know when a case is antenatal anaemia, preeclampsia, abruption, or atonic PPH before matching rubrics.
Pregnancy Dating and Antenatal Visits
Gestational age
Naegele’s rule (regular 28-day cycles): Expected date of delivery (EDD) = LMP + 7 days − 3 months + 1 year (or LMP + 9 months + 7 days). Early ultrasound refining crown–rump length is more accurate when LMP is uncertain.
Trimesters (approximate):
- First: up to 12–13 weeks
- Second: ~13–28 weeks
- Third: ~28 weeks to term
Term is often framed as 37–42 weeks; preterm is before 37 completed weeks.
Goals of antenatal care (ANC)
- Confirm pregnancy and viability; establish dating
- Identify high-risk factors (prior preeclampsia, diabetes, anaemia, multiple gestation, prior caesarean, Rhesus negativity)
- Screen maternal infections and immunisation status as per national protocols
- Monitor fetal growth, fetal heart, maternal weight, BP, urine, haemoglobin
- Educate on danger signs: bleeding, severe headache, visual symptoms, epigastric pain, reduced fetal movements, fever, leaking liquor
Visit pattern (conceptual)
Schedules vary by guideline and risk, but exam narratives often emphasise early booking with baseline labs (Hb, blood group/Rh, urine, glucose screening timing per protocol), regular BP and weight checks, and increasing frequency in late pregnancy (monthly → fortnightly → weekly near term in many traditional schedules).
Fundal height roughly matches weeks of gestation in centimetres between ~20–34 weeks in a singleton—discrepancy suggests IUGR, macrosomia, multiples, or liquor abnormalities.
Anaemia in Pregnancy
Physiological versus pathological
Plasma volume expands more than red-cell mass → physiological haemodilution. Still, WHO commonly defines anaemia in pregnancy as Hb <11 g/dL. Iron deficiency is the leading cause worldwide; folate deficiency and haemoglobinopathies matter in Indian exam contexts.
Clinical impact
Maternal: fatigue, tachycardia, decompensation in haemorrhage, higher infection risk, delayed wound healing. Fetal/neonatal: higher preterm birth, low birth weight, and perinatal morbidity with severe anaemia.
Exam approach
- Classify severity (mild/moderate/severe) using Hb cut-offs used in the stem’s guideline
- Seek cause: diet, multiparity, hookworm, chronic disease, bleeding
- Iron therapy principles: oral iron for most; parenteral when oral not tolerated/absorbed or severe; transfusion for very severe anaemia or decompensation—exact thresholds are protocol-dependent, so read the stem’s numbers carefully
Homoeopathic cases often show “weakness after menses + pregnancy pallor”—still verify Hb; do not substitute repertorisation for recognising severe anaemia needing urgent allopathic support.
Hypertensive Disorders: PIH and Preeclampsia
Pregnancy-induced hypertension (PIH) is a broad clinical phrase; modern classification prefers:
| Condition | Core idea |
|---|---|
| Gestational hypertension | New hypertension after 20 weeks without proteinuria/end-organ features |
| Preeclampsia | Hypertension after 20 weeks plus proteinuria and/or maternal end-organ dysfunction and/or uteroplacental dysfunction |
| Eclampsia | Preeclampsia with seizures (not otherwise explained) |
| Chronic hypertension | Hypertension predating pregnancy or before 20 weeks |
| Superimposed preeclampsia | Preeclampsia on chronic hypertension |
Diagnostic anchors
- Hypertension typically ≥140/90 mmHg on appropriately repeated measurements
- Proteinuria historically ≥300 mg/24 h or dipstick ≥1+ (definitions evolve; follow stem)
- Danger features: severe headache, visual scotomata, RUQ/epigastric pain, thrombocytopenia, raised liver enzymes, renal impairment, pulmonary oedema, fetal growth restriction
HELLP (Haemolysis, Elevated Liver enzymes, Low Platelets) is a severe related syndrome—urgent recognition.
Management concepts: BP control, seizure prophylaxis (magnesium sulphate in eclampsia/severe preeclampsia protocols), timed delivery based on severity and gestational age, fluid caution, and neonatal readiness.
Gestational Diabetes and Rh Concepts (high-yield extras)
GDM stems emphasise risk factors (obesity, prior macrosomia, family history, prior GDM), screening timing language, and fetal risks (macrosomia, polyhydramnios, neonatal hypoglycaemia). Maternal hyperglycaemia → fetal hyperinsulinism → postnatal hypoglycaemia is a favourite linking concept into neonatology.
Rh-negative mother / Rh-positive fetus: anti-D prophylaxis after sensitising events and routinely in the third trimester/postpartum per protocol prevents isoimmunisation. Indirect Coombs and neonatal jaundice/haemolysis language connects antenatal Rh status to pathological jaundice stems.
Antepartum Haemorrhage (APH)
APH: bleeding from the genital tract after the fetus is viable—commonly taught as after 28 weeks in many Indian texts (some systems use ≥20 weeks). Two classic causes:
Placenta previa
Placenta overlies or is near the internal os. Painless, causeless, recurrent bright-red bleeding is the textbook pattern. Malpresentation and soft non-tender uterus are clues. Vaginal examination is contraindicated until placenta location is known (ultrasound).
Abruptio placentae (placental abruption)
Premature placental separation. Painful bleeding, tense/tender uterus, hypertonus, fetal distress, and concealed haemorrhage possible. Associated with hypertension, trauma, cocaine, PROM, and sudden decompression.
Other APH causes: vasa previa, uterine rupture, local cervical lesions—always stabilise mother first (ABCs, IV access, blood products readiness).
Postpartum Haemorrhage (PPH) Concepts
Primary PPH: excessive bleeding within 24 hours of birth; secondary PPH: from 24 hours to 6 weeks.
Volume definitions commonly cited: ≥500 mL after vaginal birth or ≥1000 mL after caesarean (clinical shock can occur with less in anaemic women—treat the patient, not only the number).
The 4 Ts
- Tone — uterine atony (most common)
- Trauma — lacerations, haematoma, rupture, inversion
- Tissue — retained placenta/clots
- Thrombin — coagulopathy
Prevention emphasises active management of the third stage (oxytocics, controlled cord traction where trained, uterine massage). Homoeopathic remedies for haemorrhage (Secale, Sabina—therapeutics section) never replace emergency obstetric protocols for massive PPH.
Integrating ANC Red Flags
Teach patients and recognise in stems:
- Bleeding any amount in later pregnancy
- Severe headache / visual change / epigastric pain
- Reduced fetal movements
- Fever with abdominal pain
- Sudden swelling of face/hands with hypertension
- Leaking liquor or suspected PROM
These red flags convert “routine ANC” stems into emergency obstetric recognition items—a frequent AIAPGET pattern. When a stem mixes mild nausea with Sepia or Pulsatilla keynotes, still scan for hypertension, bleeding, and severe anaemia before settling on a polychrest.
Using Naegele’s rule for a woman with a regular 28-day cycle, how is the expected date of delivery estimated from the first day of the last menstrual period (LMP)?
Which clinical pattern best suggests placenta previa rather than placental abruption?
Preeclampsia is most accurately characterised as new-onset hypertension after 20 weeks together with which additional element?
In the ‘4 Ts’ framework for postpartum haemorrhage, which T corresponds to the most common cause?