Anaemia in Pregnancy

Overview

Anaemia in pregnancy is a condition characterized by a reduced hemoglobin level, leading to decreased oxygen-carrying capacity of the blood. It is a common complication worldwide, affecting maternal and fetal health, with risks including preterm birth, low birth weight, and increased maternal mortality. Globally, anaemia affects about 40% of pregnant women, primarily due to iron deficiency. In Sri Lanka, despite a strong public health system, anaemia remains prevalent, with recent data showing 15% among pregnant women aged 18-60 years in 2022 according to the Sri Lanka National Nutrition and Micronutrient Survey (NNMS). Other estimates include 22.9% in 2023 from World Bank data and 29.1% in 2018. Sri Lanka's national guidelines emphasize prevention through supplementation and screening, with a transition from iron-folic acid (IFA) to multiple micronutrient supplements (MMS) for non-anaemic women. Key guidelines include the National Guidelines for Maternal Care Volume III (2015) available here from the Family Health Bureau, Ministry of Health, and recommendations from the Sri Lanka College of Obstetricians & Gynaecologists (SLCOG).

Classification

According to Sri Lankan guidelines, anaemia is classified by hemoglobin (Hb) levels, irrespective of gestation:

• Mild: 10-10.9 g/dL
• Moderate: 7-9.9 g/dL
• Severe: <7 g/dL

It is often iron deficiency anaemia (IDA), but can include folate/B12 deficiency, thalassaemia, or other causes.

Signs and Symptoms

Many cases are asymptomatic, but symptoms may include fatigue, pallor, shortness of breath, dizziness, palpitations, and pica (craving non-food items). Severe cases can lead to heart failure or decompensation. In Sri Lanka, symptoms are screened during antenatal visits.

Causes and Pathophysiology

The primary cause is iron deficiency due to increased demands (up to 1,000 mg total iron needed in pregnancy), poor diet, and absorption issues. Other causes include parasitic infections (e.g., helminths), chronic diseases, hereditary conditions like thalassaemia (prevalent in Sri Lanka), and blood loss. Vitamin B12 deficiency contributes in 23.8% of anaemic cases in early pregnancy. Pathophysiology involves depleted iron stores leading to reduced erythropoiesis.

Risk Factors

Risk factors include teenage pregnancy, high parity, short birth intervals, multifetal gestation, low socioeconomic status, vegetarian diets, and history of anaemia or heavy bleeding. In Sri Lanka, diets high in cereals/legumes with low bioavailable iron increase risk.

Diagnosis

Diagnosis uses full blood count (FBC) preferred over single Hb measurement. Screening at first antenatal visit and 28-30 weeks; additional at 20-24 weeks for high-risk. Indicators of IDA: Hb <11 g/dL, MCV <80 fL, MCHC <30%, serum ferritin <20 μg/L, microcytic hypochromic blood picture. In Sri Lanka, Basic Maternal Care Manual guides screening via antenatal clinics.

Treatment

Management depends on severity and gestation:

• Mild/moderate: Oral iron 120 mg elemental daily (two 60 mg doses), with dietary advice and antihelminthics. Continue for 3 months post-correction, then supplementation.
• Severe: Immediate referral, possible blood transfusion if Hb <7 g/dL or decompensation.
• Intravenous iron for non-responders or late presentation (36-38 weeks).
• Aim: Hb >10 g/dL by delivery. In Sri Lanka, guidelines recommend therapeutic trial of oral iron; non-responders referred for further tests (e.g., ferritin). SLCOG suggests 30 mg daily for prevention if prevalence <40%.

Prevention

Daily supplementation: 60 mg elemental iron + 400 μg folate from ~12 weeks, with 50 mg vitamin C. Take 1 hour before meals, avoid tea/coffee/dairy nearby. Periconceptional folate 1 mg in first trimester. Sri Lanka provides free IFA/MMS via antenatal clinics, with counselling on iron-rich foods. Transitioning to MMS for all pregnant women. Food fortification (e.g., wheat flour since 2024) and deworming based on prevalence.

Prognosis

With treatment, most recover, but untreated increases risks of PPH, infection, and fetal issues. Postpartum FBC recommended for anaemic women. In Sri Lanka, high compliance (80.1%) to IFA, but dietary issues persist.

Epidemiology

Sri Lanka has seen progress, with prevalence dropping to 15-23% recently, classified as mild public health issue. Higher in rural areas; B12 deficiency notable in early pregnancy. Policies align with WHO, delivered via Family Health Bureau.

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