A large study of over 2 lakh pregnant women across India has found a strong link between anaemia and stillbirth risk, with severe anaemia carrying the greatest danger.

The study was published in The Lancet Regional Health Southeast Asia by researchers from the University of Oxford, the Indian Council of Medical Research (ICMR), and the ICMR-Stillbirth Pooled India Cohort (ICMR-SPIC) consortium. 

It pooled data from 214,709 pregnant women across ten states, drawn from eight observational studies and two randomised controlled trials conducted between 1994 and 2023.

The dataset included 108,982 women, or 52% of the total, who had moderate to severe anaemia. Of the 3,595 stillbirths recorded across the study, 2,091, or nearly 58%, occurred among women in this group. 

According to the study, India accounted for 17.3% of the global stillbirth burden in 2019. Over half of pregnant women in India are anaemic, according to National Family Health Survey-5 (2019-21) data cited in the paper.

The latest National Family Health Survey-6 fact sheet shows that antenatal care coverage in the country remains high on paper. 95.9% of mothers reported at least one antenatal care visit, and 76.2% had a check-up within the first trimester of pregnancy. 

However, iron folic acid supplementation, a standard measure to prevent and treat anaemia during pregnancy, tells a different story. Only 54.9% of mothers consumed iron folic acid for 100 days or more during pregnancy, and just 37.8% did so for 180 days or more, the recommended duration. 

Researchers classified anaemia using WHO haemoglobin cut-offs: severe (below 7 g/dL), moderate (7.0-9.9 g/dL), and no or mild (10 g/dL and above). Stillbirth was defined as fetal death at or after 28 weeks of pregnancy.

Because very few stillbirths occurred among severely anaemic women in some of the smaller cohorts, researchers combined the moderate and severe anaemia groups for part of the analysis. They calculated the stillbirth risk separately for each of the ten cohorts, and then combined these results to arrive at an overall figure. 

Women with severe anaemia had more than three times the risk of stillbirth compared to those with no or mild anaemia, the study found, after adjusting for factors such as maternal age, education, BMI, and hypertensive disorders. Moderate anaemia was linked to a 20% higher risk.

In absolute terms, the study noted, “The proportion of stillbirth was 1.5%, 1.8%, and 4.9% in the no/mild, moderate, and severe anaemia categories, respectively.” 

Stillbirths among severely anaemic women occurred earlier in pregnancy, the study pointed out, at a median gestational age of around 29 weeks, compared to around 31 weeks among other women.

The study also tracked how many pregnancies continued safely as gestation progressed, week by week, comparing women with different levels of anaemia. It found that among women with severe anaemia, a noticeably higher number of pregnancies ended in stillbirth as the weeks went on, compared to women with little or no anaemia. 

The study noted that this comparison confirmed that severe anaemia posed a substantially higher risk, though they cautioned that the exact size of this risk could not be pinned down with precision, given how few cases of severe anaemia were recorded in some cohorts. 

“Trimester wise analysis showed significant risk of stillbirth among women with moderate and severe anaemia,” the study said, adding, “The risk of stillbirth among women with mild anaemia was not statistically significant, except in the second trimester.” 

Researchers pointed out that this pattern in the second trimester may be linked to the fact that different haemoglobin cut-offs are used to define mild anaemia at different stages of pregnancy. 

The study described maternal anaemia as “an important and potentially modifiable risk factor for stillbirth, with severe anaemia associated with early occurrence of stillbirth.”

The researchers highlighted two possible biological pathways linking maternal anaemia to stillbirth. One is that anaemia in the mother could lead to anaemia in the foetus, causing oxidative stress and restricting foetal growth due to weakened placental blood flow. 

The other is that maternal anaemia could contribute to cardiovascular defects in the foetus, which in some cases could result in stillbirth. The study made it clear that it did not directly examine these mechanisms and said this would require further research.

The study also compared its findings with earlier Indian research. 

A 2018 study using Annual Health Survey data from nearly 9 lakh women had reported 35% higher odds of stillbirth among women with any anaemia, though that study recorded a lower overall stillbirth rate than the ICMR-SPIC dataset. The authors said the difference in cohorts included could explain the variation in findings between the two studies.

The study acknowledged some limitations. It was based on observational data, meaning it can show an association between anaemia and stillbirth but cannot establish that anaemia directly causes stillbirth. It also did not distinguish between different causes of anaemia, such as iron deficiency, infection, or genetic factors, which may respond differently to treatment.

The gap between how many women receive antenatal check-ups and how many complete the recommended course of iron folic acid tablets could help explain why anaemia, and its associated risks, remain so persistent despite decades of screening.

Expert Insights

Dr Naima Afreen, an obstetrician and gynaecologist who runs Baby Hospital in Azamgarh, Uttar Pradesh, said anaemia remains widespread among pregnant women, cutting across social and economic groups. “However, its severity often varies with income and access to nutrition,” she said.

“Around 30 to 40% of the pregnant females are anaemic,” she said. “We have found in around 50% of the cases, it is one of the common causes related to morbidity and mortality as well.”

Dr Afreen said the condition, though common, is frequently overlooked. “Anaemia can even cause death as well in pregnant females,” she said. 

“It is a silent disease which is consistent in pregnant females.”

She attributed much of this to entrenched dietary habits in Indian households, where women often eat last and are served depleted portions of nutrient-rich food. 

“By the time they sit to eat, half of the nutritious things are finished,” she said, referring to items such as salad and curd that are often not replenished once consumed by the rest of the family. “Gradually, they have nutritional deficiency, which is contributing to a lot of problems like anaemia.”

Dr Afreen said the study’s finding that severe anaemia triples the risk of stillbirth could be explained by reduced oxygen supply to the foetus in severely anaemic women. “These kinds of females have very low oxygen-sharing capacity,” she pointed out. 

“The placenta is not getting enough oxygen, which is at the end being supplied to the foetus, which leads to growth retardation and various other complications in the foetus.” 

Dr Afreen also linked severe anaemia to socioeconomic background. “Low social normative status is, of course, related to severe anaemia,” she said.

She explained that diet plays a bigger role than supplements in preventing anaemia. Even if a woman skips iron tablets, she is less likely to become severely anaemic if her regular diet is rich in iron. This, Dr Afreen said, is often why women from wealthier households show fewer signs of severe anaemia compared to those from poorer backgrounds, who may lack access to a nutritious diet regardless of whether they take supplements.

Dr Afreen highlighted that anaemia should be assessed from the first antenatal visit, even though iron supplements are typically not prescribed in the first trimester. “You have to thoroughly look into the patient for all the signs and symptoms of anaemia right from the first visit,” she said, adding that early counselling on iron-rich diets can reduce the chances of women becoming anaemic later in pregnancy.

She said poor antenatal care, often driven by the perception that pregnancy does not require medical supervision, compounds the problem. 

“The majority of people take pregnancy very casually,” she said, noting that the World Health Organisation recommends at least three antenatal visits, one in each trimester, to catch complications early.

Dr Afreen said patients often hide it from doctors when they are unable to tolerate iron supplements due to side effects such as nausea, leading to undiagnosed anaemia persisting through pregnancy. 

She pointed to newer treatment options such as ferric carboxymaltose infusions, which she said can raise haemoglobin levels significantly within weeks and are more convenient than repeated oral supplementation. 

“We find a very good rise in haemoglobin by three or four g/dL,” she said, adding that cost need not be a barrier if such compounds are administered at their landing price rather than the marked-up retail price.

Gaps in public healthcare access 

Dr Reeta Mahey, professor at the Department of Obstetrics and Gynaecology at the All India Institute of Medical Sciences (AIIMS), New Delhi, said the study’s findings reflect gaps in treatment access at public healthcare centres across the country.

“Our hospital treats many fewer patients while other government hospitals have thousands of patients coming in,” she said, adding that most patients at AIIMS are referrals from other hospitals. “In hospitals like ours, the treatment of anaemia among pregnant women starts generally at the very beginning.”

Dr Mahey referred to the study’s findings on the timing of stillbirths among severely anaemic women. “As the study rightly says, if a pregnant woman is not treated for severe anaemia, major complications can be seen during the third trimester or from the 28 weeks of pregnancy,” she said. 

She added that a single factor rarely causes anaemia in pregnancy. Poor nutrition, inadequate antenatal care, and underlying infections often act together to worsen the condition, she said.

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