# Cohort Profile: the SMRU Refugee and Migrant Pregnancy Study in Western Thailand and Eastern Myanmar

## TL;DR

This paper describes a long-term study of nearly 100,000 refugee and migrant pregnant women in Thailand and Myanmar, tracking health outcomes and informing global guidelines.

## Contribution

The study provides extensive longitudinal data from marginalized populations, revealing high maternal mortality and informing malaria treatment and maternal care guidelines.

## Key findings

- Maternal mortality rate was 176 per 100,000 livebirths, highlighting severe risks in refugee and migrant populations.
- Over 10% of pregnancies were affected by malaria, leading to changes in WHO treatment guidelines.
- Low average maternal height raises questions about the applicability of global pregnancy care guidelines in this population.

## Abstract

Marginalised populations face significant health risks in pregnancy with reduced access to preventive and life-saving services due to conflict and migration. Infectious disease risk is high and the double burden of malnutrition increases risk from non-communicable disease although only weak epidemiological data supports this in refugees and migrant communities. This manuscript describes the SMRU Refugee and Migrant Pregnancy Cohort commencing nearly 40 years ago, established in response to the very high rate of
Plasmodium falciparum maternal mortality in refugee camps on the Thailand Myanmar border

Pregnant women who registered to antenatal care clinics of the Shoklo Malaria Research Unit from 1986 to 2024 living in marginalised communities of refugee and migrants were the eligible population. Pregnancies were prospectively followed from enrolment through to childbirth. Types of data include: 1) medical and obstetric records including patient characteristics, pregnancy progress and birth outcomes and 2) investigations (such as HIV).

Among 94,645 pregnancies maternal mortality was 176 per 100,000 livebirths (120/68,024). Embedded cohorts included observational and clinical trials, providing evidence on the optimisation of treatment of malaria in pregnancy and on the rapid changes towards non-communicable diseases in refugees and migrants. Low mean height (151.4 cm), well below European and American populations from which the majority of guidelines have been created, questions appropriateness, such as gestational weight gain in pregnancy. A broad scope of research findings including tropical infections impacting pregnancy outcomes, mental health and suicide, a shared platform of “-omics” of Karen and Burmese women from first trimester, and practice of care in low-income settings have emerged and been shared.

The SMRU Refugee and Migrant Pregnancy Cohort findings have had significant local and international impact including changing the World Health Organisation Malaria Treatment Guidelines in pregnancy; and establishing a range of guidelines and tools improving maternal-child health practices.

Cohort Profile in a nutshell

The SMRU Refugee and Migrant Pregnancy Cohort is a population-based study including nearly 100,000 women, enrolled from 1986 to 2024. It includes all eligible women.Data typical of pregnancy records globally has been collected and the progress of pregnancy (weight, fundal height, fetal position, blood pressure, haematocrit) and pregnancy outcomes have been recorded by trained staff with labour monitored using the modified WHO partograph.After nearly 40 years of data collection 94,645 refugee and migrant women registered and: more than 6 in 10 had ultrasound confirmation of gestation, just over 1 in 10 women had malaria in pregnancy; and of known outcomes 13 in 1,000 newborns were stillborn and 1.8 in 1000 mothers died in relation to pregnancy.SMRU Refugee and Migrant Pregnancy Cohort uses a data on reasonable request model.

The SMRU Refugee and Migrant Pregnancy Cohort is a population-based study including nearly 100,000 women, enrolled from 1986 to 2024. It includes all eligible women.

Data typical of pregnancy records globally has been collected and the progress of pregnancy (weight, fundal height, fetal position, blood pressure, haematocrit) and pregnancy outcomes have been recorded by trained staff with labour monitored using the modified WHO partograph.

After nearly 40 years of data collection 94,645 refugee and migrant women registered and: more than 6 in 10 had ultrasound confirmation of gestation, just over 1 in 10 women had malaria in pregnancy; and of known outcomes 13 in 1,000 newborns were stillborn and 1.8 in 1000 mothers died in relation to pregnancy.

SMRU Refugee and Migrant Pregnancy Cohort uses a data on reasonable request model.