Stillbirth rates and their determinants in a national maternity hospital in Phnom Penh, Cambodia in 2017-2020: a cross-sectional assessment with a nested case-control study
Authors: Christou Aliki , Mbishi Jackline , Matsui Mitsuaki , Beňová Lenka , Rattana Kim , Numazawa Ayako , Iwamoto Azusa , Sokhan Sophearith , Ieng Nary , Delvaux Thérèse 
Published: August 2023

Background

In Cambodia, stillbirths and their underlying factors have not been systematically studied. This study aimed to assess the proportion and trends in stillbirths between 2017-2020 in a large maternity referral hospital in the country and identify their key determinants to inform future prevention efforts.

Methods

This was a retrospective cross-sectional analysis with a nested case-control study of women giving birth at the National Maternal and Child Health Centre (NMCHC) in Phnom Penh, 2017-2020. We calculated percentages of singleton births at ≥22 weeks’ gestation resulting in stillbirth and annual stillbirth rates by timing: intrapartum (fresh) or antepartum (macerated). Multivariable logistic regression was used to explore factors associated with stillbirth, where cases were all women who gave birth to a singleton stillborn baby in the four-year period. One singleton live birth immediately following each case served as an unmatched control. Multiple imputation was used to handle missing data for gestational age.

Results

Between 2017 and 2020, 3.2% of singleton births ended in stillbirth (938/29,742). The stillbirth rate increased from 24.8 per 1000 births in 2017 to 38.1 per 1000 births in 2020, largely due to an increase in intrapartum stillbirth rates which rose from 18.8 to 27.4 per 1000 births in the same period. The case-control study included 938 cases (stillbirth) and 938 controls (livebirths). Factors independently associated with stillbirth were maternal age ≥35 years compared to <20 years (aOR:1.82, 95%CI:1.39,2.38), extreme (aOR:3.29, 95%CI:2.37,4.55) or moderate (aOR:2.45, 95%CI:1.74,3.46) prematurity compared with full term, and small-for-gestational age (SGA)(aOR:2.32, 1.71,3.14) compared to average size-for-age. Breech/transverse births had nearly four times greater odds of stillbirth (aOR:3.84, 95%CI:2.78,5.29), while caesarean section reduced the odds by half compared with vaginal birth (aOR:0.50, 95%CI:0.39,0.64). A history of abnormal vaginal discharge increased odds of stillbirth (aOR:1.42, 95%CI:1.11,1.81) as did a history of stillbirth (aOR:3.08, 95%CI:1.5,6.5).

Conclusions

Stillbirth prevention in this maternity referral hospital in Cambodia requires strengthening preterm birth detection and management of SGA, intrapartum care, monitoring women with stillbirth history, management of breech births, and further investigation of high-risk referral cases.

Plain English summary

In Cambodia, there is very little information published on stillbirths to know precisely how many there are and to understand the underlying reasons they occur so they can be prevented in the future. Our study aimed to quantify the number of stillborn babies and identify some underlying risk factors from one of the largest maternity referral hospitals in the Phnom Penh, Cambodia. We examined data from almost 30,0000 health facility medical files of women who gave birth between 2017 and 2020 which included 938 stillbirths. We found that about 3.2% of births ended in a stillbirth and that this percentage increased between 2017 and 2020. Women who had preterm babies, or whose babies were small in weight for their gestational age, and babies that were born breech had a higher chance of being stillborn. Women who had abnormal vaginal discharge which can indicate a possible infection also had a higher odds of having a stillbirth. We also found that women who had a stillbirth previously had almost three times higher chance of having another stillborn baby. Having a caesarean section reduced the likelihood of having a stillborn baby by about half. These findings suggest that efforts are needed to better identify and manage women with preterm births and monitor fetal growth as well as ensure breech births are managed adequately.