Fetal macrosomia and its associated factors among pregnant women delivered at national referral hospital in Uganda, a case-control study
Authors: Wanyera Peter , Nakabembe Eve , Kagawa Mike Nantamu 
Published: November 2023

Background

The delivery of macrosomic newborns (newborns>4000gm) is associated with many complications, yet the number macrosomic newborns is increasing steadily worldwide. Studies suggest the risk factors for fetal macrosomia include weight at first antenatal visit, previous delivery of a large newborn, newly diagnosed diabetes in pregnancy, increasing number of deliveries, a male fetus, and many others. The objective of this study was to determine the risk factors for fetal macrosomia among women who delivered at a National Referral Hospital in Kampala, Uganda in order to address a gap in knowledge in this area.

Methods

An unmatched case-control study was conducted among 177 cases and 354 controls at Kawempe National Referral Hospital. Data was collected using interviewer-administered questionnaires. Bivariate and multivariate analysis was done using STATA version 16.0.

Results

Risk factors for fetal macrosomia included maternal age ≥40 years (aOR = 7.4, [95%CI 1.37 - 39.44], p value = 0.020), maternal weight ≥80kg (aOR = 4.0, [95%CI 2.15 - 7.40], p value <0.001), maternal height ≥160cm (aOR = 1.6, [95%CI 1.02 - 2.51], p value = 0.040), being married (aOR = 2.55, [95%CI 1.08 - 6.06], P value = 0.038), gestation age ≥40 weeks (aOR = 1.8,[95%CI 1.16 – 2.82], p value = 0.009), previous macrosomia (aOR = 2.2, [95%CI 1.26 - 3.81], p value = 0.006) and male babies (aOR = 1.78, [95%CI 1.14 - 2.77], p value = 0.011)

Conclusions

Maternal demographic factors at the time of birth such as weight, height as well as advanced age significantly contribute to giving birth to large newborns. Other factors such as post-datism, previous delivery of a large newborn, male fetus and being in a marital relationship, were also noted. A well-designed protocol to identify women with risk factors for fetal macrosomia may help to provided targeted interventions in this group.

Plain English Summary

The delivery of large newborns (greater than 4000gm) is associated with many complications for both the mother and the newborn, and yet the number large newborns is increasing steadily worldwide.

Documented factors shown to increase the likelihood of delivering a large newborn include weight at first antenatal visit, previous delivery of a large newborn, increased weight gain during pregnancy, maternal obesity, newly diagnosed diabetes in pregnancy, pregnancies going beyond the due date, a male fetus, and advanced maternal age.

There is paucity of information regarding delivery of delivery of large newborns in Uganda. We therefore set out to determine the factors that increase the likelihood of delivering large newborns among women who delivered at the National Referral Hospital in Kampala, Uganda.

In this study we retrospectively compared 177 women with large newborns and 354 women who had average-sized newborns.

Our findings indicate an increased likelihood of delivering a large newborn among mothers who were greater than 80kg, more than 40 years and taller than 160cm, as well as those who were married, carrying a male infant, where the pregnancy went beyond 40 weeks, and those with a previous delivery of a large newborn.

Maternal demographic factors at the time of birth such as weight, height as well as advance in age could significantly contribute to giving birth to a large newborn. Other factors such as a pregnancy going beyond its due date, having previously delivered a large newborn, a male fetus and being in a marital relationship, were also noted.