Search

Objective: To compare the performance of mid upper arm circumference (MUAC) and body mass index (BMI) for prediction of small for gestational age (SGA) in Zambia., Methods: This is a secondary analysis of an ongoing clinical cohort that included women with a single gestation and MUAC measured before 24 weeks of pregnancy. We assessed relationships between maternal MUAC and birth weight centile using regression. The performance of MUAC and BMI to predict SGA was compared using receiver operating characteristic curves and the effect of maternal HIV was investigated in sub-group analyses., Results: Of 1117 participants, 847 (75%) were HIV-negative (HIV-) and 270 (24%) were HIV-positive (HIV+). Seventy-four (7%) delivered severe SGA infants (<3rd centile), of whom 56 (76%) were HIV- and 18 (24%) were HIV+ (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.58-1.75). MUAC was associated with higher birth weight centile (+1.2 centile points, 95% CI 0.7-1.6; P < 0.001); this relationship was stronger among HIV+ women (+1.7 centile points, 95% CI 0.8-2.6; P < 0.001) than HIV- women (+0.9 centile points, 95% CI 0.4-1.4; P = 0.001). The discriminatory power was similar, albeit poor (area under the curve [AUC] < 0.7), between MUAC and BMI for the prediction of SGA. In stratified analysis, MUAC and BMI showed excellent discrimination predicting severe SGA among HIV+ (AUC 0.83 and 0.81, respectively) but not among HIV- women (AUC 0.64 and 0.63, respectively)., Conclusion: Maternal HIV infection increased the discrimination of both early pregnancy MUAC and BMI for prediction of severe SGA in Zambia., Clinical Trial Number: ClinicalTrials.gov (NCT02738892)., (© 2022 International Federation of Gynecology and Obstetrics.)

Objective: To illustrate the difference between exposure effects and population attributable effects., Methods: We examined the effect of mid-pregnancy short cervical length (<25 mm) on preterm birth using data from a prospective cohort of pregnant women in Lusaka, Zambia. Preterm birth was live birth or stillbirth before 37 weeks of pregnancy. For estimation, we used multivariable regression and parametric g-computation., Results: Among 1409 women included in the analysis, short cervix was rare (2.4%); 13.6% of births were preterm. Exposure effect estimates were large (marginal risk ratio 2.86, 95% confidence interval [CI] 1.80-4.54), indicating that the preterm birth risk was substantially higher among women with a short cervix compared with women without a short cervix. However, the population attributable effect estimates were close to the null (risk ratio 1.06, 95% CI 1.02-1.10), indicating that an intervention to counteract the impact of short cervix on preterm birth would have minimal effect on the population risk of preterm birth., Conclusion: Although authors often refer to "the" effect, there are actually different types of effects, as we have illustrated here. In planning research, it is important to consider which effect to estimate to ensure that the estimate aligns with the research objective., (© 2022 International Federation of Gynecology and Obstetrics.)

Objective: To investigate whether angiogenic biomarker concentrations differ between women who deliver small-for-gestational-age (SGA) infants (<10th centile birth weight for gestational age) compared with controls, because identifying SGA risk early could improve outcomes., Methods: This case-control study compared serum concentrations of angiogenic biomarkers before 24 weeks of pregnancy from 62 women who delivered SGA infants (cases) and 62 control women from an urban Zambian cohort. Odds of delivering an SGA infant were calculated using conditional logistic regression., Results: Placental growth factor (PlGF), soluble fms-like tyrosine kinase (sFLT-1) and soluble endoglin (sEng) in controls were 37.74 pg/mL (interquartile range [IQR] 23.12-63.15), 2525.18 pg/mL (IQR 1502.21-4265.54) and 2408.18 pg/mL (IQR 1854.87-3017.94), respectively. SGA cases had higher PlGF (40.50 pg/mL, IQR 22.81-67.94) and sFLT-1 (2613.06 pg/mL, IQR 1720.58-3722.50), and lower sEng (2038.06 pg/mL, IQR 1445.25-3372.26). Participants with sEng concentration below and concomitant sFLT-1 concentration above their respective thresholds (n = 40) had five-fold higher odds of SGA (adjusted odds ratio 4.77, 95% confidence interval 1.61-14.1; P = 0.005)., Conclusion: Biomarker concentrations were similar between cases and controls. Participants with concomitant low sEng and high sFLT-1 had the highest odds of SGA, suggesting that a combination of biomarkers may better for predicting SGA than single biomarkers., (© 2021 The Authors. International Journal of Gynecology & Obstetrics published by John Wiley & Sons Ltd on behalf of International Federation of Gynecology and Obstetrics.)

Objective: To evaluate whether maternal HIV serostatus and plasma viral load (VL) are associated with midtrimester cervical length (CL)., Methods: The Zambian Preterm Birth Prevention Study (ZAPPS) is an ongoing prospective cohort that began enrolling in Lusaka in August 2015. Pregnant women undergo ultrasound to determine gestational age and return for CL measurement at 16-28 weeks. We evaluated crude and adjusted associations between dichotomous indicators and short cervix (≤2.5 cm) via logistic regression, and between VL and CL as a continuous variable via linear regression., Results: This analysis includes 1171 women enrolled between August 2015 and September 2017. Of 294 (25.1%) HIV-positive women, 275 (93.5%) had viral load performed close to CL measurement; of these, 148 (53.8%) had undetectable virus. Median CL was 3.6 cm (IQR 3.5-4.0) and was similar in HIV-infected (3.7 cm, IQR 3.5-4.0) versus uninfected (3.6 cm, IQR 3.5-4.0) participants (P=0.273). The odds of short CL were similar by HIV serostatus (OR 0.64; P=0.298) and detectable VL among those infected (OR 2.37, P=0.323). We observed no association between log VL and CL via linear regression (-0.12 cm; P=0.732)., Conclusion: We found no evidence of association between HIV infection and short CL., (© 2019 International Federation of Gynecology and Obstetrics.)

Objective: To quantify differences in assessing preterm delivery when calculating gestational age from last menstrual period (LMP) versus ultrasonography biometry., Methods: The Zambian Preterm Birth Prevention Study is an ongoing prospective cohort study that commenced enrolment in August 2015 at Women and Newborn Hospital of University Teaching Hospital in Lusaka, Zambia. Women at less than 20 weeks of pregnancy who were enrolled between August 17, 2015, and August 31, 2017, and underwent ultrasonography examination were included in the present analysis. The primary outcome was the difference between ultrasonography- and LMP-based estimated gestational age. Associations between baseline predictors and outcomes were assessed using simple regression. The proportion of preterm deliveries using LMP- and ultrasonography-derived gestational dating was calculated using Kaplan-Meier analysis., Results: The analysis included 942 women. The discrepancy between estimating gestational age using ultrasonography and LMP increased with greater gestational age at presentation and among patients with no history of preterm delivery. In a Kaplan-Meier analysis of 692 deliveries, 140 (20.2%, 95% confidence interval [CI] 17.7-23.0) and 79 (11.4%, 95% CI 9.6-13.6) deliveries were classified as preterm by LMP and ultrasonography estimates, respectively., Conclusion: Taking ultrasonography as a standard, a bias was observed in LMP-based gestational age estimates, which increased with advancing gestation at presentation. This resulted in misclassification of term deliveries as preterm., (© 2018 International Federation of Gynecology and Obstetrics.)

Objective: To evaluate the association between severity of prior low birth weight (LBW) delivery and adverse perinatal outcomes in the subsequent delivery among an HIV-prevalent urban African population., Methods: A retrospective cohort study was conducted among 41 109 women who had undergone two deliveries in Lusaka, Zambia, between February 1, 2006, and May 31, 2013. The relationship between prior LBW delivery (<2500 g) and a composite measure of adverse perinatal outcome in the second pregnancy was assessed using multivariate logistic regression., Results: Women with prior LBW delivery (n=4259) had an increased risk of LBW in the second delivery versus those without prior LBW delivery (n=37 642). Such risk correlated with the severity of first delivery LBW. The adjusted odds ratio (AOR) was 2.89 (95% confidence interval [CI] 2.05-4.09) for a birth weight of 1000-1499 g, 3.05 (95% CI 2.42-3.86) for a birth weight of 1500-1999 g, and 2.02 (95% CI 1.81-2.27) for a birth weight of 2000-2499 g. Previous LBW delivery also increased the risk of adverse perinatal outcome, with an AOR of 1.4 (95% CI 1.2-1.7)., Conclusion: Severe prior LBW delivery conferred substantial risk for adverse perinatal outcomes in a subsequent pregnancy., (© 2016 International Federation of Gynecology and Obstetrics.)

Objective: To measure key obstetric and neonatal outcomes recorded at a tertiary hospital in Zambia over a 5-year period., Methods: A retrospective analysis was conducted among women who had delivered at the University Teaching Hospital in Lusaka, between January 1, 2008, and December 31, 2012. Data were extracted from electronic medical records. The main outcomes were maternal mortality, cesarean delivery, prenatal or intrapartum hemorrhage, stillbirth, a 5-minute Apgar score of less than 7, and admission to the neonatal intensive care unit., Results: A total of 62 470 deliveries were recorded. Rates of maternal mortality, cesarean delivery, and hemorrhage during pregnancy all declined over time. Decreased admissions to the neonatal intensive care unit were observed; however, the rate spiked temporarily in late 2011 and early 2012 before returning to previous levels. The proportion of stillbirths remained stable over time but reports of a 5-minute Apgar score of less than 7 rose., Conclusion: Routinely collected obstetric and neonatal data could aid ongoing program monitoring and should be used to guide quality improvement activities., Competing Interests: The authors have no conflicts of interest., (© 2016 International Federation of Gynecology and Obstetrics.)