The Zambian Preterm Birth Prevention Study (ZAPPS): Cohort characteristics at enrollment

Castillo, Marcela C.; Fuseini, Nurain M.; Rittenhouse, Katelyn J.; Price, Joan T.; Freeman, Bethany L.; Mwape, Humphrey; Winston, Jennifer; Sindano, Ntazana; Baruch-Gravett, Courtney; Benjamin, H.; Kasaro, Margaret P.; Litch, James A.; Stringer, Jeffrey S. A.; Vwalika, Bellington

doi:10.12688/gatesopenres.12820.2

Cited by 9 publications

(11 citation statements)

References 30 publications

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“…The Zambia Preterm Birth Prevention Study (ZAPPS) is a prospective cohort study that enrolled pregnant women in Lusaka, Zambia 19 . Study procedures are described elsewhere 19 .…”

Section: Methodsmentioning

confidence: 99%

“…The Zambia Preterm Birth Prevention Study (ZAPPS) is a prospective cohort study that enrolled pregnant women in Lusaka, Zambia 19 . Study procedures are described elsewhere 19 . Briefly, between August 2015 and September 2017, women aged 18 years or older were enrolled before 24 weeks of pregnancy.…”

Section: Methodsmentioning

confidence: 99%

“…19 Study procedures are described elsewhere. 19 Briefly, between August 2015 and September 2017, women aged 18 years or older were enrolled before 24 weeks of pregnancy. We estimated gestational age by ultrasound using INTERGROWTH-21.…”

Section: Study Populationmentioning

confidence: 99%

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Different effects for different questions: An illustration using short cervix and the risk of preterm birth

Ross

Cole

Westreich

et al. 2022

Intl J Gynecology & Obste

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Much clinical epidemiologic research aims to identify exposures as potential targets for interventions to prevent adverse health outcomes. When the objective is to improve population health, it is important that such an intervention would have a meaningful reduction of outcome risk at the population level. 1 For example, to inform interventions to improve perinatal outcomes, one objective may be to identify maternal factors for which either prevention or the sequence of screening, diagnosis, and treatment would reduce the population burden of preterm birth.In the practice of pursuing such work, researchers typically begin by estimating exposure effects. 2 The exposure effect, sometimes called the sample average causal effect, 3,4 contrasts exposed individuals and unexposed individuals. Clinical trials typically aim to estimate this effect, implicitly asking the question: how would the

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“…The Zambia Preterm Birth Prevention Study (ZAPPS) is a prospective cohort study that enrolled pregnant women in Lusaka, Zambia 19 . Study procedures are described elsewhere 19 .…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Different effects for different questions: An illustration using short cervix and the risk of preterm birth

Ross

Cole

Westreich

et al. 2022

Intl J Gynecology & Obste

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“…Lusaka, Zambia. Building on prior work of our pilot project nested in the ZAPPS-1 study, we partnered with UNC-GPZ to implement metabolic analysis for the participants of two existing study cohorts: the Zambian Preterm Birth Prevention Study (ZAPPS-2) and Improving Pregnancy Outcomes with Progesterone (IPOP) 9 , 10 . All enrollees are recruited prior to 24 weeks’ gestation in this cohort, and ultrasound occurs at the time of enrollment.…”

Section: Methodsmentioning

confidence: 99%

Metabolic gestational age assessment in low resource settings: a validation protocol

Bota¹,

Ward

Hawken³

et al. 2020

Gates Open Res

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Preterm birth is the leading global cause of neonatal morbidity and mortality. Reliable gestational age estimates are useful for quantifying population burdens of preterm birth and informing allocation of resources to address the problem. However, evaluating gestational age in low-resource settings can be challenging, particularly in places where access to ultrasound is limited. Our group has developed an algorithm using newborn screening analyte values derived from dried blood spots from newborns born in Ontario, Canada for estimating gestational age within one to two weeks. The primary objective of this study is to validate a program that derives gestational age estimates from dried blood spot samples (heel-prick or cord blood) collected from health and demographic surveillance sites and population representative health facilities in low-resource settings in Zambia, Kenya, Bangladesh and Zimbabwe. We will also pilot the use of an algorithm to identify birth percentiles based on gestational age estimates and weight to identify small for gestational age infants. Once collected from local sites, samples will be tested by the Newborn Screening Ontario laboratory at the Children’s Hospital of Eastern Ontario (CHEO) in Ottawa, Canada. Analyte values will be obtained through laboratory analysis for estimation of gestational age as well as screening for other diseases routinely conducted at Ontario’s newborn screening program. For select conditions, abnormal screening results will be reported back to the sites in real time to facilitate counseling and future clinical management. We will determine the accuracy of our existing algorithm for estimation of gestational age in these newborn samples. Results from this research hold the potential to create a feasible method to assess gestational age at birth in low- and middle-income countries where reliable estimation may be otherwise unavailable.

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“…We estimated the baseline risk of the composite outcome (p1) as 24%, based on estimates of preterm birth (21%) plus stillbirth (3%) among HIV-infected women in Zambia from our own local data [18, 19] and from modeled data [2]. We hypothesize that 17P will reduce the proportion of HIV-infected women experiencing the composite endpoint by 38% (from 24 to 15%) [12].…”

Section: Methodsmentioning

confidence: 99%

Intramuscular 17-hydroxyprogesterone caproate to prevent preterm birth among HIV-infected women in Zambia: study protocol of the IPOP randomized trial

Price

Vwalika

Freeman

et al. 2019

BMC Pregnancy Childbirth

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Background Each year, an estimated 15 million babies are born preterm, a global burden borne disproportionately by families in lower-income countries. Maternal HIV infection increases a woman’s risk of delivering prematurely, and antiretroviral therapy (ART) may compound this risk. While prenatal progesterone prophylaxis prevents preterm birth among some high-risk women, it is unknown whether HIV-infected women could benefit from this therapy. We are studying the efficacy of progesterone supplementation to reduce the risk of preterm birth among pregnant women with HIV in Lusaka, Zambia. Methods The Improving Pregnancy Outcomes with Progesterone (IPOP) study is a Phase III double-masked, placebo-controlled, randomized trial of intramuscular 17-alpha hydroxprogesterone caproate (17P) to prevent preterm birth in HIV-infected women. A total of 800 women will be recruited prior to 24 weeks of gestation and randomly allocated to 17P or placebo administered by weekly intramuscular injection. The primary outcome will be a composite of live birth prior to 37 completed gestational weeks or stillbirth at any gestational age. Secondary outcomes will include very preterm birth (< 34 weeks), extreme preterm birth (< 28 weeks), small for gestational age (<10th centile), low birth weight (< 2500 g), and neonatal outcomes. In secondary analysis, we will assess whether specific HIV-related covariates, including the timing of maternal ART initiation relative to conception, is associated with progesterone’s prophylactic efficacy, if any. Discussion We hypothesize that weekly prenatal 17P will reduce the risk of HIV-related preterm birth. An inexpensive intervention to prevent preterm birth among pregnant women with HIV could have substantial global public health impact. Trial registration NCT03297216 ; September 29, 2017.

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The Zambian Preterm Birth Prevention Study (ZAPPS): Cohort characteristics at enrollment

Cited by 9 publications

References 30 publications

Different effects for different questions: An illustration using short cervix and the risk of preterm birth

Different effects for different questions: An illustration using short cervix and the risk of preterm birth

Metabolic gestational age assessment in low resource settings: a validation protocol

Intramuscular 17-hydroxyprogesterone caproate to prevent preterm birth among HIV-infected women in Zambia: study protocol of the IPOP randomized trial

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