Replication code for "Humid-heat shifts conceptions and increases pregnancy termination risks in Nigeria" published in PNAS 2025.
# PNAS-WBGT-fertility-Nigeria
Replication code for "Humid-heat shifts conceptions and increases pregnancy termination risks in Nigeria" published in PNAS 2025.
The materials in this repository includes public data and the scripts used to produce the figures and tables appearing in the main text and supplementary information of the paper.
If you find errors in the code or have questions or suggestions, please contact Nina Brooks at nrbrooks@bu.edu.
## Organization of repository
To replicate the analysis your directory should be structured as followed:
data/raw: stores raw DHS data (see note below)
data/clean: stores clean data files for analysis
scripts/: scripts for cleaning, merging data, and analyzing data.
figures/: stores pdf figures output by analysis script.
tables/: stores latex tables produced by analysis script.
## Data
### DHS
We used Nigeria DHS data extracted from IPUMS DHS. DHS data is publicly available, with a registered user account. To replicate this analysis, you must first register for a DHS account and if you wish to use IPUMS DHS to extract the data, also register for an IPUMS DHS account (both free). Both IPUMS and the DHS have extensive guides and tutorials on working with the data. The IPUMS Climate Change and Health Research Hub also has resources on how to import IPUMS data into R using the `ipumsr` package. Once you have accounts, this analysis utilizes the 2008 and 2018 surveys with the fertility calendar module and the complete births history from the 1990, 2003, 2008, 2018 waves. In addition to demographic, fertility, and conceptrceptive use variables, you must also obtain access to the GPS data (which requires specific permission).
### Heat
We estimate daily maximum shaded wet bulb globe temperature (WBGTmax) for Nigeria DHS clusters from 1983 - 2016 using CHIRTS-daily. The raw CHIRTSdaily heat record is publicly available from the University of California, Santa Barbara Climate Hazards Center at
data.chc.ucsb.edu …