(269) Identification of Maternal Characteristics, Pregnancy Characteristics and Pregnancy Outcomes through Linked Maternal and Infant Databases in Brazil

Background: Pregnant women are actively excluded from experimental research, i.e., trials, thus there is limited or no safety data for this large and important segment of the Brazil population. In recent years, there is increased use of secondary data for product safety evaluation in pregnancy. SIH (Sistema de Informação sobre Hospitalização) and SINASC (Sistema de Informação sobre Nascidos Vivos) databases provide national coverage in Brazil.

Objectives: To conduct a proof-of-concept exercise to identify pregnancies, outcomes and determine linkage feasibility for secondary (administrative) data sources in Brazil.

Methods: Women with a pregnancy episode end date between January 2021 and December 2022 in the SIH database were identified and probabilistically linked to their corresponding infant data from the SINASC database using the mother's date of birth, month of the hospitalization, month of birth, and hospital identification code. Maternal socio-demographic characteristics were extracted. Number of pregnancies resulting in spontaneous abortions (SA) were described. For linked pregnancies, delivery method (Caesarean section) was identified. Diagnoses and procedures codes were used to identify pregnancy safety outcomes, including live, full term births, preterm births (LB, FTB and PTB). Birth weight categories, low, very low and high birth weight (LBW, VLBW nd HBW) were identified. Descriptive analysis were performed using R - version 4.2.0 and Python - version 3.10.6.

Results: A total of 4,338,098 pregnancies were identified in SIH. Median age of women was 25 years, mostly living in the Southeast (40.3%) and Northeast (30.7%). 5.9% resulted in a SA. Overall, 1,809,864 (41.7%) of all pregnancies resulting in a singleton LB were linked to the corresponding infant’s records from SINASC, 46.3% were caesarean deliveries, 90% were FTB and 9.4% PTB. Gestational age ranged between 19 and 45 weeks. A majority of infants had normal BW (87.9%), 6.3% had LBW, 0.5% had VLBW and 4.8% had HBW.

Conclusions: A robust 42% linkage was achieved applying probabilistic methods. Linkage is essential for reliably evaluating pregnancy safety in secondary data sources. Using the same approach, further research will focus on application of algorithms in these linked databases to estimate gestational age to identify exposure during first trimester, the key period of foetal development, and identify infant safety outcomes in linked infant data.