Rh immunization in Manitoba: progress in prevention and management.

Area of Science:

• Obstetrics and Gynecology
• Perinatal Medicine
• Immunology

Background:

• Erythroblastosis fetalis, a condition causing perinatal mortality, has seen decreasing incidence in Manitoba over two decades.
• Improved management of Rh-immunized pregnancies and prevention of Rh immunization have contributed to this decline.

Purpose of the Study:

• To evaluate the effectiveness of Manitoba's antenatal prophylaxis program in preventing Rh immunization.
• To assess the impact of Rh immunoglobulin administration on perinatal mortality and infant outcomes.

Main Methods:

• Implementation of an antenatal prophylaxis program administering Rh immunoglobulin to Rh-negative women at 28 weeks' gestation.
• Combination of antenatal, post-abortion, and postpartum prophylaxis strategies.
• Monitoring of Rh immunization incidence and perinatal mortality rates over a 20-year period.

Main Results:

• The antenatal prophylaxis program reduced the incidence of Rh immunization during pregnancy by 93% within its first 6 years and 8 months.
• The overall death rate among infants affected by Rh immunization decreased from 10.8% to 3.4%.
• The incidence of Rh immunization decreased from 9.1 to 2.2 per 1000 total births, with a 98.6% protection rate in at-risk primigravidas when prophylaxis was combined.

Conclusions:

• Rh immunoglobulin prophylaxis is highly effective in preventing Rh immunization and reducing perinatal mortality.
• Antenatal administration of Rh immunoglobulin, combined with other prophylactic measures, offers substantial protection for Rh-negative women.
• Continued implementation and potential expansion of these programs are expected to yield further improvements in perinatal outcomes.