Table 1

Rhesus (Rh) isoimmunisation in unsensitised Rh-negative individuals seeking abortion at <12 weeks

Author, year, fundingStudy design, location, year(s) of data collection, follow-upPopulationInterventionComparisonResultsStrengthsWeaknessesRisk of bias
Gavin (1972)
Funding: Ortho Research Foundation and the Kaiser Foundation Hospital		Design: prospective
double-blind
Location: Kaiser Foundation Hospital in Los Angeles, California
- Bellflower and Panorama City
Duration of data collection: 1 November 1969–15 August 1970
Follow-up:
4 months with indirect Coombs and paternal genotyping (this was only done in 50% of couples)		491 women underwent therapeutic abortions
180 treated for spontaneous abortion
57 were found to be Rh-negative and indirect Coombs at the time of abortion
n=57

  • Three refused participation

  • Nine lost to follow-up

  • One had a husband found to be Rh-negative


Remaining 44
- Combined with 13 patients identified the same way at Bellflower and Panorama City
*Ectopic was included as a ‘method of abortion’? …same with hysterotomy 		Within 72 hours of abortion given RhoGAM
- 21 patients 8–16 weeks and a 24- week preterm delivery received RhoGAM		Within 72 hours given placebo
- 36 patients received placebo 4–20 weeks		2/36 sensitisations from placebo group
Patient 1 – G1 with TA at 81 days under GA. 1:16 positive indirect Coombs 7 and 9 months after, no history of transfusions or previous pregnancies
Patient 2 – G1 TA at 76 days under GA. 1:2 positive indirect Coombs test 3 months and 19 days after abortion, no history of termination or previous pregnancies
No patients receiving RhoGAM sensitised

  1. Described as “double-blinded RCT” (poor)

  2. Objective measurement of outcome; titres

  1. Randomisation and blinding are not detailed

  2. Follow-up rate of patients is not reported

  3. No defined sample size

  4. No power calculations

  5. There is no ‘Table 1’ on the demographics of the patients

  6. No statistics performed (eg, intention to treat analysis)

*Giving someone no RhoGAM at 4 weeks is not helpful, as we know the yolk sac hasn’t even been developed yet		High
Goldman and Eckerling (1972)
Funding: source not noted		Design: prospective?
Location: not noted, but ?Tel Aviv
Duration of data collection: not noted
Follow-up: 6 months or more

  • Antibody titres at 6 weeks, 3 months and 6 months after abortion

  • Patients with antibodies at 3 months → ask to continue serological follow-up for 24 months after abortion

170 postabortion patients >6 months in Rh-negative mothers (no Rh antibodies in her blood and a negative Coombs test)
- When possible, husband’s ABO blood group determined to ensure compatibility with wife’s		48 patients in treated group

  • Prior to Rh injection, serological test to confirm ABO group and Rh type, indirect Coombs and antibody titres

  • None were sensitised

5/122 patients in control group sensitisedIncidence of Rh immunisation in a period of 6 months or more postabortion in Rh-negative mothers

  1. Table documenting “admin” – who got anti-D and who didn’t

  2. Follow-up of Rh-negative patients

  1. Patients were not randomised; placed in the control group when anti-D was not available

  2. No allocation concealment

  3. No follow-up rate reported

  4. No sample size calculation

  5. No power calculation

High

  • G1, primiparous; GA, general anaesthesia; TA, therapeutic abortion.