J Egypt Public Health Assoc. 1993;68(3-4):265-75.
Oral contraceptive and twinning: case-control study.
Kotb MM, El-Ghannam MA.
Community Medicine Department, Faculty of Medicine, Ain
Shams University.
A retrospective case-control study was conducted to
investigate the risk of twinning following oral
contraceptive (OC) use. A total of 157 women with twin
deliveries were included from two major hospitals
located in Cairo. Two controls selected from women with
singletone deliveries were matched to each case of twin
delivery on basis of maternal age and parity.
Information on (OC) use prior to last pregnancy and date
of last menstrual period was provided by interviewing
the study women. Potential biases in the study design
were discussed. The overall (OC) use prior to the last
pregnancy was significantly higher in twin group in
comparison with the controls (P < 0.05). The study
provides an evidence of increased risk of twinning among
conceptions occurring within less than 3 months from
cessation of (OC) use (OR = 2.3, 95% confidence limits:
1.2 - 4.4).
