Perinatal HIV-1 transmission: interaction between zidovudine prophylaxis and mode of delivery in the French Perinatal Cohort.
BACKGROUND
It is unclear whether elective cesarean delivery may have a protective effect against the transmission of human immunodeficiency virus 1 (HIV-1).


OBJECTIVE
To investigate whether mode of delivery has an impact on perinatal HIV-1 transmission in the presence of zidovudine prophylaxis.


METHODS
A prospective cohort study.


METHODS
The 85 perinatal centers in the French Perinatal Cohort, from 1985 to 1996.


METHODS
A total of 2834 singleton children born to mothers with HIV-1 infection.


METHODS
Human immunodeficiency virus 1 infection of the infant.


RESULTS
No zidovudine was used in 1917 pregnancies and zidovudine prophylaxis was used in 902 pregnancies. Cesarean deliveries were performed in 10.9% on an emergent basis and in 8.3% electively, prior to labor or membrane rupture. In 1917 mothers who did not receive zidovudine, of 1877 with information on mode of delivery, 17.2% transmitted HIV-1 to their child. Risk factors statistically significantly associated with transmission were maternal p24 antigenemia, cervicovaginal infections during pregnancy, amniotic fluid color, and rupture of membranes 4 hours or more before delivery. Mode of delivery was not related to transmission. In 902 mothers receiving zidovudine, transmission was 6.4% in 872 with information on mode of delivery, and elective cesarean delivery (n = 133) was associated with a lower transmission rate than emergent cesarean or vaginal delivery (0.8%, 11.4%, and 6.6%, respectively; P=.002). In a multivariate analysis of all mother-child pairs, including obstetrical risk factors, maternal p24 antigenemia, and zidovudine prophylaxis, interaction between mode of delivery and zidovudine prophylaxis was significant (P=.007). In the multivariate analysis of pregnancies with zidovudine prophylaxis, factors related to transmission rate were maternal p24 antigenemia, amniotic fluid color, and mode of delivery. Adjusted odds ratios (95% confidence intervals) were 1.6 (0.7-3.6) for emergent cesarean delivery and 0.2 (0.0-0.9) for elective cesarean delivery (P = .04) in comparison with vaginal delivery.


CONCLUSIONS
We observed an interaction between zidovudine prophylaxis and elective cesarean delivery in decreasing transmission of HIV-1 from mother to child. This observation may have clinical implications for prevention.
Mandelbrot
L
L
Service de Gynécologie-Obstétrique I, Hôpital Cochin-Port Royal and the Institut National de la Santé et de la Recherche Médicale U149, Paris, France. laurent.mandelbrot@cch.ap-hop-paris.fr
Le Chenadec
J
J
Berrebi
A
A
Bongain
A
A
Bénifla
J L
JL
Delfraissy
J F
JF
Blanche
S
S
Mayaux
M J
MJ
D019380:Anti-HIV Agents / Q000627:therapeutic use*; D002585:Cesarean Section; D036861:Delivery, Obstetric; D005260:Female; D015658:HIV Infections / Q000517:prevention & control* / Q000635:transmission*; D015497:HIV-1; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D015999:Multivariate Analysis; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control*; D011446:Prospective Studies; D012307:Risk Factors; D015215:Zidovudine / Q000627:therapeutic use*
D019380:Anti-HIV Agents; D015215:Zidovudine