Where the indication for PLCS is PMTCT, the earlier timing reflects the importance of avoiding the onset of labour. In these cases, the risk of MTCT associated with labour and ROMs is considered to outweigh the risk of TTN. Where PLCS is undertaken only for obstetric indications, the optimal timing of PLCS is between 39 and 40 weeks . The risk of TTN at this gestation is approximately 1 in 300 and this risk doubles for every week
earlier that delivery occurs. The administration of steroids to the mother to reduce the risk of TTN should be considered for PLCS prior to 38 completed weeks. 7.3.1 In all cases of term pre-labour spontaneous ROM, delivery should be expedited. Grading: this website 1C 7.3.2 If maternal HIV VL is <50 HIV RNA copies/mL immediate induction of labour is recommended, with a low threshold for CDK assay treatment of intrapartum pyrexia. Grading: 1C 7.3.3 For women with a last measured plasma VL 50–999 HIV RNA copies/mL, immediate CS should be considered, taking into account the actual VL, the trajectory of the VL, length of time on treatment, adherence issues, obstetric factors and the woman’s views. Grading: 1C 7.3.4 If maternal HIV VL is ≥1000 RNA copies/mL plasma, immediate CS is recommended. Grading: 1C In the pre-HAART era, several studies ,, suggested that prolonged duration of ruptured membranes, usually analysed as >4 h, in women
who were either untreated or if treated were largely receiving zidovudine monotherapy, resulted in a significantly increased risk of MTCT. A widely quoted meta-analysis (not reporting VL data) subsequently showed a 2% increase in relative risk of transmission per hour of membrane rupture (AOR 1.02). Transmission increased from 12% with <1 h membrane rupture to 19% with >12 h of membrane
rupture . There are few published studies from the HAART era. A study from Spain of 500 HIV-positive women examined the effect of various obstetric risk factors on MTCT rates in women on no treatment, monotherapy or dual therapy, and finally unless in those on HAART. ROMs >6 h compared to <6 h was only significantly associated with MTCT in the group of women on no treatment (26.6% vs. 11.9%; P ≤ 0.01). Corresponding transmission rates for the mono–dual therapy group were 14.3% vs. 7.1% (P = NS) and in the women on HAART (0.8% vs. 0.0%; P = NS) . The NSHPC study of HIV-positive women in the UK and Ireland reported on 1050 women where length of time of ROM was recorded from 2007. In 618 women delivering with a VL <50 HIV RNA copies/mL when comparing those with ROM ≤4 h to >4 h the MTCT rate was 0.3% (one of 326) and 0.0% (none of 292), respectively (P = 0.34). Restricting the analysis to the 386 women with a VL <50 copies/mL who delivered vaginally did not alter this conclusion . Therefore, for women on HAART who rupture their membranes at term with a VL <50 HIV RNA copies/mL and who do not have an obstetric contraindication to vaginal delivery, a CS is not recommended.