Maternal viral load and timing of mother-to-child HIV transmission, Bangkok, Thailand. Bangkok Collaborative Perinatal HIV Transmission Study Group.

OBJECTIVES: To determine the proportion of HIV-1-infected infants infected in utero and intrapartum, the relationship between transmission risk factors and time of transmission, and the population-attributable fractions for maternal viral load. DESIGN: Prospective cohort study of 218 formula-fed infants of HIV-1-infected untreated mothers with known infection outcome and a birth HIV-1-positive DNA PCR test result. METHODS: Transmission in utero was presumed to have occurred if the birth sample (within 72 h of birth) was HIV-1-positive by PCR; intrapartum transmission was presumed if the birth sample tested negative and a later sample was HIV-1-positive. Two comparisons were carried out for selected risk factors for mother-to-child transmission: infants infected in utero versus all infants with a HIV-1-negative birth PCR test result, and infants infected intrapartum versus uninfected infants. RESULTS: Of 49 infected infants with an HIV-1 birth PCR result, 12 (24.5%) [95% confidence interval (CI), 14 -38] were presumed to have been infected in utero and 37 (75.5%) were presumed to have been infected intrapartum. The estimated absolute overall transmission rate was 22.5%; this comprised 5.5% (95% CI, 3-9) in utero transmission and 18% (95% CI, 13-24) intrapartum transmission. Intrapartum transmission accounted for 75.5% of infections. High maternal HIV-1 viral load (> median) was a strong risk factor for both in utero [adjusted odds ratio (AOR) 5.8 (95% CI, 1.4-38.8] and intrapartum transmission (AOR, 4.4; 95% CI, 1.9-11.2). Low birth-weight was associated with in utero transmission, whereas low maternal natural killer cell and CD4(+) T-lymphocyte percentages were associated with intrapartum transmission. The population-attributable fraction for intrapartum transmission associated with viral load > 10 000 copies/ml was 69%. CONCLUSIONS: Our results provide further evidence that most perinatal HIV-1 transmission occurs during labor and delivery, and that risk factors may differ according to time of transmission. Interventions to reduce maternal viral load should be effective in reducing both in utero and intrapartum transmission.

Clinical management and outcome of eclampsia at Rajavithi Hospital.

The purpose of this clinical study was to review experience in the management, and outcome of eclamptic patients at Rajavithi Hospital. Standardized treatment for all cases of eclampsia has consisted of magnesium sulfate intravenously and intramuscularly to control convulsions by means of Chesley and Tepper's regimen, intravenous hydralazine intermittently to lower diastolic blood pressure when it exceeds 110 mmHg, and initiation of delivery as soon as the patient has regained consciousness and is stable. During a ten-year period there were 167,200 deliveries and 90 eclamptic patients, yielding an incidence of eclampsia of 1 in 1,857 deliveries. There were three maternal deaths (3.3%) due to intracerebral hemorrhage. Serious adverse maternal outcomes were more frequent in women whose convulsions occurred before delivery. Excluding postpartum cases, perinatal mortality of fetuses weighing 1,000 g or more was 11.7 per cent. Magnesium sulfate is the drug of choice for treatment of eclamptic convulsions. In most situations, clinical assessment of deep tendon reflexes, respirations, and urine output is adequate to monitor maternal magnesium toxicity without the need to determine actual maternal serum magnesium levels.

PIP: Since 1977, all cases of eclampsia at Rajavithi Hospital in Bangkok, Thailand, have been treated with intravenous and intramuscular magnesium sulfate to control convulsions, intermittent intravenous hydralazine to lower diastolic blood pressure, and initiation of labor as soon as the woman is stable. During 1987-96, there were 167,200 deliveries at the hospital and 90 cases of eclampsia, for an incidence of 1 per 1857 deliveries. 50 eclampsias (55.5%) were antepartum, 25 (27.8%) intrapartum, and 15 (16.7%) postpartum. 57 cases (76%) of antepartum and intrapartum eclampsia were delivered by cesarean section. There were 3 maternal deaths (3.3%) in this series, all from intracerebral hemorrhage, and 9 perinatal deaths (11.7%). Serious adverse maternal outcomes were more frequent in women whose convulsions occurred before delivery. These findings document the effectiveness of magnesium sulfate in the prevention and treatment of eclampsic convulsions.

Perinatal-neonatal and weight specific neonatal mortality in Thailand in 1996 and comparison with 1976 and 1986: a hospital based study.

The study on perinatal mortality, neonatal mortality and weight specific death rate of neonatal infants born at Rajavithi Hospital in 1996 was carried out and compared with the rates of 1976 and 1986. It was found that in 1996 the total number of births was 15613 with 106 stillbirths. The perinatal mortality rate was 9.09 per 1000 births and neonatal mortality rate was 2.90 per 1000 live births. Reduction in perinatal and neonatal mortality rates from 1976 and 1986 to 1996 was observed. The neonatal mortality rate was close to the rate of developed countries but not the perinatal mortality rate. The weight specific neonatal mortality in 1996 was reduced from 1986 and 1976 in all weight groups. It is concluded that the neonatal mortality rate in 1996 was improved because of effective neonatal care. To reduce the low birth weight infant rate by means of an effective family planning program and antenatal care may improve the perinatal mortality rate at Rajavithi Hospital.

Successful pregnancy after heart-lung transplantation: a case report.

A successful pregnancy outcome in a patient with previous heart-lung transplantation is reported. A 22-year-old primigravid woman received heart-lung transplantation for Eisenmenger's ASD and conceived 22 months postoperatively. She had been continuously treated with cyclosporine, azathioprine and prednisone during pregnancy. Her antenatal course was uneventful. At 39 weeks' gestation, she developed leakage of amniotic fluid and went into spontaneous labor. She vaginally delivered a 2,550 g male infant by elective forceps extraction, with Apgar scores of 8 and 9 at 1 and 5 minutes, respectively. Mother and baby had an uneventful postpartum course.

HIV prevalence, risk, and partner serodiscordance among pregnant women in Bangkok. Bangkok Collaborative Perinatal HIV Transmission Study Group.

CONTEXT: Most prior studies of the human immunodeficiency virus (HIV) epidemic in Thailand have focused on commercial sex encounters; however, because the epidemic increasingly concerns stable heterosexual relationships, determining risk factors for this form of transmission is warranted. OBJECTIVES: To determine temporal trends in HIV prevalence, risk factors for HIV seropositivity, and rates of partner serodiscordance for pregnant women in Bangkok, Thailand. DESIGN: Retrospective review of hospital antenatal clinic HIV test results from 1991 through 1996. Baseline demographic and behavioral risk factors for HIV were assessed for subjects enrolled from November 1992 through March 1994. SETTING: Two Bangkok hospitals with routine antenatal clinic HIV counseling and testing. PARTICIPANTS: The HIV-positive pregnant women enrolled in a perinatal HIV transmission study and their partners and HIV-negative pregnant controls. RESULTS: From 1991 through 1996, antenatal clinic HIV seroprevalence increased from 1.0% to 2.3%. On multivariate analysis of data from 342 HIV-positive and 344 HIV-negative pregnant women, more than 1 lifetime sex partner, history of a sexually transmitted disease, and a high-risk sex partner were the most important factors for seropositivity (all P<.001). Twenty-six percent of partners of HIV-positive women were HIV negative. Women reporting more than 1 lifetime sex partner were more likely to have an HIV-negative partner than women reporting only 1 (45% vs 8%; relative risk, 5.5; 95% confidence interval, 3.2-9.5; P<.001); women reporting no high-risk behaviors were less likely to have an HIV-negative partner (10% vs 44%; relative risk, 0.2; 95% confidence interval, 0.1-0.4; P<.001). CONCLUSIONS: Prevalence of HIV in pregnant women has increased steadily in Bangkok from 1991 through 1996. Sex with current partners was the only identified risk exposure for about half (52%) of the HIV-positive women. Although few HIV-positive pregnant women reported high-risk behaviors, more than 1 lifetime partner and a partner with high-risk behavior were strong risk factors for seropositivity. Together with the unexpected finding that one fourth of partners of seropositive pregnant women were seronegative, these data emphasize that women in the general population are at risk for HIV because of the risk behavior of both current and previous partners.

Short-course zidovudine for perinatal HIV-1 transmission in Bangkok, Thailand: a randomised controlled trial. Bangkok Collaborative Perinatal HIV Transmission Study Group.

BACKGROUND: Many developing countries have not implemented the AIDS Clinical Trials Group 076 zidovudine regimen for prevention of perinatal HIV-1 transmission because of its complexity and cost. We investigated the safety and efficacy of short-course oral zidovudine administered during late pregnancy and labour. METHODS: In a randomised, double-blind, placebo-controlled trial, HIV-1-infected pregnant women at two Bangkok hospitals were randomly assigned placebo or one zidovudine 300 mg tablet twice daily from 36 weeks' gestation and every 3 h from onset of labour until delivery. Mothers were given infant formula and asked not to breastfeed. The main endpoint was babies' HIV-1-infection status, tested with HIV-1-DNA PCR at birth, 2 months, and 6 months. We measured maternal plasma viral concentrations by RNA PCR. FINDINGS: Between May, 1996, and December, 1997, 397 women were randomised; 393 gave birth to 395 live-born babies. Median duration of antenatal treatment was 25 days, and median number of doses during labour was three. 99% of women took at least 90% of scheduled antenatal doses. Adverse events were similar in the study groups. Of 392 babies with at least one PCR test, 55 tested positive: 18 in the zidovudine group and 37 in the placebo group. The estimated transmission risks were 9.4% (95% CI 5.2-13.5) on zidovudine and 18.9% (13.2-24.2) on placebo (p=0.006; efficacy 50.1% [15.4-70.6]). Between enrolment and delivery, women in the zidovudine group had a mean decrease in viral load of 0.56 log. About 80% of the treatment effect was explained by lowered maternal viral concentrations at delivery. INTERPRETATION: A short course of twice-daily oral zidovudine was safe and well tolerated and, in the absence of breastfeeding, can lessen the risk for mother-to-child HIV-1 transmission by half. This regimen could prevent many HIV-1 infections during late pregnancy and labour in less-developed countries unable to implement the full 076 regimen.

Maternal virus load and perinatal human immunodeficiency virus type 1 subtype E transmission, Thailand. Bangkok Collaborative Perinatal HIV Transmission Study Group.

To determine the rate and risk factors for human immunodeficiency virus (HIV)-1 subtype E perinatal transmission, with focus on virus load, pregnant HIV-infected women and their formula-fed infants were followed prospectively in Bangkok. Of 281 infants with known outcome, 68 were infected (transmission rate, 24.2%; 95% confidence interval, 19.3%-29.6%). Transmitting mothers had a 4.3-fold higher median plasma HIV RNA level at delivery than did nontransmitters (P<.001). No transmission occurred at <2000 copies/mL. On multivariate analysis, prematurity (adjusted odds ratio [AOR], 4.5), vaginal delivery (AOR, 2.9), low NK cell percentage (AOR, 2.4), and maternal virus load were associated with transmission. As RNA quintiles increased, the AOR for transmission increased linearly from 4.5 to 24.8. Two-thirds of transmission was attributed to virus load>10,000 copies/mL. Although risk is multifactorial, high maternal virus load at delivery strongly predicts transmission. This may have important implications for interventions designed to reduce perinatal transmission.