Mid-trimester cervical length not associated with HIV status among pregnant women in Botswana.

OBJECTIVE: HIV-infected women on antiretroviral therapy have a higher risk of preterm birth than HIV-uninfected women in Botswana. To better understand the mechanism for preterm birth among HIV-infected women, we evaluated whether mid-trimester cervical length differed by HIV status as cervical shortening is associated with an increased risk for preterm birth. METHODS: We conducted a prospective cohort study among pregnant women receiving care at the Scottish Livingstone Hospital in Molepolole, Botswana. Consecutive women referred for routine obstetrical ultrasound were consented and enrolled if between 22w0d and 24w6d by ultrasound biometry. Blinded to maternal HIV status, an obstetrician measured transvaginal cervical length using standardized criteria. Cervical length, as well as the proportion of women with a short cervix (<25mm), were compared among HIV-infected and HIV-uninfected women. The acceptability of transvaginal ultrasound was also evaluated. RESULTS: Between April 2016 and April 2017, 853 women presenting for obstetric ultrasound were screened, 187 (22%) met eligibility criteria, and 179 (96%) were enrolled. Of those enrolled, 50 (28%) were HIV-infected (86% on antiretroviral therapy), 127 (71%) were HIV-uninfected, and 2 (1%) had unknown HIV status. There was no significant difference in mean cervical length between HIV-infected and HIV-uninfected women (32mm vs 31mm, p = 0.21), or in the proportion with a short cervix (10% vs 14%, p = 0.44). Acceptability data was available for 115 women who underwent a transvaginal ultrasound exam. Of these, 112 of 115 (97%) women deemed the transvaginal scan acceptable. CONCLUSIONS: The increased risk of preterm birth observed among HIV-infected women receiving antiretroviral therapy in Botswana is unlikely associated with mid-trimester cervical shortening. Further research is needed to understand the underlying mechanism for preterm birth among HIV-infected women.

Modulation of IL10 and Its Receptor Subunits in Normal and Progesterone-Prolonged Gestation in the Mouse.

These experiments aimed to understand the relationship between interleukin 10 (IL10), the IL10 receptor subunits, and progesterone (P4) at the time of parturition. We hypothesized that there is a biologic connection between IL10 and P4, supporting an immunomodulatory mechanism for the onset of labor. Using samples from control and P4-treated pregnant mice, we assessed the production of IL10 and its receptor subunits (IL10Rα and IL10Rß) in gestational tissues. After preliminary studies, P4-treated pregnant mice were compared with controls to assess for differences in IL10 and IL10 receptor subunit expression throughout gestation. To investigate the contribution of the P4 receptor at the onset of labor, we performed timed studies on pregnant mice after treatment with RU486. Samples collected included placentas, placentation sites, and maternal livers. IL10, IL10Rα, and IL10Rß levels were measured in homogenized tissue using ELISA assays; the cytokine results were normalized for homogenate protein concentration. Control mice delivered on gd 18-19, and P4 treatment prevented parturition to beyond gd 20, as expected. In treated mice, P4 not only prevented the anticipated nadir of IL10 at term, but maintained elevated levels of IL10 through gd 20 (p < 0.05). P4 also reversed the anticipated decrease of the IL10Rα, which was increased in P4-treated mice (p < 0.05). Treatment with RU486 did not modulate the expression of IL10 or IL10Rα, but showed a significant decrease in the level of IL10Rß (p < 0.05). Progesterone functions at least in part through the IL10 signaling pathway to prolong gestation.

Fetal Anatomic Imaging Between 11 and 14 Weeks Gestation.

Fetal imaging between 11 and 14 weeks is a standard component of prenatal risk assessment for aneuploidy. Evaluating the fetus during this gestational age window provides the opportunity to reliably examine anatomic structures. Using a defined imaging protocol, approximately 50% of major abnormalities can be detected. Some abnormalities should almost always be detected, some may be detected on occasion and others are not currently detectable. Imagers must be familiar with embryologic patterns of development and natural history of anomalies. Patients must be informed of the limitations of early anatomic evaluation. Currently, early anatomic evaluation does not replace the standard second trimester evaluation.