Research looks at the science showing associations between microcephaly and Zika virus. Plus: Can cervical pessaries help prevent preterm birth? Also, a study examines whether inadvertent HPV vaccination during pregnancy leads to adverse outcomes for mother and baby.
Results of a study by Colombian investigators underscore the correlation between decreased brain volume on fetal magnetic resonance imaging (MRI) and ultrasound-detected microcephaly in Zika-exposed fetuses. The findings were presented at the 37th Annual Pregnancy Meeting of the Society for Maternal-Fetal Medicine, held in Las Vegas.
The goal of the prospective cohort study was to assess fetal brain findings and volumetric composition with MRI in fetuses with confirmed Zika virus from the current outbreak in Barranquilla, Colombia. Among 214 pregnant women with Zika exposure, 13 fetuses were found on ultrasound to have abnormal brain findings such as microcephaly, ventriculomegaly, callosal dysgenesis, calcifications, and cortical anomalies. Seven women who were Zika-positive received fetal MRI at 29±4.4 weeks and were gestational age matched to 7 healthy controls at 29.87±4.61 weeks.
Total brain volume in the Zika-infected fetuses differed significantly from that in controls (9422.42±2169.11 versus 20529.7±7049.95; P<0.001) as did total intracranial volume (16390.42±3690.41 versus 35593.42±12281.71; P<0.01. No significant difference was seen in ventricular volume, brainstem volume, or cerebellar volume. The ratio of cerebrospinal fluid to supratentorial brain parenchyma was higher in Zika-affected fetuses (1.36±0.20 versus 0.99±0.16; P<0.01), suggesting microcephaly.
Sanz-Cortes M, Zarutskie AJ, Yepez M, et al. Characterization of brain malformations and volume assessment in fetuses with Zika virus infection using MRI. Abstract 73. Presented Friday, January 27 at the 37th Annual Pregnancy Meeting of the Society for Maternal-Fetal Medicine in Las Vegas, Nevada.
Cervical pessaries and preterm birth prevention
Placing a cervical pessary may not be enough to prevent preterm birth (PTB), according to results of a multicenter randomized controlled trial presented at the 37th annual Pregnancy Meeting for the Society for Maternal-Fetal Medicine, in Las Vegas, Nevada.
The researchers included asymptomatic women with singleton gestations with a transvaginal ultrasound (TVU) cervical length (CL) ≤ 25 mm at 180 to 236 weeks and no prior PTB. The women were randomly assigned to receive the Bioteque cup pessary or no pessary and the pessaries were inserted by maternal-fetal medicine staff trained in proper placement. Randomization was stratified by CL (≤ 20 mm or >20-25 mm) and study site. Any women with a TV CL ≤ 20 mm were recommended for treatment with vaginal progesterone. Analysis was by intention-to-treat and the researchers required a total sample size of 242.
Of a total of 17,388 screened for TVU CL, 446 (2.6%) were found to have a TVI CL ≤ 25 mm. Three hundred ninety-four (88.3%) met the eligibility criteria and 122 (31.0%) agreed to be randomized. When the study was submitted for the meeting, 111 of the women had delivered: 56 in the pessary and 55 in the no pessary group. Demographic characteristics were similar across both groups and no significant differences were seen between the pessary and no pessary group in the rates of PTB < 37 weeks, PTB < 34 weeks, PTB < 28 weeks, gestational age at delivery, birth weight, and composite neonatal outcome.
The investigators concluded that treatment with a cervical pessary did not appear to prevent PTB in women with a singleton gestation and a TVU CL ≤ 25 mm at 180 to 236 weeks. The study recruitment was halted before the researchers were able to meeting their enrollment, but they state that the findings are similar to other recent studies that have also found pessaries to be ineffective.
Is inadvertent HPV vaccination in pregnancy safe?
Inadvertently receiving a dose of the quadrivalent human papillomavirus vaccine (4vHPV) may not be a cause for adverse pregnancy outcomes, according to a retrospective, observational cohort study presented at the 37th annual Pregnancy Meeting for the Society for Maternal-Fetal Medicine, in Las Vegas, Nevada.
The researchers used administrative and healthcare data from the Vaccine Safety Datalink to look at a cohort of insured women aged 11 to 27 with singleton pregnancies that ended in a live birth between January 2007 and September 2013. Women who received the 4vHPV either during pregnancy or in the peri-conception period were classified as exposed. Controls were women with singleton pregnancies and a live birth during the same period who had received the 4vHPV vaccine in the 4 to 18 months prior to the start of pregnancy.
Risks of major structural birth defects, chorioamnionitis, small for gestational age birth, hypertensive disorders of pregnancy, gestational diabetes, and preterm birth (< 37 weeks’ gestation) were evaluated. Adjusted relative risk tied to receiving the 4vHPV vaccine pregnancy, the peri-conception period, and the risks for both periods combined were evaluated using a generalized estimating equation method.
The researchers found 720 women who received the 4vHPV vaccine peri-conception and 638 who had received the vaccine during pregnancy with 8166 women with distal 4vHPV exposures. Overall, vaccination with 4vHPV during the peri-conception period and pregnancy was not associated with an increased risk of adverse obstetrical events such as gestational diabetes (peri-conception adjusted risk ratio [aRR]1.06, 95% confidence interval [CI] [1.02]; during pregnancy aRR .98 [.67 – 1.4]; combined period aRR 1.0 [.77 – 1.3]); birth outcomes like preterm birth (peri-conception aRR .93 [.69 – 1.2]; during pregnancy aRR .97 [.72 – 1.3]; combined period aRR .97 [.79 – 1.2]); and major structural birth defects (peri-conception aRR .94 [.49 – 1.8]; during pregnancy aRR .91 [.46 – 1.8]; combined period aRR .96 [.59 – 1.6]).
The researchers concluded that inadvertent 4vHPV vaccine administration is not linked to adverse outcomes for either mother or infant.