Should we adjust for gestational age when analysing birth weights? The use of z-scores revisited

Birth weight is the single most important risk indicator for neonatal and infant mortality and morbidity, which has led to the idiom that 'every ounce counts'. Birth weight in turn, however, tends to vary widely across populations as a result of differential fetal growth velocity with such demographic factors as ethnicity, maternal and paternal height and altitude of residence. Accordingly, it has been acknowledged that the appraisal of birth weight should rely on its position relative to the birth weight distribution of the background population. This is commonly done by standardizing birth weight through its deviation from the population mean in the given gestational age stratum, as can be obtained from population-customized birth weight nomograms. This issue was recently revisited in 'Human Reproduction' through a plea for reporting birth weight as z-scores. In this article, we argue that adjustment for factors, such as gestational age, which may lie on the causal pathway from exposures present at the time of conception [e.g. single-embryo transfer (SET) versus double-embryo transfer (DET)] to birth weight, may induce bias, regardless of whether the adjustment happens via stratification, regression or through the use of z-scores.     

Contraceptive practices among unmarried women in China, 1982–2017: systematic review and meta-analysis

Objective: Premarital sexual practices and contraceptive prevalence rate (CPR) among unmarried women in China remain unclear. We conducted a systematic review and meta-analysis to estimate CPR and analyse contraceptive methods used by unmarried women between 1982 and 2017.

Methods: Wanfang, The China National Knowledge Infrastructure Database, MEDLINE, PubMed and Web of Science were systematically searched. Data on CPR and use of major contraceptive methods were extracted and pooled using a DerSimonian–Laird random effects model.

Results: Of 188 articles retrieved from five databases, 22 studies met our inclusion criteria. Overall CPR based on a random effects meta-analysis was 32.2% (95% confidence interval [CI] 24.7%, 39.8%). Pooled rates of contraceptive use were 61.4% (95% CI 47.9%, 74.9%) for condoms, 25.9% (95% CI 14.5%, 37.4%) for pills, 19.8% (95% CI 8.9%, 30.8%) for the rhythm method and 25.4% (95% CI 14.2%, 36.7%) for the withdrawal method.

Conclusions: The sexual and reproductive health situation of unmarried women in China seems to have improved little since the 1990s. Our findings may help to optimise reproductive health care programmes and thereby reduce the alarming rates of unplanned pregnancies and abortions among unmarried women in China.     

Placental inflammation and perinatal transmission of HIV-1

The effect of placental membrane inflammation on mother-to-child transmission (MTCT) of HIV-1 is reported. Placentas from HIV-1-infected women were examined as part of a perinatal HIV-1 project in Mombasa, Kenya. Polymerase chain reaction analysis was used to test for HIV-1 in the infants at birth and at 6 weeks. The maternal HIV-1 seroprevalence was 13.3% (298 of 2,235). The overall rate of MTCT of HIV-1 was 25.4%; polymerase chain reaction analysis revealed that of the 201 infants 6.0% (12) were already HIV-1-positive at birth (intrauterine transmission) and 19.4% (39) were infected during the peripartum period or in early neonatal life (perinatal transmission). The prevalence of acute chorioamnionitis was 8.8%, that of deciduitis was 10.8%, and that of villitis was 1.6%. Acute chorioamnionitis was independently associated with peripartum HIV-1 transmission but not with in utero MTCT (17.9% vs. 6.7%, respectively; adjusted odds ratio, 3.9; 95% confidence interval, 1.2-12.5; p =.025). Other correlates of perinatal MTCT were presence of HIV in the genital tract and in the baby's oral cavity and a high maternal viral load in peripheral blood. The adjusted population attributable fraction of 12.8% (95% confidence interval, 1.5%-22.8%) indicated that approximately 3% of MTCT could be prevented if acute chorioamnionitis was eliminated. We suggest that further research on the role of antimicrobial treatment in the prevention of chorioamnionitis and the reduction of peripartum MTCT needs to be performed.     

The value of magnetic resonance imaging in the differentiation between malignant peripheral nerve-sheath tumors and non-neurogenic malignant soft-tissue tumors

Objective To assess the sensitivity and specificity of MRI criteria in the differentiation between malignant peripheral nerve sheath tumors (MPNST) and non-neurogenic malignant soft-tissue tumors (MSTT).Design and patients MRI examinations of 105 patients with pathologically proven malignant soft-tissue lesions (35 MPNST and 70 MSTT) were retrospectively reviewed, the reviewers being unaware of the pathological diagnosis. Using a standardized protocol, the tumors were evaluated for multiple parameters regarding morphology and appearance on different sequences before and after gadolinium contrast administration (location, distribution, delineation, homogeneity, size, shape, relationship to bone and neurovascular bundle, intralesional hemorrhage, necrosis, perilesional edema, lymphangitis and signal intensities). Results were compared using a chi-square or Fisher’s exact test.Results MRI findings suggestive of MPNST (p<0,05) were intermuscular distribution, location on the course of a large nerve, nodular morphology, and overall non-homogeneity on T1-weighted images, T2-weighted images and T1-weighted images after gadolinium contrast injection. MRI findings in favor of MSTT were intramuscular distribution, ill-delineated appearance of more than 20% of the lesion’s circumference, and presence of intralesional blood vessels, perilesional edema and lymphangitis. There is no significant difference for degree and pattern of enhancement after gadolinium contrast injection, nor for presence of bone involvement or cystic or necrotic areas.Conclusion MRI provides several features that contribute to the differentiation between MPNST and non-neurogenic malignant soft-tissue tumors. MRI findings suggestive of MPNST should be helpful to pathologists in the strategy for further examination.     

Female genital mutilation: knowledge, attitudes and practices of Flemish gynaecologists.

ObJECTIVE: To assess the knowledge, attitudes and practices with regard to female genital mutilation (FGM) among gynaecologists in Flanders, Belgium. METHODS: A questionnaire-based survey was sent to 724 Flemish gynaecologists and trainees. RESULTS: Three-hundred-and-thirty-four questionnaires were returned. The survey revealed gaps in the knowledge of FGM and the provision of care by Flemish gynaecologists to women who had been mutilated. It also appeared that FGM was not properly addressed in the basic and specialized medical training in Flanders, that little was known about codes of conduct issued by the hospitals when these were not lacking altogether, and that knowledge about legislation concerning FGM was deficient. There was much confusion whether re-infibulation is authorized, and what its legal status is. Some respondents considered cosmetic vaginal surgery as a form of FGM and many were in favour of the medicalization of FGM. Gynaecologists were most commonly confronted with complaints related to sexual problems caused by FGM. Finally, the study also showed that only about a third of the gynaecologists were discouraging women from having their daughters excised. CONCLUSION: There is a need for a thorough discussion among all those concerned of the ethical and legal aspects of re-infibulation, medicalization of FGM and cosmetic vaginal surgery.     

Prenatal ultrasound and magnetic resonance imaging in fetal varicella syndrome: correlation with pathology findings

OBJECTIVES: To assess the diagnostic value of prenatal magnetic resonance imaging (MRI) in addition to prenatal ultrasound in a case of fetal varicella syndrome. METHODS: Comparison of prenatal ultrasound and MRI features obtained at 26 and 32 weeks, respectively, with neonatal imaging (ultrasound, MRI and CT) and macroscopic and microscopic pathology findings in a fatal case of varicella embryopathy. RESULTS: Prenatal ultrasound correlated fairly well with neonatal imaging and pathology findings. Most lesions of thoracic, abdominal and retroperitoneal viscera, limb involvement and even dermatologic features were apparent on ultrasonography. Involvement of the CNS, including cerebellar hypoplasia, was not apparent on ultrasound examination, but was clearly demonstrated by prenatal MRI. CONCLUSION: If maternal seroconversion for the varicella-zoster virus is suspected, combining prenatal ultrasound and magnetic resonance imaging may document the extent of tissue damage in fetal varicella syndrome to a larger extent than has been reported until now and therefore contribute to due counselling following maternal varicella exposure.