Validity of pre and post-term birth rates based on the date of last menstrual period compared to early obstetric ultrasonography

Influence of different methods for calculating gestational age at birth on prematurity and small for gestational age proportions: a systematic review with meta-analysis

BACKGROUND

Recognizing premature newborns and small-for-gestational-age (SGA) is essential for providing care and supporting public policies. This systematic review aims to identify the influence of the last menstrual period (LMP) compared to ultrasonography (USG) before 24 weeks of gestation references on prematurity and SGA proportions at birth.

METHODS

Systematic review with meta-analysis followed the recommendations of the PRISMA Statement. PubMed, BVS, LILACS, Scopus-Elsevier, Embase-Elsevier, and Web-of-Science were searched (10-30-2022). The research question was: (P) newborns, (E) USG for estimating GA, (C) LMP for estimating GA, and (O) prematurity and SGA rates for both methods. Independent reviewers screened the articles and extracted the absolute number of preterm and SGA infants, reference standards, design, countries, and bias. Prematurity was birth before 37 weeks of gestation, and SGA was the birth weight below the p10 on the growth curve. The quality of the studies was assessed using the New-Castle-Ottawa Scale. The difference between proportions estimated the size effect in a meta-analysis of prevalence.

RESULTS

Among the 642 articles, 20 were included for data extraction and synthesis. The prematurity proportions ranged from 1.8 to 33.6% by USG and varied from 3.4 to 16.5% by the LMP. The pooled risk difference of prematurity proportions revealed an overestimation of the preterm birth of 2% in favor of LMP, with low certainty: 0.02 (95%CI: 0.01 to 0.03); I² 97%). Subgroup analysis of USG biometry (eight articles) showed homogeneity for a null risk difference between prematurity proportions when crown-rump length was the reference: 0.00 (95%CI: -0.001 to 0.000; I²: 0%); for biparietal diameter, risk difference was 0.00 (95%CI: -0.001 to 0.000; I²: 41%). Only one report showed the SGA proportions of 32% by the USG and 38% by the LMP.

CONCLUSIONS

LMP-based GA, compared to a USG reference, has little or no effect on prematurity proportions considering the high heterogeneity among studies. Few data (one study) remained unclear the influence of such references on SGA proportions. Results reinforced the importance of qualified GA to mitigate the impact on perinatal statistics.

TRIAL REGISTRATION

Registration number PROSPERO: CRD42020184646.

Magnitude e características dos nascimentos termo tardio e pós-termo e complicações maternas e neonatais no Brasil, 2011

Este estudo analisou o nascimento termo tardio e pós-termo, avaliando o perfil materno, suas características e as complicações maternas e neonatais. Foram selecionados 23.610 bebês do estudo Nascer no Brasil (2011), sendo realizada uma análise descritiva da população de estudo. A associação entre o nascimento termo tardio e pós-termo e seus desfechos foi efetuada pela utilização de regressões logísticas (valor de p < 0,05). A prevalência encontrada foi de 7,4% para o termo tardio e de 2,5% para o pós-termo, tendo ambos sido mais frequentes nas regiões Norte e Nordeste, em adolescentes, mulheres negras, de baixa escolaridade, multíparas, atendidas no setor público. As gestações termo tardio tiveram maior chance de indução do parto vaginal (OR = 2,02; IC95%: 1,67-2,45), de cesariana (OR = 1,32; IC95%: 1,16-1,52), de laceração grave (OR = 3,75; IC95%: 1,36-10,36) e de uso oxigenoterapia para os recém-nascidos (OR = 1,52; IC95%: 1,02-2,26). Nas gestações pós-termo, os recém-nascidos tiveram menor chance de amamentação ao nascer (OR = 0,74; IC95%: 0,56-0,97) e durante a hospitalização (OR = 0,62; IC95%: 0,40-0,97) e maior chance de nascerem pequenos para a idade gestacional (OR = 4,01; IC95%: 2,83-5,70). Os resultados utilizando somente a ultrassonografia como medida da idade gestacional confirmaram os achados anteriores. Gestações termo tardio e pós-termo ocorrem com maior frequência nas regiões Norte e Nordeste e em mulheres com maior vulnerabilidade social, associando-se a complicações maternas e neonatais.

Association of genitourinary infections and cervical length with preterm childbirth

A prospective cohort study was conducted on a convenience sample of 1370 pregnant women with a gestational age of 20 to 25 weeks in the city of Ribeirão Preto. Data on obstetrical history, maternal age, parity, smoking habit, and a history of preterm delivery was collected with the application of a sociodemographic questionnaire. Cervical length was determined by endovaginal ultrasound, and urine and vaginal content samples were obtained to determine urinary tract infection (UTI) and bacterial vaginosis (BV), respectively. The aim of this study was to verify the association of cervical length and genitourinary infections with preterm birth (PTB). Ultrasound showed no association of UTI or BV with short cervical length. PTB rate was 9.63%. Among the women with PTB, 15 showed UTI (RR: 1.55, 95%CI: 0.93–2.58), 19 had BV (RR: 1.22, 95%CI: 0.77–1.94), and one had both UTI and BV (RR: 0.85, 95%CI: 0.13–5.62). Nineteen (14.4%) PTB occurred in women with a cervical length ≤2.5 cm (RR: 2.89, 95%CI: 1.89–4.43). Among the 75 patients with PTB stratified as spontaneous, 10 showed UTI (RR: 2.02, 95%CI: 1.05–3.86) and 14 had a diagnosis of BV (RR: 1.72, 95%CI: 0.97–3.04). A short cervical length between 20 and 25 weeks of pregnancy was associated with PTB, whereas UTI and BV determined at this age were not associated with short cervical length or with PTB, although UTI, even if asymptomatic, was related to spontaneous PTB.

Soluble CD14 levels in plasma and breastmilk of Malawian HIV+ women: Lack of association with morbidity and mortality in their exposed infants

PROBLEM

Data on soluble CD14 (sCD14) during pregnancy and lactation are scarce. We assessed the levels of sCD14 in plasma and breastmilk of Malawian HIV-positive women and evaluated the possible association with morbidity and mortality in the HIV-exposed children.

METHOD OF STUDY

One hundred and forty-nine mother/child pairs were studied. Women received antiretroviral therapy from 26 weeks of gestation to at least 6 months of exclusive breastfeeding. sCD14 concentrations were determined using an enzyme-linked immunosorbent assay.

RESULTS

sCD14 levels measured at 26 weeks of pregnancy (median: 1418 ng/mL, IQR: 1086-1757) were inversely correlated to maternal CD4+ cell count (r = -.283, P = .001) and to neonatal birthweight (r = -.233, P = .008). At 6 months, sCD14 plasma levels were significantly higher compared to baseline (1993 ng/mL, IQR: 1482-2604, P < .001), and breastmilk sCD14 levels (7668 ng/mL, IQR: 5495-10207) were 4-fold higher than in plasma (although the concentrations in the two compartments were not correlated). No association was found between sCD14 levels in plasma or breastmilk and morbidity or mortality in children.

CONCLUSION

Higher sCD14 levels in HIV-positive women were associated with a more compromised maternal immunological status and to a lower neonatal birthweight, but not to poorer clinical outcomes in the HIV-exposed children.