The effect of human papilloma virus vaccination on embryo yield and clinical in vitro fertilisation outcomes: a matched retrospective cohort study

ObjectiveHead circumference is considered a reliable assessment of the volume of the underlying brain. We sought to identify risk factors (maternal factors or antenatal antecedents) for microcephaly and to assess the effects of microcephaly on neonatal outcomes.DesignRetrospective cohort study.SettingData for all births in 2009-2017 were obtained from the Guangzhou Maternal-Fetal Care Database.ParticipantsAll singleton liveborn infants between 33 and 42 weeks’ gestation (n=45 663) were categorised using the Intergrowth-21st standard for microcephaly.Main outcome measuresPrevalence of mild, absolute and relative microcephaly at birth. We estimated associations of (1) maternal characteristics including Cantonese origin, parity, exposure to teratogens, TORCH infections (ie, Toxoplasmagondii, rubella virus, cytomegalovirus, herpes simplex virus), in vitro fertilisation conception, pre-eclampsia and maternal congenital anomalies with risk of each category of microcephaly, and (2) microcephaly with risk of in-hospital mortality and severe morbidity.ResultsA total of 2709 infants had a head circumference z-score >2 SD, resulting in an overall prevalence of microcephaly of 59.3 per 1000 infants, consisting of mild (54.1 per 1000), absolute (2.8 per 1000) and relative microcephaly (2.4 per 1000). In multiple logistic regression, absolute microcephaly was associated with in utero exposure to teratogens (OR 4.2, 95% CI 2.0 to 8.8) and TORCH agents (OR 3.2, 95% CI 1.1 to 9.5). Mild microcephaly was associated with Cantonese descent (OR) 1.5, 95% CI 1.3 to 1.7) and primiparity (OR 1.7, 95% CI 1.5 to 2.0). Absolute microcephaly was associated with a significantly higher odds of neonatal seizure (OR 8.7, 95% CI 1.1 to 69.1). Mild microcephaly was not associated with adverse neonatal outcomes overall.ConclusionsCantonese origin, exposure to teratogens, pre-eclampsia and TORCH infection may be risk factors for microcephaly. The high prevalence of relative microcephaly and associated poor outcomes suggests that high-risk women merit closer clinical management and follow-up to maximise fetal head development during pregnancy.

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The mediation effect of multiple gestations on the association between in vitro fertilisation and severe maternal morbidities: a retrospective cohort study

BMJ Open ◽

10.1136/bmjopen-2018-022670 ◽

2019 ◽

Vol 9 (7) ◽

pp. e022670 ◽

Cited By ~ 1

Author(s):

Jing Tan ◽

Ya-Na Qi ◽

Jing Zhang ◽

Wen Wang ◽

Gui-Ting Zhang ◽

...

Keyword(s):

Cohort Study ◽

Pregnant Women ◽

Retrospective Cohort Study ◽

Retrospective Cohort ◽

Pregnancy Termination ◽

Mediation Effect ◽

In Vitro Fertilisation ◽

Multiple Gestations ◽

Interaction Term

ObjectiveTo investigate whether the association between in vitro fertilisation (IVF) and severe maternal morbidity (SMM) was mediated by multiple gestations.DesignA retrospective cohort study.SettingThe study was conducted at six hospitals in China.ParticipantsPregnant women at 20 gestational weeks or longer.Outcome measureThe outcome was SMM, which was a composite of potential life-threatening conditions, the use of critical medical interventions, or the status of maternal near-miss that occurred during pregnancy, childbirth or within 42 days of pregnancy termination, as defined by WHO.ResultsIn total, 22 368 eligible pregnant women were included, among whom 497 (2.2%) received IVF, and 776 developed SMM (incidence 34.7/1000 live births, 95% CI 32.3/1000 to 37.1/1000). Four multivariable logistic regression models were constructed. Model 1, without including the variable of multiple gestations, showed that IVF was associated with higher risk of SMM (adjusted OR (aOR) 1.54, 95% CI 1.03 to 2.29). Model 2, assessing the association between IVF and multiple gestations, showed that IVF was strongly associated with multiple gestations (aOR 14.75, 95% CI 11.38 to 19.10). Model 3, by adding the variable of multiple gestations to model 1, showed that IVF was not statistically associated with SMM (aOR 0.89, 95% CI 0.58 to 1.36), but multiple gestations were associated with higher risk of SMM (aOR 5.92, 95% CI 4.88 to 7.83). Model 4, investigating the association between IVF and SMM among singleton pregnancies, showed no statistically significant association (aOR 0.70, 95% CI 0.37 to 1.32). An additional analysis by adding the interaction term of IVF by multiple gestations to model 3 showed no statistical significance of the interaction term (aOR 1.15, 95% CI 0.36 to 3.68), confirming the absence of exposure-mediator interaction.ConclusionsUsing the established rule for judging mediation effect, the results suggested that multiple gestations might mediate the association between the use of IVF and higher risk of SMM. Further prospective studies are warranted to test our finding.

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