Is growth restriction in twin pregnancies a double challenge? - A narrative review

Placental abruption and perinatal mortality in twins: novel insight into management at preterm versus term gestations

Twins suffer a disproportionately higher burden of adverse perinatal outcomes than singletons. However, the degree to which preterm delivery shapes the relationship between abruption and perinatal mortality in twins is unknown. Through causal mediation decomposition, we examine how preterm delivery mediates the effect of abruption on perinatal mortality among twins using the US-matched multiple birth data (1995-2000). We estimated the hazard ratio (HR) from Cox models with gestational age as the timescale. We decomposed the total effect (TE) into counterfactual natural direct (NDE) and natural indirect (NIE) effects. 557,220 matched twin births, 1.3% (n = 7032) resulted in abruption with higher perinatal mortality rates than non-abruption births (143 versus 36 per 1000 births, respectively) and a 4.53-fold (95% confidence interval [CI]: 4.23, 4.82) increased hazard of perinatal mortality. HRs for NDE and NIE were 3.05 (95% CI: 2.84, 3.24) and 1.49 (95% CI: 1.49, 1.47, 1.50), respectively, and the proportion mediated (PM) was 41%. PM increased as the gestational age at delivery decreased. Associations persisted after correction for unmeasured confounders. The best strategies to improve perinatal delivery are delivery when abruption complicates twin pregnancies at term gestations and expectant management (avoiding early preterm delivery), if feasible, when abruption complicates twin pregnancies at preterm gestations.

Screening, investigation and follow-up of neonates with small for gestational age in a metropolitan hospital in Australia-observational retrospective study

Background

Infants with small for gestational age (SGA) have an increased risk of short and long-term health outcomes, with potentially modifiable risk factors. This study aims to determine the prenatal risk factors associated SGA and evaluate the clinical management of affected infants.

Methods

An observational retrospective study of medical records of infants born at Nepean Hospital and discharged with a diagnosis of SGA over 5 years (1st January 2015 to 31st December 2019). Data included demographic details, antenatal care, maternal risk factors and clinical management of the infants.

Results

Six hundred and seven infants had a discharge diagnosis of SGA, from 20,392 infants born. Of the 607 infants identified, 487 (80%) had SGA, 97 (16%) had asymmetrical SGA, 175 (29%) had symmetrical SGA, and 50 (8%) were incorrectly diagnosed with SGA based on growth measurements taken at birth. The most prevalent maternal risk factors were the presence of chronic disease (n=402, 66.23%), current smoking (n=159, 26.19%), social work input (n=108, 17.79%), gestational diabetes mellitus (n=96, 15.82%) and Aboriginal background (n=73, 12.03%). Prenatal genetic testing was conducted in 89.62% (n=544); 58.81% (n=357) had placental abnormalities; 36.57% (n=222) were recommended follow-up with a general practitioner (GP) and paediatrician, and 21.09% (n=128) were recommended a combination of midwifery in the home (MITH), GP, and paediatric follow-up. Two infants were recorded with no follow-up.

Conclusions

Diagnostic inaccuracies were found in infants with SGA. More intensive antenatal care for women with risk factors for SGA might improve the health of those with chronic disease; support for smoking cessation could also be offered.

Gestational hypertensive disease and small for gestational age infants in twin pregnancy: A systematic review and meta-analysis

AIM

The review is to explore the connection between gestational hypertension diseases (GHD) and small for gestational age (SGA) in twin pregnancies.

METHODS

According to the recommendations of PRISMA, relevant studies were systematically searched through PubMed, Web of Science, Cochrane Library, Embase from inception until January 16, 2022. Subgroup analysis was performed according to chorionicity and diagnostic criteria of SGA. Odds ratios (OR) were assessed to judge the link between GHD and SGA in twin pregnant women. A random-effect model was used to estimate the pooled hazard ratio when there was significant heterogeneity (I²  > 50%); otherwise, a fixed-effect model was conducted.

RESULTS

Seven articles containing 470 589 twin pregnant women were included. The increased risk of SGA was connected to the twin pregnancies complicated with GHD (OR = 1.57, 95% confidence interval [CI] = 1.10-2.24, p = 0.01). After subgroup analysis, the connection between SGA and GHD had no statistical significance (OR = 1.17, 95% CI = 0.95-1.44, p = 0.14) when the enrolled studies using the SGA diagnosis referred to singleton birth weight, but significant (OR = 2.14, 95% CI = 1.77-2.60, p<0.001) in the group using the SGA diagnosis referred to twin birth weight. Stratified by chorionicity, SGA was relevant to GHD in the dichorionic (DC) group (OR = 1.68, 95% CI = 1.17-2.42, p = 0.005), while not in the monochorionic (MC) group (OR = 1.68, 95% CI = 0.93-3.03, p = 0.09). More future articles are warranted to confirm these outcomes.

CONCLUSIONS

Our review demonstrated that GHD in DC twin pregnancies was related to an enlarged risk of SGA. Two SGA diagnosis references led to different results. Twin pregnancies complicated with GHD were at significantly higher risk of SGA when twin birth weight reference was used.