Maternal risk factors for paediatric inguinal hernia

Association between Maternal Birth Weight and Prevalence of Congenital Malformations in Offspring: The Japanese Environment and Children's Study

Congenital malformations are functional and structural alterations in embryonic or foetal development resulting from a variety of factors including maternal health status. This study aimed to investigate the association between maternal birth weight (MBW) and the prevalence of congenital malformations in offspring using data from a nationwide birth cohort study in Japan including 103,060 pregnancies. A binary logistic regression model with adjustment for various covariates revealed that an MBW of <2500 g (low MBW) was associated with an increased risk of congenital heart disease (adjusted odds ratio: 1.388, [95% confidence interval: 1.075-1.792]), angioma (1.491 [1.079-2.059]), and inguinal hernia (1.746, [1.189-2.565]), while those with an MBW of ≥4000 g (high MBW) were associated with congenital anomalies of the urinary tract (2.194, [1.261-3.819]) and arrhythmia (1.775, [1.157-2.725]) compared with those with an MBW of 3000-3499 g. Low MBW was associated with cleft lip and/or palate (1.473, [1.052-2.064]), congenital heart disease (1.615, [1.119-2.332]), genital organs (1.648, [1.130-2.405]), hypospadias (1.804, [1.130-2.881]), and inguinal hernia (1.484, [1.189-1.851]) in male infants and CAKUT (1.619, [1.154-2.273]) in female infants, whereas high MBW was associated with congenital heart disease (1.745, [1.058-2.877]) and CAKUT (2.470, [1.350-4.517]) in male infants. The present study is the first to demonstrate a link between MBW and congenital malformations in Japanese children. While these results must be interpreted with caution, MBW should be considered a major predictor of congenital malformation risk.

The inheritance of groin hernias: an updated systematic review with meta-analyses

PURPOSE

The aim of this systematic review was to assess the inheritance of groin hernias.

METHODS

The primary outcome was to assess the inheritance based on the family history of groin hernias. We included studies that reported family history in patients with groin hernias, assessed the development of groin hernias in patients with a positive family history, or assessed the development of groin hernias in twins. Searches were conducted in PubMed, EMBASE, and Cochrane CENTRAL in November 2021. Results were synthesized narratively and with meta-analyses.

RESULTS

Twenty-two studies with unique participants were included. While two twin studies did not show convincing results of a genetic origin in children, database studies with low risk of bias showed that a positive history in parents or siblings increased the risk of inguinal hernia in children, and the risk was highest between mothers and daughters and between sisters. In adults, patients with inguinal hernia had higher odds of having a positive family history compared with patients without groin hernia (odds ratio 5.3, 95% confidence interval 3.3-8.7), and a nationwide study found the highest risk of inguinal hernia repair when a sister had been repaired compared with a brother. This study also found that having a sibling repaired for a groin hernia increased the risk of femoral hernia repair.

CONCLUSION

Despite studies being heterogeneous, there is overwhelming evidence that a positive family history is a risk factor for developing inguinal hernia in both children and adults, seemingly with a pronounced female-female inheritance pattern.

Sex-based differences in inguinal hernia factors

BACKGROUND

Much of our knowledge about inguinal hernias is based on males. Meanwhile, it is established that women have worse outcomes after inguinal hernia repair, with more chronic pain and higher recurrences. Pediatric literature shows inguinal hernias in females are more likely to be bilateral, incarcerated, and carry a stronger genetic predisposition than males. We aimed to evaluate sex-based differences in inguinal hernia factors in adults, to help supplement the paucity of literature in the adult population.

METHODS

An institutional database of patients undergoing repair of primary inguinal hernias was queried with focus on preoperative risk factors and operative characteristics. Multivariate analysis was performed looking for independent variables associated with a greater number of hernia defects found intraoperatively.

RESULTS

Among 494 patients, 202 (40.9%) were female. Number of risk factors among females was significantly higher than males (1.53 vs 1.2, p = 0.003). Females had significantly more constipation, GERD, and asthma and lower BMI than males. Family history of hernias was similar between both sexes. As expected, females had significantly less direct hernias (12.9% vs 32.9%, p < 0.001) and more femoral hernias (38.5% vs 12.2%, p < 0.001) than males. Bilaterality was similar. Females undergoing inguinal hernia repair averaged 1.23 prior deliveries. Regression analysis showed age, sex, BMI, and number of deliveries were not correlated with the number of defects.

CONCLUSIONS

Females undergoing primary inguinal hernia repair had more preoperative risk factors for inguinal hernia than males. In our population, there was no higher incidence of bilaterality or significant genetic predisposition in females as noted by family history of hernias. Age, sex, BMI and number of deliveries did not correlate with the number of hernia defects found. Our study promotes awareness of inguinal hernias in females and presents new data to quantify sex-based differences and predispositions to inguinal hernias.