Obstetric Outcome After Threatened Miscarriage With and Without a Hematoma on Ultrasound:

Intrauterine Hematoma in the First Trimester and Pregnancy Complications: A Systematic Review and Meta-Analysis

Background

Studies evaluating the relationship between intrauterine hematoma in the first trimester and prenatal complications are conflicting.

Objectives

To evaluate whether intrauterine hematoma identified in the first trimester in women with singleton pregnancies is associated with adverse perinatal outcomes.

Search Strategy

A comprehensive literature search of three databases (Embase, PubMed, and Web of Science) was performed up to September 2021.

Selection Criteria

Cohort and case-control studies that have evaluated the relationship between intrauterine hematoma identified before 14 gestational weeks and the risk of prenatal complications, in women with a singleton pregnancy.

Data Collection and Analysis

Two members of our team independently assessed the studies for inclusion, collected the data of interest, and assessed the risk of bias, and calculated pooled odds ratios (ORs) using random-effects models.

Main Results

Nine studies, including 1,132 women with intrauterine hematoma and 11,179 controls met the inclusion criteria. Intrauterine hematoma increased the risk of spontaneous abortion [OR 2.15, 95% confidence interval (CI) 1.23–3.75], preterm birth (OR 1.83, 95% CI 1.37–2.43), fetal growth restriction (OR 2.33, 95% CI 1.13–4.83) and placental abruption (OR 3.16, 95% CI 1.23–8.13). No statistically significant association was found between intrauterine hematoma and preeclampsia (OR 1.30, 95% CI 0.87–1.94).

Conclusion

Intrauterine hematoma in the first trimester of pregnancy increases the risk of spontaneous abortion, preterm birth, placental abruption, and fetal growth restriction.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/.

First-trimester intrauterine hematoma and pregnancy complications

OBJECTIVE

To assess whether sonographic diagnosis of intrauterine hematoma (IUH) in the first trimester of pregnancy is associated with first-trimester miscarriage and antenatal, delivery and neonatal complications.

METHODS

This was a prospective observational cohort study of women with an intrauterine singleton pregnancy between 5 and 14 weeks' gestation recruited at Queen Charlotte's and Chelsea Hospital, London, UK, between March 2014 and March 2016. Participants underwent serial ultrasound examinations in the first trimester, and the presence, location, size and persistence of any IUH was evaluated. First-trimester miscarriage was defined as pregnancy loss before 14 weeks' gestation. Clinical symptoms, including pelvic pain and vaginal bleeding, were recorded at each visit using validated symptom scores. Antenatal, delivery and neonatal outcomes were obtained from hospital records. Logistic regression analysis and the chi-square test were used to assess the association between the presence and features of IUH and the incidence of adverse pregnancy outcome. Odds ratios (OR) were first adjusted for maternal age (aOR) and then further adjusted for the presence of vaginal bleeding or pelvic pain in the first trimester.

RESULTS

Of 1003 women recruited to the study, 946 were included in the final analysis and of these, 268 (28.3%) were diagnosed with an IUH in the first trimester. The presence of IUH was associated with the incidence of preterm birth (aOR, 1.94 (95% CI, 1.07-3.52)), but no other individual or overall antenatal, delivery or neonatal complications. No association was found between the presence of IUH in the first trimester and first-trimester miscarriage (aOR, 0.81 (95% CI, 0.44-1.50)). These findings were independent of the absolute size of the hematoma and the presence of vaginal bleeding or pelvic pain in the first trimester. When IUH was present in the first trimester, there was no association between its size, content or position in relation to the gestational sac and overall antenatal, delivery and neonatal complications. Diagnosis of a retroplacental IUH was associated with an increased risk of overall antenatal complications (P = 0.04).

CONCLUSIONS

Our findings demonstrate that there is no association between the presence of IUH in the first trimester and first-trimester miscarriage. However, an association with preterm birth, independently of the presence of symptoms of pelvic pain and/or vaginal bleeding, is evident. Women diagnosed with IUH in the first trimester should be counseled about their increased risk of preterm birth and possibly be offered increased surveillance during the course of their pregnancy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Early-pregnancy events and subsequent antenatal, delivery and neonatal outcomes: prospective cohort study

OBJECTIVE

To assess prospectively the association between pelvic pain, vaginal bleeding, and nausea and vomiting occurring in the first trimester of pregnancy and the incidence of later adverse pregnancy outcomes.

METHODS

This was a prospective observational cohort study of consecutive women with confirmed intrauterine singleton pregnancy between 5 and 14 weeks' gestation recruited at Queen Charlotte's & Chelsea Hospital, London, UK, from March 2014 to March 2016. Serial ultrasound scans were performed in the first trimester. Participants completed validated symptom scores for vaginal bleeding, pelvic pain, and nausea and vomiting. The key symptom of interest was any pelvic pain and/or vaginal bleeding during the first trimester. Pregnancies were followed up until the final outcome was known. Antenatal, delivery and neonatal outcomes were obtained from hospital records. Logistic regression analysis was used to assess the association between first-trimester symptoms and pregnancy complications by calculating adjusted odds ratios (aOR) with correction for maternal age.

RESULTS

Of 1003 women recruited, 847 pregnancies were included in the final analysis following exclusion of cases due to first-trimester miscarriage (n = 99), termination of pregnancy (n = 20), loss to follow-up (n = 32) or withdrawal from the study (n = 5). Adverse antenatal complications were observed in 166/645 (26%) women with pelvic pain and/or vaginal bleeding in the first trimester (aOR = 1.79; 95% CI, 1.17-2.76) and in 30/181 (17%) women with no symptoms. Neonatal complications were observed in 66/634 (10%) women with and 11/176 (6%) without pelvic pain and/or vaginal bleeding (aOR = 1.73; 95% CI, 0.89-3.36). Delivery complications were observed in 402/615 (65%) women with and 110/174 (63%) without pelvic pain and/or vaginal bleeding during the first trimester (aOR = 1.16; 95% CI, 0.81-1.65). For 18 of 20 individual antenatal complications evaluated, incidence was higher among women with pelvic pain and/or vaginal bleeding, despite the overall incidences being low. Nausea and vomiting in pregnancy showed little association with adverse pregnancy outcomes.

CONCLUSIONS

Our study suggests that there is an increased incidence of antenatal complications in women experiencing pelvic pain and/or vaginal bleeding in the first trimester. This should be considered when advising women attending early-pregnancy units. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Subchorionic Hematoma: Correlation of Grading Techniques With First-Trimester Pregnancy Outcome

OBJECTIVES

To evaluate and compare grading systems of subchorionic hematoma (SCH) on first-trimester ultrasound examinations with live embryos to assess which best correlates with early pregnancy outcome and to assess the effect of gestational age at the time of diagnosis on outcome.

METHODS

First-trimester live singleton pregnancies between 6 and 11 weeks' gestational age with SCH were identified by an institutional database search. First-trimester outcome was categorized as "live" or "demise" based on ultrasound or medical record documentation. Hematomas were categorized in 4 ways: (1) subjective (small, moderate, or large); (2) subjective size based on fraction comparison with gestational sac size; (3) subjective grading based on the estimated percentage of the gestational sac surrounded by hematoma; and (4) 3 orthogonal measurements of the hematoma.

RESULTS

A total of 434 sonograms met study inclusion criteria. The overall rate of first-trimester pregnancy failure was 12.0%. The rate of demise was significantly higher for hematomas diagnosed at or before 7 weeks (19.6%) than for those after 8 weeks (3.6%; P < .001). The size of the hematoma estimated as a fraction of gestational sac size significantly correlated with first-trimester pregnancy loss (P < .001). There was no statistical significance between first-trimester outcome and the other 2 subjective grading methods. Volume-based measurements provided spurious results because of the irregular shape of most hematomas.

CONCLUSIONS

Subjective hematoma size based on the fraction of gestational sac size correlates best with first-trimester pregnancy outcome. The earlier in pregnancy an SCH is detected, the higher the rate of subsequent pregnancy failure.