Impact of subchorionic hematoma in early pregnancy on obstetric complications: A retrospective cohort study in women who had live births after frozen-thawed embryo transfer

Pregnancy and perinatal outcomes in pregnancies following frozen embryo transfer (FET) after transcervical resection of adhesions (TCRA): A retrospective cohort study with propensity score matching analysis

OBJECTIVE

To compare the pregnancy and perinatal outcomes of frozen-thawed embryo transfer (FET) in patients following transcervical resection of adhesions (TCRA) versus patients with normal uterine morphology, and to investigate the factors influencing pregnancy outcomes in patients undergoing FET after TCRA.

METHODS

We retrospectively analyzed FET cycles from September 2014 to September 2023, comparing patients with normal uterine morphology to those with intrauterine adhesions (IUAs) treated with TCRA. Propensity score matching (PSM) adjusted for confounding factors. LASSO regression and multivariate logistic regression identified predictors of outcomes, which were visually represented in nomograms. Model performance was assessed using calibration curves, ROC curves, and DCA, with bootstrap method for internal validation.

RESULTS

Post-PSM analysis showed higher live birth rates in patients with normal uterine morphology after clinical pregnancy (75.1% vs. 61.7%, P < 0.001). No significant differences were noted in clinical pregnancy rates and perinatal outcomes between the groups. Factors influencing clinical pregnancy in FET after TCRA included basal progesterone levels, endometrial thickness, parity, infertility cause, embryo stage at transfer, number and quality of embryos transferred, IUA severity, and TCRA surgical procedures. Body mass index, basal LH levels, and day 14 HCG levels post-embryo transfer were determinants of live birth outcome.

CONCLUSION

FET cycles following TCRA showed a lower rate of successful live births, but TCRA did not increase adverse perinatal outcome risks. Our study introduces an innovative predictive model for clinical pregnancy and live birth outcomes in patients undergoing FET following TCRA, addressing a significant void in existing research.

Association between subchorionic hematoma in the first trimester and outcomes of singleton pregnancies achieved through assisted reproductive technology: a systematic review and meta-analysis

PURPOSE

To evaluate the association between first trimester (≤ 12 weeks gestation) subchorionic hemorrhage (SCH), and maternal and neonatal outcomes in women who conceived with the help of assisted reproductive technique (ART).

METHODS

PubMed, Embase, Web of Science, and Scopus databases were searched for observational studies that specifically focused on women who achieved pregnancy via ART and investigated the relationship between early pregnancy (within 12 weeks of gestation) SCH and maternal and neonatal outcomes. Only studies with singleton pregnancies and reporting data on the comparator group (women without SCH) were included. Primary outcomes of interest included incidences of early (within 20 weeks of gestation) pregnancy loss, preterm delivery, caesarean section, and live birth rates. Pooled effect sizes were reported as odds ratio (OR) with 95% confidence intervals (CI).

RESULTS

Nine studies were included. All studies had a cohort design. In all studies, the primary assisted reproduction technique used was in-vitro fertilization (IVF). Compared to pregnancies without SCH, women with diagnosed early pregnancy SCH have a similar risk of preterm birth (< 37 weeks) (OR 1.01, 95% CI 0.83, 1.22), low birth weight (< 2500 g) (OR 1.01, 95% CI 0.59, 1.73) and fetal growth restriction (OR 1.57, 95% CI 0.62, 4.02). The gestational age (in weeks) (weighted mean difference (WMD) - 0.06, 95% CI - 0.18, 0.06) and the birth weight (in grams) (WMD - 16.5, 95% CI - 62.9, 29.8) were also similar in the two groups. The odds of early pregnancy loss (OR 1.39, 95% CI 0.97, 2.01), live birth (OR 0.77, 95% CI 0.55, 1.08) and caesarean delivery (OR 0.97, 95% CI 0.81, 1.16) were statistically similar in both groups. The risk of maternal adverse outcomes such as gestational diabetes (OR 0.98, 95% CI 0.74, 1.29), hypertensive disorder (OR 0.95, 95% CI 0.63, 1.43), premature rupture of membranes (PROM) (OR 1.36, 95% CI 0.90, 2.05) and placental abruption (OR 2.44, 95% CI 0.57, 10.5) was also similar in both the groups. There was no evidence of publication bias.

CONCLUSION

The findings suggest that SCH may not significantly increase the risk of adverse maternal and perinatal outcomes in pregnancies conceived through ART, particularly IVF.

TRIAL REGISTRATION

PROSPERO registration number CRD42024533996.

Subchorionic hematoma: Research status and pathogenesis (Review)

Subchorionic hematoma (SCH) is a hematoma in which blood accumulates between the chorion and decidua basalis due to the separation of the chorion and decidua basalis. It is common in patients with threatened abortion in early pregnancy and is mainly detected by ultrasound. SCH mainly manifests as an hypoechoic or anechoic crescent-shaped fluid dark area on ultrasound images. Although there are numerous studies on SCH, its pathogenesis and etiology remain unclear, and its influence on pregnancy outcomes is also controversial; there are also no uniform clinical treatment guidelines. Current studies suggest that the occurrence of SCH may be related to several factors, such as abnormal coagulation function, autoimmune factors of pregnant women, assisted reproduction, drug use during pregnancy and reproductive tract infection; however, its exact etiology remains unclear. Some studies suggest that SCH is associated with adverse pregnancy outcomes such as miscarriage, preterm birth, preeclampsia and fetal growth restriction, although other studies have found that SCH does not increase the risk of adverse pregnancy outcomes. Therefore, the present review mainly discusses the pathogenesis, etiology and treatment of SCH in an aim to provide a reference for the clinical treatment of this condition in pregnant women.

Early pregnancy bleeding after assisted reproductive technology: a systematic review and secondary data analysis from 320 patients undergoing hormone replacement therapy frozen embryo transfer

STUDY QUESTION

How common is bleeding in early pregnancy after Hormone Replacement Therapy (HRT) Frozen Embryo Transfer (FET) and does bleeding affect the reproductive outcome?

SUMMARY ANSWER

A total of 47% of HRT-FET patients experience bleeding before the eighth week of gestation, however, bleeding does not affect the reproductive outcome.

WHAT IS KNOWN ALREADY

Bleeding occurs in 20% of spontaneously conceived pregnancies, although most will proceed to term. However, our knowledge regarding bleeding in early pregnancy after HRT-FET and the reproductive outcome is sparse.

STUDY DESIGN, SIZE, DURATION

We performed a systematic review of the existing literature on early pregnancy bleeding after assisted reproductive technology (ART) to evaluate the bleeding prevalence and resulting reproductive outcome in this population. A random-effects proportional meta-analysis was conducted. Subsequently, we performed a prospective cohort study including 320 pregnant patients undergoing HRT-FET and a secondary analysis of the cohort study was performed to evaluate bleeding prevalence and reproductive outcome. The trial was conducted from January 2020 to November 2022 in a public fertility clinic.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A systematic literature search was performed, using MESH terms and included studies with data from ART patients and with early pregnancy bleeding as a separate outcome. The cohort study included patients with autologous vitrified blastocyst transfer treated in an HRT-FET protocol. In the event of a positive HCG-test, an early pregnancy scan was performed around 8 weeks of gestation. During this visit, patients answered a questionnaire regarding bleeding or spotting and its duration after the positive pregnancy test. The information was verified through medical files, and these were used to obtain information on reproductive outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

The review revealed a total of 12 studies of interest. The studies reported a prevalence of early pregnancy bleeding ranging from 2.1% to 36.2%. The random effects proportional meta-analysis resulted in a pooled effect estimate of the prevalence of early pregnancy bleeding in the ART population of 18.1% (95% CI (10.5; 27.1)). Four of the included studies included data on miscarriage rate following an episode of bleeding. All four studies showed a significantly increased risk of miscarriage in patients with early pregnancy bleeding as compared to patients with no history of bleeding. No studies investigated bleeding after HRT-FET specifically. In our HRT-FET cohort study, we found that a total of 47% (149/320) of patients with a positive pregnancy test experienced bleeding before 8 weeks of gestation. Generally, the bleeding was described as spotting with a median of 2 days (range 0.5-16 days). Out of 149 patients with one or several bleeding episodes, a total of 106 patients (71%) had an ongoing pregnancy at 12 weeks of gestation. In comparison, 171 patients reported no bleeding episodes and a total of 115 (67%) of these patients had an ongoing pregnancy at 12 weeks of gestation. This difference was not significant (P = 0.45). Furthermore there was no difference in the live birth rate between the two groups (P = 0.29).

LIMITATIONS, REASONS FOR CAUTION

Most studies included in the review were older and not all studies specified the type of ART. Moreover, the studies were of moderate methodological quality. The patients in the cohort study were treated in a personalized HRT-FET protocol using a rectal supplementary rescue regimen if serum progesterone levels were <35 nmol/l at embryo transfer. The results may not be applicable to other FET protocols, and the present data were based on self-reported symptoms. The systematic review revealed an increased risk of miscarriage following an episode of early pregnancy bleeding. However our cohort study found no such association. This discrepancy can partly be due to the fact, that the four studies in the review only included episodes of heavy bleeding. Also, none of the four studies included data on HRT-FET cycles making them unfit for direct comparison.

WIDER IMPLICATIONS OF THE FINDINGS

Episodes of early bleeding during pregnancy are associated with distress for the pregnant woman, especially in a cohort of infertile patients. Our cohort study showed that at least minor bleeding seems to be a common adverse event of early pregnancy after HRT-FET. From the systematic review, it seems that this prevalence is higher than what has previously been described in relation to other types of ART. However, minor bleeding during early pregnancy after HRT-FET does not seem to affect the reproductive outcome. Knowledge regarding the frequent occurrence of bleeding during early pregnancy after HRT-FET and the fact that this should not be used as a prognostic parameter will help the clinician in counselling patients.

STUDY FUNDING/COMPETING INTEREST(S)

Gedeon Richter Nordic supported this investigator-initiated study with an unrestricted grant as well as study medication (Cyclogest). B.A. has received an unrestricted grant from Gedeon Richter Nordic and Merck and honoraria for lectures from Gedeon Richter, Merck, IBSA, and Marckyrl Pharma. P.H. received honoraria for lectures from Merck, Gedeon Richter, Institut Biochimique SA (IBSA), and Besins as well as unrestricted research grants from Merck, Gedeon Richter, and Institut Biochimique SA (IBSA). The other authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

EudraCT no.: 2019-001539-29.

Is intrauterine hematoma associated with adverse pregnancy and obstetric outcomes of ART singletons? A systematic review and meta-analysis

The objective of our meta-analysis was to estimate the effect of intrauterine hematoma (IUH) on obstetric and pregnancy outcomes of assisted reproductive technology (ART) pregnancies. Four electronic databases were searched up to December 2021 to find studies reporting relevant outcomes of ART pregnancies with IUH. Dichotomous data were expressed as odds ratios (OR) with 95% confidence intervals (CI). Continuous data were expressed as weighted mean difference (WMD) with 95% CI. A total of six observational studies were included in this meta-analysis. Our data suggested that IUH in pregnancies achieved by ART are not associated with increased risks of miscarriage, low birth weight, placenta previa, or premature rupture of membranes. Similar birthweight was noted between the two groups. However, IUH was associated with significantly shorter gestational age at delivery (GA) as well as higher risks of preterm birth. Subgroup analyses have found that the presence of retroplacental haematoma was associated with an increased risk of miscarriage. IUH may be associated with decreased GA and an increased risk of preterm birth. Therefore, Women diagnosed with IUH should be offered increased surveillance during the course of their pregnancy.

Subchorionic hematoma and risk of preterm delivery: a systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate the association between early pregnancy with subchorionic hematoma and preterm delivery and other adverse pregnancy outcomes in singleton pregnancies.

DATA SOURCES

English studies published from 2000 to July 15, 2022 were retrieved from PubMed, Web of Science, and the Cochrane Library.

STUDY ELIGIBILITY CRITERIA

The inclusion criteria were: singleton pregnancy, subchorionic hematoma, and perinatal outcomes. Studies including multiple pregnancy, basic molecular studies, case reports (series), and conference reviews were excluded.

METHODS

Data analysis was mainly conducted with Review Manager (RevMan) and Stata, and the results were represented with odds ratios and 95% confidence intervals. The methodological quality of the included studies was evaluated by the Cochrane risk assessment scale.

RESULTS

In total, 370 studies were retrieved from the above databases. Our review included 16 studies and divided them into 2 subgroups: natural pregnancy (12 studies) and assisted reproductive pregnancy (4 studies). The relevant characteristics of each study were analyzed in detail. The primary outcome was preterm delivery. The secondary outcomes were miscarriage, fetal growth restriction, cesarean delivery, and preeclampsia. We found that subchorionic hematoma in the first trimester was not significantly associated with preterm delivery (odds ratio, 1.11; 95% confidence interval, 0.82-1.51) or other adverse outcomes in singleton pregnancy. Regression analysis found that the large heterogeneity of the included studies might be related to whether the included study population (early pregnancy with subchorionic hematoma) was complicated with threatened abortion (P<.05). However, no studies caused large heterogeneity according to sensitivity analysis. Finally, 15 studies related to preterm delivery did not have publication bias (Egger test: P=.26). However, subchorionic hematoma in the first trimester was associated with miscarriage in single pregnancies (natural pregnancy: odds ratio, 3.07; 95% confidence interval, 1.98-4.75; assisted reproductive pregnancy: odds ratio, 1.45; 95% confidence interval, 1.1-1.90).

CONCLUSION

In singleton pregnancy, we found no association between subchorionic hematoma in the first trimester and preterm delivery. Although there was a correlation with miscarriage, the possible gestational age of miscarriage was not stated. More studies are needed to further address the herein posed research questions.