Associations between hypothyroidism and adverse obstetric and neonatal outcomes: a study of a population database including over 184,000 women with hypothyroidism

Abstract

Background

Maternal hypothyroidism has been associated with multiple adverse pregnancy outcomes. These findings have not been confirmed in a large population database study. Therefore, a large population-based cohort study was established to study the associations between maternal hypothyroidism and pregnancy and perinatal complications.

Methods

This is a retrospective population-based cohort study utilizing data from the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample (HCUP-NIS) over 11 years from 2004 to 2014. A cohort of all deliveries between 2004 and 2014 inclusive, was created. Within this group, all deliveries to women with hypothyroidism were identified as part of the study group (n = 184,869), and the remaining deliveries were categorized as non-hypothyroidism births and comprised the reference group (n = 8,911,919). The main outcome measures were pregnancy and perinatal complications.

Results

Maternal hypothyroidism is associated with several pregnancy and perinatal complications, including gestational diabetes mellitus (aOR 1.43, 95%CI 1.38–1.47), gestational hypertension (aOR 1.17, 95%CI 1.11–1.22) and preeclampsia (aOR 1.21, 95%CI 1.16–1.27) (all p < 0.001). These patients are more likely to experience preterm premature rupture of membranes (aOR 1.19, 95%CI 1.09–1.29, p < 0.001), preterm delivery (aOR 1.12 95%CI 1.08–1.17, p < 0.001), are more likely to deliver by cesarean section (aOR 1.21, 95% CI 1.18–1.24, p < 0.001), and suffer from postpartum hemorrhage (aOR 1.07, 95%CI 1.01–1.13, p = 0.012), disseminated intravascular coagulation (aOR 1.20, 95%CI 1.00-1.43, p = 0.046), and undergo hysterectomy (aOR 1.42, 95% CI 1.13–1.80, p = 0.003).

As for neonatal outcomes, small for gestational age and congenital anomalies are more likely to occur in the offspring of women with hypothyroidism (aOR 1.20, 95% CI 1.14–1.27 and aOR 1.34, 95% CI 1.22–1.48, both p < 0.001).

Conclusions

Women with hypothyroidism are more likely to experience pregnancy, delivery and neonatal complications. We found an association between hypothyroidism and hypertensive disorders, postpartum hemorrhage, transfusions, infections, preterm delivery and hysterectomy, among other problems. This data from a population sized database confirms the findings of smaller previous studies in the literature.

Keywords:

• Population database
• pregnancy outcome
• obstetric
• delivery
• neonatal
• hypothyroidism

Acknowledgments

None

Authors contribution

Ranit Hizkiyahu

1. Made substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data; or the creation of new software used in the work;

2. Drafted the work or revised it critically for important intellectual content;

3. Approved the version to be published; and

4. Agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Ahmad Badeghiesh

1. Made substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data; or the creation of new software used in the work;

2. Drafted the work or revised it critically for important intellectual content;

3. Approved the version to be published; and

4. Agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Haitham Baghlaf

1. Made substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data; or the creation of new software used in the work;

2. Drafted the work or revised it critically for important intellectual content;

3. Approved the version to be published; and

4. Agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Michael H. Dahan

1. Made substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data; or the creation of new software used in the work;

2. Drafted the work or revised it critically for important intellectual content;

3. Approved the version to be published; and

4. Agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data Availability Statement

The data that support the findings of this study are publicly available in NIS Database Documentation at https://www.hcup-us.ahrq.gov/db/nation/nis/nisdbdocumentation.jsp.

Additional information

Funding

There is no funding information to declare.