Pregnancy complications and PCOS.
Pregnancy complications are increased in patients with PCOS. In
one study, 5/13 patients with PCOS developed gestational diabetes by the 3rd
trimester. Additionally, increases in pre-eclampsia, pre-term labor, and
stillborns have been reported. The risk of early 1st trimester pregnancy loss
is 30 %, compared to about 15 % in the general population. This high
miscarriage rate may be due to low progesterone levels, tonic elevations of
Luteinizing Hormone, endometrial dysfunction (luteal phase defect), or poor
eggs derived from degenerating follicles. Recently, insulin resistance has been
shown to be associated with decreased uterine vascularity, decreased
IGF-Binding Protein 1 (a protein that helps implantation), and decreased
glycodelin (a protein that protects the fetus from attack by the maternal
immune system). Insulin resistance is likely the mechanism for many of the
complications related to PCOS and pregnancy. Meta-analyses summarizing research papers on the pregnancy complications
of PCOS show; increased gestational diabetes, pregnancy induced hypertension,
pre-eclampsia, preterm birth, small for gestational age babies, admission to
neonatal intensive care units and perinatal mortality unrelated to multiple
gestations.
Studies have shown that on-going pregnancies are increased when
the insulin resistance is treated.
Most of the work has been done with metformin therapy. By correcting the hyperinsulinemia,
metformin was shown to reduce the 1st trimester pregnancy loss
rate. Additionally, some
investigators continued the metformin throughout the 2nd and 3rd
trimesters and found no increase in anomaly rates. At 18 months of life,
metformin had no adverse effects on birth length and weight as well as motor
and social development of the children.
Hopefully, by better pre-conceptual treatment appears to be very beneficial. Metformin is a Category B drug in pregnancy and has been in use for decades and should be the 1st line treatment during the 1st and possibly later trimesters.