[1
]
Department of Obstetrics and Gynecology, Medical Center, VU University, Amsterdam,
The Netherlands; Department of Obstetrics and Gynecology, Onze Lieve Vrouwe Gasthuis,
Amsterdam, The Netherlands. Electronic address: vsvisser@hotmail.com.
[2
]
Department of Obstetrics and Gynecology, Medical Center, VU University, Amsterdam,
The Netherlands; Department of Obstetrics and Gynecology, Medical Center Haaglanden,
the Hague, The Netherlands.
[3
]
Medical Library, VU University, Amsterdam, The Netherlands.
[4
]
Department of Obstetrics and Gynecology, Onze Lieve Vrouwe Gasthuis, Amsterdam, The
Netherlands.
[5
]
Department of Obstetrics and Gynecology, Leiden University Medical Center, Leiden,
The Netherlands.
[6
]
Department of Obstetrics and Gynecology, University Medical Center Utrecht, Utrecht,
The Netherlands.
[7
]
Department of Obstetrics and Gynecology, Amsterdam Medical Center, Amsterdam, The
Netherlands.
[8
]
Department of Obstetrics and Gynecology, Medical Center, VU University, Amsterdam,
The Netherlands.